Deployment of BEST buildup evaluation shut-in tool was a key enabler that resulted in successful zonal isolation and well testing, delivering high-quality, accurate, and actionable data for Cairn Oil & Gas to book reserves.

Well testing challenges for land exploration in remote locations

Data acquisition in land oil and gas exploration environments can be limited because of the commoditized nature of services, as well as cost constraints related to remote environments. These limitations rendered the implementation of an extended drill stem test cost prohibitive for an upcoming exploration well for Cairn Oil & Gas, Vedanta Limited in India. The operator needed to acquire interpretable downhole pressure data necessary for accurate reservoir characterization to fulfill their responsibilities to shareholders and regulating agencies.

Slickline-deployed lightweight well testing solution that doesn’t compromise data quality

Cairn Oil & Gas wanted a practical, solution-based well testing approach. By combining in-house technology, SLB offered the operator a turnkey solution deploying a lightweight well testing package comprising downhole memory pressure gauges and the BEST tool. The solution was deployed on a single slickline run using a SIMplus retrievable bridge plug from Peak Well Systems, a SLB company. The BEST tool provided zonal isolation through its instant downhole shut-in action, significantly reducing wellbore storage effects. Combined, these technologies proved capable of delivering high-quality, interpretable data, resulting in both tangible cost savings and efficiency gains for the operator.

Hydrocarbon discovery from high-quality reservoir characterization

Wellbore storage effects are known to affect the interpretation of downhole pressure-transient data. The effects can mask important near-wellbore formation characteristics, which can be key to determining a well’s production potential. The effects also impact the interpretation of the late buildup phase from which key reservoir information is derived and used for reserve quantification and booking.

The quality and interpretability of the data acquired using the testing approach enabled by the BEST tool, contributed to the assessment of the well that the operator declared as a discovery. The operation was completed with zero HSE incidents or nonproductive time. Cairn Oil & Gas plans to adopt this well testing technique for other exploration wells in the project and additional scopes of work.