| Popis: |
The Fayetteville Shale is one of the newest and fastest-growing shale gas plays gaining significant prominence in North America. This unconventional reservoir is located in the Arkoma basin of Arkansas. Drilling horizontal wells coupled with hydraulic fracturing makes this reservoir highly prolific and comparable to the Barnett Shale. However, the area presents numerous challenges including loss of circulation, wellbore instability, and significant connection times reducing efficiency while drilling the curve and lateral sections. To address these challenges, a detailed engineering analysis was performed using a proven drilling optimization procedure. As a result of the study, engineers determined that surface pressure limitations with high rates of penetration (ROP), together with pumping of loss circulation material (LCM) to control fluid losses negatively affected the performance of downhole measurement while drilling (MWD) equipment. Existing standard mudpulse technology could not operate efficiently while drilling with loss circulation, no fluid returns or high LCM concentrations. Wired-pipe technology is typically cost- prohibitive in this application. An electromagnetic (EM) MWD system was used and the transmission of real-time data was done via EM signals through the formation instead of fluid pressure pulses through the inner bore of the pipe. The system was designed to provide accurate real-time MWD data and reliable directional control and was not hindered by the presence of multi-phase fluids, high-density solids, or LCM in the wellbore. The results achieved are 33% to 36% increase in the average ROP and 13% reduction in drilling time to reach target depths. The authors will describe the significance of applying principles of EM technology to improve drilling performance. |
