LWD and “DTB” Technology Pushing Subsurface Understanding beyond Conventional Limits in a Heavy Oil Belt, India

The northern part of Cambay basin, western India, is characterized by a heavy oil belt. A thermal EOR method widely known as In-situ Combustion (ISC) was adopted in this belt to enhance oil recovery. To capture EOR displaced oil and also to improve primary recovery, horizontal wells are being planned and drilled for last 8 years in this belt. Initially horizontals were drilled with MWD technology only but in 2011, LWD technology was introduced. A primary driving force for this technology switch was to use LWD data in real time to understand the nature of flue gas distribution and complex structural features in these fields. Additionally for drain hole sections, “Distance to Boundary” (DTB) technology was adopted for proactive navigation. LWD data from 7 infill horizontal wells drilled in this belt provided important information on flue gas saturation and distribution across these fields. This information was used to place drainholes sufficiently below the flue gas saturation level to avoid premature gassing out of wells.The use of “DTB” technology in drainhole improved well productivity owing to better controlled placement in the sweet zone. The gamut of information provided by LWD and DTB technology has comprehensively helped in better planning and recovery.