Oil-Based Drilling Fluid Plugging Method for Strengthening Wellbore Stability of Shale Gas
Oil-Based Drilling Fluid Plugging Method for Strengthening Wellbore Stability of Shale Gas
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DOI：
10.1155/2021/6674574
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发表时间：
2021-02
期刊：
影响因子：
1.7
通讯作者：
Pengcheng Wu;Chen Zhong;Zheng Li;Zhen Zhang;Zhiyuan Wang;Weian Huang
中科院分区：
文献类型：
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作者：
Pengcheng Wu;Chen Zhong;Zheng Li;Zhen Zhang;Zhiyuan Wang;Weian Huang
找出龙马溪组、五峰组井眼失稳的原因，提出加强和稳定井眼的钻井液技术对策，对水平井钻井至关重要。通过x射线衍射、电镜扫描、线性膨胀实验和热轧分散实验，揭示了复杂地层中井筒失稳的物理化学机理，提出了“加强微孔堵塞、抑制滤液侵入、减缓压力传递”的井筒协调稳定方法。利用砂层过滤测试仪、高温高压封堵模拟实验装置、微孔膜等实验装置，对油基钻井液处理剂进行了研究和选择，构建了一套适用于页岩气水平井的增强封堵钻井液体系。耐温135℃，具有较好的耐污染性（10% NaCl, 1% CaCl2, 8%贫粘土）。400 μm裂缝的承载能力为5 MPa， 0.22 μm和0.45 μm微孔膜的过滤损失为零。与以往的油田钻井液相比，所构建的油基钻井液体系的封堵能力大大提高，在其他方面也具有优异的性能。
Finding out the reasons for wellbore instability in the Longmaxi Formation and Wufeng Formation and putting forward drilling fluid technical countermeasures to strengthen and stabilize the wellbore are very crucial to horizontal drilling. Based on X-ray diffraction, electron microscope scanning, linear swelling experiment, and hot-rolling dispersion experiment, the physicochemical mechanism of wellbore instability in complex strata was revealed, and thus, the coordinated wellbore stability method can be put forward, which is “strengthening plugging of micropores, inhibiting filtrate invasion, and retarding pressure transmission.” Using a sand bed filtration tester, high-temperature and high-pressure plugging simulation experimental device, and microporous membrane and other experimental devices, the oil-based drilling fluid treatment agent was researched and selected, and a set of an enhanced plugging drilling fluid system suitable for shale gas horizontal well was constructed. Its temperature resistance is 135°C and it has preferable contamination resistibility (10% NaCl, 1% CaCl2, and 8% poor clay). The bearing capacity of a 400 μm fracture is 5 MPa, and the filtration loss of 0.22 μm and 0.45 μm microporous membranes is zero. Compared with previous field drilling fluids, the constructed oil-based drilling fluid system has a greatly improved plugging ability and excellent performance in other aspects.