西南石油大学学报(自然科学版) ›› 2023, Vol. 45 ›› Issue (6): 95-103.DOI: 10.11885/j.issn.1674-5086.2021.10.05.34

• 石油与天然气工程 • 上一篇    下一篇

准噶尔南缘冲断带破碎地层井壁稳定性机理

叶成1, 任涛1, 尹泽斌1, 李成2, 白杨2   

  1. 1. 中国石油新疆油田公司工程技术研究院, 新疆 克拉玛依 834000;
    2. 油气藏地质及开发工程全国重点实验室·西南石油大学, 四川 成都 610500
  • 收稿日期:2021-10-05 发布日期:2024-01-06
  • 通讯作者: 白杨,E-mail:baiyanghyq@foxmail.com
  • 作者简介:叶成,1987年生,男,汉族,湖北荆州人,高级工程师,硕士,主要从事钻井工程研究。E-mail:sunych66@petrochina.com.cn;任涛,1996年生,男,汉族,甘肃平凉人,助理工程师,硕士,主要从事油气井工程研究。E-mail:rent2022@petrochina.com.cn;尹泽斌,1997年生,男,汉族,辽宁抚顺人,助理工程师,主要从事油气井工作液方面的研究工作。E-mail:915689387@qq.com;李成,1996年生,男,汉族,陕西咸阳人,助理工程师,硕士,主要从事油气井工作液及开发地质方面的研究工作。E-mail:lichengsc@foxmail.com;白杨,1985年生,男,汉族,新疆昌吉人,研究员,博士研究生导师,主要从事油气井工作液方面的研究工作。E-mail:baiyanghyq@foxmail.com
  • 基金资助:
    国家自然基金面上项目(52274008);国家重点研发计划(2019YFA0708303);中国石油-西南石油大学创新联合体科技合作项目(2020CX040102, 2020CX040201)

Wellbore Stability Mechanism of Fractured Formation in the Thrust Belt of Southern Margin of Junggar Basin

YE Cheng1, REN Tao1, YIN Zebin1, LI Cheng2, BAI Yang2   

  1. 1. Engineering Technology Research Institute of Xinjiang Oilfield Company, CNPC, Karamay, Xinjiang 834000, China;
    2. National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China
  • Received:2021-10-05 Published:2024-01-06

摘要: 准噶尔盆地南缘地质构造复杂、地层破碎、可钻性差,钻井过程中井漏、卡钻和垮塌频发。为实现南缘破碎地层安全钻井,研究了以吐谷鲁、呼图壁背斜为代表的地层岩性、水化和岩石力学特征,对比了不同地层的黏土矿物含量、水化强度和抗压强度,并结合地震解释剖面和抗压强度损失模型,分析了南缘破碎地层钻井过程中的井壁失稳机理和钻井液稳定井壁机理。结果表明,南缘地层岩性以泥岩和砂岩为主,全岩矿物以黏土矿物、斜长石和石英为主,黏土矿物以伊利石和伊蒙混层为主,水化特征非均质性强,包括极强-较弱分散、强-中等-弱膨胀;黏土矿物水化膨胀分散和井周破碎地层发育微孔缝延伸拓宽增压剥裂作用叠加,造成地层抗压强度降低、坍塌压力增高、钻井液密度窗口降低,导致井壁失稳;合理的钻井液密度、良好的水化抑制性、全面的孔缝封堵性、严格的高温高压滤失性和高效的携岩性,是实现南缘破碎地层安全钻井和井壁稳定的必要措施。该研究成果可为南缘乃至准噶尔盆地深部复杂破碎地层钻井液关键参数设计提供参考。

关键词: 准噶尔盆地, 南缘, 破碎地层, 井壁稳定性, 钻井液

Abstract: The southern margin of Junggar Basin is characterized by complex geological structure, fractured formation and poor drillability, and frequent lost circulation, tending to stick and collapse during drilling. In order to achieve safe drilling of fractured formation in the southern margin, the lithology, hydration and rock mechanics characteristics of the formation represented by Tugulu and Hutubi anticlines are studied, and the clay mineral content, hydration strength and compressive strength of different formation are compared. Combined with the seismic interpretation section and the compressive strength loss model, the mechanism of wellbore instability and the mechanism of drilling fluid stability in the fractured formation in the southern margin are analyzed. The results show that the southern margin of the formation is dominated by mudstone and sandstone, the whole rock minerals are dominated by clay minerals, plagioclase and quartz, and the clay minerals are dominated by illite and illite/smectite, and the hydration characteristics are highly heterogeneous, including extremely strong-weak dispersion and strong-medium-weak expansion. The hydration expansion and dispersion of clay minerals and the expansion and expansion of micro-pores and fractures in the fractured formation around the well lead to the decrease of formation compressive strength, the increase of collapse pressure, and the decrease of drilling fluid density window, leading to wellbore instability. Reasonable drilling fluid density, excellent hydration inhibition, comprehensive porosity sealing, strict high temperature and high pressure filtration and efficient lithology carrying are the necessary measures to achieve safe drilling and wellbore stability in the fractured formation in the southern margin. The research results can provide a reference for the design of key parameters of drilling fluids in deep complex fractured formations in the southern margin and even Junggar Basin.

Key words: Junggar Basin, southern margin, fractured formation, wellbore stability, drilling fluid

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