控压固井分段降密度环节井筒温压场预测模型研究  

Predictive modeling of wellbore pressure during the managed pressure cementing segmented density reduction step

作　　者：刘金璐 李军[2] 柳贡慧[2] 李宁[1] 张权[1] 周宝 孙红宇 LIU Jinlu;LI Jun;LIU Gonghui;LI Ning;ZHANG Quan;ZHOU Bao;SUN Hongyu(Petrochina Tarim Oilfield company,Korla 841000,China;College of Petroleum Engineering,China University of Petroleum-Beijing,Beijing 102249,China;R&D Center for Ultra Deep Complex Reservior Exploration and Development,CNPC,Korla 841000,China;Engineering Research Center for Ultra-deep Complex Reservoir Exploration and Development,Xinjiang Uygur Autonomous Region,Korla 841000,China;Xinjiang Key Laboratory of Ultra-deep Oil and Gas,Korla 841000,China)

机构地区：[1]中国石油塔里木油田公司,库尔勒841000 [2]中国石油大学(北京)石油工程学院,北京102249 [3]中国石油天然气集团有限公司超深层复杂油气藏勘探开发技术研发中心,库尔勒841000 [4]新疆维吾尔自治区超深层复杂油气藏勘探开发工程研究中心,库尔勒841000 [5]新疆超深油气重点实验室,库尔勒841000

出　　处：《石油科学通报》2025年第1期107-119,共13页Petroleum Science Bulletin

基　　金：国家自然科学基金重大科研仪器研制项目“钻井复杂工况井下实时智能识别系统研制”(52227804);国家自然科学基金联合基金项目“特深井复杂温压场测量与井筒压力剖面控制基础研究”(U22B2072);中国石油天然气集团有限公司科技项目“海相碳酸盐岩油气规模增储上产与勘探开发技术研究”(2023ZZ16)联合资助。

摘　　要：控压降密度是控压固井技术的关键环节,该环节对保证固井施工安全具有重要意义。控压降密度工艺可分为一次降密度工艺和分段降密度工艺,在现场应用中,分段降密度工艺的适用性更强、需求量更高,因此如何精确预测分段降密度过程中的井筒压力场成为了该技术的关键。结合“先下后降、再下再降”的分段降密度工序,采用拉格朗日法推导了环空浆柱结构描述方程。开展了高温(220℃)、高压(180 MPa)钻井液流变性实验,研究发现:当温度小于140℃时,温度对流变性影响显著;当温度大于140℃时,温度对流变性影响较小。对此,考虑温度、压力和流变性的相互影响,建立了分段降密度全过程井筒温压场预测模型。利用实测井口压力对模型进行了验证,最大相对误差小于3.6%。与传统模型相比,本文模型弥补了其工艺适用性的不足,且预测精度更高。基于X井数据对两种分段降密度工艺的关键参数进行了预测,结果表明:环空流体类型分布受初始浆柱结构、排量等因素的综合影响,三次降密度作业所需的时间分别为5.24 h、5.12 h、4.78 h;井筒温度场受工况影响明显,不同工况相同位置处的环空温度最大相差35.1℃;三次降密度工艺所需时间多1.42 h,但在第一次降密度过程中井底压力较低,不易压漏地层;利用本文模型设计的井口回压,可以保证井底压力处于安全范围内。研究结果可为控压固井分段降密度环节井筒压力的准确预测及精细控制提供理论支撑。Managed pressure density reduction is the key step of managed pressure cementing(MPC)technology,which is of great significance to ensure the safety of cementing construction.Managed pressure density reduction process can be divided into primary density reduction process and segmental density reduction process.In the field application,the segmental density reduction process is more applicable and in higher demand,so how to accurately predict the pressure field of the wellbore in the process of segmental density reduction has become the key of this technology.Combined with the segmented density reduction process which is“first down,then down,then down again”,the Lagrangian method was used to deduce the descriptive equation for the structure of the annular slurry column.Experiments on the rheology of drilling fluid at high temperature(220℃)and high pressure(180 MPa)were carried out.It was found that when the temperature was less than 140℃,the temperature had a significant effect on the rheology;when the temperature was greater than 140℃,the temperature had a smaller effect on the rheology.In this regard,considering the mutual influence of temperature,pressure and rheology,a prediction model of temperature and pressure field in the wellbore during the whole process of segmented density reduction was established.The model was validated using the measured wellhead pressure,and the maximum relative error was less than 3.6%.Compared with the traditional model,the model in this paper makes up for the lack of its process applicability and has higher prediction accuracy.Based on the well X data,the key parameters of the two segmented density reduction processes are predicted,and the results show that:the distribution of fluid type in the annulus is affected by the initial slurry column structure,displacement and other factors,and the time required for the three density reduction operations is 5.24 h,5.12 h and 4.78 h,respectively;the wellbore temperature field is significantly affected by the working conditions,an

关 键 词：控压固井 分段降密度环节 钻井液流变性 井筒温度 井筒压力 

分 类 号：TE256[石油与天然气工程—油气井工程] TP18[自动化与计算机技术—控制理论与控制工程]