Recovering the confidence to drill in a Field after dealing with a Blowout, the Managed Pressure Drilling approach. Operator finds an effective way to address the high potential for blowouts and drilling challenges in a field in Utah

摘要

After a blowout event that destroyed a rig, incurring in environmental issues as well as personnel injuries, loss of credibility for all parties involved in the drilling operation and loss of confidence for several other operators drilling in the area, a specific operator decided to proactively plan ahead for facing the possible challenges using a full automatic Managed Pressure Drilling technology called Microflux Control System (MFCS). MFCS enabled the well to reach total depth with enhanced safety, drilling efficiency, and with fewer casing strings than originally planned. Early influx detection along with the ability to quickly increase BHP allowed for the use of a mud weight which was approximately 2.0 ppg lower than offset well data provided. Lower mud weights resulted in an increased ROP and improved drilling efficiency. The use of lower mud weights also enabled the exact pore pressure to be identified when overpressure zones where encountered. Ballooning events were quickly identified and unnecessary mud weight increases were avoided. Compared to offset wells, MPD saved 20 hrs to weight up mud given the apparent water influxes, which in the current MPD well were identified as a ballooning. For the offset well, at the depth of 4,260 ft, 17 hrs were spent increasing the MW from 9.1 ppg to 10.3 ppg due to the apparent water flow, in the MPD well case the MW was raised from 8.8 to 9.0 and it was done in MPD mode. The casing was run through the RCD and returns aligned to the MPD system in order to maintain BHP constant and monitor for influxes/losses while running the casing to bottom. Without and MPD system, the well would have required to be rolled over to a Kill Mud Weight, which may have led to fluid losses while circulating with the casing at bottom. The casing cementing operation was conducted having the MPD system aligned to the returns as a closed loop system, obtaining excellent process quality monitoring and pressure control.