Abstract
Uncertainty in predicting formation integrity as well as pressure regimes poses significant risks to drilling operations. Several technologies can predict downhole environments in terms of formation strength, kick detection etc., but no solution currently exists for kick isolation. This paper presents an innovative well control and risk mitigation technology that is deployed while drilling and the result of a field test offshore Italy.
The new system is integrated in the bottom hole assembly (BHA), and in case of a kick can shut-in the annulus and the drillstring on demand to confine the influx at the well bottom below the sealing elements. A bypass port that establishes communication with the drillstring and annulus can be opened above the sealing elements to allow adjusting of the mud weight. Downhole pressure above and below the annular seal and inside the string can be monitored in real time. The system is deployed in combination with Wired Drill Pipe to ensure activation and bi-directional communication that is independent of any fluid flow.
The system was run on top of the directional rotary steerable BHA while drilling an 8½-in. hole section. The field test was conducted after drilling more than 500 m of new formation and 90 hours in hole. Prior to the test, the system was pulled to surface for visual inspection. No irregularities were observed. The system was then run back in open hole, activated according to operating procedures and tested by applying pressure into the annulus. The well was monitored and no leakage was observed concluding a successful test. Finally, the bypass was opened, circulation was re-established, and the system was deactivated and then pulled out of hole.
This paper describes the technology features and summarizes the first field test results of a new risk mitigation technology for well control situations. This document also shows how deploying new solutions can help E&P operators improve well control through a cost-effective solution and reduce operational risk in case of formation fluid influx into a wellbore.
