Study Of Controlled Mud Cap Drilling Technology

Advanced drilling technics and technology is an important method for promoting oil/gas exploration activity fast. Managed pressure drilling technology has been widely developed abroad, and the advantage and tendency of this technology has showed that MPD will be the first choice of drilling in future. This paper describes the Controlled Mud Cap drilling technology, which is one front porch technology of MPD, to supply an advanced drilling method for deepwater drilling for our country.By extensive literature research, the working principle, basic technique and the relevant equipment of CMC is concluded in this paper. The main problems which CMC can solve in deepwater operation and the solution of challenges in CMC were presented. The basic working principle and foundation is settled in this part for future research for well pressure distribution analysis and characteristic calculation.In view of unique feature of CMC, well temperature field modeling is found, according to principle of energy, combining the fluid property of each well section, the temperature field computational method is elaborated for CMC, and the modeling effort is showed by well temperature curve. Combining the multiphase flow effect, the distribution of pressure of different part of CMC is established by theoretical analysis in this paper. According to the given definite condition, the mesh conFig.uration and the difference method, the CMC calculating software program is compiled, and the modeling effort is showed by the pressure distribution curve.Considering water well drilling feature, the mud density change along with the water depth is summarized. According to the CMC drilling characteristic, the circulating pressure lose, the mud cap height and the pump pressure was calculated separately. Finally, this paper proposes that the CMC drilling technology has the superiority in deep water well drilling by comparing with conventional well drilling.