深井高温岩石破岩机理及生热分析  

Rock Breaking Mechanisms and Heat Generation Analysis on High Temperature Rocks in Deep Wells

作　　者：陈浩[1] 李邦润 蔡灿[1,2,3] 谢松 曹煜磊 杨迎新 Chen Hao;Li Bangrun;Cai Can;Xie Song;Cao Yulei;Yang Yingxin(School of Mechanical Engineering,Southwest Petroleum University;Drill Bit Institute,National Engineering Laboratory of Oil and Gas Drilling Technology,Southwest Petroleum University;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University)

机构地区：[1]西南石油大学机电工程学院 [2]西南石油大学油气钻井技术国家工程实验室钻头研究室 [3]西南石油大学油气藏地质与开发国家重点实验室

出　　处：《石油机械》2021年第1期1-10,共10页China Petroleum Machinery

基　　金：国家自然科学基金项目“交变轨迹切削破岩机理与配套工具的设计理论研究”(51504209);中国石油化工集团有限公司横向项目“冲击刮削复合钻头设计及破岩机理研究”(19-ZC0609-0001);西南石油大学“启航计划”项目“超临界CO 2射流辅助切削干热岩高效破岩机理研究”(2019QHZ009)。

摘　　要：为了提高深井高温地层PDC齿的破岩效率,分别将花岗岩和砂岩加热至不同温度以模拟深部井底高温岩石,结合岩石岩性及其在高温条件下的力学特性,进行PDC单齿切削破岩室内试验,利用切削力传感器、高速摄影机和热红外成像仪对不同温度岩样的切削力、破岩过程和切削温度场进行深入分析。分析结果表明:花岗岩和砂岩均存在使自身力学特性发生较大变化的临界温度,超过该临界温度切削效率和切削生热将发生突变,当花岗岩温度低于其临界温度、砂岩温度高于其临界温度时可大大提高PDC钻头的破岩效率;花岗岩和砂岩受温度影响力学特性的变化规律不同,而在不同温度条件下它们自身的力学特性也存在差异,特别是突破临界温度值后会产生较大的变化;钻井作业时可根据不同岩石及它们在不同温度环境下呈现出的力学特性,科学制定钻井方案,降低破岩难度,提高钻井效率。所得结论可为高温地层高效钻井和配套PDC钻头设计提供理论指导和技术支撑。In order to improve the rock breaking efficiency of PDC cutter in high temperature formations in deep wells,granite and sandstone are heated respectively to different temperatures to simulate the high temperature rocks at the deep bottom hole.And combined with rock lithology and its mechanical properties under high temperature,the laboratory test of cutting and rock breaking of single PDC cutter is carried out.In addition,cutting force,rock breaking process and cutting temperature field of rock samples with different temperature are analyzed deeply by virtue of cutting force sensor,high speed camera and thermal infrared imager.The results show that granite and sandstone both have the critical temperature above which the mechanical characteristics of their own change greatly and cutting efficiency and cutting induced heat change suddenly.The rock breaking efficiency of PDC bit can be increased greatly when the temperature of granite is lower than its critical temperature and the temperature of sandstone is higher than its critical temperature.Under different temperatures,granite and sandstone present different change laws of mechanical characteristics.The mechanical characteristics of their own are also different under different temperature conditions,and especially change greatly above the critical value.Drilling scheme can be formulated scientifically based on different rocks and their mechanical characteristics under different temperatures,so as to reduce the rock breaking difficulty and improve the drilling efficiency.The research conclusions can provide theoretical guidance and technical support for the efficient drilling in high temperature formations and the design of support PDC bits.

关 键 词：深井钻井 高温地层 PDC齿 破岩机理 生热规律 砂岩 切削力 温度场 

分 类 号：TE921[石油与天然气工程—石油机械设备]