摘要
超深井作业过程常因将井下管柱伸缩管启动瞬间引起的环空压力骤变误判为管柱泄漏而中断施工,影响作业进度和措施效果。针对这一问题,基于伸缩管作用原理,在伸缩管启动瞬间状态变化分析的基础上,结合PVT状态方程,综合考虑伸缩管体积变化、管柱变形、环空流体体积变化和环空压力耦合影响,建立了伸缩管启动瞬间环空压力瞬变预测模型。经某酸压测试作业的超深井环空压力瞬变值预测和影响因素研究表明:预测值与实测值相对误差仅1.4%,满足现场生产要求;环空流体压缩性和伸缩管体积变化是影响环空压力瞬变的主要因素,油套管弹性模量影响较小。分析结果可为现场施工人员提供指导,避免因伸缩管启动过程的环空压力骤变而引起误判。
During the operation of ultra-deep wells,the sudden change of annulus pressure caused by the start-up of expansion tube is often misjudged as a leak in the string,which interrupts the construction and affects the progress of the operation and the measure efficacy.To address this problem,firstly,the coupling effects of expansion tube volume,annular fluid volume,string deformation,and annular pressure are considered comprehensively.Then,based on the operating principle of expansion tube and the state analysis of the expansion tube start-up,a transient prediction model of annular pressure at the expansion tube start-up was established by combining with PVT state equation.After studying the influencing factors and predicting the transient annulus pressure of an ultra-deep well with acid pressure test,we concluded that:1)The result of prediction model meets the field production requirements with a relative error of only 1.4%;2)The main factors affecting transient change of annulus pressure are compressibility of the annular fluid and volume change of the expansion tube.The elastic modulus of oil casing has little effect.This paper provides guidance for field constructor to address misjudgment caused by sudden changes of annulus pressure during the start-up of expansion tube.
作者
陈科
任俊松
CHEN Ke;REN Junsong(Downhole Operation Company of Sinopec Southwest Petroleum Engineering Co.,Ltd.,Deyang,Sichuan,618000,China)
出处
《天然气与石油》
2023年第2期87-92,共6页
Natural Gas and Oil
基金
中国石油化工股份有限公司科技部项目“超高压酸性气井试气关键技术研究”(P22048)。
关键词
超深井
伸缩管
油套环空
环空压力
瞬变预测
Ultra-deep well
Expansion tube
Tubing-casing annulus
Annulus pressure
Transient forecast
