INTEGRATION OF LOGS AND SEISMIC DATA FOR DELINEATION OF DEPOSITIONAL ENVIRONMENT OF CLASTIC SEDIMENTS IN TOMBOY FIELD, NIGER DELTA

Abstract

The depositional environment of Clastic sediments in Tomboy Field Onshore Niger Delta were delineated using 3D Seismic and lithological logs. Well log suites from 5 wells comprising Spontaneous potential, Gamma ray, Sonic, Resistivity, Density, and Neutron logs were obtained and analyzed. Reverse estimation was done for the Neutron log and Bulk Density log using volumetric method. Gamma-ray log were used to calibrate Log motifs and correlate sand bodies TMB-01, TMB-02, TMB-03, TMB-04, and TMB-06. Prediction of depositional environment was made through the usage of wireline log shapes of facies combined with result from seismic data. Results of correlation across the five wells showed that. there was continuity at depth interval of 4000-5000ft across the wells as well 3 did not have any gamma information to correlate accros it. The seismic section showed two major growth faults and a channel fill on seismic (inline 5940, crossline1660) between 3.3-3.6ms. According to the paleo-reconstruction from the correlated wells within the tomboy field, the reservoir is made up of sands from fluvial and tidal channels, barrier, and barrier bar. These sand bodies are likely to contain hydrocarbons because of the rollover anticline, which is found at the fault’s downthrown block. This study has revealed that the Clastic sediments in Tomboy Field Onshore Niger Delta were deposited within a predominantly deltaic environment (transitional).

Keywords

• tomboy field
• clastic sediments
• depositional environment
• deltaic
• seismic and log data