The Evolution of Seismic Imaging to Illuminate the Complex Structure beneath a Giant Shallow Gas Body of a NW-Borneo Field: A Chronicle of Streamer, Multicomponent OBN, and FWI Imaging

Since its discovery, seismic imaging of the K-Field has been a major issue, especially at the reservoir level. These illumination challenges arise from the presence of a large gas body hovering above the main reservoir. Furthermore, the complex thrust fault setting of the K-Field further limited the ability to seismically image its structure.

The first seismic survey conducted for the K-Field was a streamer survey in 1995. Since then, the seismic data has gone through multiple rounds of seismic processing which did not yield great imaging. In 2019, an OBN survey was fulfilled and subsequently processed for both PP and PS-converted waves using 3D Q-TORT RTM, which gave a major subsurface imaging improvement. To further delineate K-Field’s imaging, a 3D Tilted-Orthorhombic Q-FWI Imaging (up to 40Hz) was performed on the 2019 OBN dataset. Through enhanced seismic survey design acquisition and advancement of seismic processing, K-Field was imaged with better clarity, allowing better structural understanding for further exploration and development.

This paper’s main objective is to highlight and discuss the improvement in subsurface imaging quality by advancement in seismic processing (OBN and FWI Imaging in particular), especially in resolving complex geological structures in the K-Field for further exploration and/or development opportunities.