EVALUATION OF HYDROCARBON PROSPECT OF TOMBOY CFIELD OFFSHORE NIGER DELTA, NIGERIA

Abstract

3D Seismic data and well logs were used to re- evaluate the hydrocarbon prospects of Tomboy C- field located
offshore Niger Delta Basin, Nigeria. The study was aimed at identifying the unharnessed hydrocarbon prospects
in the field . Three lithostratigraphic units of Niger Delta: Akata, Agbada and Benin Formations were analyzed
from seismic reflection time interval of 0 to 5800ms, with the Akata , Agbada and Benin Formations occurring
beyond 3800ms, between 1550 to 3800ms and 0 to 1550ms respectively. The depositional environments of the
reservoirs were interpreted as distributary channel (lower deltaic plain), distributary mouth bar ( part of deltaic
front) and lower shoreface (part of pro-delta) in agradation. A total of eight faults (FLT1 to FLT8) were
identified and mapped respectively. FLT2 and FLT3 were identified as major growth faults that partitioned the
field into three fault blocks named FBLK1, FBLK2 and FBLK3. Thirteen horizons were mapped and integrated
with the mapped faults to produce both time and depth structural maps. Facies and petrophysical analysis were
carried out with hydrocarbon prospects identified within FBLK2 and FBLK3. Hydrocarbon prospects were
identified in the undrilled fault blocks with fault assisted anticlinal closures. Bypassed hydrocarbon prospects
identified in the field occur in the form of low resistivity pay zones (low contrast) with a range between 1.50 to
2.02ohms for wellsTMB01 and TMB04 respectively. Stratigraphic traps were identified as pinchout in well
TMB01.