裂缝性碳酸盐岩微细观组构及力学性能研究  

Micro-mechanical Structure and Mechanical Properties of Fractured Carbonate Rock

作　　者：刘厚彬 崔帅[1,2] 孟英峰 邓虎 韩旭[1,2] Liu Houbin;Cui Shuai;Meng Yingfeng;Deng Hu;Han Xu(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(Southwest Petroleum University),Chengdu,Sichuan 610500,China;Southwest Petroleum University,Chengdu,Sichuan 610500,China;CNPC Chuanqing Drilling Engineering Company Limited,Guanghan,Sichuan 618300,China)

机构地区：[1]油气藏地质及开发工程国家重点实验室,四川成都610500 [2]西南石油大学,四川成都610500 [3]中国石油川庆钻探工程有限公司,四川广汉618300

出　　处：《特种油气藏》2020年第1期155-161,共7页Special Oil & Gas Reservoirs

基　　金：国家自然科学基金“气体钻井技术基础研究”（51134004）;国家青年科学基金“泥页岩黏土矿物表面电化学反应及岩体膨胀数值模拟研究”（51204142）

摘　　要：针对川西马鞍塘—雷口坡组碳酸盐岩地层多口井发生不同程度井壁坍塌和掉块的情况,开展了该地区碳酸盐岩被钻井液浸泡前后微细观组构及力学性能变化研究,分析了井壁失稳原因。结果表明:马鞍塘—雷口坡组碳酸盐岩主要以方解石和白云石为主,膨胀性能较弱;该地区碳酸盐岩微裂缝、孔洞十分发育,相对于基岩,渗透率沿裂缝发育方向有显著提高,但裂缝的存在和走向对孔隙度无明显影响;钻井液浸泡效应对碳酸盐岩的力学性能影响不是特别明显,裂缝走向及力学弱面效应对碳酸盐岩力学性能影响最为显著,当裂缝倾角为60°时力学强度降至最低。该研究为评价裂缝性碳酸盐岩井壁稳定性提供了理论依据。In response to borehole collapse and chipping in multiple wells within the carbonate strata of the Maantang-Leikoupo Formation in western Sichuan,the microstructure and mechanical properties of carbonate rock in this zone before and after soaking with drilling fluid were studied to analyze the causes of borehole instability.Result indicates that the carbonate rock in the Maantang-Leikoupo Formation are dominated by calcite and dolomite with poor swelling performance.The carbonate rock shows a well development in micro-fracture and cave.The reservoir permeability along the fracture development direction has been significantly increased comparing with that of bedrock.The porosity is independent on fracture and its strike direction.There is no distinct influence of drilling fluid soaking on the mechanical properties of carbonate rock.The mechanical properties of carbonate rock are closely correlated with the fracture strike direction and mechanical weak surface.The mechanical strength reaches the minimum value when the fracture dip angle is 60°.This research could provide a theoretical basis for the wellbore stability evaluation in fractured carbonate drilling.

关 键 词：碳酸盐岩 裂缝 井壁稳定 马鞍塘-雷口坡组 

分 类 号：TE142[石油与天然气工程—油气勘探]