MPD through CT

摘要

A combined solution for HP/HT cementing enhances safe and effective wellbores in extreme pressure profiles. Managed pressure drilling (MPD) methods that regularly enable drilling in difficult environments are proving to be an effective tool in cementing operations. In a vertical exploratory HP/HT well in British Columbia, Canada, MPD methods were applied through coiled tubing (CT) to successfully cement an openhole section to temporarily abandon the well after drilling and logging operations. In HP/HT drilling environments, managing the bottomhole pressure (BHP) to cement an open hole is very difficult to accomplish with conventional methods, which are typically unable to respond quickly or effectively to counter fluctuations in wellbore pressure without exceeding the window limits. With excessive pressure, the fracture gradient is exceeded and fluid losses occur; however, an insufficient amount of pressure can precipitate a kick as formation pore pressure pushes gas into the wellbore. By closing the loop, the MPD system provided early kick/loss detection and control while displacing kill fluids prior to cementing and while cementing. MPD allowed real-time flow detection and modeling to help avoid costly cement, additives and higher cement weight, eliminate mud and cement losses (and related formation damage), and minimize high standpipe pressure.