3-D Seismic Interpretation and Volumetric Estimation of “Osaja Field” Niger Delta, Nigeria

2016 ◽  
Vol 59 ◽  
pp. 14-28
Author(s):  
Lawson Jack Osaki ◽  
Alexander Iheanyichukwu Opara ◽  
Chikwendu Njoku Okereke ◽  
Uche Petters Adiela ◽  
Ikechukwu Onyema Njoku ◽  
...  

3-D seismic interpretation and petrophysical analysis of the Osaja Field, Niger Delta, was carried out with aim of carrying out a detailed structural interpretation, reservoir characterization and volumetric estimation of the field. Four wells were correlated across the field to delineate the lithology and establish the continuity of reservoir sand as well as the general stratigraphy of the area. The petrophysical analysis carried out, revealed two sand units that are hydrocarbon bearing reservoirs (Sand_A and Sand_B).The spatial variation of the reservoirs were studied on a field wide scale using seismic interpretation. Time and depth structural maps generated were used to establish the structural architecture/geometry of the prospect area of the field. The depth structure map revealed NE-SW trending anticlinal structures with F5and F6as faults assisted closures to the reservoir. Furthermore, reservoir parameters such as net pay, water saturation porosity, net-to-gross etc, were derived from the integration of seismic and well log data. The structural interpretation on the 3-D seismic data of the study area revealed a total of seven faults ranging from synthetic to antithetic faults. The petrophysical analysis gave the porosity values of the reservoir Sand_A ranging from 18.1 - 20.3% and reservoir Sand_B ranging from 13.1-14.9% across the reservoir. The permeability values of reservoir Sand_A ranging from 63-540md and reservoir Sand_B ranging from 18-80md hence there is decrease in porosity and permeability of the field with depth.The net-to-gross varies from 22.1% to 22.4% in Rerservoir Sand A to between 5.34- 12% for Rerservoir Sand _A while Sw values for the reservoirs ranges from 38-42% in well 2 to about 68.79-96.06% in well 11. The result of original oil in place for all the wells calculated revealed that well 2 has the highest value with 9.3mmbls. These results indicate that the reservoirs under consideration have a poor to fair hydrocarbon (oil) prospect.

2015 ◽  
Vol 3 (4) ◽  
pp. T183-T195 ◽  
Author(s):  
Augustine Ifeanyi Chinwuko ◽  
Ajana Godwin Onwuemesi ◽  
Emmanuel Kenechukwu Anakwuba ◽  
Clement Udenna Onyekwelu ◽  
Harold Chinedu Okeke ◽  
...  

Coblending of seismic attributes is used in the interpretation of channel geometries in the Rence Field of Niger Delta, Nigeria. We aimed at seismically defining the geometries of hydrocarbon reservoirs with particular emphasis on channels in the shallow marine (offshore) Niger Delta. The coblending application enhanced the ease of detection and the continuity of the channels, leaving the channel environs unchanged. The result of the seismic facies analysis revealed that the Rence Field can be distinguished into two seismic facies, namely, layered complexes and chaotic complexes. The result of well to seismic ties revealed high- and low-amplitude reflection events for sand and shale units, respectively. Seismic structural interpretation of the Rence Field revealed 4 major regional faults and 12 minor faults. Seven of the faults were antithetic, and the rest were synthetic faults. One mega-channel feature that trends east–west was identified in the attribute maps generated. It was characterized by sinuosity of 1.3, with a length of 22,500 m, and a distance of 17,500 m. The average depth of the channel was approximately 170 m with amplitude of 1670 m and the wavelength as high as 7640 m. A depositional model generated from the attribute maps indicated a prograding fluvial environment of deposition. The attribute map also determined that there was shifting in the location of barrier bars within the area. This shifting could be attributed to the growth fault mechanism. At the stoss side of the sinusoidal channel, there were prominent sand point bar sequences. The petrophysical analysis of the well data revealed 90% net-to-gross, 28% porosity, 27% volume of shale, and 24% water saturation indicating that the reservoir was of pay quality. Based on the petrophysical analysis, results, and identification of channel deposits, the study area proved highly promising for hydrocarbon exploration.


Author(s):  
K. A. Obakhume ◽  
O. M. Ekeng ◽  
C. Atuanya

The integrative approach of well log correlation and seismic interpretation was adopted in this study to adequately characterize and evaluate the hydrocarbon potentials of Khume field, offshore Niger Delta, Nigeria. 3-D seismic data and well logs data from ten (10) wells were utilized to delineate the geometry of the reservoirs in Khume field, and as well as to estimate the hydrocarbon reserves. Three hydrocarbon-bearing reservoirs of interest (D-04, D-06, and E-09A) were delineated using an array of gamma-ray logs, resistivity log, and neutron/density log suites. Stratigraphic interpretation of the lithologies in Khume field showed considerable uniform gross thickness across all three sand bodies. Results of petrophysical evaluations conducted on the three reservoirs correlated across the field showed that; shale volume ranged from 7-14%, total and effective porosity ranged from 19-26% and 17-23% respectively, NTG from 42 to 100%, water saturation from 40%-100% and permeability from 1265-2102 mD. Seismic interpretation established the presence of both synthetic and antithetic faults. A total of six synthetic and four antithetic faults were interpreted from the study area. Horizons interpretation was done both in the strike and dip directions. Time and depth structure maps revealed reservoir closures to be anticlinal and fault supported in the field. Hydrocarbon volumes were calculated using the deterministic (map-based) approach. Stock tank oil initially in place (STOIIP) for the proven oil column estimated for the D-04 reservoir was 11.13 MMSTB, 0.54 MMSTB for D-06, and 2.16 MMSTB for E-09A reservoir. For the possible oil reserves, a STOIIP value of 7.28 MMSTB was estimated for D-06 and 6.30 MMSTB for E-09A reservoir, while a hydrocarbon initially in place (HIIP) of 4.13 MMSTB of oil equivalents was derived for the undefined fluid (oil/gas) in D-06 reservoir. A proven gas reserve of 1.07 MMSCF was derived for the D-06 reservoir. This study demonstrated the effectiveness of 3-D seismic and well logs data in delineating reservoir structural architecture and in estimating hydrocarbon volumes


2018 ◽  
Vol 9 (2) ◽  
pp. 1025-1040 ◽  
Author(s):  
Akindeji Opeyemi Fajana ◽  
Michael Ayuk Ayuk ◽  
Pius Adekunle Enikanselu ◽  
Ajibola Rasidat Oyebamiji

2016 ◽  
Vol 4 (2) ◽  
pp. 28 ◽  
Author(s):  
Sunmonu Ayobami ◽  
Adabanija Adedapo ◽  
Adagunodo Aanuoluwa ◽  
Adeniji Ayokunnu

Hydrocarbon resources have become the most essential commodity contributing to any nation’s growth and development in the recent years. For the past decades now, the quest for hydrocarbon resources has been increasing in an arithmetic rate that its supply can no longer meets the demand for its consumption today. In petroleum industry, seismic and well log analyses play a vital role in oil and gas exploration and formation evaluation. This study is aimed to effectively characterize the reservoirs and analyze the by-passed pay in Philus Field, Niger-Delta, Nigeria in order to look into the economic viability and profitability of the volume of oil in the identified reservoir(s). The faults in the study area trend in NW-SE direction and dip towards the south. Seven reservoirs were mapped on Philus field. A discovery trap and a by-passed (new prospect) trap were mapped out on the field. The petrophysical analysis showed that porosity of Philus field was 0.24. The volumetric analysis showed that the Stock Tank Original Oil in Place of discovery trap (Philus field) ranged from 1.6 to 43.1 Mbbl while that of new prospect trap ranged from 18.1 to 211.3 Mbbl. It is recommended that the oil reserve of Philus field needs to be recalculated.


2021 ◽  
Vol 11 (2) ◽  
pp. 601-615
Author(s):  
Tokunbo Sanmi Fagbemigun ◽  
Michael Ayu Ayuk ◽  
Olufemi Enitan Oyanameh ◽  
Opeyemi Joshua Akinrinade ◽  
Joel Olayide Amosun ◽  
...  

AbstractOtan-Ile field, located in the transition zone Niger Delta, is characterized by complex structural deformation and faulting which lead to high uncertainties of reservoir properties. These high uncertainties greatly affect the exploration and development of the Otan-Ile field, and thus require proper characterization. Reservoir characterization requires integration of different data such as seismic and well log data, which are used to develop proper reservoir model. Therefore, the objective of this study is to characterize the reservoir sand bodies across the Otan-Ile field and to evaluate the petrophysical parameters using 3-dimension seismic and well log data from four wells. Reservoir sands were delineated using combination of resistivity and gamma ray logs. The estimation of reservoir properties, such as gross thickness, net thickness, volume of shale, porosity, water saturation and hydrocarbon saturation, were done using standard equations. Two horizons (T and U) as well as major and minor faults were mapped across the ‘Otan-Ile’ field. The results show that the average net thickness, volume of shale, porosity, hydrocarbon saturation and permeability across the field are 28.19 m, 15%, 37%, 71% and 26,740.24 md respectively. Two major faults (F1 and F5) dipping in northeastern and northwestern direction were identified. The horizons were characterized by structural closures which can accommodate hydrocarbon were identified. Amplitude maps superimposed on depth-structure map also validate the hydrocarbon potential of the closures on it. This study shows that the integration of 3D seismic and well log data with seismic attribute is a good tool for proper hydrocarbon reservoir characterization.


2018 ◽  
Vol 27 (4) ◽  
pp. 1087-1094 ◽  
Author(s):  
Emele U. Okpogo ◽  
Chukwuemeka P. Abbey ◽  
Ifeyinwa O. Atueyi

Petrophysical analysis is key to the success of any oil exploration and exploitation work and this task requires evaluation of the reservoir parameters in order to enhance accurate estimation of the volume of oil in place. This research work involves the use of suite of well logs from 4-wells to carry out the petrophysical analysis of ‘Bright’ Field Niger Delta. The approach used includes lithology identification, reservoir delineation and estimation of reservoir parameters. Two sand bodies were mapped across the entire field showing their geometry and lateral continuity, gamma ray and resistivity logs were used to delineate the reservoirs prior to correlation and relevant equations were used to estimate the reservoir parameters. The result of the petrophysical analysis showed variations in the reservoir parameters within the two correlated sand bodies with high hydrocabon saturation in sand 1 well 1 while the remaining wells within the correlated wells are water bearing. The porosity values range from 0.19 to 0.32, volume of shale from 0.15 to 0.40, water saturation from 0.20 to 0.92 for the sand bodies.


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