深层页岩气水平井钻进中井筒-地层瞬态传热模型  

Well-formation transient heat transfer model during drilling of deep shale gas horizontal wells

作　　者：吴鹏程 钟成旭 严俊涛 万秀梅 陈烨 杨谋[3] WU Pengcheng;ZHONG Chengxu;YAN Juntao;WAN Xiumei;CHEN Ye;YANG Mou(Research Institute of Shale Gas,PetroChina Southwest Oil&Gas Field Company,Chengdu 610056,Sichuan,China;PetroChina Sichuan-Chongqing Shale Gas Frontline Headquarters,Chengdu 610056,Sichuan,China;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(Southwest Petroleum University),Chengdu 610500,Sichuan,China)

机构地区：[1]中国石油西南油气田公司页岩气研究院 [2]中国石油川渝页岩气前线指挥部 [3]油气藏地质及开发工程国家重点实验室·西南石油大学

出　　处：《石油钻采工艺》2022年第1期1-8,共8页Oil Drilling & Production Technology

基　　金：国家自然科学基金“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”(编号:52174008);中国石油集团公司重大现场试验项目“深层页岩气有效开采关键技术攻关与试验”(编号:2019F-31);中国石油西南油气田公司科研项目“川渝地区深层页岩气水平井降温技术研究与应用”(编号:20200302-09)。

摘　　要：目前深层页岩气井常用的旋转导向工具服役环境温度为135℃,准确预测深层页岩气水平井钻进中循环温度对延长井下测量工具使用寿命与有效延伸水平段长度非常重要。基于能量守恒原理,考虑井筒-地层各控制区域--钻柱内流体、钻柱壁、环空流体及近井壁地层在径向与轴向传热机理,建立了井筒-地层瞬态传热模型,应用全隐式有限差分法对数学模型求解,分析了各敏感因素对井筒温度的影响。研究表明:页岩气水平井流体循环初期环空流体温度高于原始地层温度;增加循环时间、流体比热容与密度、降低入口温度可以降低井底温度;排量过高引起摩阻生热,使得井筒温度非降反升;通过地面降温装置降低入口温度能抵消水平段延伸产生的热量,增加水平段钻进距离;结合Y101H26-1井数据,当入口温度为35、65℃,对应钻进井深分别为5650、5250 m时,不超过旋转导向工具服役环境温度,计算误差在3%以内。该研究成果可避免井筒降温技术应用的盲目性和低效性。At present,the service environment temperature of rotary steering tools commonly used in deep shale gas wells is 135°C.Accurately predicting the circulating temperature during the drilling of deep shale gas horizontal wells plays an important role in scientifically extending the service life of downhole measurement tools and effectively extending the length of horizontal sections.Based on the principle of energy conservation,considering radial and axial heat transfer mechanisms among well,fluid in the drill string,drill string wall,annular fluid,and formation near the well,a well-formation transient heat transfer model was established.Solve the mathematical model with fully implicit finite difference method,and analyze the influence of various sensitive factors on the well temperature.The research shows that the annular fluid temperature is higher than the original formation temperature in the initial period of fluid circulation in shale gas horizontal wells;the increase in circulation time,fluid specific heat capacity and density,and the decrease in inlet temperature can reduce the bottom hole temperature;excessive displacement will cause heat generation because of friction,making well temperature rise;reducing the inlet temperature through the surface cooling device can offset the heat generated by the extended distance of the horizontal section,prolonging the safe drilling distance of the horizontal section.Combined with the data from Well Y101 H26-1,when the inlet temperature is 35℃and 65℃,the temperatures corresponding to the drilling depths of5650 and 5250 m do not exceed the service environment temperature of the rotary steering tools,and the calculation error is within3%.The research results can overcome the blindness and inefficiency in applying well cooling engineering technology.

关 键 词：深层页岩气井 井筒-地层温度 瞬态传热模型 瞬态传热机理 循环温度 

分 类 号：TE21[石油与天然气工程—油气井工程]