高温深井温压耦合下流体性质对井筒压力的影响特性  

Study on Effects of Fluid Properties on Borehole Pressure under Temperature and Pressure Coupling in High Temperature Deep Wells

作　　者：刘平江 和建勇 张晔 毕毅 张瑞华 杨谋 LIU Pingjiang;HE Jianyong;ZHANG Ye;BI Yi;ZHANG Ruihua;YANG Mou(Bohai Drilling Engineering Company Limited,CNPC,Tianjin 062552;Cementing Company Of Cementing Technology Research Center,Karamay,Xinjiang 834000;National Key Laboratory of Oil and Gas Geology and Exploration,Southwest Petroleum University,Chengdu,Sichuan 618300)

机构地区：[1]中国石油集团渤海钻探工程有限公司第一固井分公司,天津062552 [2]西部钻探固井公司(固井技术研究中心),新疆克拉玛依834000 [3]“油气藏地质及开发工程”全国重点实验室•西南石油大学,成都618300

出　　处：《钻井液与完井液》2024年第3期288-295,共8页Drilling Fluid & Completion Fluid

基　　金：国家自然科学基金项目“干热岩型地热泡沫钻井流体相变行为下井筒温度压力响应特性研究”(52174008)。

摘　　要：深井高温高压环境对流体密度和流体流变参数影响较大,忽略其作用使得井筒压力认识不准确,制约着钻完井作业安全。基于能量守恒原理,建立了井筒温度计算模型,考虑流体流态对温度压力影响,建立了温压耦合条件下井筒压力计算方法,结合现场实测数据验证了温度压力模型计算可靠性。研究表明:温度对流体密度和流变参数影响程度大于压力,随着井深增加,环空流体密度和动切力逐渐增大。随着循环时间增加,井底温度逐渐降低,环空流体密度、动切力及流性指数逐渐增大,而稠度系数逐渐降低;温压耦合条件下环空ECD低于未考虑工况,两者相差0.067 g/cm3。因此,若不考虑耦合对流体密度和流变参数影响时,使得设计流体密度偏低,易诱发溢流或井喷事故发生。该研究成果与认识为深层超深井井筒温度压力精细评价奠定了关键理论基础,降低了钻完井井下作业风险。High temperature high pressure(HTHP)environment in deep wells plays an important role in mud rheology control;omitting its effects will lead to an inaccurate knowledge of hole pressures and a negative influence on safe drilling.Based on the principle of energy conservation,a borehole temperature computation model is established.In this model a method of computing borehole temperature by coupling the effects of temperature and pressure is built up taking into account the effects of the fluid flow state on temperature and pressure.The reliability of the model is verified using data acquired from field operations.The study results show that the effect of temperature on the density and rheology of a drilling fluid is more important than the effect of pressure.As a well becomes deeper,the density and yield point of the drilling fluid in the annulus are also increasing.As the circulation time increases,the bottom hole temperature is decreasing,the density,yield point and flow index of the drilling fluid in the annulus are increasing,while the thickening index is decreasing.The ECD of the drilling fluid in the annulus under coupled temperature and pressure condition is lower than the ECD of the fluid in the same annulus without considering the coupling of temperature and pressure,the difference between the two ECD is 0.067 g/cm3.Hence,if the effects of temperature and pressure coupling on the density and rheology of a drilling fluid are not considered,a mud density lower than that is necessary to balance the formation pressure will be designed,and well kick and blowout may be induced.The results and understanding of this study provide a key theoretical base for precise evaluation of temperature and pressure in an ultra-deep well.

关 键 词：高温高压 温压耦合 流体密度 流变参数 压力分布 

分 类 号：TE[石油与天然气工程]