摘要
由于可连续起下钻、不间断循环等优势,连续管钻井已成为近年来发展最快的石油钻井技术之一,开发煤矿井下连续管钻进技术是煤矿实现“少人化”甚至“无人化”钻探的重要技术途径。针对该技术在煤矿井下应用存在的管柱优选、钻进方法等关键问题,提出了连续管射流定向钻进方法,根据煤矿井下钻探用泥浆泵能力和孔深设计,分析了不同管径、不同弯曲比(r0/Rb)连续管流体摩阻;采用数值模拟方法,分析了不同连续管管径与钻孔孔径比(管孔比rc)情况下近水平钻进管柱屈曲形态及与孔壁接触应力;通过旋转射流水力学参数研究和破岩效果实验,给出了最佳射流钻头参数:通过连续管射流定向钻进实验,分析了射流定向钻进造斜规律,不同流量、钻进速度与钻孔孔径的关系。结果表明:?19~?31.75 mm连续管的弯曲半径可满足煤矿坑道空间要求;连续管流体摩阻的主要影响因素为管径和流量,在井下常用泥浆泵流量200 L/min、压力31.5 MPa、钻孔深度200 m情况下,?31.75 mm连续管为最佳管柱方案;管孔比rc=0.454时,连续管与孔壁接触应力稳定,压应力呈线性变化;采用?34.5 mm/5×1.0 mm(5个孔径1.0 mm的喷嘴)喷射钻头+?40 mm液力换向器+?31.75 mm连续管钻具组合钻进,平均增倾角能力0.67 (°)/m,平均降倾角能力为0.61 (°)/m,平均增/减方位能力0.45 (°)/m;通过控制射流流量和钻进速度,钻孔直径可控制在?70 mm左右;研究成果为煤矿井下连续管钻进技术与装备的开发提供了理论基础。
Due to continuous tripping, uninterrupted circulation and other technical advantages, coiled tubing drilling has become one of the fastest developing oil-drilling-technologies in recent years. Developing the coiled tubing drilling technology for underground coal mine is an essential technical means to realize “less humanized” or even “unhumanized”coal drilling. Aiming at solving the key problems existing in the application of this technology in underground coal mine, such as pipe string optimization and drilling method, the coiled tubing jet directional drilling method was proposed. According to the mud pump capacity and borehole depth design for underground coal mine drilling, the fluid friction resistance of coiled tubing with different diameters and bending ratios(r0/Rb) was analyzed. Numerical simulation was used to analyze the buckling morphology of horizontal drilling string and the contact stress with borehole wall at different ratios of coiled tubing diameter to borehole diameter(rc). Besides, the optimum jet bit parameters were given through the study on rotary jet hydraulic parameters and rock breaking effect test. Specifically, the deviation rule of jet directional drilling, as well as the relationship of different flow rate, drilling speed and borehole diameter, were studied based on the coiled tubing jet directional drilling test. The results show that the bending radius ?19 mm-?31.75 mm of coiled tubing can meet the space requirements of coal mine tunnel. Tubing diameter and flow rate are the main factors affecting the fluid friction resistance of coiled tubing. Under the conditions of a flow rate of 200 L/min, a pressure of 31.5 MPa and a drilling depth of 200 m, ?31.75 mm coiled tubing is preferred for the optimal drilling string scheme.When the tube hole ratio is rc=0.454, the contact stress between the coiled tubing and borehole wall is stable and the compressive stress changes linearly. Drilling with ?34.5 mm/5×1.0 mm jet bit + ?40 mm hydraulic commutator+ ?31.75 mm coiled tubing assembly, the average inclination increase capacity was 0.67(°)/m, the average inclination decrease capacity was 0.61(°)/m, and the average azimuth increase/decrease capacity was 0.45(°)/m. By controlling the jet flow rate and drilling speed, the borehole diameter can be controlled around ?70 mm. Generally, the research results could provide a theoretical foundation for the development of coiled tubing drilling technology and equipment in underground coal mine.
作者
姚宁平
王力
张金宝
豆旭谦
魏宏超
YAO Ningping;WANG Li;ZHANG Jinbao;DOU Xuqian;WEI Hongchao(China Coal Research Institute,Beijing 100013,China;CCTEG Xi’an Research Institute(Group)Co.,Ltd,Xi’an 710077,China)
出处
《煤田地质与勘探》
CAS
CSCD
北大核心
2023年第1期298-308,共11页
Coal Geology & Exploration
基金
国家科技重大专项课题(2016ZX05045003-002)
中煤科工西安研究院(集团)有限公司科技创新项目(2021XAYKF09)。
关键词
连续管钻进
流体摩阻
旋转水射流
定向钻进
煤矿井下
coiled tubing drilling
fluid friction
rotating water jet
directional drilling
underground coal mine