塔里木盆地库车坳陷克深构造带克深8区块裂缝性低孔砂岩储层地质模型

塔里木盆地库车坳陷克拉苏冲断带克深地区是天然气勘探开发的重要阵地，储层埋深为6 000~8 000m，储层基质孔隙度均值为5.5%，基质渗透率均值为0.089×10^-3μm²，裂缝渗透率为（0.5～30）×10^-3μm²，地层储层总渗透率为（1～50）×10^-3μm²，储层性质总体为特低孔、特低渗—低渗。为揭示深层相对优质储层发育规律，以克深8区块深层白垩系巴什基奇克组为例，基于大量实验分析、露头储层模型及测井FMI成像资料，通过基质建模与裂缝建模相融合的方法，建立了裂缝—孔隙型双重介质储层地质模型。研究表明：克深8区块储层构造裂缝开度主要为25~150μm，其中构造核部裂缝开度一般为50~250μm，翼部裂缝开度<100μm；基质粒间孔半径主要为5~160μm，孔隙连通率平均为48%；孔隙喉道半径主要为0.01~1μm，其中产气层有效喉道半径>0.05μm，占比91%。储层基质孔隙度相对高值段主要分布于白垩系巴什基奇克组中部和上部，相对高渗透段主要集中于构造背斜高部位、东西向翼部、南北边界断裂带及内部次级断裂带。该地质模型及技术方法为克深8区块天然气高效勘探开发及克深气田60亿m产能建设提供重要依据。

Reservoir geological model of fracture low porosity sandstone of Keshen 8 wellblock in Kuqa Depression，Tarim Basin

In Kuqa Depression of Tarim Basin crassus thrust belt，deep region is one of the important positions of natural gas exploration and development.Reservoir burial depth is 6 000m to 8 000m，the reservoir matrix porosity has an average value of 5.5%，the matrix permeability averages at 0.089×10^-3μm²，fracture permeability is (0.5-30)×10^-3μm²，and formation permeability is (1-50)×10^-3μm².The reservoir is mainly characterized by low porosity and low permeability.To reveal the model of the relatively high quality reservoirs，this paper took the deep Cretaceous Bashijiqike Group as a case.Based on a large number of experimental analyses，the outcrop reservoir model and FMI log data，through three steps/qualitative modeling and the integration of three-step crack modeling method，we established a fracture-pore type double medium reservoir geological model.Research shows that:The effective reservoir structural fractures opening radius is mainly for 25-150μm，the core structure of the crack opening is generally 50-250μm，and the limb fracture opening is <100μm;Substrate mainly intergranular pore radius is 5μm to 160μm，the pore connectivity rate averaged 48%;Pore throat radius is 0.01-1μm，and the producing gas effective throat radius is >0.05μm which accounts for 91%.Relative good quality matrix porosity of the reservoirs is mainly distributed in the structure of the Cretaceous anticline zone chick group in the upper.Relatively high permeability section focuses on constructing anticline structure parts，east-west wing，the north and the south boundary fault zone and internal secondary fault zone.The geological model and the technical method important for deep natural gas efficient development and provide an important basis for the construction of a productivity of 0.6 billion of keshen Gas Field.