控压钻井井筒压力控制技术初探

An approach to annular pressure control by managed pressure drilling

常规钻井技术钻遇压力衰竭或复杂地层时,经常遇到钻井液安全密度窗口窄,并引起漏、喷、卡、塌等井下复杂问题。控压钻井(MPD)通过控制井筒环空循环流体介质的流量与流态、井口施加压力等因素,结合环空压降模型计算,使环空压力保持在一定的范围,就可以降低甚至避免这些钻井问题,减少非钻井作业时间,提高钻井效率,降低作业成本。

Narrow operation window is quite common in conventional drilling while encountering pressure depletion or complex formation,leading to downhole problems such as leaking,sticking,blowout,and hole collapse,etc.Managed pressure drilling(MPD) can mitigate or even avert these drilling problems by manipulating annular pressure through controlling the flow rate and regime of annulus circulating media and the pressure applied at wellhead in conjunction with model calculation of annular pressure drop.This technology can reduce non-production time,enhance drilling efficiency,and reduce operation cost.