Acquire crucial data in high overbalance conditions
Schlumberger proposed the StethoScope formation pressure-while-drilling service to efficiently acquire formation pressure data. The service is capable of meeting the overbalance requirement and mitigating the sticking risk of wireline-conveyed formation testers. While the tool is designed for 6,000-psi differential pressure, the StethoScope service is configurable for up to 9,500-psi differential pressure. Key design features include a stabilized collar designed with a series of offsets to minimize surface contact area. When deployed, the only points of contact are the set pistons, probe, and stabilizer. Short time-optimized pretest sequences (5 min) will enable short overall stationary times (~10–12 min).
Saved rig time while improving understanding of formation pressure
Talos used StethoScope service to acquire 20 valid formation pressures over two hole sections, providing more reliable data for understanding the formation pressure in the regional aquifer and producing horizon. A maximum overbalance of 9,365 psi was observed in the depleted zone. And StethoScope service enabled Talos to resolve vertical
connectivity uncertainties in individual lobes of the primary pay sand. This eliminated wireline logging runs at the conclusion of each hole section, and along with the short time-optimized pretest sequences, saved 2 days of rig time and more than USD 500,000.