南海流花超大位移井井身结构设计方法

CASING PROGRAM DESIGN METHOD FOR LIUHUA MEGA-EXTENDED-REACH WELLS IN SOUTH CHINA SEA

覃成锦 高德利 唐海雄 魏宏安

Tan Chengjin Gao Deli Tang Haixiong Wei Hongan

中国石油大学, 北京 102249 中国海洋石油深圳分公司, 深圳 518067

超大位移井井身结构复杂,为合理设计其井身结构,从垂直井井身结构设计的压力平衡原理出发,针对大斜度井段垂深变化小且裸眼井段很长、大斜度裸眼井段最容易在测深最大处被压裂的特点,通过计算钻井液的当量循环密度,研究了超大位移井大斜度裸眼井段的地层压力、破裂压力和环空压耗之间的关系,得出套管最大下深及允许最大环空压耗的计算公式。研究结果表明,在一定的地质条件下,超大位移井井身结构设计的重要可控因素是环空压耗。采用文中推导的公式分析一个超大位移井井身结构设计及当量循环密度监控的案例,验证了该公式的正确性,为大位移井的井身结构设计提供了理论依据。

Casing program design of mega-extended-reach wells is complex,and in order to design in reason its casing program,based on the principle of pressure balances in the casing program design in the vertical wells,the relationships among pore pressure,fracture pressure and annular pressure loss in the long open-hole section with high inclination in mega-extended-reach wells are discussed.The formulae are deduced for calculating the maximum depth of casing point and the maximum annular pressure loss permitted.The research shows that the most important and manageable factor is annular pressure loss.With the formulae deduced in this paper,the instance of the design of casing program and the management of ECD in a mega-extended-reach well is analysed.The method provides a theoretic gist for mega-extended-reach well.

10.3969/j.issn.1000-7393.2006.01.004