高压气井油套环空带压模拟及对井筒完整性影响研究  

Study on pressure simulation of sustained casing pressure and its influence on wellbore integrity in high-pressure gas wells

作　　者：练章华[1] 李帅 丁亮亮 赵朝阳 曾努[3] LI AN Zhang-hua;LI Shuai;DING Liang-liang;ZHAO Zhao-yang;ZENG Nu(State Key Laboratory of Oil and Gas Reservoir Geology and Development Engineering,Southwest Petroleum University,Chengdu 610500,China;School of Mechanical Engineering,Southwest Petroleum University,Chengdu 610500,China;Oil&Gas Engineering Research Institute of Petro China Tarim Oil Field Company,Korla 841000,Xinjiang,China)

机构地区：[1]西南石油大学“油气藏地质及开发工程”国家重点实验室,成都610500 [2]西南石油大学机电工程学院,成都610500 [3]中国石油塔里木油田公司油气工程研究院,新疆库尔勒841000

出　　处：《安全与环境学报》2022年第2期749-755,共7页Journal of Safety and Environment

基　　金：国家自然科学基金面上项目(51974271);国家自然科学基金联合基金项目(U19A2097)。

摘　　要：高压气井油套持续环空带压严重影响井筒安全。为此,基于弹塑性力学及渗流力学理论,建立了环空液面高度预测模型及油套环空带压预测模型。利用环空液面高度预测模型对不同环空压力下的液面高度进行了预测;以环空液面预测结果为基础,利用油套环空带压预测模型对油管漏点当量直径进行了拟合,并对环空带压参数进行了敏感性分析。结果表明:所建立的环空液面预测模型可快捷、准确地预测出环空液面高度;所建立的油套环空带压预测模型可准确地拟合出油管漏点综合当量直径;漏点深度越浅、环空保护液压缩系数及密度越小、液面高度越低及漏点当量直径越大,井筒安全风险性越高。Based on the theory of elastoplastic mechanics and percolation mechanics,the prediction model of annular liquid level height and tubing-casing annulus pressure is established in this paper.The liquid level prediction model is used to predict the liquid level under different annular pressure,and the results are compared with in-situ measurement;Based on the prediction results of annular liquid level,the equivalent diameter of tubing leakage point is fitted by using the prediction model of tubing-casing annulus pressure,and the sensitivity analysis of annular pressure parameters is carried out.The results show that comparing the calculated results of the annular liquid level prediction model with the measured values,the maximum relative error occurs when the annular pressure is 46.01 MPa,and the error is only 0.955%.The second highest error occurred at the annulus pressure of 9.78 MPa with an error of 0.836%.In other words,when the annular pressure is in the early stage of recovery and tends to be stable,the accuracy of the model is relatively low,but the overall accuracy of the model is higher.When the fitting value of the equivalent diameter of leakage point of tubing is 0.72 mm,the annular pressure predicted by the tubing-casing annulus pressure prediction model at different times is compared with in-situ measurement,the maximum relative error occurred around 46.6 h,but only 0.21%.The equivalent diameter of leakage point and the compression coefficient of annular protective liquid mainly affect the recovery rate of annular pressure,but do not affect the stable value of annular pressure,while the depth of leakage point,the density of the annular protective liquid,and height of liquid level influence the recovery rate and stable value of annular pressure.The shallower the leak point depth is,the smaller the compression coefficient and density of the annular protective fluid are;the lower the liquid level height is and the larger the equivalent diameter of the leak point is,the higher the safety risk of the wellbor

关 键 词：安全工程 高压气井 环空带压 液面高度 敏感性分析 井筒安全 

分 类 号：X937[环境科学与工程—安全科学]