Enhancing Fault Identification in the Complex Geological Structures of Sanga Sanga Region with Offset VSP

The Sanga Sanga Region in East Kalimantan, Indonesia, has a unique geological challenge, characterized by a considerable weathered layer with extensive coal deposits that reach depths of 30 to 40 meters and complex geological structure. This distinctive geological setting poses challenges in achieving a high frequency of seismic image and identifying the fault structure. In this case, Vertical Seismic Profiling (VSP) is used to obtain high resolution of seismic image and to identify fault targets around the borehole. VSP processing for both surveys is performed to derive the Time-Depth Relationship (TDR), VSP Corridor Stack, and 2D VSP image. Those VSP products are utilized to verify subsurface layers and identify fault targets surrounding the borehole.