Study on Mechanical Characteristics and Wellbore Stability of Hard Brittle Shale in Western Sichuan

doi:10.11885/j.issn.1674-5086.2019.09.17.10

Abstract

Abstract: In the drilling process of hard brittle shale formation, the phenomenon of wellbore instability occurs frequently, which seriously hinders the process of field drilling. In view of the phenomenon of downhole collapse in the process of shale drilling in Xiaotangzi Formation, we carryied out systematic laboratory tests of the shale cores of Xiaotangzi Formation established the theoretical model with experimental data, and evaluated and analyzed the wellbore stability of Xiaotangzi Formation. The results showed that Xiaotangzi Formation is the typical hard brittle shale with developed bedding cracks, which can produce tensile fracture under external force or high stress. Drilling fluid immersion effect can reduce the mechanical strength of shale formation in Xiaotangzi Formation. The influence of bedding strike and weak plane effect on the mechanical properties of shale in Xiaotangzi Formation is obvious. Fracture strike, wellbore trajectory and wellbore seepage field affect wellbore stability of shale in Xiaotangzi Formation. When the angle between fracture surface and borehole axis satisfies a certain relationship, the borehole wall rock is prone to slip and collapse along the fracture surface.

Key words: hard brittle shale, fracture, bedding plane, wellbore stability, weak plane effect

CLC Number:

TE122

LIU Houbin, CUI Shuai, MENG Yingfeng, WU Shuang, WU Ke. Study on Mechanical Characteristics and Wellbore Stability of Hard Brittle Shale in Western Sichuan[J]. 西南石油大学学报(自然科学版), 2019, 41(6): 60-67.

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References

[1] 刘锋报,邵海波,周志世,等. 哈拉哈塘油田硬脆性泥页岩井壁失稳机理及对策[J]. 钻井液与完井液, 2015, 32(1):38-41,100. doi:10.3969/j.issn.1001-5620.2015.-01.0010 LIU Fengbao, SHAO Haibo, ZHOU Zhishi, et al. Mechanism and strategy to deal with borehole instability of hard and brittle shales in Halahatang Oilfield[J]. Drilling Fluid & Completion Fluid, 2015, 32(1):38-41, 100. doi:10.3969/j.issn.1001-5620.2015.01.0010
[2] LIANG Lixi, XIONG Jian, LIU Xiangjun. Experimental study on crack propagation in shale formations considering hydration and wettability[J]. Journal of Natural Gas Science and Engineering, 2015, 23:492-499. doi:10.1016/j.jngse.2015.02.032
[3] YU Mengjiao, ChENEVERTET M C, SHARMA M M. Chemical-mechanical wellbore instability model for shales:Accounting for solute diffusion[J]. Journal of Petroleum Science and Engineering, 2003, 38(3):131-143. doi:10.1016/S0920-4105(03)00027-5
[4] YEW C H, CHENEVERT M E, WANG C L, et al. Wellbore stress distribution produced by moisture adsorption[J]. SPE Drilling Engineering, 1990, 5(4):311-316. doi:10.2118/19536-PA
[5] JAEGER J C, COOK N G W. Fundamentals of rock mechanics[J]. Engineering Geology, 1970, 4(2):168-169. doi:10.1016/0013-7952(70)90015-3
[6] 金衍,陈勉. 井壁稳定力学[M]. 北京:科学出版社, 2012:13-66. JIN Yan, CHEN Mian. Wellbore stability mechanics[M]. Beijing:Science Press, 2012:13-66.
[7] 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. doi:10.11698/PED.2014.06.16 WEN Hang, CHEN Mian, JIN Yan, et al. A chemomechanical coupling model of deviated borehole stability in hard brittle shale[J]. Petroleum Exploration and Development, 2014, 41(6):748-754. doi:10.11698/PED.2014.06.16
[8] 陈平,马天寿,夏宏泉. 含多组弱面的页岩水平井坍塌失稳预测模型[J]. 天然气工业, 2014, 34(12):87-93. doi:10.3787/j.issn.1000-0976.2014.12.012 CHEN Ping, MA Tianshou, XIA Hongquan. A collapse pressure prediction model of horizontal shale gas wells with multiple weak planes[J]. Natural Gas Industry, 2014, 34(12):87-93. doi:10.3787/j.issn.1000-0976.2014.12.-012
[9] 刘向君,叶仲斌,陈一健. 岩石弱面结构对井壁稳定性的影响[J]. 天然气工业, 2002, 22(2):41-42. doi:10.3321/j.issn:1000-0976.2002.02.012 LIU Xiangjun, YE Zhongbin, CHEN Yijian. Influence of rock plane texture on sidewall stability[J]. Natural Gas Industry, 2002, 22(2):41-42. doi:10.3321/j.issn:1000-0976.2002.02.012
[10] 马天寿,陈平. 层理页岩水平井井周剪切失稳区域预测方法[J]. 石油钻探技术, 2014, 42(5):26-36. MA Tianshou, CHEN Ping. Prediction method of shear instability region around the borehole for horizontal wells in bedding plane[J]. Petroleum Drilling Techniques, 2014, 42(5):26-36. doi:10.11911/syztjs.201405005
[11] 罗诚,吴婷,朱哲显. 硬脆性泥页岩井壁稳定性研究[J]. 西部探矿工程, 2013, 25(6):50-52. doi:10.3969/j.issn.1004-5716.2013.06.017 LUO Cheng, WU Ting, ZHU Zhexian. Study on the wellbore stability of hard brittle shale[J]. West-china Exploration Engineering, 2013, 25(6):50-52. doi:10.3969/j.issn.1004-5716.2013.06.017
[12] 王平全,邓嘉丁,白杨,等. 钻井液浸泡对延长组页岩坍塌压力的影响[J]. 特种油气藏, 2018, 25(2):159-163.doi:10.3969/j.issn.1006-6535.2018.02.032 WANG Pingquan, DENG Jiading, BAI Yang, et al. Effect of drilling fluid soaking on the shale collapse pressure in Yanchang Formation[J]. Special Oil & Gas Reservoirs, 2018, 25(2):159-163. doi:10.3969/j.issn.1006-6535.2018.02.032
[13] 陈勉,金衍,张广清. 石油工程岩石力学[M]. 北京:科学出版社, 2008. CHEN Mian, JIN Yan, ZHANG Guangqing. Rock mechanics in petroleum engineering[M]. Beijing:Science Press, 2008.
[14] JAEGER J C. Shear failure of anistropic rocks[J]. Geological Magazine, 1960, 97(1):65-72. doi:10.1017/S0016756800061100
[15] 丁乙,刘向君,罗平亚,等. 硬脆性泥页岩地层井壁稳定性研究[J]. 中国海上油气, 2018, 30(1):142-149. doi:10.11935/j.issn.1673-1506.2018.01.018 DING Yi, LIU Xiangun, LUO Pingya, et al. Research on wellbore stability for hard brittle shale[J]. China Offshore Oil and Gas, 2018, 30(1):142-149. doi:10.11935/j.issn.-1673-1506.2018.01.018