钻井液驱替下古龙页岩力学特性及弱化规律

Mechanical properties and weakening law of Gulong shale under drilling fluid displacement

摘要

在页岩油钻井过程中,造斜段和水平段井眼周围地应力的重新分布及水化作用加剧,开展古龙页岩油层的微观理化性质和宏观力学性质分析。结果表明:古龙页岩油层层理缝平均孔径为160.94μm,砂质条带孔隙平均孔径为1.50μm;页岩具有显著的各向异性渗透特征,其中,平行层理方向的渗透率大约是垂直层理方向的2倍;明确页岩层理面破坏的上下极限夹角,制作在不同围压下页岩强度随弱面倾角分布图表,建立考虑页岩油层理面的破坏模型并验证实验结果,平均误差为8.25%。在垂直层理方向,水基钻井液、醇基钻井液、油基钻井液驱替后,岩石三轴抗压强度分别降低20.31%、17.67%、13.69%;在水平层理方向,水基钻井液、醇基钻井液、油基钻井液驱替后,岩石三轴抗压强度分别降低36.15%、31.78%、22.44%,同时,修正弱化后页岩破坏准则。根据现场数据,结合古龙页岩井壁失稳研究进展,确定青山口组安全钻井液密度窗口为1.71~1.73g/cm³,可对井壁形成有效的力学支撑,有助于预防地层剥落,并明确主、辅助乳化剂最优配比调整方向。该结果对古龙页岩油钻井工程的安全钻进具有指导意义。

Abstract

In the process of shale oil drilling, due to the redistribution of ground stress around the wellbore and the intensification of hydration, wellbore instability becomes an urgent problem to be solved. The microphysical and macroscopic mechanical properties of the Gulong shale oil layer are studied. The results show that the average pore diameter of the bedding seam is 160.94μm, and the average pore diameter of the sandy strip is 1.50μm. The shale has significant anisotropic permeability, in which the permeability parallel to the bedding direction is about twice that of the vertical bedding direction. The upper and lower limit angles of shale bedding plane failure are defined, and a chart showing the distribution of shale strength with the dip angle of weak plane under different confining pressures is made. The failure model considering shale oil bedding plane is established and verified with the experimental results. The average error is about 8.25%. In the vertical bedding direction, the triaxial compressive strength of rock after displacement by water-based drilling fluid, alcohol-based drilling fluid and oil-based drilling fluid decreased by 20.31%, 17.67% and 13.69%, respectively. In the horizontal bedding direction, the rock triaxial compressive strength of water-based drilling fluid, alcohol-based drilling fluid and oil-based drilling fluid after displacement decreased by 36.15%, 31.78% and 22.44%, respectively, and the failure criterion of shale after weakening was modified. Based on the field data, this paper summarizes the current progress in the study of wellbore instability in Gulong shale, and determines the safe drilling fluid density window of Qingshankou Formation: 1.71-1.73g/cm³. The drilling fluid with this parameter can form an effective mechanical support to the wellbore, help to effectively prevent formation spalling, and provide a clear adjustment direction for the optimal ratio of main and auxiliary emulsifier. The research results have certain guiding significance for the safe drilling of Gulong shale oil drilling project.

关键词

古龙页岩油 / 井壁失稳 / 钻井液 / 各向异性 / 破坏模型 / 力学特性 / 弱化规律

Key words

Gulong shale oil / wellbore instability / drilling fluid / anisotropy / failure model / mechanical properties / weakening law

参考文献

[1] 赵文智, 胡素云, 侯连华, 等 . 中国陆相页岩油类型、资源潜力及与致密油的边界[J]. 石油勘探与开发, 2020, 47(1): 1-10.

[2] ZHAO Wenzhi , HU Suyun , HOU Lianhua , et al. Types and resource potential of continental shale oil in China and its boundary with tight oil[J]. Petroleum Exploration and Development, 2020, 47(1): 1-10.

[3] 庞彦明, 张元庆, 蔡敏, 等 . 松辽盆地古龙页岩油水平井开发技术经济界限[J]. 大庆石油地质与开发, 2021, 40(5): 134-143.

[4] PANG Yanming , ZHANG Yuanqing , CAI Min , et al. Technical and economic limit of horizontal well development for Gulong shale oil in Songliao Basin[J]. Petroleum Geology & Oilfield Development in Daqing, 2021, 40(5): 134-143.

[5] 张瀚之, 翟晓鹏, 楼一珊 . 中国陆相页岩油钻井技术发展现状与前景展望[J]. 石油钻采工艺, 2019, 41(3): 265-271.

[6] ZHANG Hanzhi , ZHAI Xiaopeng , LOU Yishan . Development status and prospect of the drilling technologies used for continental shale oil reservoirs in China[J]. Oil Drilling & Production Technology, 2019, 41(3): 265-271.

[7] 王玉华, 梁江平, 张金友, 等 . 松辽盆地古龙页岩油资源潜力及勘探方向[J]. 大庆石油地质与开发, 2020, 39(3): 20-34.

[8] WANG Yuhua , LIANG Jiangping , ZANG Jinyou , et al. Resource potential and exploration direction of Gulong shale oil in Songliao Basin[J]. Petroleum Geology & Oilfield Development in Daqing, 2020, 39(3): 20-34.

[9] SUO Yu , SU Xianheng , WANG Zijian , et al. A study of inter-stratum propagation of hydraulic fracture of sandstone-shale interbedded shale[J]. Engineering Fracture Mechanics, 2022, 275: 108858.

[10] SUO Yu , ZHAO Yanjie , FU Xiaofei , et al. Acoustic and mechanical tests of sandstone-shale composites in Songliao Basin and prediction of uniaxial compressive strength[J]. Geoenergy Science and Engineering, 2023, 228: 12034.

[11] 索彧, 李芬芬, 何文渊, 等 . 钻井液侵入纹层状页岩的模型[J]. 工程科学学报, 2024, 46(3): 547-555.

[12] SUO Yu , LI Fenfen , HE Wenyuan , et al. Invasion of drilling fluid into laminated shale model[J]. Chinese Journal of Engineering, 2024, 46(3): 547-555.

[13] 唐国旺, 于培志 . 油基钻井液随钻堵漏技术与应用[J]. 钻井液与完井液, 2017, 34(4): 32-37.

[14] TANG Guowang , YU Peizhi . Mud loss control while drilling with oil base drilling fluid[J]. Drilling Fluid & Completion Fluid, 2017, 34(4): 32-37.

[15] 姜逸明, 张定宇, 李大华, 等 . 重庆地区页岩气钻井井壁稳定主控因素研究[J]. 中国石油勘探, 2016, 21(5): 19-25.

[16] JIANG Yiming , ZHANG Dingyu , LI Dahua , et al. Major factors for wellbore stabilities of shale gas wells in Chongqing Area[J]. China Petroleum Exploration, 2016, 21(5): 19-25.

[17] 谭秀华, 熊鑫, 曾强渗 . 渝东南地区页岩气钻井泥浆优化技术[J]. 重庆科技学院学报(自然科学版), 2018, 20(1): 67-70.

[18] TAN Xiuhua , XIONG Xin , ZENG Qiangshen . Optimization technology of shale gas drilling mud in Southeast Chongqing[J]. Journal of Chongqing University of Science and Technology (Natural Science Edition), 2018, 20(1): 67-70.

[19] 崔月明, 郝忠宝, 白向双, 等 . 深井水平井欠平衡钻井液技术研究[J]. 中国石油勘探, 2009, 14(4): 66-69.

[20] CUI Yueming , HAO Zhongbao , BAI Xiangshuang , et al. Research on underbalanced drilling techniques for deep horizontal wells[J]. China Petroleum Exploration, 2009, 14(4): 66-69.

[21] SUO Yu , DONG Muyu , FU Xiaofei , et al. Experimental and Numerical simulation research on hot dry rock wellbore stability under different cooling methods[J]. Geothermics, 2024, 119: 102977.

[22] 徐加放, 邱正松 . 泥页岩水化应力模拟[J]. 大庆石油学院学报, 2010, 34(3): 73-76.

[23] XU Jiafang , QIU Zhengsong . Laboratory simulation of shales hydration pressure[J]. Journal of Daqing Petroleum Institute, 2010, 34(3): 73-76.

[24] 温航, 陈勉, 金衍, 等 . 硬脆性泥页岩斜井段井壁稳定力化耦合研究[J]. 石油勘探与开发, 2014, 41(6): 748-754.

[25] WEN Hang , CHEN Mian , JIN Yan , et al. A chemo-mechanical coupling model of deviated borehole stability in hard brittle shale[J]. Petroleum Exploration and Development, 2014, 41(6): 748-754.

[26] 丁乙, 刘向君, 梁利喜, 等 . 应力卸载-水化协同作用下页岩井壁稳定性模型[J]. 石油勘探与开发, 2023, 50(6): 1289-1297.

[27] DING Yi , LIU Xiangjun , LIANG Lixi , et al. Wellbore stability model in shale formation under the synergistic effect of stress unloading-hydration[J]. Petroleum Exploration and Development, 2023, 50(6): 1289-1297.

[28] 金衍, 薄克浩, 张亚洲, 等 . 深层硬脆性泥页岩井壁稳定力学化学耦合研究进展与思考[J]. 石油钻探技术, 2023, 51(4): 159-169.

[29] JIN Yan , BO Kehao , ZHANG Yazhou , et al. Advancements and considerations of chemo-mechanical coupling for wellbore stability in deep hard brittle shale[J]. Petroleum Drilling Techniques, 2023, 51(4): 159-169.

[30] 刘向君, 曾韦, 梁利喜, 等 . 页岩层理对井壁稳定性影响分析[J]. 中国安全生产科学技术, 2016, 12(11): 88-92.

[31] LIU Xiangjun , ZENG Wei , LIANG Lixi , et al. Analysis on influence of shale bedding on wellbore stability[J]. Journal of Safety Science and Technology, 2016, 12(11): 88-92.

[32] 林海, 邓金根, 谢涛, 等 . 地层各向异性对硬脆性泥页岩井壁稳定性的影响[J]. 东北石油大学学报, 2021, 45(1): 85-94.

[33] LIN Hai , DENG Jingen , XIE Tao , et al. Effect of formation anisotropy on wellbore stability of hard brittle shale[J]. Journal of Northeast Petroleum University, 2021, 45(1): 85-94.

[34] LI Jia , QIU Zhengsong , ZHONG Hanyi , et al. Effects of water-based drilling fluid on properties of mud cake and wellbore stability[J]. Journal of Petroleum Science and Engineering, 2022, 208: 109704.

[35] SUO Yu , DONG Muyu , HE Wenyuan , et al. Modeling wellbore instability in hot dry rock under various temperature conditions[J]. Unconventional Resources, 2023, 3: 275-283.

[36] WEI Yaoran , FENG Yongcun , TAN Zhenlai , et al. Borehole stability in naturally fractured rocks with drilling mud intrusion and associated fracture strength weakening: a coupled DFN-DEM approach[J]. Journal of Rock Mechanics and Geotechnical Engineering, 2024, 16(5): 1565-1581.

[37] 齐悦, 陈绍云, 李海, 等 . 松辽盆地古龙页岩水平井井壁失稳机理[J]. 大庆石油地质与开发, 2022, 41(3): 147-155.

[38] QI Yue , CHEN Shaoyun , LI Hai , et al. Mechanism of horizontal wellbore instability for Gulong shale in Songliao Basin[J]. Petroleum Geology & Oilfield Development in Daqing, 2022, 41(3): 147-155.

[39] 李士斌, 梁凯, 王昶皓, 等 . 层理性页岩各向异性井壁失稳机理研究[J]. 当代化工, 2022, 51(3): 550-554.

[40] LI Shibin , LIANG Kai , WANG Changhao , et al. Study on anisotropic wellbore instability mechanism of bedding shale[J]. Contemporary Chemical Industry, 2022, 51(3): 550-554.

[41] 金之钧, 张谦, 朱如凯, 等 . 中国陆相页岩油分类及其意义[J]. 石油与天然气地质, 2023, 44(4): 801-819.

[42] JIN Zhijun , ZHANG Qian , ZHU Rukai , et al. Classification of lacustrine shale oil reservoirs in China and its significance[J]. Oil & Gas Geology, 2023, 44(4): 801-819.

[43] 马天寿 . 页岩气水平井井眼坍塌失稳机理研究[D].成都:西南石油大学, 2015: 94-96.

[44] MA Tianshou . Research on the mechanisms of borehole collapse instability for horizontal wells in shale gas reservoirs[D]. Chengdou: Southwest Petroleum University, 2015: 94-96.

[45] JAEGER J C . Shear failure of anistropic rocks[J]. Geological Magazine, 1960, 97(1): 65-72.

基金资助

新时代龙江优秀硕士、博士论文资助项目(LJYXL2022-002)

黑龙江省博士后面上基金资助项目(LBH-Z22044)

黑龙江省博士后特别资助基金项目(LBH-TZ2301)

黑龙江省“揭榜挂帅”科技攻关项目(DQYT-2022-JS-758)