顺北一区小井眼超深井井筒温度场特征研究与应用  

Study and Application of Wellbore Temperature Field Characteristics in the Ultra-Deep Slim-Hole Wells in the Shunbei No.1 Area

作　　者：苏雄 杨明合 陈伟峰 张俊[3] SU Xiong;YANG Minghe;CHEN Weifeng;ZHANG Jun(Yangtze University Laboratory,CNPC Key Laboratory for Petroleum Drilling Engineering,Wuhan,Hubei,434000,China;CNPC Engineering Technology R&D Company Limited,Beijing,102206,China;Petroleum Engineering Technology Research Institute,Sinopec Northwest Oilfield Company,Urumqi,Xinjiang,834000,China)

机构地区：[1]中国石油钻井工程重点实验室长江大学研究室,湖北武汉434000 [2]中国石油集团工程技术研究院有限公司,北京102206 [3]中国石化西北油田分公司石油工程技术研究院,新疆乌鲁木齐834000

出　　处：《石油钻探技术》2021年第3期67-74,共8页Petroleum Drilling Techniques

基　　金：中国石化科技攻关项目“特深层油气钻井工程关键技术与工具——顺北一区水平井循环降温能力研究”(编号:P17049-3)资助。

摘　　要：顺北一区小井眼超深井井筒温度高,部分井超过国内现有测量仪器抗温能力,易引起测量仪器探管烧毁和无信号等问题。为此,建立了井筒瞬态温度场数学模型,分析了不同参数下的井筒温度场剖面特征,提出了“临界温度井深”概念。基于此概念,为了降低井底循环温度,使临界温度井深下移并到达井底,对钻井液的流变性、热属性、排量、入口温度及钻柱热属性等7个参数进行了敏感性分析,得到了能够显著影响井筒温度场的物理参数。分析发现:根据井筒温度变化曲线,可以把临界温度井深分为真实、过渡和当量3种类型;井筒温度场对钻柱导热系数、钻井液比热容、钻井液导热系数等3个参数敏感,其敏感程度为钻柱导热系数>钻井液比热容>钻井液导热系数,与之对应的是当量临界温度井深。研究结果表明,改变钻井液热属性或降低钻柱导热系数,能够有效降低顺北一区的井底循环温度。The ultra-deep slim-hole wells in the Shunbei No.1 Area have high wellbore temperatures.In some wells,the temperatures even exceed the temperature resistance of the existing domestic measuring instruments,which often leads to probe burnout and no signal input to the instruments.To solve this problem,a mathematical model was established for transient wellbore temperature fields,which analyzed the field profiles at different parameters,and introduced the concept of“well depth at critical temperature”(WDCT).On this basis,in order to reduce the bottomhole circulating temperature and move the WDCT down to the bottom,the sensitivity of seven parameters were analyzed,including rheology,thermal property,displacement,and inlet temperature of drilling fluid,and the thermal property of the drill string.Then the physical parameters that could significantly influence the wellbore temperature field were obtained.It is found by analysis that WDCT could be divided into true,transitional,and equivalent categories according to the variation curves of wellbore temperature.The wellbore temperature field was sensitive to the thermal conductivity of the drill string,the specific heat capacity of drilling fluid,and the thermal conductivity of drilling fluid in a descending order,which corresponded to the equivalent WDCT.The results showed that changing the thermal properties of drilling fluid or reducing the thermal conductivity of the drill string could effectively lower the bottomhole circulating temperature in the Shunbei No.1 Area.

关 键 词：小眼井 超深井 敏感性分析 井筒温度场 临界温度井深 顺北一区 

分 类 号：TE246[石油与天然气工程—油气井工程]