深水CML双梯度钻井钻井液液位高度优化设计  

Optimized design of mud level of deepwater CML dual gradient drilling

作　　者：张更 李军[1,2] 柳贡慧 杨宏伟[1] 王江帅[1] 鲁慧 ZHANG Geng;LI Jun;LIU Gonghui;YANG Hongwei;WANG Jiangshuai;LU Hui(College of Petroleum Engineering,China University of Petroleum(Beijing),Beijing 102249,China;Karamay Campus,China University of Petroleum(Beijing),Karamay 834000,Xinjiang,China;PetroChina Tarim Oilfield Company,Korla 841000,Xinjiang,China)

机构地区：[1]中国石油大学(北京)石油工程学院 [2]中国石油大学(北京)克拉玛依校区 [3]中国石油塔里木油田分公司

出　　处：《石油钻采工艺》2021年第5期607-612,共6页Oil Drilling & Production Technology

基　　金：国家自然科学基金重点项目“深水油气钻采井筒压力控制基础研究”(编号:51734010)。

摘　　要：为了优化井筒压力剖面,实现更大的钻进深度,建立了CML双梯度钻井钻井液液位高度优化模型。模型以地层压力窗口为约束条件,以井底压差最小化作为优化目标,对钻井液液位高度进行优选。通过案例分析了钻井液密度、泥浆泵排量、安全余量等参数对优化结果的影响。研究结果表明,相比于泥浆泵排量,最大钻进深度、井底压差与最优钻井液液位高度受钻井液密度的影响更显著;相比于不考虑安全余量,考虑安全余量会使井筒压力更加安全地落在压力窗口内,但会明显降低最大钻进深度。采用优选后的钻井液液位高度,既能实现更大的钻进深度又能降低井底压差,同时保护储层。A mud level optimization model of CML dual gradient drilling was established in order to optimize the wellbore pressure profile and improve the drilling depth.In this model,the mud level is optimized by taking the minimization of bottom hole pressure difference as the optimization objective under the constraint of formation pressure window.In addition,the influences of drilling fluid density,pump rate and safety margin on optimization results were analyzed based on case analysis.It is indicated that compared with pump rate,drilling fluid density has more influence on maximum drilling depth,bottom hole pressure difference and optimal mud level.If safety margin is taken into consideration,wellbore pressure will be within the pressure window more safely,but maximum drilling depth is reduced greatly.What’s more,the optimized mud level can not only improve drilling depth,but also decrease bottom hole pressure difference while realizing reservoir protection.

关 键 词：CML双梯度钻井 钻井液液位高度 井底压差 最大钻进深度 

分 类 号：TE21[石油与天然气工程—油气井工程]