PETROPHYSICAL ANALYSIS AND VOLUMETRIC ESTIMATION IN SURE

ABSTRACT

Petrophysical analysis and volumetric estimation were carried out using 3D seismic and well log data to evaluate the reservoir potentials of Sure Field in the Niger Delta Basin of Nigeria. One hydrocarbon bearing reservoir, sand A was mapped out of several identified sands. The top of the reservoir was tied to the seismic section and mapped throughout the entire volume by using a generated synthetic seismogram and check shot of Sure 02 well. Faults were mapped and a structure map for the reservoir top was produced. The reservoir top is at the depth of about 3079.6ft. The reservoir was mapped at a depth range between 3038.8ft and 3520.3ft. The average Oil-water contact (OWC) is at depth of about 3297.3ft. Since the reservoir was intercalated with shale, the net thickness varied between 11.89ft and 18.04ft. The gross thickness of the reservoir varied between 59.39ft and 60ft. The petrophysical parameters obtained were total porosity (ϕ) ranging from 0.29 to 0.30, effective porosity of about 0.29, water saturation (Sw) ranging from 0.14 to 0.43, hydrocarbon saturation (SH) varies between 0.57 and 0.86 and net to gross (N/G) which ranges from 0.2 to 0.3. Two prospect areas were delineated, with the bigger prospect (2199.6 acres) having a higher risk of drilling related to the trapping mechanism, when compared with the small prospect (1004.3 acres). The prospect areas gotten from the structure maps were combined with the relevant petrophysical parameters to estimate the volume of hydrocarbon in place. The estimation of the volume of hydrocarbon revealed that in the two prospect areas are 65,351,562bbl and 29,838,413.3bbl respectively. A material balance method as well as reservoir simulation process can be subsequently carried out, in order to ascertain a more robust estimation of the reserve in place.