临汾区块煤系地层泥页岩防塌钻井液技术研究  

Study on anti sloughing drilling fluid technology of shale in coal measure strata in Linfen Block

作　　者：王维 韩金良[1,2] 亓宗凯 辛江 苗强 杨干 陈刚 WANG Wei;HAN Jinliang;QI Zongkai;XIN Jiang;MIAO Qiang;YANG Gan;CHEN Gang(Engineering Technology Research Institute of PetroChina Coalbed Methane Co.,Ltd.,Xi’an 710000,China;Zhonglian Coalbed Methane National Engineering Research Center Co.,Ltd.,Beijing 100095,China;Exploration,Development and Construction Branch of PetroChina Coalbed Methane Co.,Ltd.,Xi’an 710000,China)

机构地区：[1]中石油煤层气有限责任公司工程技术研究院,西安710000 [2]中联煤层气国家工程研究中心有限责任公司,北京100095 [3]中石油煤层气有限责任公司勘探开发建设分公司,西安710000

出　　处：《非常规油气》2023年第2期107-114,共8页Unconventional Oil & Gas

基　　金：中国石油勘探与生产分公司科技项目“鄂东缘致密砂岩气钻完井技术研究及现场试验”(kt2020-10-08)。

摘　　要：临汾区块煤系地层山西组泥页岩易发生井壁失稳,导致钻井非生产时效多,钻井周期长,是影响临汾区块致密气水平井钻井提速提效的主要原因之一。为解决泥页岩失稳问题,采用钻井岩心观察、扫描电镜、X射线衍射分析以及膨胀率和回收率测定等方法,分析了山西组泥页岩宏观、微观特征和理化特性,探讨了其对山西组泥页岩井壁稳定的影响。研究表明,山西组泥页岩在清水中浸泡7天后破裂,扫描电镜观察发现微裂缝宽度为0.32~7.69μm,黏土矿物中高岭石占比为37.2%、伊蒙混层占比为35.2%。为此,提出了强封堵、强抑制和低滤失量的防塌钻井液技术对策,形成了高性能防塌钻井液体系配方。评价表明,该体系老化后中压失水2.4 mL,高温高压失水8.8 mL,泥页岩膨胀率为0.73%,滚动回收率为99.3%。该体系已在临汾区块1口井进行了现场试验,应用效果良好,表明该技术能够有效解决脆性泥页岩的井壁失稳问题,具有推广应用价值。The shale of Shanxi Formation in Linfen Block coal measure stratum is prone to wellbore instability, resulting in more non production time and long drilling cycle, which is one of the main reasons affecting the drilling speed and efficiency of tight gas horizontal wells in Linfen Block. In order to solve the problem of shale instability, experiments such as drilling core observation, scanning electron microscope, X-ray diffraction analysis, expansion rate and recovery rate measurement are used to analyze the macro, micro and physicochemical characteristics of shale in Shanxi Formation, and its influence on the wellbore stability of shale in Shanxi Formation is discussed. The study shows that the shale of Shanxi Formation ruptured after being soaked in water for seven days. The width of microcracks is 0.32~7.69 μm by scanning electron microscope, in clay minerals, kaolinite accounts for 37.2% and illite mixed layer accounts for 35.2%. Therefore, the technical countermeasures of anti sloughing drilling fluid with strong plugging, strong inhibition and low filtration loss are put forward, and the formula of high-performance anti sloughing drilling fluid system is formed. The evaluation shows that after aging, the medium pressure water loss is 2.4 mL, the high temperature and high pressure water loss is 8.8 mL, the shale expansion rate is 0.73% and the rolling recovery rate is 99.3%. The system has been tested in a well in Linfen Block, and the application effect is good, which shows that the technology can effectively solve the problem of wellbore instability of brittle shale, and has the value of popularization and application.

关 键 词：井壁稳定 碳质泥页岩 强抑制 强封堵 封堵性能评价 

分 类 号：TE254[石油与天然气工程—油气井工程]