页岩脆性评价岩石物理模型及地震预测  

Rock physics model for shale brittleness evaluation and seismic prediction

作　　者：周欣 巴晶[1] 符力耘 张琳[1] 曹青业 余村 ZHOU Xin;BA Jing;FU Li-yun;ZHANG Lin;CAO Qing-ye;YU Cun(Hohai University,Nanjing 211100,China;China University Of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]河海大学,南京211100 [2]中国石油大学(华东),青岛266580

出　　处：《地球物理学进展》2020年第5期1736-1744,共9页Progress in Geophysics

基　　金：江苏省双创计划、江苏特聘教授计划(2016B1203509);国家111计划培育项目(BC2018019);中央高校科研业务费项目(2016B13114);国家科技重大专项(2017ZX05008-007)联合资助.

摘　　要：基于页岩低孔、特低渗的储层特征,自然状态下难以获得工业产能,在开采过程中通常需要采取水力压裂等增产改造措施,脆性指标可用于指示岩石易压裂区,因此我们将开展页岩储层脆性特征研究.本文基于扫描电镜及X射线衍射分析实验,对四川某地区龙马溪组岩石样本矿物组成及微观孔隙结构进行分析,结合岩石物理等效介质理论模型对实际岩石进行模拟.根据岩石物理模型构建了关于孔隙度、矿物组分对岩石地震属性及地质力学特性影响的岩石物理模板,分析模板可以得到岩石孔隙度、矿物组分对弹性性质与脆性特征的共同影响,并在此基础上得到了适用于该工区的储层脆性预测新公式.利用测井数据对岩石物理模板进行了对比验证,结果表明模板与测井数据吻合较好,结合地震数据对储层脆性进行了定量预测,对比实际产气结果显示,反演得到的脆性分布结果对储层产气情况具有较好的指示性.Due to the characteristics of shale low porosity and ultra-low permeability reservoirs,it is difficult to obtain commercially viable production of hydrocarbons under natural conditions.It is necessary to take some measures to improve production such as hydraulic fracturing.The brittleness index of the reservoirs rock is essential for effective hydraulic fracturing that indicate the rock fracturing zone,so we will discuss the brittleness characteristics of shale reservoirs in this paper.Based on scanning electron microscopy and X-ray diffraction analysis,this paper analyzes the mineral composition and microscopic pore structure of the Longmaxi shale rocks in the work area of Sichuan Basin,China,and the actual rocks are modelled by the effective medium model of rock physics.According to the model,a rock physics template is established for relating porosity,mineral composition to the rock seismic properties and geomechanical properties,and the joint effects of rock porosity and mineral composition on elastic and brittle characteristics can be obtained from the template.A new prediction method of the brittleness index which is suitable for this work area is also obtained.The rock physical template is verified by using the sonic log data and the results show that they are in good agreements.The reservoir brittleness is predicted by combining the template with seismic data.A comparison with the actual gas production results show that the estimated brittleness distribution results are effectively indicative of the shale reservoir gas production.

关 键 词：龙马溪组页岩 岩石物理模型 矿物组分 孔隙度 脆性预测 

分 类 号：P315[天文地球—地震学]