摘要
常规测井方法难以准确评价黏土、碎屑岩和碳酸盐等矿物,而ECS测井仪的晶体探测器可测量由中子源和地层矿物碰撞产生的伽马射线,因此依据地层矿物和伽马射线的对应关系,建立了ECS元素测井响应方程,利用优化反演方法确定矿物类型、计算矿物含量、骨架密度及脆性指数。利用该方法对页岩气A区块X井的ECS测井资料进行了解释,选择Si,Al,Fe,Ca,Su和K元素,反演出石英、长石、灰岩、白云岩、伊利石、绿泥石、蒙脱石、黄铁矿、云母和硬石膏等10种矿物中的6-8种及其含量,反演结果与岩心矿物分析结果具有较好的一致性,并根据矿物的含量计算出该井页岩地层的骨架密度为2.65-2.75g/m^3,脆性指数为40-60。这说明利用ECS测井资料可以评价页岩地层的矿物及含量,能据此计算页岩地层的骨架密度和脆性指数,可提供准确的评价结果,从而指导页岩地层的压裂设计与施工。
It is difficult to accurately evaluate clay minerals,including those that contain clasolite and carbonates by using conventional logging methods.The crystal detector of the ECS logger measures gamma rays produced by collision of neutron sources and the strata minerals,so the ECS element log response equation was established according to the corresponding relationship between minerals and gamma rays.The optimized inversion method was used to determine mineral types,and calculate mineral content,grain density and brittleness index.By using this method,the ECS logging data of Well X in shale gas block A was interpreted,the elements including Si,Al,Fe,Ca,Su and K were selected to determine six to eight kinds of minerals and their contents,related to 10 minerals such as quartz,feldspar,limestone,dolomite,illite,chlorite,montmorillonite,pyrite,mica and anhydrite.Eventually,the inversion results coincided well with the core mineral analysis results,the grain density of the shale formation in this well was calculated according to the contents of the minerals,which ranged from 2.65-2.75g/m^3,the brittle index is40-60.It showed that shale formation minerals and their contents can be evaluated by using ECS logging data,and the grain density and brittleness index of shale formation can be calculated.These results could provide an accurate evaluation for shale formations and guide shale formation fracturing.
出处
《石油钻探技术》
CAS
CSCD
北大核心
2015年第4期102-107,共6页
Petroleum Drilling Techniques
基金
中国石化科技攻关项目"页岩地层工程特性测井技术研究"(编号:P13012)
中国石化油田事业部科技攻关项目"测井资料在压裂工程设计中的应用"(编号:PT1305)部分研究内容
关键词
元素测井
测井解释
矿物
反演
脆性指数
element logging
logging interpretation
mineral
inversion
brittleness index
