压井过程中井底压力的控制方法  

A method of controlling the bottomhole pressures in well killing

作　　者：李黔[1] 杨先伦 伍贤柱 

机构地区：[1]西南石油大学石油工程学院 [2]陕西延长石油(集团)有限责任公司研究院 [3]中国石油川庆钻探工程公司

出　　处：《天然气工业》2013年第9期87-90,共4页Natural Gas Industry

基　　金：国家科技重大专项"井控设计与分析系统软件"(编号:2011ZX05021-006)

摘　　要：随着窄安全密度窗口和高压油气藏井数的越来越多,井控风险日益突出,对现场常规压井技术提出了更高的要求。立压和套压是井控作业中两个重要的压力数据,随着井控技术的发展和随钻井底压力测量技术(PWD)的应用,套压作为重要的井控参数,作用越来越突出。为此,通过分析套压在常规压井中的应用,套压操作受到地层破裂压力、套管抗内压强度、井控装置的工作压力的限制,而井口节流阀的操作关系到及时准确地控制井底压力以及顺利实施压井作业。针对立压控制法和套压控制法在常规压井技术中的压力传递的延迟性,指出应充分利用立压和套压变化趋势及特点,优化节流阀操作,改进常规压井技术操作,并提出了井底压力控制法的使用原则和操作步骤。最后,分析了压井过程中随钻压力测量技术(PWD)实时记录的井内钻井液当量密度,有助于工程师准确控制井口回压,实现井底压力基本恒定的控制,以便顺利完成压井作业。With the rapid growth in drilling such wells under narrow density window and in high-pressure hydrocarbon reservoirs, the well control risk is becoming a critical issue, resulting in higher requirements for conventional well killing on site. Standpipe pressure and casing pressure are two important types of data in well control. Particularly with the development of well control technology and the application of bottomhole pressures measured while drilling （PWD）, the casing pressure, as a key well control parameter, is playing an increasingly prominent role. Therefore, through the analysis of the casing pressure application in conventional well killing, it was demonstrated that the casing pressure is subject to the restrictions of the formation fracture pressure, internal pressure strength in casing, and operating pressure of well control equipment. In addition, the wellhead choke operation is crucial to accurate bottom hole pressure control and smooth well killing. Furthermore, according to the pressure transmission delay of standpipe and casing pressure control methods applied in conventional well killing, it was proposed that the variance trend and characteristics should be fully utilized for optimizing choke operation and conventional well killing; in addition, the operation principles and procedures were presented for the bottomhole pressure control methods. Finally, the equivalent density of drilling fluid in a well recorded with the PWD measurement technology during well killing in real time was analyzed. Based on the results, an engineer can accurately control the wellhead back pressure to maintain a basically constant bottomhole pressure, thereby to facilitate the well killing.

关 键 词：井控风险 常规压井 立压 套压 井底压力控制 节流阀 压力传递 延迟性 随钻压力测量 

分 类 号：TE37[石油与天然气工程—油气田开发工程]