| Autor: |
Opara, A. I., Chukwu, S. A., Onyekuru, S. O., Ekwe, A. C., Okereke, C. N., Anyiam, U. O., Njoku, I. O., Echetama, H. N. |
| Předmět: |
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| Zdroj: |
Petroleum & Coal; 7/1/2018, Vol. 60 Issue 4, p696-721, 26p |
| Abstrakt: |
Seismic interpretation of the "Bawi Field", Greater Ughelli Depobelt Niger Delta Nigeria was carried out with the objective of characterizating the reservoirs of the study area using 3-D seismic attributes. Hydrocarbon exploration of complex subsurface configuration as found in the study area requires an enhanced seismic interpretation approach. Several extracted seismic attributes which include variance, acoustic impedance, average energy, spectral decomposition, etc were used to enhance the interpretation of subtle hydrocarbon traps. Suites of signatures from wire-line logs and seismic volume were utilized to gain insight into the hydrocarbon saturated areas and the possible hosting (trapping) units outside the vicinity of well control. Well-to-seismic tie revealed that reservoir tops are tied to direct hydrocarbon indicators (Bright spots) on the vertical seismic section. Seismic variance attribute greatly enhanced geologic discontinuities and aided fault interpretation across the study area while spectral decomposition technique helped to delineate channel geometry and to appropriately select the best band for channel in-fill identification. Two major growth faults (F1 and F2, trending northwest to southeast respectively) were mapped at the central part of the field were revealed to have demarcated the field into three major blocks. Fault 1 (F1) has a southerly dip, while Fault 2 (F2) has a northerly dip. Six faults designated F1, F2, F4, F5, F6& F8 and four seismic horizons of interest were identified and mapped. Structural maps generated from the study revealed that the main hydrocarbon trapping mechanism in the field are fault closures. The trapping elements that can be distinguished include anticlinal dip closures, up thrown fault closures, and down thrown fault closures. Prospective hydrocarbon accumulation spots identified in the study area occur in the downthrown side of F1 and F2 and within the enclosed channel-fill sands in the "Bawi" Field. Four hydrocarbon bearing reservoirs (R1, R2, R3, and R4) were delineated.The reservoirs have an average porosity range of 19% to 38%; water saturation range of 28% to 44%, and net to gross range of 60% to 88%. Estimation of hydrocarbon volume in place revealed that R1 has less than a million cubic feet aof gas while R2 contains 795 million barrels of oil. Reservoirs R3 and R4 have estimated volume reserves of 177 and 227million barrels of oil respectively. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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