Well log sequence stratigraphic analyses for reservoir delineation and hydrocarbon distribution in the eastern part of the central swamp depobelt, Niger Delta

摘要

Sequence stratigraphic analysis was conducted employing Gamma Ray andResistivity logs from five wells in the eastern part of central swamp depobelt, NigerDelta. Interpretation by Kingdom Suite software shows that lithologies are definedby Sequences I, II and III comprising two marine transgressive shale markers andcorrespond to MFS. Sequences I and III are incomplete comprising one SB whileSequence II is complete. Types 1 and 2 sequence boundaries are contained withinthe sequences. Key stratigraphic surfaces subdivide strata into LST, TST and HST.LST consisting of SF and PC. Sequence I comprises LST and HST while sequenceIII comprises SMST bounded by type 2 unconformity. The TST of sequence IIcomprises a retrogradational set of parasequences while the HST of sequences I andII comprise a progradational set of parasequences. The LST shows high reservoirpotential and may act as a stratigraphic trap for hydrocarbon because the shalesoverlying the LSF act as a seal and within the SF complex. To assign ages anddepositional cycles to the identified surfaces, an integrated sequence stratigraphicanalysis should be conducted to accurately model the lithostratigraphic andchronostratigraphic settings of the depositional sequence of the study area.