Exploration and exploitation for hydrocarbon are associated with a lot of complexities, it is therefore necessary to integrate available geologic models for accurate hydrocarbon prospecting and risk analysis. This study is aimed at determining the structural, petrophysical and volumetric parameters for reservoir evaluation within the Rancho field. 3D seismic data was used for evaluating the hydrocarbon potential of the field. A suite of well logs but not limited to gamma ray logs (GR), deep resistivity log (DRES), neutron log (NPHI) and density log (RHOB) from four (4) wells were employed in characterising dynamic properties of the reservoirs. The GR log was used in lithology identification while the resistivity log was used in identifying probable hydrocarbon bearing sands. A correlation exercise was carried out to identify lateral continuity and discontinuity of facies across the wells. Thereafter petrophysical parameters were analysed from the suite of wire line logs. Major faults were mapped on the 3D seismic data and identified hydrocarbon bearing sand tops from the well logs were mapped as horizons on the seismic section, maps were generated and volumetric analysis was done. Nine (9) hydrocarbon sands (Sands A -I) were identified within the study area. The well log revealed an alternation of sand and shale layers as well as shale layers increased in thickness with depth, while the sand bodies reduced in thickness with depth which characterized the Abgada Formation of the Niger Delta. The effective porosities of the sands range from 21% -31%, the permeability ranges from 28% -44%, 70% -80% for the net to gross, volume of shale range from 14% -40% and hydrocarbon saturation ranges from 63% -82%. Twelve (12) faults were mapped within the study area and the structural styles revealed a fault assisted closures. The volumetric analysis showed that Sand F had Stock Tank Oil Initially In Place

No abstract

The cost of drilling exploration and production wells is high and the price of crude oil in the capital market is fluctuating, therefore, there is the need to mitigate the risk of improper investigation of time/age-dependent reservoir rocks continuity within a field. Sequence stratigraphic analysis was carried out in OSP field with the aim of identifying and correlating hydrocarbon reservoirs that are deposited contemporaneously. Key stratigraphic surfaces (maximum flooding surfaces and sequence boundaries) were interpreted from biostratigraphic, well log and seismic data. Biostratigraphic interpretation subdivide the study area into three floral subzones-P780, P820 and P830. Three maximum flooding surfaces dated 10.4 Ma, 9.5 Ma and 7.4 Ma and four sequence boundaries dated 10.6 Ma, 10.35 Ma, 8.5 Ma and 6.7 Ma were identified. Three depositional sequences (sequences 1-3) were identified from the integration of the biostratigraphic, well log and seismic data. The identified key stratigraphic surfaces and depositional sequences were employed in the delineation and correlation of the hydrocarbon reservoirs which were found to fall within the highstand and lowstand systems tracts. Sequence stratigraphic correlation technique aided the local arrangement and geometries of reservoirs within the field and in locating potential reservoirs.

The mineralogical compositions of the Gerinya claystone, Patti Formation, Southern Bida Basin, Nigeria, were investigated to infer their sedimentological process and industrial application. Mineralogical analysis of the claystone was carried out using the X-ray diffraction (XRD) method. The diffractogram peaks aided the identification of the clay and non-clay minerals in the study area. The XRD showed kaolinite as the major clay mineral with compositions ranging from 10.8 - 67.6 wt%. The non-clay minerals were quartz, anatase, diopside, goethite, hematite, rutile, muscovite and micro-cline. Among the non-clay minerals, quartz had the highest percentage mineralogical composition of 21.2 to 83.4 wt%. The mineral assemblage is typical of a hot and humid climate where chemical alteration and hydrolysis of silicate minerals are severe. The sediments are of mafic and felsic crystalline rocks origin. The sediments are of low energy floodplain/interchannel depositional environment. The Gerinya claystone vary from low to high porosity and very low to low permeability. The claystone can be used as clay liners and as raw material for ceramic production. The application of the claystones in fertiliser production will require some processing. The clay-stone can be used for haemorrhage control in the pharmacological/medical sector. Although, the ingestion of the clay-stones could lead to dental damage and possible perforation of the sigmoid colon in the gastrointestinal tract.

No abstract