基于残余岩溶强度表征和裂缝预测的碳酸盐岩储层评价——以塔中西部上奥陶统良里塔格组为例

我国目前在碳酸盐岩油气勘探阶段常用的储层分类评价标准已难以满足溶蚀孔洞缝广泛存在及构造裂缝发育的古岩溶储层评价的实际需要。选择塔中西部上奥陶统良里塔格组古岩溶储层, 在系统分析储层特征的基础上, 通过表征残余岩溶和开展构造裂缝预测, 引入残余岩溶强度(R)和岩体破坏接近度系数(η)2个参数, 作为古岩溶储层评价的重要定量指标;并与多项储层地质参数综合, 进一步完善了碳酸盐岩古岩溶储层的分类评价标准, 并用于对该地区良里塔格组叠加型古岩溶储层的评价预测。将本区良里塔格组古岩溶储层划分为Ⅰ、Ⅱ、Ⅲ、Ⅳ4类, 并应用多因素综合分析叠合成图法在平面上进行储层评价预测, 认为Ⅰ、Ⅱ类储层主要分布于S2井TZ45井TZ12井一带和 Z11井TZ10井TZ11井一带。

Evaluation of Carbonate Reservoir Based on Residual Karst Intensity Characterization and Structural Fracture Prediction:A Case from the Upper Ordovician Lianglitage Formation in the West of Center Tarim Basin

At present,because of the wide existence of karst genetic pore,cave and seam and the development of structural fractures,usual standards of reservoir classification and evaluation have been difficulties to meet the actual needs of palaeokarst reservoir evaluation in china.Palaeokarst reservoir of the Upper Ordovician Lianglitage Formation in the west of center Tarim basin is studied.The reservoir characteristics are analysed systematically firstly.Then,by characterizing residual karst and predicting structural fractures,residual karst intensity(R)and rock failure approach index coefficient(η)are chosen as the important quantitative indexes of palaeokarst reservoir evaluation.Combining R andη with the relevant parameters of reservoir geology,a better standard of carbonate reservoir classification and evaluation is established,which is used for evaluation and prediction of superimposed type palaeokarst reservoir of Lianglitage Formation in the west of center Tarim basin.Palaeokarst reservoir of Lianglitage Formation is divided into 4 types:Ⅰ,Ⅱ,Ⅲ,Ⅳ.The palaeokarst reservoir is evaluatedand predicted by applying multi factors synthetical analysis-Laminate maps method.Ⅰ,Ⅱtype of the palaeokarst reservoir mainly distributed in Well S2 Well TZ45 Well TZ12 area and in Well Z1 1 Well TZ10 Well TZ1 1 area.