充气控压钻井过程压力影响因素分析

Factor analysis of pressure used in managed pressure drilling on injected gas

王延民 孟英峰 李皋 李永杰

WANG Yanmin MENG Yingfeng LI Gao LI Yongjie

西南石油大学“油气藏地质及开发工程”国家重点实验室，四川成都　610500

State Key Laboratory of Oil and Gas Geology and Exploration, Southwest Petroleum University, Chengdu 610500, China

常规钻井技术钻遇复杂地层时，钻井液安全密度窗口??，钻井液性能可能发生剧变，压差卡钻、粘附卡钻、喷漏同层、上漏下喷和井壁垮塌等复杂问题??常发生，甚至导致钻井作业无法正常进行，增加诸多非钻井作业时间，使钻井周期和费用大幅度上升；充气控压钻井（MPD）作为一种新的钻井技术，能够降低甚至避免诸类钻井问题，结合环空多相流水力学模型，综合分析了钻井液排量、注气量、机械钻速、井口回压和井身结构等因素对MPD环空压力的影响，实现MPD环空及井底压力保持在一定的范围内准确、快速可调，从而提高钻井效率，降低作业成本。在不久的将来，控压钻井将会是一种更安全、更快、更有效的钻井技术。

The narrow operation window is quite common in conventional drilling, the dirty performance of mud may result in serious drilling problems, such as differential pipe sticking, blowout and loss simultaneous and hole collapse. It may affect normal drilling, prolong none production and drilling time, and increase cost. Managed Pressure Drilling（MPD）, a new drilling technology, can be used to solve such problems. Combined with the hydraulic model of multiphase flow in annulus, this paper analyzes the effect of such factors as the volume of mud, the volume of gas, ROP, back pressure and well profile on annulus pressure in MPD, aiming at quick and accurate adjustment of the annulus pressure and the bottomhole pressure within a certain range. So the drilling efficiency is enhanced and the cost is reduced. In near future, MPD will be developed with more security and validity.