Showing papers on "Effective porosity published in 2021"

Three-Dimensional Structural and Petrophysical Modeling for Reservoir Characterization of the Mangahewa Formation, Pohokura Gas-Condensate Field, Taranaki Basin, New Zealand

Abstract: This study integrated three-dimensional (3D) structural and petrophysical models to establish the reservoir characteristics of the Mangahewa Formation within the Pohokura Gas-Condensate Field. The 3D structural model, in which 3 horizons and 51 faults were interpreted, was developed using an algorithm for volume-based modeling. The complex structural mechanism was observed as compressional and extensional stresses resulting in steeply dipping normal and reverse faults. The fault throw was estimated to be up to 85 m, and 33% of the faults had throws of less than 10 m. This explains the fault growth system as small, younger faults have merged to develop larger faults. Well log analysis was used to evaluate important petrophysical parameters such as effective porosity, net-to-gross ratio, shale volume, and water and hydrocarbon saturation. After applying a cutoff, the estimated values for effective porosity, net-to-gross ratio, shale volume, and water and hydrocarbon saturation were 12–18%, 13–31%, 13–26%, 6–22%, and 78–94%, respectively. The estimated values were then incorporated into the grid cells to design 3D petrophysical modeling using the algorithm for sequential Gaussian simulation. The structural model indicated effective trapping and the presence of a conduit mechanism for hydrocarbons. The well log analysis identified significant effective porosities containing substantial hydrocarbon saturation, whereas the petrophysical models showed very good dissemination of the petrophysical parameters. From these models, which also incorporate the gas–water contact, proposed drilling sites for future exploration and well development were proposed. The results characterize the Mangahewa Formation as a good reservoir within the Pohokura Gas-Condensate Field.

Measure of porosity in flax fibres reinforced polylactic acid biocomposites

Abstract: The paper describes an optimised strategy to measure the porosity in natural fibre composites. Particular emphasis is placed on thermoformed flax fibres reinforced poly-lactic acid (FFRPLA) laminates. Six different methods to measure the porosity were evaluated and compared: gravitometry in ethanol and in water, scanning electron microscopy (SEM), computed tomography (CT) scanning, optical microscope measurements and inverse identification from tensile tests. The measurements indicate porosity levels ranging from 3.5% to 21%. A measurement approach consisting of defining lower and upper bounds of porosity provided by CT-scanning and gravimetric measurements in water was identified. The lower bound of this interval represents the best approximation of the effective porosity, which is 8.3 ± 2.3% for the FFRPLA tested in this work. The approach could be also extended to other similar classes of natural fibre reinforced composites.

Stress sensitivity of porosity and permeability under varying hydrostatic stress conditions for different carbonate rock types of the geothermal Malm reservoir in Southern Germany

Abstract: In geothermal reservoir systems, changes in pore pressure due to production (depletion), injection or temperature changes result in a displacement of the effective stresses acting on the rock matrix of the aquifer. To compensate for these intrinsic stress changes, the rock matrix is subjected to poroelastic deformation through changes in rock and pore volume. This in turn may induce changes in the effective pore network and thus in the hydraulic properties of the aquifer. Therefore, for the conception of precise reservoir models and for long-term simulations, stress sensitivity of porosity and permeability is required for parametrization. Stress sensitivity was measured in hydrostatic compression tests on 14 samples of rock cores stemming from two boreholes of the Upper Jurassic Malm aquifer of the Bavarian Molasse Basin. To account for the heterogeneity of this carbonate sequence, typical rock and facies types representing the productive zones within the thermal reservoir were used. Prior to hydrostatic investigations, the hydraulic (effective porosity, permeability) and geomechanical (rock strength, dynamic, and static moduli) parameters as well as the microstructure (pore and pore throat size) of each rock sample were studied for thorough sample characterization. Subsequently, the samples were tested in a triaxial test setup with effective stresses of up to 28 MPa (hydrostatic) to simulate in-situ stress conditions for depths up to 2000 m. It was shown that stress sensitivity of the porosity was comparably low, resulting in a relative reduction of 0.7–2.1% at maximum effective stress. In contrast, relative permeability losses were observed in the range of 17.3–56.7% compared to the initial permeability at low effective stresses. Stress sensitivity coefficients for porosity and permeability were derived for characterization of each sample and the different rock types. For the stress sensitivity of porosity, a negative correlation with rock strength and a positive correlation with initial porosity was observed. The stress sensitivity of permeability is probably controlled by more complex processes than that of porosity, where the latter is mainly controlled by the compressibility of the pore space. It may depend more on the compaction of precedented flow paths and the geometry of pores and pore throats controlling the connectivity within the rock matrix. In general, limestone samples showed a higher stress sensitivity than dolomitic limestone or dolostones, because dolomitization of the rock matrix may lead to an increasing stiffness of the rock. Furthermore, the stress sensitivity is related to the history of burial diagenesis, during which changes in the pore network (dissolution, precipitation, and replacement of minerals and cements) as well as compaction and microcrack formation may occur. This study, in addition to improving the quality of input parameters for hydraulic–mechanical modeling, shows that hydraulic properties in flow zones largely characterized by less stiff, porous limestones can deteriorate significantly with increasing effective stress.

Porosity-based models for estimating the mechanical properties of self-compacting concrete with coarse and fine recycled concrete aggregate

Abstract: Predicting the mechanical properties of Self-Compacting Concrete (SCC) containing Recycled Concrete Aggregate (RCA) generally depends, in great part, on the RCA fraction in use. In this study, predictive equations for estimating SCC mechanical properties are developed through SCC porosity indices, so they are applicable to any RCA fraction and amount that may be used. A total of ten SCC mixes were prepared, nine of which containing different proportions of coarse and/or fine RCA (0%, 50% or 100% for both fractions), and the tenth mixed with 100% coarse and fine RCA, and RCA powder 0–1 mm. The following properties were evaluated: compressive strength, modulus of elasticity, splitting tensile strength, flexural strength, and effective porosity as measured with the capillary-water-absorption test. Negative effects on the above properties were recorded for increasing contents of both RCA fractions. The application of simple regression models yielded porosity-based estimations of the mechanical properties of the SCC with an accuracy margin of ±20%, regardless of the RCA fraction and amount. The results of the multiple regression models with compressive strength as a secondary predictive variable presented even greater robustness with accuracy margins of ±10% and almost no significant effect of accidental porosity variations on prediction accuracy. Furthermore, porosity predictions using the 24-h effective water also yielded accurate estimations of all the above mechanical properties. Finally, comparisons with the results of other studies validated the reliability of the models and their accuracy, especially the minimum expected values at a 95% confidence level, at all times lower than the experimental results.

Investigating the Interaction Effects between Reservoir Deformation and Hydrate Dissociation in Hydrate-Bearing Sediment by Depressurization Method

Abstract: Natural gas hydrate (NGH) has been widely focused on having great potential for alternative energy. Numerous studies on gas production from hydrate-bearing sediments have been conducted in both laboratory and field. Since the strength of hydrate-bearing sediments depends on the saturation of NGH, the decomposition of NGH may cause the failure of sediments, then leading to reservoir deformation and other geological hazards. Plenty of research has shown that the reservoir deformation caused by hydrate decomposition is considerable. In order to investigate this, the influence of sediment deformation on the production of NGH, a fully coupled thermo-hydro-chemo-mechanical (THMC) model is established in this study. The interaction effects between reservoir deformation and hydrate dissociation are discussed by comparing the simulation results of the mechanical coupling and uncoupled models on the laboratory scale. Results show that obvious differences in behaviors between gas and water production are observed among these two models. Compared to the mechanical uncoupled model, the mechanical coupling model shows a significant compaction process when given a load equal to the initial pore pressure, which leads to a remarkable decrease of effective porosity and reservoir permeability, then delays the pore pressure drop rate and reduces the maximum gas production rate. It takes a longer time for gas production in the mechanical coupling model. Since the reservoir temperature is impacted by the comprehensive effects of the heat transfer from the boundary and the heat consumption of hydrate decomposition, the reduced maximum gas production rate and extended gas production process for the mechanical coupling model lead to the minimum reservoir temperature in the mechanical coupling model larger than that of the mechanical uncoupled model. The reduction of the effective porosity for the mechanical coupling model causes a larger cumulative water production. The results of this paper indicate that the reservoir deformation in the gas production process should be taken into account by laboratory and numerical methods to accurately predict the behaviors of gas production on the field scale.

Prediction of spontaneous imbibition in fractal porous media based on modified porosity correlation

Abstract: Spontaneous imbibition plays a significant role in different technical applications, and several analytical models have been proposed for predicting the fluid imbibition mass into porous media based on the fractal theory. Herein, these previous models are reconsidered in view of the obvious difference between the effective porosity and the areal porosity of porous media. Firstly, an implicit equation for fractal tortuosity is proposed and a modified correlation for the areal porosity is presented; then, a semi-analytical prediction model for fluid imbibition mass with gravity pressure is derived; finally, comparisons of predictions among several previous models with the present model are carried out. The modeling results show consistency with the experimental data published in the literature. Cited as: Li, Y., Yu, D., Niu, B. Prediction of spontaneous imbibition in fractal porous media based on modified porosity correlation. Capillarity, 2021, 4(1): 13-22, doi: 10.46690/capi.2021.01.02

Geometric and Fractal Characterization of Pore Systems in the Upper Triassic Dolomites Based on Image Processing Techniques (Example from Žumberak Mts, NW Croatia)

Abstract: Karst aquifers are important sources of thermal and groundwater in many parts of the world, such as the Alpine–Dinaric–Carpathian region in Europe. The Upper Triassic dolomites are regionally recognized thermal and groundwater aquifers but also hydrocarbon reservoirs. They are characterized by predominantly fractured porosity, but the actual share of depositional and diagenetic porosity is rarely investigated. In this research, we presented the geometric characterization of the measured microporosity of the Upper Triassic dolomites of the Žumberak Mts (Croatia), through thin-section image processing and particle analysis techniques. Pore parameters were analyzed on microphotographs of impregnated thin sections in scale. A total of 2267 pores were isolated and analyzed. The following parameters were analyzed: pore area, pore perimeter, circularity, aspect ratio (AR), roundness, solidity, Feret AR, compactness, and fractal dimension. Furthermore, porosity was calculated based on the pore portion in each image. The effective porosity on rock samples was determined using saturation and buoyancy techniques as an accompanying research method. We analyzed distributions of each parameter, their correlation, and most of the parameters are characterized by an asymmetric or asymmetric normal distribution. Parameters that quantify pore irregularities have similar distributions, and their values indicate the high complexity of the pore geometry, which can significantly impact permeability.

Reservoir quality of Abu Roash (G) member in Karama Oil Field, East Bahariya Concession, North Western Desert, Egypt

Abstract: In the present study, well logs and petrophysical core data are integrated to analyze Abu Roash (G) reservoir characteristics in Karama oil field, North Western Desert, Egypt. Conventional core data analysis of about 64 samples from Karama-4 well had been used in characteristic evaluation of the target reservoir. These data include permeability (horizontal and vertical), porosity (helium and fluid summation), and matrix density. The available core data were used to generate statistical analysis, histograms and new relations for porosity, and permeability data. The core analysis results show fair porosity and permeability values where the lithology is mainly carbonate (limestone and dolomite) with some sandstone. Well logging data of 4 wells were analyzed to evaluate the reservoir petrophysical parameters. These parameters include gross thickness, net pay, effective porosity, shale volume, water saturation, and hydrocarbon saturation. These reservoir parameters are mapped to illustrate vertical plotting and the aerial distribution. The aerial distribution maps showed that the best locations of hydrocarbon accumulation are at south, southeastern, and southwestern directions of study area. The petrophysical parameters also offered in the form of vertical variation logs (vertical litho saturation cross plots). They indicate that the lithology is intercalations of carbonate, mud, and sand streaks. In sand streaks, there is an observed increasing in the values of total and effective porosities and hydrocarbon saturation as well as decreasing in shale volume and water saturation. The results give an impression that the sand streaks in the studied formation are good reservoirs where the effective porosity ranges from 18.3 to 33.3% and the hydrocarbon saturation reaches up to 61.5% in in some zones in the different wells.

Geophysical and hydrocarbon prospect evaluation of Nukhul Formation at Rabeh East oil field, Southern Gulf of Suez Basin, Egypt

Abstract: Nukhul Formation is one of the primary oil reservoirs in the Gulf of Suez Basin. Rabeh East is an oil producer field located at the southern border of the Gulf of Suez. The present work deals with the geophysical investigation of Nukhul Formation in Rabeh East field using seismic lines and well log data of four wells, namely RE-8, RE-22, RE-25 and Nageh-1. The interpreted seismic profiles display that the RE-8 Well is the only well drilled within the up-thrown side of a significant horst fault block bounded by two normal faults. However, the other wells penetrated the downthrown side. The qualitative interpretation of the well logging data for RE-8 Well delineated two intervals have good petrophysical parameters and ability to store and produce oil. These zones locate between depths 5411.5 and 5424 ft (zone I) and between 5451 and 5459.5 ft (zone II). The calculated petrophysical parameters for zone I display water saturation (22–44%), shale volume (10–23%), total porosity (18–23%), effective porosity (12–20%) and bulk volume of water (0.04–0.06). Zone II exhibits water saturation (13–45%), shale volume (10–30%), total porosity (18–24%), effective porosity (11–20%) and bulk volume of water (0.03–0.05). This analysis reflects excellent petrophysical characteristics for the sandstones of Nukhul Formation in Rabeh East oil field for producing oil if the wells drilled in a suitable structural closure.

Clay Analysis of Upper Assam Basin for Chemical Enhanced Oil Recovery

Abstract: The success and failure of different chemical enhanced oil recovery (CEOR) techniques can control to a large extent by the presence of different types of clay, its surface area and the reactivity of the clay with the injected chemicals during CEOR techniques. Therefore, reservoir clay analysis is important to study the CEOR process in general and to formulate the CEOR slug in particular. This study pertains to the underground porous media of upper Assam basin. In this paper effective porosity, absolute permeability, minerals and clays present in porous media is studied. Effective porosities were determined to estimate the total pore volume and more importantly the connecting pores and the throat volumes. The absolute permeability are exclusively the properties of the porous media, which determines the ease of flow of fluid through the porous media. Rock petrography study was done by examining the thin sections under optical microscope, Scanning Electron Microscope (SEM) and X-ray Diffractometer (XRD). From these studies the mineral and clay content of the reservoir was characterized, which helps to study the feasibility of a CEOR in upper Assam basin. This petrography study provides two and three dimensional accurate description of minerals of reservoir rock and clay particles. The porous media is a sandstone with high porosity and low absolute permeability. The clays present are smectite, kaolinite and illite with a dominance of smectite and kaolinite, conforming to the swelling and disintegration.

Detection of Effective Porosity and Permeability Zoning in an Iranian Oil Field Using Fractal Modeling

Abstract: Identification and delineation of different zones in oil fields are among the fundamental tasks in petroleum explorations. Fractal methods are useful tools for such purposes. The aim of this paper is to conduct a comparative study of Concentration-Area (C-A) and Number-Size (N-S) fractal models to separate effective porous and permeable zones based on core logging samples collected from one of the oilfields in southern Iran. However, permeability and porosity threshold values were calculated based on the C-A and N-S log-log plots. A comparison between the C-A and N-S fractal results showed that the C-A method is more compatible with reality, and it is capable of separating permeable and porous zones in this oilfield.

Nanoscale Accessible Porosity as a Key Parameter Depicting the Topological Evolution of Organic Porous Networks.

Abstract: A significant part of the hydrocarbons contained in source rocks remains confined within the organic matter-called kerogen-from where they are generated. Understanding the sorption and transport properties of confined hydrocarbons within the kerogens is, therefore, paramount to predict production. Specifically, knowing the impact of thermal maturation on the evolution of the organic porous network is key. Here, we propose an experimental procedure to study the interplay between the chemical evolution and the structural properties of the organic porous network at the nanometer scale. First, the organic porous networks of source rock samples, covering a significant range of natural thermal maturation experienced by the Vaca Muerta formation (Neuquen Basin, Argentina), are physically reconstructed using bright-field electron tomography. Their structural description allows us to measure crucial parameters such as the porosity, specific pore volume and surface area, aperture and cavity size distributions, and constriction. In addition, a model-free computation of the topological properties (effective porosity, connectivity, and tortuosity) is conducted. Overall, we document a general increase of the specific pore volume with thermal maturation. This controls the topological features depicting increasing accessibility to alkane molecules, sensed by the evolution of the effective porosity. Collectively, our results highlight the input of bright-field electron tomography in the study of complex disordered amorphous porous media, especially to describe the interplay between the structural features and transport properties of confined fluids.

Facies-Controlled Geostatistical Porosity Model for Estimation of the Groundwater Potential Area in Hongliu Coalmine, Ordos Basin, China

Abstract: Accurate and reliable evaluations of potential groundwater areas are of significance in the hydrogeological assessments of coalfields because water inrush disasters may be caused by unclear groundwater potential. A three-dimensional geological model of porosity based on deterministic modeling and a facies-controlled method are used to determine the groundwater potential of the coal measure aquifer. The modeling processes are as follows: based on the interlayer and discontinuity (faults) data extracted from boreholes and geological maps, an integrated sequence framework model is developed. Using the results of sedimentary microfacies identification and the method of deterministic modeling, a sedimentary microfacies model is successfully established. Finally, based on facies-controlled and sequential Gaussian methods, an effective porosity model is established that can predict the groundwater potential. The predicted results show that sandstones sedimented in channel, point bar, and batture environments possess high effective porosity and strong groundwater potential; however, the sandstones sedimented in interdistributary bays, flood plains, and sand sheets possess low effective porosity. Model validation was performed based on the hydrological pumping test data collected from observation boreholes, drainage water inflow data from dewatered boreholes in the tunnel around workface, and the mine water inflow in tunnels and the workfaces. The validation analysis results show that the effective porosity and sedimentary facies were correlated with the actual flux. The predicted results are consistent with the actual flux data, validating the predicted model.

Evaluation of the effective porosity of an open cell foam material for using in heat and mass transfer numerical simulations

Abstract: A comparison of the efficiency of the open cell foam (OCF) models is carried out. Geometrical models are constructed by the methods of simple cubic, body-centered cubic, and face-centered cubic. The parameter of the material efficiency is defined as the composition of the material surface area and the gas residence time in the porous media. The analytical evaluation shows different values of effective porosity for different construction models of the material. In this case, for all considered models, the effective porosity is in the range of 0.741-0.821.

Integrated source rock evaluation along the maturation gradient. Application to the Vaca Muerta Formation, Neuquén Basin of Argentina

Abstract: [Petroleum system modelling showing present‐day maturity (%Ro) of the Vaca Muerta Formation from from the Agrio Fold and Thrust Belt (west) to the NE Platform (east). The increase in TOC0 values from east to west is associated with thickening of the unit, which suggests the potential larger volumes of generated hydrocarbons for the same thermal gradient. The E–W thermal maturity trend is consistent with the decrease in HI and increase in TR values to the west, indicating that in conjunction with increased TOC0, organic pores represent the main control on total porosity in organic‐rich intervals of the unit. , Abstract The Vaca Muerta Formation (Tithonian–early Valanginian) is the main source rock in the Neuquen Basin and the most important unconventional shale resource in South America. In the present study, organic geochemistry, electron microscopy and basin and petroleum system modelling (BPSM) were combined to evaluate source rock properties and related processes along a transect from the early oil (east) to the dry gas (west) window. The unit is characterized by high present‐day (1%–8% average) and original (2%–16% average) total organic carbon contents, which increase towards the base of the unit and basinal (west) settings. Scanning electron microscopy shows that organic pores derived from the transformation of type II kerogen. Isolated bubble pores are typical of the oil window, whereas bubble and densely distributed spongy pores occur in the gas stage, indicating that the maturity gradient exerts strong control on organic porosity. Organic geochemistry, pressure and porosity data were incorporated into a 2D basin petroleum system model that includes the sequential restoration of tectonic events and calculation of compaction trends, kerogen transformation, hydrocarbon generation and estimation of pore pressure through geologic time. The W–E regional model extends from the Agrio Fold and Thrust Belts to the basin border and allows us to evaluate the relationship between thermal maturity and timing of hydrocarbon generation from highly deformed (west) to undeformed (east) regions. Modelling results show a clear decrease in maturity and organic matter (OM) transformation towards the eastern basin margin. Maximum hydrocarbon generation occurred in the inner sectors of the belt, at ca. 120 Ma; long before the first Andean compression phase, which started during the Late Cretaceous (ca. 70 Ma). Miocene compression (15–7 Ma) promoted tectonic uplift of the inner and outer sectors of the belt associated with a reduction in thermal stress and kerogen cracking, as well as massive loss of retained fluids and a decrease in pore pressure. The OM transformation impacted (a) the magnitude of effective porosity associated with organic porosity development, and (b) the magnitude and distribution of pore pressure within the unit controlled by hydrocarbon generation and compaction disequilibrium. BPSM shows a progressive increase in effective porosity from the top to the base and towards the west region related to the original organic carbon content and maturity increasing along the same trend. Overpressure intervals with high organic carbon contents are the most prone to develop organic pores. The latter represent favourable sites for the storage of hydrocarbons in the Vaca Muerta Formation.]

Large-scale hydraulic conductivity distribution in an unconfined carbonate aquifer using the ocean tidal propagation

Abstract: The hydraulic conductivity of an unconfined carbonate aquifer at the uplifted atoll of Minami-Daito, Japan, was evaluated by a combination of cross-spectral analysis, analytical solution, and density-dependent groundwater modeling based on observed groundwater levels in 15 wells and at sea level. The island area was divided into 10 subregions based on island morphology and on inland propagation of ocean tides. The hydraulic conductivity was obtained for each subregion using analytical solutions based on phase lags of M2 constituents of ocean tides at each well by assuming two aquifer thicknesses (300 and 1,800 m) and two effective porosities (0.1 and 0.3). The density-dependent groundwater model evaluated the hydraulic conductivity of the subregions by reproducing observed groundwater levels. The hydraulic conductivity in the subregions was estimated as 3.46 × 10−3 to 6.35 × 10−2 m/s for aquifer thickness of 300 m and effective porosity of 0.1, and as 1.73 × 10−3 to 3.17 × 10−2 m/s for aquifer thickness of 1,800 m and the effective porosity of 0.3. It was higher in southern and northern areas, and higher in interior lowland than in the western and eastern areas. Fissures and dolomite distributions on the island control differences of the omnidirectional ocean tidal propagation and cause these differences in hydraulic conductivity. The method used for this study may also be applicable to other small islands that have few or no data for hydraulic conductivity.

Extending DFA-based multiple linear regression inference: Application to acoustic impedance models

Abstract: In this paper we propose three distinct points for improving scale sensitive DFA based multiple linear regression inference: the scale dependent standardized Regression Coefficients β ˆ s t d D F A s as a measure of dependent variables relative importance, scale dependent effect size f 2 ( s ) , and Intersection-Union hypothesis test, which can handle the composite hypothesis of no cross-correlation, and of having no advantage over the standard OLS linear regression model. We applied this framework on a model for acoustic impedance of well log data, as a function of neutron effective porosity, shale volume, and resistivity. We find that the neutron effective porosity is more important for modeling acoustic impedance than resistivity and, that both are more important than the shale volume, for all scales. Results from Intersection-Union test suggest the rejection of compound null hypothesis for neutron effective porosity and resistivity for scales between 40 and 500 ft, suggesting a robust model for acoustic impedance based on neutron effective porosity and resistivity on these scales. This approach represents a novel framework for scale sensitive regression models, and we believe that it can be useful for time series studies in many diverse areas.

Hydrocarbon Play Assessment of “Oswil” Field,Onshore Niger Delta Region

Abstract: Hydrocarbon play assessment of any field involves the evaluation of the production capacity of hydrocarbon reservoir unit in the field. This involves detail study of the reservoir petrophysical properties and geological interpretation of structures suitable for hydrocarbon accumulation in the field as observed from seismic reflection images. This study details the assessment of hydrocarbon play in OSWIL field onshore in Niger Delta, with the intent of appraising its productivity using a combination of seismic, well logs,petrophysical parameters and volumetric estimation using proven techniques which involves an integrated methodology. Two reservoir windows “R1” and “R2” were defined from five wells OSWIL-02, 04, 06, 07 and 12.The top and base of each reservoir window was delineated from the wells.Structural interpretation for inline 6975 revealed two horizons (X and Y) and eight faults labelled (F1, F2, F6, F8, F10, F16, F17 and F18). Five faults (F1, F6, F10, F17 and F18) were identified as synthetic faults and dip basin wards while three faults (F2, F8 and F16) were identified as antithetic faults and dips landwards. Time-depth structural map at top of reservoirs R1 and R2 revealed structural highs and closures. These observations are characteristics of growth structures (faults) which depicts the tectonic style of the Niger Delta. Results of petrophysical evaluation for reservoirs “R1” and “R2” across the five wells were analysed. For reservoir “R1” effective porosity values of 27%, 26%, 23%, 20% and 22% were obtained for wells OSWIL-04, 12, 07, 06 and 02 respectively with an average of 23.6%, while for reservoir “R2” effective porosity values of 26%, 22%, 21%, 24% and 23% for wells OSWIL-04, 12, 07, 06 and 02 were obtained respectively with an average of 23.2%. This porosity values correspond with the already established porosity range of 28-32% within the Agbada formation of the Niger Delta. Permeability index of the order (K > 100mD) were obtained for both reservoirs across the five wells and is rated very good. Hydrocarbon saturation (Shc) across the five wells averages at 61.6% for reservoir “R1” and 67.4% for reservoir “R2”. Result of petrophysical model for porosity, permeability and water saturation reveal that the reservoir system in R1 and R2 is fault assisted and fluid flow within both reservoirs is aided by presence of effective porosity and faulting. Volumetric estimation for both reservoirs showed that reservoir R1 contains an estimate of 455 × 106 STB of hydrocarbon in place, while reservoir R2 contains an estimate of 683 ×106 STB of hydrocarbon in place. These findings impact positively on hydrocarbon production in the field and affirm that the two reservoirs R1 and R2 are highly prospective.