Integration of Microbial Survey Data With a Revised Structural Model to Improve Assessment of Infill Opportunities in NW Borneo

Abstract

Efforts to develop shallow hydrocarbon reservoirs within the Field have been historically hampered by poor seismic resolution, a lack of shallow well mudlog data and problematic resistivity based hydrocarbon discrimination resulting from low salinity formation brine. The application of a high resolution microbial survey was identified as a new application of an existing technology to mitigate risks resulting the previous mentioned issues. The technique is based on seepage of hydrocarbon gases (C1–C5) from subsurface reservoirs to surface which provide suitable conditions for the development and growth of microbial communities. Both shallow gas and soil samples have been acquired from more than 1000 surface locations. The gas samples are analyzed for methane concentrations and gas type (biogenic or thermogenic), whilst the soil sample are analyzed to determine the concentration of specific microbial content in the laboratory. A comparison of the hydrocarbon gases with the microbial presence potentially enables identification of additional or bypassed subsurface hydrocarbon accumulations when integrated with subsurface models. The resulting surface data can also be integrated to improve understanding structural framework by highlighting previously unidentified fault extensions etc. The preliminary results received to date have been integrated into a fit for purpose structural model and indicate a previously unidentified opportunity with the field with the potential of delivering between 50-100MMboe.

AAPG Datapages/Search and Discovery Article #90328 © 2018 AAPG Middle East Region GTW, Maximizing Asset Value: Integrating Geoscience with Reservoir Management & Facilities Optimization, Muscat, Oman, April 30 – May 1, 2018