龙马溪页岩井壁失稳机理及高性能水基钻井液技术

发布时间：2018-03-01 20:28

本文关键词： 页岩气井壁失稳微纳米尺度孔隙结构水基钻井液　出处：《钻井液与完井液》2017年03期 　论文类型：期刊论文

【摘要】：目前长水平井段井壁失稳问题仍是制约国内外页岩气资源钻探开发的重大工程技术难题。为解决龙马溪组页岩长水平井段的井壁失稳问题,采用X射线衍射分析、氦气孔隙体积测试、高压压汞测试、高分辨率场发射扫描电镜、CT扫描、岩石连续刻划强度等实验,分析了龙马溪组页岩微观组构特征及理化特性,探讨了微观组构特征、理化特性对龙马溪组页岩井壁稳定的影响。研究表明:龙马溪页岩富含脆性矿物,黏土矿物以伊蒙混层为主,微纳米孔隙发育,微裂隙呈缝状、近平行分布,敏感性矿物的存在及其层理、微裂缝发育是导致页岩井壁失稳的主要内在因素。为此,针对性地提出了多元协同稳定井壁水基钻井液防塌技术对策,即"强化封堵-适度抑制-合理密度-高效润滑"。应用该技术对策构建了高性能水基钻井液优化配方,评价表明,该体系有较好的封堵性和抑制裂缝扩展的能力。该体系在黄金坝区块2口井三开进行了现场试验。现场试验结果表明,该体系较好地解决了页岩长水平井段的井壁失稳和水平段摩阻较大的问题,为中国采用水基钻井液技术高效钻探开发页岩气资源提供了新的思路及经验。
[Abstract]:At present, the problem of shaft wall instability in long horizontal section is still a major engineering technical problem restricting the development of shale gas resources at home and abroad. In order to solve the problem of wellbore instability in long horizontal shale section of Longmaxi formation, X-ray diffraction analysis is used. Helium pore volume test, high pressure mercury injection test, high resolution field emission scanning electron microscope and CT scanning, rock continuous delineation strength and other experiments were carried out. The microstructure and physicochemical characteristics of the Longmaxi formation shale were analyzed, and the microscopic fabric characteristics were discussed. The effect of physicochemical properties on the stability of shale wellbore in Longmaxi formation is studied. The results show that Longmaxi shale is rich in brittle minerals, and the clay is mainly composed of eumonium layer, micropore is developed, microfractures are in the form of cracks and nearly parallel distribution. The existence and stratification of sensitive minerals and the development of microfractures are the main internal factors leading to the instability of shale wellbore. That is, "strengthening plugging, moderate inhibition, reasonable density and high efficiency lubrication". The optimized formula of high performance water-based drilling fluid was constructed by using the technical countermeasures. The evaluation results show that, The system has good plugging ability and ability to restrain fracture propagation. Field tests were carried out in two wells and three wells in Jinba block. The field test results show that, The system has solved the problems of the instability of the shaft wall and the large friction in the horizontal section of the long horizontal shale well, and provided a new idea and experience for the high efficiency drilling and exploitation of shale gas resources in China by using the water base drilling fluid technology.
【作者单位】：中国地质大学(北京);中国石化石油工程技术研究院;页岩油气富集机理与有效开发国家重点实验室;
【基金】：国家重大专项“彭水地区常压页岩气勘探开发示范工程”(2016ZX05061) 国家自然科学基金重大项目“页岩油气高效开发基础理论研究”(51490650),“川西低渗气藏低伤害钻井液技术研究”(2016ZX05021004-002)联合资助
【分类号】：TE254

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