INTEGRATED ANALYSIS FOR ASSESSMENT OF DEEPER HYDROCARBON PLAY POTENTIAL IN REBAB-1, CENTRAL LUCONIA PROVINCE, SARAWAK

Abstract

The basin history, thermal maturity, and hydrocarbon entrapments of Rebab-1 Well in Central Luconia have been relooked through the study of seismic, well log, and geochemical data to find new hydrocarbon potential in the deeper section of the well. The quality of source rocks in this area was based on assumptions, and hydrocarbon exploitation only occurs on shallow hydrocarbon plays making the potential for deeper plays difficult to ascertain. This study was conducted based on two 2D seismic lines, integrated with well lithological and stratigraphy data and geochemical data such as total organic carbon, pyrolysis, and vitrinite reflectance. Integration of these data was used to determine the deeper hydrocarbon play of Rebab-1 in Central Luconia Province. The seismic data were interpreted using Petrel software with validation from the report. Cross-plots from bulk geochemical analysis data were interpreted for the source rock's organic richness, kerogen quality, hydrocarbon-generating potentials, and thermal maturation levels. The results of seismic interpretations showed that extensional and compressional tectonics shaped the field of Rebab-1, with structures mainly trending to the NW-SE and NE-SW directions. Geochemical analysis showed that the total organic carbon content (TOC) of the samples analysed ranges between 0.06 and 2.98 wt.% indicating fair to very good source rocks producing mainly type II and mixed type II-III kerogen as the dominant kerogen. These types can generate mainly gas and mixed oil and gas accumulations upon attaining thermal maturation level. Also, Rebab-1 shows fair to very good hydrocarbon-generating potentials. The vitrinite reflectance (Ro) and Tmax results showed that the analysed samples are generally plotted in the immature, mature, and post-mature stages of oil generation but still within the gas generation window. Overall, source rocks from Rebab-1 can be said to have attained maturity at the youngest during depositions of Cycle III to older than that, and faulting and folding serves as hydrocarbon trap systems, indicative of potential in having deeper hydrocarbon plays in Rebab-1 well.