ENHANCING PORE PRESSURE PREDICTION IN OIL WELL DRILLING: A COMPREHENSIVE STUDY OF WELL PLANNING AND COST-EFFECTIVE MODELING IN THE NIGER DELTA REGION

Accurate pore pressure prediction is pivotal in drilling operations, impacting safety, well design, and cost-effectiveness. This research paper aims to assess various pore pressure prediction methods, particularly in transition zones. It introduces a novel descriptive model for quick and reliable pore pressure estimation when essential data parameters are unavailable. The study underscores the importance of selecting appropriate prediction methods based on geological conditions. The research findings reveal that Eaton's correlation utilizing transit compressive wave velocity offers superior pore pressure prediction when drilling through transition zones. Additionally, the developed descriptive model is a valuable tool for quick look pore pressure estimation, ensuring operational efficiency when data parameters for traditional methods like Eaton's are lacking. However, a critical caveat emerges as the model's suitability for pore pressure prediction in fractured or shaled-out reservoirs is questioned, necessitating caution in its application in such geological settings. This paper recommends the continued use of Eaton's method as a reliable pore pressure prediction tool and advocates for the adoption of the proposed descriptive model in scenarios where time constraints or data limitations are prevalent. By amalgamating these approaches, drilling operations can achieve enhanced accuracy and efficiency in pore pressure assessment, ultimately contributing to safer and more cost-effective well-drilling processes.


INTRODUCTION
Accurately predicting pore pressure is a paramount concern in the oil and gas industry, particularly in exploration areas such as the Niger Delta Region (Aluola et al., 2022;Madu and Akinfolarin, 2013).Pore pressure and fracture gradient dictate the optimal mud weight required for safe drilling operations (McCaskill, 1972;Onyeji et al., 2017).Insufficient mud weight can lead to the influx of formation fluids into the wellbore, potentially resulting in blowouts if not promptly controlled.Conversely, excessive mud weight can cause rock fractures, further complicating drilling endeavors (Zoback, 2010).
Pore Pressure Prediction (PPP) is an early warning system, allowing drillers to adjust mud weight preemptively, thus averting gas kicks and their associated costly drilling delays (Norcross et al., 2014;Zhao and Choo, 2020).Gas kicks can escalate into blowouts, with catastrophic consequences, including the loss of the entire well (Sule et al., 2019).Moreover, pore pressure prediction significantly influences the decisionmaking process regarding the placement of casing strings.The stability of the well at specific levels and the perceived risk of encountering a gas kick heavily influence casing placement choices.In deep-water drilling, where costs are exceptionally high, drillers often adopt a conservative approach, installing more casing strings than optimally necessary.
precise pore pressure prediction during drilling operations.Additionally, it seeks to introduce an economically efficient model for total quality time management, specifically tailored to accurately estimate pore pressures in the Niger Delta.The primary research objective significantly contributes to the oil well production domain, particularly in regions with comparable geological characteristics.This contribution is intended to inform and enhance the planning of future drilling and completion endeavors within the Niger Delta region, ultimately optimizing operations in this area.

LITERATURE REVIEW
Pore pressure prediction in shale-based formations is paramount across various oil and gas industry disciplines, including reservoir, production, and drilling engineering.This section provides an in-depth analysis of key aspects of pore pressure prediction, highlighting its significance and implications.Accurate pore pressure prediction is indispensable for ensuring the safety and efficiency of drilling operations, particularly in overpressured regions.The selection of casing points, an integral component of well design, relies heavily on precise pore pressure estimates (Yu et al., 2023).Pore pressure predictions also serve as essential data for reservoir planning and reserve estimation, further underlining their critical role in oil and gas operations (Ciriaco et al., 2020;Settari, 2002).
The study of pore pressure prediction encompasses several approaches and research areas, including analyzing correlated d-exponent, resistivity, and sonic log data.These approaches aim to quantify pore pressure variations based on changes in rock properties, particularly alterations in sonic velocity and resistivity (Wang and Wang, 2015;Zhang, 2011).One of the primary goals in developing a pore pressure prediction strategy is to accurately estimate pore pressure based on sonic data from offset wells (Couzens-Schultz et al., 2013;Farsi et al., 2021).Successful strategies, especially those leveraging sonic log data, are commonly employed in regions characterized by disequilibrium compaction.
Overpressures in sedimentary basins are primarily associated with disequilibrium compaction, particularly in young, rapidly deposited clastic rocks such as sandstones and shales (Li et al., 2022;Radwan, 2022).This section examines the factors contributing to overpressure and the mechanisms behind its generation.The occurrence of overpressure is influenced by three main components: the rate of sediment burial, temperature, and sediment permeability (Radwan, 2022).Regions with high sedimentation rates, often found along continental margins like offshore West Africa, are prone to overpressure due to the rapid accumulation of sediments from major river systems (e.g., Niger and Congo rivers).These sediments consist of sandstones (reservoirs) and shales (seals) and form complex patterns of distributary systems (Dugan and Sheahan, 2012).
Traditionally, predicting pressure in shale-rich rocks involves the analysis of well-log data (Sperrevik et al., 2002).High pressure is correlated with higher-than-expected porosity, and parameters capturing porosity are carefully assessed, particularly those with high-quality data density.The Eaton ratio method, an empirical approach utilizing constraints for sonic velocity, is widely accepted in the industry for quantifying pore pressure (Francisca et al., 2023).

Mechanisms for overpressure generation
Several mechanisms have been suggested for the generation of overpressure in sedimentary basins.Overpressure mechanisms can be broadly separated into fluid expansion and disequilibrium compaction (Tingay et al., 2009).These two categories are discussed herein, emphasizing mechanisms that can develop high-magnitude overpressures, such as those observed in Niger Delta.The function of overpressure transfer is also examined.

Fluid Expansion Mechanism
Fluid expansion mechanisms of overpressure generation involve increased pore-fluid volume within a confined rock framework.Hence, pore volume cannot increase as the pore fluid expands and pore pressure increases (Tingay et al., 2009).Several potential fluid expansion mechanisms were observed, most commonly Kerogene-to-gas transformation, clay digenesis, and aqua thermal expansion mechanisms.The maturation of Kerogen into gas during hydrocarbon generation results in a large fluid volume expansion (Tingay et al., 2013).In low permeability sediments, the fluid volume expansion from gas generation may potentially generate sub-lithostatic magnitude overpressures.Clay diagenesis (e.g. the transformation of smectite to illite), aqua thermal expansion, osmosis, and other fluid expansion mechanisms have been hypothesized to generate high-magnitude overpressure (Tingay et al., 2009).
However, modelling of these techniques under ideal conditions (e.g., the transformation of 100% smectite into illite) indicates that these mechanisms can only generate minor amounts of overpressure, although they may be mechanisms for creating hydrodynamic seals that promote disequilibrium compaction overpressure.Hence, all fluid expansion mechanisms other than kerogen-to-gas maturation are believed to be of secondary significance but may locally contribute to minor overpressures in some regions.Sediments that first compact under normal pore-pressure conditions and subsequently become over-pressured (either by fluid expansion or vertical effective stress to decrease).However, compaction is mostly an irreversible process, and over-pressuring generated by kerogen-to-gas or vertical transfer is only associated with a small change in porosity because of the slight elastic contraction of sediment grains and secondary porosity (Yang et al., 2016).

Disequilibrium Compaction Mechanisms
Disequilibrium compaction overpressure involves an imbalance between increasing compressive stress and the ability of a formation to expel water.Increased compressive stress caused by burial or tectonic forces causes rocks to compact and expel fluid.Given a gradual increase in compressive stress, most rocks compact normally.That is, a balance between the increased compressive stress and the expulsion of pore fluid exists; thus, pore pressure remains hydrostatic (Tingay et al., 2009).

Pore pressure prediction strategies
There are different methods of pore pressure modelling, and these include; Terzaghi developed a simple relationship between pore pressure and the effective stress of the rock in 1943.Even though his relationship was determined empirically, it was proved later that it can be derived analytically from the 1-D compaction theory.Terzaghi noted that the stresses in any point of a section through a mass of soil can be computed from the total principal stresses that act in this point.If the voids of the soil are filled with water under stress, the total principal stress consists of two parts.One part acts in the water and the solid in every direction with equal intensity.It is called the neutral stress or the pore water pressure (Bahmaei and Hosseini, 2020;Reid, 1994;Zhang et al., 2023).
Equation 1 represents an excess over the neutral stress, and it has its seat exclusively in the solid phase of the soil.This fraction of the principal stress will be called the effective principal stress.
A change in the neutral stress produces practically no volume change and does not influence the stress conditions for failure.Porous materials (such as sand, clay, and concrete) react to a change as if they were incompressible and as if their internal friction were equal to zero.All the measurable effects of a change of stress, such as compression, distortion, and a change of shearing resistance, are exclusively due to changes in the effective stress.This statement indicates that this is a conceptual stress.
Only the effects of an effective stress change are measurable, not the effective stress itself.
Terzaghi determined the following mathematical relationship (Equation 2) (Terzaghi, 1943): Therefore, pore pressure can be calculated from the difference between principal and effective stresses acting in a given direction.In the case of drilling for oil and gas, the principal stress in the vertical direction is the overburden stress, which can be determined by several published correlations or by integration of the bulk density log data.The unknown variable is the corresponding conceptual effective stress.Over-pressuring during compaction is generally associated with a slower porosity decrease with depth.If the assumption is made that vertical strains dominate during the compaction process, Terzaghi's principle would imply that the effective vertical stress is the exclusive cause of shale porosity variations.Therefore, pore pressure is determined from the effective vertical stress and the overburden stress by the following relationship in Equation 3:   =   −   (3) Where   is the pore pressure,   is the overburden stress and   is the effective vertical stress, all with units in psi.
Later, Hottman and Johnson adapted Terzaghi's effective stress relation and provided a correlation of pore fluid pressure and petro physical data without considering the effect of vertical overburden stress (Hottman and Johnson, 1965;Terzaghi's, 1943).Eaton modified Hottman and Johnson's pore pressure modelling correlation to consider the effect of vertical overburden stress (Eaton, 1972).However, it assumed a constant vertical overburden stress.Eaton (1975) later modified his (1972) pore pressure modelling correlation in shale-based formation by combining Terzaghi's, Holtman, and Johnson's correlation to formulate Eaton's sonic compressional transit time pore pressure model that takes care of the variation of the vertical overburden stress with burial depth but considers the normal compaction trend to be a constant and not depth dependent.
Equation 4 presents the modified Eaton's sonic compressional velocity model for pore pressure prediction: However, substituting Equation 5 in Equation 4: Nevertheless, substituting Equation 7 in Equation 6: Therefore, Where   = pore pressure,   = normal vertical effective stress,   = vertical overburden stress, ∆  = Normal sonic transient time, and ∆  = Deviated ∆ from the normal compaction trend line.
Slotnick recognized that compressional velocity is a function of depth (i.e.velocity increases with depth in the subsurface formations (Slotnick, 1936).Therefore, the normal compaction trend line of travel time should be a function of depth.The oldest and simplest normal compaction trend for seismic velocity is a linear relationship given by Slotmick in Equation 9: Where  is the seismic velocity at depth of , and   is the velocity at the sea bed or ground surface.
A group researchers used Slotnick's relationship as the normally pressured velocity for pore pressure prediction (Sayers et al., 2002).A normal compaction trend for shale acoustic travel time with depth in the Carnarvon basin was established by fitting an exponential relationship to average acoustic travel times from 17 normally pressured wells.
Thus: Thus: ∆  = 176.5 + 461.5  −0.007 (11) The following well-pressure concepts and well-pressure relationships will be explored, and the causal attributes of abnormal well pressures will be explored.The formational fracture gradients will be reviewed.The terms of equilibrium and balanced pressure will be defined.Insufficient pressure or underbalanced pressure will be reviewed.The verified true vertical depth will be delineated.The assessed or measured depth will be reviewed.

Concepts of Well Pressure
The distinct formations found in well operations play a substantial role in the exploitation and exploratory aspects of accessing the hydrocarbon fossil fuel reservoir.The distinct reservoir categories normally found in drilling activities are widely distributed into their three primary components.These components are hydrostatic pressure, overburdened pressure, and formational pressure.The implications of hydrostatic pressure are the pressure that is applied by a water column that extends from the well's depths to the well's surface aperture.The variable P will represent the outcome of the unitary mass and the height in the vertical axis of the fluid column.The fluid columns' dimensions and form do not influence the intensity of the pressure exerted.The mathematical relationship which will be applied is: In this mathematical relationship, P represents the hydrostatic pressure, ρ is representative of the mean density, h is the vertical height of the column of fluid and g is represented by the value of the gravitational force.In the context of well planning and well drilling, the mathematical relation can be demonstrated as This is the hydraulic gradient that will be applied in this research.In order to ascertain the hydrostatic pressure of a reservoir of 40⁰ API oil located in a well at depths of 4000 ft., the mathematical formula that would be applied is: SG = .0825,the mathematical formula yields (0.433) (.825) (4000) = 1428.9psi.
The saturation of distinct solutes and gaseous mixtures present in the fluid column at distinct and differing thermal gradients influences the hydrostatic pressure gradient.In increasing the concentration of dissolved solutes, the conventional pressure gradient is increased.Increasing the concentration of the gases that are present in the solution and increasing the thermal energy would have the effect of diminishing the conventional hydrostatic pressure gradient.When the saline concentration is raised in a solution found in a well, the conventional pressure gradient rises.In increasing the concentration of gases in a solution, the conventional P gradient increases.Increasing the temperature aspect of the solution found in a well environment increases the conventional pressure gradient.

Overburdened Pressure
The loads are frequently designated as overburden, geostatic, and lithostatic pressures.This is a pressure that originates in the combined mass of the formation systems.This solution comprises solutes, fluids, and gas positioned in the pore voids above the formation being reviewed.The formula is demonstrated in Equation 14; 0 = mass fluids + rock system area. ( The porous aspect of the sediment diminishes under the influences of compaction.This aspect is proportional to the augmenting of the load pressure.In the circumstance of the clay materials, this diminishing relies on the mass of the sediment layers.When the clay porous aspect is represented mathematically, the correlation between these two limits can be expressed as an exponential function.In the circumstance of the carbonates and the sandstones, this correlation is an operation of many limits aside from compaction.These aspects incorporate the digenetic influences, separation, and initial composition.In diminishing the porosity, the density of the bulk also increases.In the superior section of the sediment column, the bulk's increased gradient density is much more elevated than at its depths.The comprehensive qualities of the load are reinforced by the porous pressure and the pressure of the rock grain (Ismail, 2014).

Pore Pressure
A formation's pore pressure is referent to the section of the load that does not receive support from the rock system.Instead, the pore pressure is supported by the gases or fluids present in the pore voids of the formation.
The conventional pore pressure is equivalent to the hydrostatic pressure of a fluid column vertically measured from the bottom to the superior aspect of the well.The fluids eventually become confined in the formation and in the situation of the formations that are under load; the characteristic of the grain in comparison to the granular pressure diminishes as a function of the fluids positioned within the interstices providing the buoyancy of the load.In this circumstance, there is transmission in the fluids maintained at the depths.If the superficial pressure is stopped, the fluids will not have the capacity to flow.They will not be able to calibrate the pressure forces in the matrix (Ismail, 2014).
When the pore pressure is less than the conventional hydrostatic pressure, the formation can be defined as having abnormal pressures.In the circumstance of the porous pressure at the depths exceeding the anticipated hydrostatic pressure for said depth, the area is designated as possessing abnormal pressure.If the depth is more than the hydrostatic pressure for said depth, the area is defined as having abnormal pressure (Ismail, 2014).As the solitary grains do not exist in a rock formation, the pressure of the rock grain is delineated as a hypothetical proportion of the load that receives support from the rock system of the formation.As a rock mass is not uniform, the aspects of pressure will not be applied equilaterally as in the circumstance of the fluid pressures (Ismail, 2014).

The Pressure of the Formation
The pressure exerted on the fluids by the (gas, oil, and water) in the spaces of the pore formation is detailed as the formation pressure.This infers that the fluid pressure of the formation is equivalent to the pore pressure.This can be detailed in psi, kg/cm 2 , or atmosphere.The conventional pressure formation of the geologic establishment is equivalent to the hydrostatic pressure of r the hydrostatic head of the water, which is vertically measured from the subsurface formations to the surface of the well opening.The conventional pressures of the hydrostatic reservoirs must also be considered.The conventional trend possesses a deviation, which is detailed as the abnormal pressure.There is an abnormally elevated formation pressure when the formation is more elevated than the hydrostatic pressure.When the hydrostatic pressure is higher than the formation pressure, the well is said to possess subnormal pressure.The excess pressures are more frequent than pressure deficiencies (Ismail, 2014).
The subsurface pressures and the stress concepts possess a correlation.This correlation can be demonstrated mathematically as follows; Where δ is equivalent to the aggregates of the stress of the matrix, the effective aspect of stress, and the vertically aligned rock frame stress.In conventional environments, the hydrostatic pressure is equivalent to the formation pressure (Ismail, 2014).

Physics of Pore Pressure Modeling while Drilling
Given the model analysis, a comparison will be done to ascertain the accuracy of pore pressure prediction and reliability.Hence, the model's physics will be based on the subsurface integrity and constraints.It has been a conventional approach to foretell pore pressure prior to the commencement of drilling activities using the traditional seismic stacking speeds with a conventional compaction tendency analysis as employed by (Eaton (1972).The speeds that appear less rapid than the normal speeds indicate over-pressurization, which the application of an empirical mathematical relationship can then assess.There are several challenges to this approach.Initially, the seismic stacking speeds are not usually appropriate for forecasting pressure as they do not have the aspects of propagation or rock speeds.In the second consideration, the velocities are deficient in the resolution in profoundness.In the third circumstance, in deep water surrounding, the loading of sediment has frequently been so rapid that the pressurized forces which are associated with the sediments are more than the geological pressure (hydrostatic) to the point which is directly beneath the mud line (Spikes and Dvorkin, 2004).
This condition is dissimilar to the conditions presented in the Gulf of Mexico.This aspect deters the production of a conventional compaction tendency in the comprehensive approach of the deep water drilling endeavour.In the situation where the deep water paradigm is formulated with the inclusion of profoundness as one of the variables using the application of curve adapting data from an analogue oil well, the majority of these tendencies violate the regulations of rock physics.The speed does not approximate the appropriate sediment speed beneath the mud line.It does not approximate a restricting velocity, which is suitable for highly diminished porosity of rocks that experience a significantly elevated overburden pressure (Spikes and Dvorkin, 2004).

Comparative analysis
In the past few decades, the oil exploration and exploitation organizations operating in the Niger Delta have effectively applied the pore pressure forecasting to plan cost-avoidant aspects and hazard-avoidant measures.Notwithstanding, the pressure formations have the aspect of being challenging in their accurate assessment in the presence of the existence of unusual pressures.The technologies that influence pore pressure prediction are experiencing continuous improvement.The aspects of novel computer technologies, new formulas, new seismic prediction paradigms, and deep water boring have assertively influenced the aspect of well planning (Chukwuma et al., 2013;Nweke and Dosunmu, 2013).The most extensively applied pore pressure estimation model implemented is Eaton's method.The exponents of the Sonic Delta, the resistivity, and the overburden are often substituted for distinct regions in order to provide a match with the pore pressures that have been acquired from other information.The primary challenge is the majority of trend line paradigms.
Comparative research methods are frequently applied in the initial stages of producing scientific disciplines.These perspectives can enable the researcher to progress from the beginning levels of exploring case studies to a more sophisticated level of reviewing universal theoretical paradigms, which consider invariances.Evolution and causality should be considered in the sophisticated review of theoretical paradigms (He and Zhu, 2006;Naehr et al., 2007).The principles which underlie comparative research are straightforward.The objects are samples or cases with similarities to the models presented for consideration.These distinctions evolve into becoming the focus of the review.The objective is to ascertain the distinctions in the cases and to reveal the conventional underlying foundation that formulates or enables this type of variation.The aspect of comparative analysis is one of the most effective manners for providing explanations or applying tacit experiential knowledge.This can be accomplished by demonstrating the two comparisons in a parallel perspective and asking observers to detail the distinctions between the two.This method has several applications.It can be applied in a detailed analysis, or it can be applied as a complement to other approaches.
Another strategy is to enable the entire framework of a research project to be the subject of the analysis of several cases (He and Zhu, 2006;Naehr et al., 2007).
In a comparative evaluation, the examination of two or more samples, events, or cases is conducted.The information regarding each case is usually presented in table form.The novel aspects can be added to the evaluation process, or the non-pertinent aspects can be excluded.The aspects which possess similarities in the two or more cases are not required to be documented.This is attributable to the premise that the two cases are not being evaluated; the similarities between the two cases are being reviewed (He and Zhu, 2006;Naehr et al., 2007).The ultimate objective of research is usually the revelation of a methodological structure group population or invariance.The objective is to provide a generalization of the findings in order to confirm a hypothesis.It would not be advantageous to conduct assertions regarding a larger-sized group if the research was composed of two groups.The confidence in the generalizations would be augmented if there were evidence of identical invariance or population tendencies from both groups.Statistical methods which may be applied in order to ascertain the statistical significance of the findings may be applied.The challenge is determining if the invariance is revealed outside the population (He and Zhu, 2006;Naehr et al., 2007).
In reviewing several observations, the underlying framework of a collection may be categorized into classes.In order to provide a basis for categorization, a characteristic must be selected which can be documented for the individual cases.The cases which have similar characteristics can be categorized into a class.The research which is conducted on the assumptions of an earlier paradigm of the population may be delineated by the question that is being researched.The study could be a collection of oil wells in the Niger Delta region (Chukwuma et al., 2013;He and Zhu, 2006;Lüthje et al., 2009;Naehr et al., 2007;Nweke and Dosunmu, 2013).
The focus of the study will provide the basis for defining which categories are required in the analysis.Quite frequently, classes that have been delineated in previous typology research may be applied.Oil wells may be characterized by choosing suitable aspects of typology.Typology is a classification model where the individual classes are created around a conventional example.Each oil well in the collected data is contrasted to the examples and will be designated into a category with the most similarities with the exemplar.This aspect may be conducted concerning the Eaton method.In an exploratory study, the oil well may be chosen among the reviewed samples, or it can be delineated as having the aspects enabling agglomeration into a category (He and Zhu, 2006;Lüthje et al., 2009;Naehr et al., 2007).

Improvements over the existing pore pressure prediction methods
The application of seismic imaging has been a primary implement that evaluates the pore pressure manifest at the subsurface level before drilling activities.These steps incorporate the following elements: • The application of an adapted seismic velocity which has a facsimile to the rock speed and not the speed of processing.
• The production of a lithological paradigm for the correlation of the lithological aspects of Poisson's ratio, speed, and porosity is more elevated than conventional pore pressure or more diminished than normal differential or effective pressure.This is delineated as the stress which is exerted upon the lithological system.
• The evaluation of the attributed of overpressure.The effects of clay dehydration and compaction are significant considerations (Spikes and Dvorkin, 2004).
The fluid incorporated in the pore does not facilitate the basic wave transmission, and the deficient granular contacts with minimal effective stress influence the S wave speed to a greater extent than the P wave speed.The ratio of the S waves' velocity to the P waves' velocity is an important parameter that correlates to the minimal effective pressure or the elevated pore pressure.This is particularly valid in the SWF conditions where there is a slight difference between the fracture and pore pressure.This aspect has not received attention in the methodologies encompassing pore pressure prediction.This is attributable to the perspective of the conventional seismic approach applying the P wave velocity information exclusively (Spikes and Dvorkin, 2004).
The manner of addressing the questions posed regarding the fabrication of more effective wells can be addressed by the formulation of pseudo wells.The pseudo wells and the correlated artificial seismic information were produced for the location of particular geological potentials, which may not have been represented in the actual well data collected (Spikes and Dvorkin, 2004).The initial step is to set a mock physical paradigm that quantitatively explains the information.The subsequent step incorporates the construction of a geological paradigm below the subsurface.This example can be founded upon the geological understanding or the experiential knowledge of the site environment.The assumptions regarding the formation and the intervals of the architecture of the well are also incorporated into the simulation (Spikes and Dvorkin, 2004).
When the digenetic and depositional tendencies have been identified, the geological forms are filled with clay composition, which complies with the predictable and conventional matrices; the well log scales may be formulated.The shale content is usually not equivalent to the clay content.
For this simulation, the content of the distinct components is equated (Spikes and Dvorkin, 2004).
The comprehensive porosity and hydrocarbon concentration values are designated after the geological forms are filled with clay.In this model, the comprehensive porosity and the hydrocarbon content are correlated with the clay composition and the capillary pressure in the simulated model.Afterwards, the rock physics paradigm is established to acquire mineralogy, fluid, porosity, density, S-wave speed, and P-wave speed.
Finally, the synthesized seismograms are formulated in order to measure the influences of the lateral positioning, reservoir geometry and lithology, fluidity, and porosity with respect to the seismic signatures (Spikes and Dvorkin, 2004).This methodology implements the application of pseudo wells, which are accompanied by log curves at any point of spatial trajectory from the exclusive clay composition of the geological section.Monte Carlo modelling is applied to generate well information considering the anticipated target intervals' potential physical and stratigraphic characteristics.The lithological physics correlations are applied to formulate the pseudo-log information where the data was unavailable due to the borehole conditions (Spikes and Dvorkin, 2004).
The next step in the methodology is to create a combination of lithological physics with the location-specific aspects of deposition.This perspective is anticipated to diminish the aspects of uncertainty in the interpretation of seismic data.The lithological physics diagnostics are conducted to formulate a paradigm that quantitatively approximates the well data.
Initially, the P-wave sub-wave exchange is performed in the event that the S-wave data is not accessible or of an unconfirmed characteristic.This will be performed to comply with the requisite 100% brine concentration.Consequently, the Poisson's ratio and the impedance are graphically plotted against the comprehensive porosity and the application of gammaray color coding.This is conducted to illustrate the quality of the lithology (Spikes and Dvorkin, 2004).The curves correlated to the clay composite indexes from zero percent clay composition to one hundred percent clay composition are delineated in twenty percent intervals, in accordance with the paradigm established by (Raymer, 1980).This mathematical model is demonstrated in Equation 16.
in the situation where vm is equivalent to the speed of the mineral segment, and vt is the speed of the wave in the pore liquid.The application of the Greenberg computes the speed of the s-wave-Castagna construct, which, in consideration of clays that are water saturated, is approximated to the equation for mud rock, which is: The density of the bulk is demonstrated by: In the circumstance of the density of the lithological aspect of the mineral, phase is represented by am, and the density of the liquid in the pore is represented by at (Spike and Dvorkin 2004).
The paradigm introduced by Greenberg-Castagno and Ramer appropriately delineates the borehole data and is suitable for the analysis of the lithological aspects being reviewed in well planning.The model proposed by Ramer is suitable for the examination of consolidated residues (Ramer, 1980).The premise that the model correlates to the data implies that the shale-sand sequences being examined are consolidated and mature (Spikes and Dvorkin, 2004).This approach, which will be explored to predict pore pressure and construct more effective oil wells, is independent of the trend line.This approach applies a rock paradigm for the evaluation of geological pressure.This is applied primarily to assess the stress manifesting as a lithological function.This evaluation incorporates temperature, speed, and porosity.This is the paradigm which encourages the interpretation of the seismic information.The input information is founded upon evaluating a few seismic qualities (Spikes and Dvorkin, 2004).
These qualities are amplitudes and velocities adjusted to the information derived from offset wells.The pore pressure is computed as the value between effective stress and overburden stress.The effective stress influences the seismic waves that travel through the rock formation.This lithological paradigm possesses a few elements.These elements are the correlation between Poisson's ratio of the residues to the effective stress present through the framework, the dehydration of the clay, the velocity, and porosity.The primary inputs which the lithological paradigm is centred upon, the iterative velocity interpretation and calibration, are the two important steps that must be applied in the forecasting process in order to guarantee that the velocity fields comply with the anticipated rock wave propagation speeds (Spikes and Dvorkin, 2004).
The premise assumed in the application of the pseudo-well model is that if there is a correlation between the seismic reactions, then there will be a correlation with the physical reactions.Notwithstanding, a diverse number of situations about the physical characteristics of the borehole may yield an identical seismic response.A potential solution is the application of the distinct aspects of fluidity, porosity, and lithology to provide a signature to each borehole condition.In the circumstance of their validation, these correlations may provide additional parameters to the discipline of seismic interpretation.This methodology aimed to manifest the characteristics in lithological physics regarding the deposition tendencies of the geological bodies.In the computation of pseudo boreholes and wells at an identical depth, it is difficult to consider the mechanical compacting tendencies or the aspect of digenesis as functions of pressure and temperature.In a more elaborate simulation, the aspects of the compaction tendencies could be factored in as functions of pressure and temperature (Spikes and Dvorkin, 2004).

Contributions to the current body of knowledge
The working plan, which will be applied to facilitate the analysis and select the most effective pore pressure forecasting strategy, is delineated in this thesis.The work plan has been conducted for several offset wells located in the Niger Delta area.The data acquired from the offset well in the Niger Delta region will incorporate the assessed pressure information, the drilling documentation, and the seismic and geological information from the oil wells.A pore pressure forecasting model will be formulated from the seismic and petroleum physical information collected.The data will be incorporated into the pore pressure forecasting model.The pore pressure forecasting model will be adjusted when necessary.The model will then be compared to the drilling records (Nweke and Dosunmu, 2013).
This will be applied in order to formulate a precise pore pressure forecasting model which will be applied toward well planning in the Niger Delta region.The adapted Eaton's equation, which will be applied, will incorporate the D exponent mathematical model.This model aims to normalize the penetration index, which has been derived from the borehole drilling parameters.This model is based on the work of (Jorden and Shirley, 1966).The research conducted by Bingham is a refinement of the mathematical model (Bingham, 1969).This model was developed by Bingham in order to consider the effects of mud mass ( Bingham, 1969;Nweke and Dosunmu, 2013).
The D exponential mathematical formula is derived from the following mathematical relationship: This mathematical relationship considers the following assumptions: The present mass of the mud is represented by "ρactual" in ppg.The conventional hydrostatic gradient is represented by "ρnormal" in ppg.The weight of the drilling bit is represented by "W" in lbs.The drilling bit diameter is represented by "D" measured in inches.The number of revolutions completed in a minute is represented by "N" which is assessed in rpm.The drilling bit's penetration rate is represented by "R" which is assessed in feet per hour (Nweke and Dosunmu, 2013).This paradigm assesses the relationship between the feasibility of drilling and the shale sequences under overly pressured conditions encountered in the Gulf of Mexico using tri-conic drilling bits.This equation also considers the influence of the overburdening gradient (Nweke and Dosunmu, 2013).
The Gulf of Mexico is distinct from the geological environment of the Niger Delta.The sequence of lithological sediments in the Niger Delta region incorporates the intermittent shale and sand environment encountered in the marine environments.The hills of the Niger Delta region are recipients of intense lateral stresses.The maximum stress in the horizontal planes of the hills in the Niger Delta region is greater than the vertical planes of stress which are exerted.The stress on the horizontal planes is substantially greater than the stress in the vertical planes (Nweke and Dosunmu, 2013).
The theory which will be applied is the evaluation of experimental data.In the experimental data, it can be demonstrated that in many of the lithological samples devoid of humidity, the Poisson's ratio diminishes with the decrease in differential pressure.This implies that in lithological samples saturated with gas, the Poisson's ratio diminishes with the increased pore pressure.The pore pressure increases with adequate pressure augmenting in the lithological samples saturated with liquid.The reproduction of theoretical modeling can observe this.This influence can be applied as novel implements for predicting pore pressure in the Niger delta oil well system.In addition, it can serve as an overpressure forecasting tool for the sonic logs, cross well, and surface seismic evaluations performed prior to drilling (Dvorkin, 2001) Typically, the velocity of the elastic waves in rocks devoid of humidity is assessed in a laboratory environment by changing the pressure, which confines the lithological sample and sustains the pore pressure.As the velocity of the wave responds to the difference in pressure, which is the pressure of the confinement less the pore pressure, this information can be applied in order to forecast the on-site variations in velocity in the lithological samples that result from the gaseous content at a continuous overburden point.The in situ velocity conditions of concentration can be computed from the velocity of the dry lithological samples by applying fluid substitution equations (Dvorkin, 2001).
As a result of the increased compressible aspect of the gases, the velocity measured in situ in the lithological samples containing gas is similar to the points of differential pressure for air in laboratory conditions.The measurement of the pressure versus the velocity in the laboratory conditions in conjunction with fluid substitution can be applied to forecast the elasticity of the lithological sample alterations in the oil reservoirs during the exploration and exploitation of oil deposits.These aspects are the consequences of the pore fluid changes over time and the pore pressure, including space variations.In addition, this information can be a foundation for comprehending the seismic assessments for the fluid variation and the pore pressure in space and time (Dvorkin, 2001).
The empirical experiments' temporal scale is much less than the geological temporal models of pressure production.Notwithstanding, the empirical experiments where the pressure alterations occur at a rapid pace can be applied to simulate the late pressure reactions elicited when the fluid pressure in the lithological mass is enabled to increase in relation to the hydrothermal pressure.This may be the outcome of the heated liquid thermal expansion, the maturation of the hydrocarbon sources, and the expulsion of fluid.This results from clay diagenesis and the fluid being pumped from the intervals where there is a deeper pressure in addition to the overburden, which results from the tectonic responses (Dvorkin, 2001).The diminishing of the P wave speed about increasing the pore pressure has been applied to detect overpressure.Notwithstanding, velocity is not the only indicator of pore pressure because it relies on the lithological layer's lithological texture, mineralogy, and porosity.This methodology section is based on a literature review of experiments that apply the Poisson's ratio to detect the overpressure burden, computed from the S-wave and the P-wave velocities.as indicators of the pore.

Current methods of pore pressure prediction
In optimal situations, the data derived from surface reflection may not only provide the average speeds over the rough intervals located in the intervals between the major reflectors, but the deficient aspect of speed resolution also influences the precision and the location of the following pressure predictions.A third category of challenges, which is less substantial than the other categories, develops if a prediction planning paradigm is acquired by applying well data that is not representative of all of the rock formations manifest in the boring process.Some boring paradigms are adjusted by applying sonic velocities (Araujo et al., 2005;Nelson et al., 2005;Villaescusa et al., 2002).This is conducted in the intervals in which the boring is conducted through shale mediums.This decision to perform this type of boring in the shale mediums may be derived by applying gamma radiation.Consequently, it would not be appropriate to actively implement this type of forecast with the use of seismic information, which considers all of the evaluations of the rock formations, not exclusively the shale formations.A correlated challenge may present itself in the adjustment process if the shale boring segments' information is not applied for the pressure forecasting and contrasted with the existing pressure information derived from the boring activities conducted at non-shale intervals.Suppose there are distinctions between the two data models.In that case, the temptation may arise to perceive that the pore pressure is distinct between the sand portions that envelop the shale and the shale.This distinction is also persistent over any given period of geologically measured time.If this is mutually valid, this assumption would have the capacity to invalidate the computations that rely on the assertion of the pressures that are equalized between the sands that envelope the shale and the shale segments (Araujo et al., 2005;Nelson et al., 2005;Villaescusa et al., 2002).
As a result of these challenges, it becomes apparent that the issue of pore pressure forecasting has no solitary solution.The challenge of approximating the rock formations' pore pressure that encases an existent borehole is more effectively addressed if numerous data sets are applied.Effective forecasts may be formulated if the corresponding aspects of uncertainty are considered.In order to achieve this outcome, it may be helpful to have access to the diverse prediction algorithms, which are distinct from one another in category instead of intensity.When the diverse algorithms concur in their forecasts, an individual may have enhanced confidence.To the extent that the diverse algorithms do not concur, this aspect motivates the well planner to conduct further investigation (Sayers et al., 2005).
There are a few algorithms that do not display significant autonomy from all of the algorithms that have been examined in peer-reviewed literature.The consensus of algorithms that have been applied utilizes the information that has been collected at a particular point in order to approximate or forecast the pore pressure that is present in the layer.This is conducted on a layer-by-layer analysis.This aspect may be manifested by the researcher's perspective concerning the independent analysis.The layer-by-layer analysis is similar to the analysis of samples present in a laboratory.In comparison, these items acknowledge the diverse layers' correlation.The means of the processes and the geological antecedence interconnect the litho-logical layers.This interconnected litho-logical aspect must be considered from the well planner's perspective (Sayers et al., 2005).

Other categories of drilling paradigms
One of the most applied drilling methods is applying the air hammering method for drilling oil wells.This method is particularly adapted to drilling solid metamorphic and igneous lithological formations (Wu et al., 2020).
The air hammering method is not a genuine rotary method but a rotary rig adapted to fit an air percussion mechanism.This type of drilling rig entails the application of a pneumatic air-driven hammer, similar to a construction jackhammer (Adams and Charrier, 1985;Daneshy et al., 1998).The air hammering drilling method incorporates the application of its operation on the lower end of the drilling tube with an air pressure of one hundred pounds per square inch.The flattened aspect of the hammer is fitted with inserts composed of tungsten carbides.The tungsten carbide inserts are applied to fragment the lithological layers.The air hammering implements are produced in sizes ranging from three inches to seventeen inches and supply a pummeling force equivalent to two thousand hits per minute.The drilling pipe and the hammering tool are subtly gyrated to enable the tungsten carbide inserts to continuously hit a deeper surface to provide homogeneous penetration and a hole that is vertically straight.The aerated exhaust from the air hammering tool is directed to remove any fragments that are a product of the air hammering strikes.This implantation enables a drilling surface that is liberated from fragments.The liberation of the lithological fragments enables a drilling velocity up to twice as fast as the tritone rollers (Adams and Charrier, 1985;Daneshy et al., 1998).
The exhausted air delivers the lithological fragments up through the annular void and in a direction that facilitates their egress from the borehole.In the circumstance of conducting drilling operations beneath the stationary water level, the air hammer's pressure differential must be sustained to conduct the drilling operations effectively.The application of foams is implemented in order to alleviate the pressure that is present in the borehole.The expansive air hammers have the requisite of being supplied with extensive quantities of air, which an air compressor must apply.Operating air compressors at the borehole sites implies a significantly elevated drilling expense (Adams and Charrier, 1985;Daneshy et al., 1998).

Reverse Circulating
In the application of reverse circulating, the thinly applied mud is enabled to seep through the annular void, upwards to the drilling pipe, and to the aspirating aspect of the pump.It is collected inn a reservoir or a tank.The lithological cuttings are transported in a drilling pipe with a less expansive diameter than the annular ring.The aspirating action causes this paradigm to have operational restrictions maintained up to a depth of approximately one hundred and fifty meters (Adams and Charrier, 1985;Daneshy et al., 1998).This is the conventional drilling paradigm applied for geopressure oil wells.This method applies a pipe contained in the drilling pipe to provide an upward lift.
As the cuttings are transported to the surface of the borehole, a separator or a cyclone is applied in order to distinguish the cuttings from the air.The vacuum action which is provided by this method enhances the drilling depth capacity.The level of the fluid that is present in the annular void is sustained at a pressure that is equivalent to the surface air pressure.The applied drilling pipe is similar to the standard air drilling conduit.The benefits of reverse circulating are that the drilling liquids can be foams, air, water, polymers, or bentonite.The normal reverse circulating effect implies that when the water descends into the conduit and in an upward direction through the annular ring.This aspect diminishes the potential of the borehole wall becoming eroded (Adams and Charrier, 1985;Daneshy et al., 1998).

Directed Rotary Rig
This drilling device is usually operated with an air-or water-directing liquid.This drill category penetrates the lithological layers at a more incredible velocity than the cable tooling rig.The drill bit conventionally of a tritone roller aspect is gyrated by applying the hollowed drill support and the drilling pipe.Torque is applied in the movement of the kelly and the rotary drill (Adams and Charrier, 1985;Daneshy et al., 1998).The drilling liquid is transported into the drilling pipe and egresses from the apertures in the drilling bit, where the liquid conducts the function of rinsing the lithological fragments that the directed rotary drill has created.This is performed in order to provide a clean drilling surface.This action also lubricates the drilling bit, and the cuttings are transported to the surface of the well.A separator is applied at the well surface to distinguish the cuttings from the air.The traveling block sustains the drilling pipe.In the circumstance of too much force being applied to the drill, the result is a borehole that is not vertically straight in its aspect.Excessive force on the directed rotary bit deters the drilling activities due to the inadequate drill-cutting cleansing at the bottom of the borehole.The platforms with a topped head drive do not apply a Kelly and a rotary drill (Adams and Charrier, 1985;Daneshy et al., 1998).
Instead of the kelly and the Rotary drill, the topped head drive applies a hydraulic engine, which is transported upward and downward on the pipe, providing the torque to the drill.In many situations, a less extensive collar is applied, and the drilling platforms are composed of chains with a pulldown feature.Notwithstanding that they are smaller in dimension, the topped head drives can drill the majority of directed usage wells.The platforms that possess masts and draw assemblies can raise almost 75 metric tons.

Regression of the Drilling Fluid
An alternative reverse circulating paradigm applies drill pipes that are fifteen centimeters or more significant in conjunction with applying ejector and centrifugal pumps.The pipe connections were conventionally flanged, measuring more than twenty-five centimeters in diameter.These aspects were the causal attributes of the diameters of the boreholes being restricted to thirty-five centimeters or more.This was designed for the sustenance of the fluid speeds in the proximity of the flanges (Adams abd Charrier, 1985;Daneshy et al., 1998).
This aspect caused the creation of considerable challenges in the casing cementation.As an outcome of the expansive well diameters, this paradigm does not apply to the wells with a geological pressure aspect.This drilling paradigm is adapted to drilling in minimally consolidated lithological formations and applies the implementation of drag fragments, which cannot overcome the lithological barriers that are present.More expansive drilling bits are produced; however, they are not cost-avoidant in their economic aspect of application (Adams and Charrier, 1985;Daneshy et al., 1998).
The circulatory indexes of five hundred gallons per minute are frequently encountered in this drilling paradigm.As a result of the massive volumes of water that are applied in this drilling paradigm, particular sampling containers are applied.The pipes are fitted with threading in the more recently produced reverse circulating conduits.This aspect enables the perforation of boreholes, which are smaller in diameter, with the implementation of tritone drilling bits.Consequently, the drilling velocities are increased as an outcome of the temporal intervals needed to aggregate or extract the drill piping segments significantly diminished (Adams and Charrier, 1985;Daneshy et al., 1998).
A tertiary reverse circulating matrix applies a double ducted swiveling mechanism and a particular drilling pipe, which is applied in order to transform a standard loop into a reversing circulation top-headed drive.The compressed air is impelled into the swiveling mechanism and the particular topped coupling, which is directed to the area away from the drilling pipes.This fluid is redirected to the primary part of the drilling pipe.This aspect enables the vacuuming action for the fragmented lithological rocks transported toward the top of the borehole.The standard drilling pipe is applied in the location of injection, which has the potential of being positioned several hundred meters beneath the ground surface.
The air rotating rigs, the direct circulating rigs, and the topped head drive rigs possess casing drivers affixed to the drilling mast.As the casing segments are required to possess the similar aspects of length as the drilling pipe, these units are conventionally constructed in a modular manner to enable assembly at the borehole site.These devices are impelled into the borehole by applying a pneumatic pile driver.In applying the pneumatic pile driver, the casing can be impelled into the borehole simultaneously as the drilling occurs.This is identical to the drive and drill methods applied by the cable tooling rigs.The inferior aspect of the casing is fitted with a drive boot.
In the drilling of unconsolidated sections, the drilling bit is fitted into the casing and the drive boot shaves away the accumulating processed formations created by the drilling activities.The casing is restricted by the aspect of friction, which is created in a borehole during the drilling activities.The casing components may be impelled prior to the installation of the drilling rigs that extract the plug.The drilling bit can also be applied after the installation of the casing.The casing can also be installed simultaneously as the drilling activities occur (Adams and Charrier, 1985;Daneshy et al., 1998).
In the event that it becomes a requisite to establish the casing in a lithological formation that is consolidated, a bit that is designated as an under-reaming bit can be applied.This is also designated as being a downhole hammering device.As the casing excludes all of the lithological fragments at the bottom of the borehole, the precision of sampling the lithological formations become enhanced.In addition, the circulation problems of loss are eradicated, and precise assessments of water production may be acquired (Adams and Charrier, 1985;Daneshy et al., 1998).

METHODOLOGY
The optimization of pore pressure prediction for over 46 reservoirs with datum TVDss (ft) > 5,000ft and reservoir temperatures ( 0 f) > 170 in the Niger Delta was considered in this study.In this work, a simple descriptive model was developed to optimize the pore pressures for effective wellplanning.The various case scenarios for pore pressure prediction optimization considered in this study included; • Pore pressure prediction in a virgin reservoir • Pore pressure prediction in a reservoir that has a sand continuity/communication with an adjacent reservoir of known pressure.
• Pore pressure prediction in a reservoir whose pressure data is consistent with historical trend.
• Pore pressure prediction in a reservoir that there hasn't been any production for a relatively short period.
• Pore pressure prediction in a reservoir that experiences water injection.
These case scenarios were considered in this study to help in providing a model that can optimize pore pressure prediction at a reduced cost and minimize non-productive time (NPT).
Where   = pore pressure,   = normal vertical effective stress,   = vertical overburden stress, ∆  = Normal sonic transient time, and ∆  = Deviated ∆ from the normal compaction trend line.
Using the case scenarios listed above for this study, estimate pore pressures with the following assumptions.
a) If the reservoir is virgin, assuming it's a normal pressure zone, use the normal pressure gradient of 0.433psi/ft to estimate the pore pressure.
b) Suppose the new drill is to be done in a reservoir with sand communication with an adjacent reservoir of known pressure.In that case, the known pore pressure should be used for the new drill reservoir.
c) Suppose the pressure data is consistent with historical trend.In that case, then pressure decline profile should be used to estimate the pore pressure.
d) If there hasn't been any production, the last static bottom hole pressure (SBHP) estimate should be used.
e) If the reservoir experiences water injection, use the last acquired pore pressure.
f) If the voidage replacement ratio (VRR) is ~ 1.0 or 1.5, use pressure incline or material balance (MBAL) estimate to estimate the pore pressure.
These assumptions were used to estimate the pore pressure for the various case scenarios considered in this study.For each reservoir description, the assumptions stated above were used to obtain reliable pore pressures.The pore pressure estimates obtained from this work were compared with the values obtained using the modified Eaton's sonic compression velocity model for pore pressure prediction.This study did not look into estimating pore pressures in partially /entirely faulted reservoirs or shaled out because of the rather complex nature of such reservoirs.Error analysis was also performed to ascertain the model's accuracy developed in this study.

ANALYSIS OF RESULT AND DISCUSSION
The results of the pore pressure prediction obtained from Eaton's correlation and the model developed in this study were compared with the Niger Delta well data obtained from offset wells.This is shown in Table 1 and 2.

Error Analysis
Error analysis was performed on the pore pressure values obtained in this study, the Eaton's model compared to pore pressures estimated from actual well data.This was done in order to ascertain the accuracy of the model developed in this study.The statistical error analysis mathematical models used for accuracy verification included, 1. Minimum absolute error: This is the modulus of the least error obtained in the data set 2. Maximum absolute error: This is the modulus of the highest error obtained in the data set.
3. Average absolute error (AAE): This is given as Where Pactual = well data pore pressure (psi), Predicted = pore pressure obtained from this study, and N = total number of data points Applying the statistical equations of accuracy above in comparing the results of actual and predicted pore pressures as shown in Tables 1 and 2, the following were obtained in Table 3:  From the results of the pore pressure values obtained for the new drills in various reservoir descriptions above, it can be seen that the descriptive model developed in this study gave accurate results for predicting the pore pressures with an average absolute error of 66psi as compared to Eaton's model of 38psi average absolute error and indicating that the Eaton's model was more accurate.However, in the absence of (costly and timeconsuming) data parameters required for pore pressure estimation using Eaton's model, the descriptive model prescribed in this study is a good alternative.
For a virgin reservoir, for instance, assumed to be under normal pressure, the high estimate value from the normal pressure gradient is seen to predict the pore pressures accurately.In the case of reservoirs experiencing water injection, it is assumed that the pore pressures have not changed significantly.Hence, previous or last estimated pore pressures could be used.For pressure data consistency, there are similarities in the pore pressure profile; hence, pore pressure values from the last acquired data could be used.Furthermore, suppose there has not been any production from the reservoir over a while.In that case, the pore pressures are expected not to have changed.In that case, the last acquired SBHP could be used.For new drills in reservoirs with sand continuities or communication with an adjacent reservoir of known pressures, the pore pressure values could be used to estimate pore pressures for the new drills.It was also seen that when voidage replacement ratios (VRR) ~ 1.0 or 1.5, the pressure incline or material balance (MBAL) estimate in estimating pore pressures proved to be accurate.However, the descriptive model prescribed above could not accurately predict the pore pressures for reservoir sections that were totally or partially faulted or shaled out.

CONCLUSION
In summary, the findings of this study offer valuable insights into pore pressure prediction in drilling operations.Firstly, it is evident that when drilling through the transition zone, utilizing Eaton's correlation with transit compressive wave velocity provides a superior method for accurately predicting pore pressures.Secondly, our developed model, presented in this study, is a valuable tool for quick and reliable pore pressure estimation, especially when essential data parameters for Eaton's model are unavailable.However, it is crucial to emphasize that the model introduced in this research should be strictly avoided when dealing with pore pressure prediction in fractured or shaled-out reservoirs, as its effectiveness may be compromised in such geological conditions.
Moving forward, our recommendations are twofold.Firstly, we advocate using Eaton's method as a reliable and well-established tool for pore pressure prediction.Secondly, we endorse the application of the descriptive model outlined in this study as a quick-look alternative for pore pressure estimation.It demonstrates relative accuracy and offers a cost-effective and time-efficient solution for pore pressure prediction, mainly when data constraints or time limitations are a concern.By combining the strengths of both Eaton's method and our proposed model, drilling operations can benefit from enhanced accuracy and efficiency in pore pressure assessment.

10 )
Tingay et al. (2009) formulated a similar relationship for the petroleum basin in Brunei.

Table 1 :
Comparison of pore pressure estimation using Eaton's model, this study against actual offset well data Cite The Article: Kelechi Anthony Ofonagoro, Olawe Alaba Tula, Joachim Osheyor Gidiagba, Tina Chinwe Ndiwe (2023).Enhancing Pore Pressure Prediction in Oil Well Drilling: A Comprehensive Study of Well Planning and Cost-Effective Modeling in The Niger Delta Region.Engineering Heritage Journal, 4(2): 167-177.

Table 2 :
Comparison of pore pressure estimation using Eaton's model, this study against actual offset well data

Table 3 :
Statistical Error Analysis