【摘要】 哈拉哈塘奥陶系浅覆盖区发育缝洞型储层,勘探效果较好。基于地震层位数据、钻井资料对该区进行古地貌恢复及古水系刻画,表明良里塔格岩溶期古地貌以丘丛洼地为主,南部发育了多条切穿至一间房组河流(河流深度大于50m);前志留纪岩溶期以微岩溶地貌为主,水系由北往南汇入岩溶湖。利用钻井、岩心、测井、地震剖面等资料,总结浅覆盖区储层有3种类型:洞穴型、孔洞型和裂缝-孔洞型;垂向上分布两套储层:上部一间房组裂缝-孔洞储层,下部鹰山组洞穴储层;横向上上部储层分布于浅覆盖区,下部储层分布可延至桑塔木组覆盖区。综上探讨浅覆盖区岩溶储层形成机理,认为下部储层带形成于良里塔格岩溶期径流带岩溶,南部深切河流为径流排泄点控制了储层发育;而上部储层带形成于前志留纪岩溶期径流带岩溶,南部岩溶湖为径流排泄区,控制了上部储层带发育。结合现代美国猛犸洞穴系统的特征,提出哈拉哈塘浅覆盖下碳酸盐岩两类岩溶模式,为下一步储层预测和勘探实践提供理论借鉴。更多还原

【Abstract】 Several sets of fracture-cavity reservoir develop in the Ordovician shallow coverage zone of Halahatang area,with good exploration results.The palaeogeomorphology and drainage system of this area are restored and depicted based on the seismic horizon and drilling data.The results show that the geomorphology in Lianglitage paleokarst period is mainly mounds and depressions.There are several rivers(>50m)in the south,which often cut through to Yijianfang formation.The geomorphology of pre-Silurian paleokarst period is mainly characterized by karst and the water system which flowed from north to south and into karst lake.Three types of reservoirs can be summarized with the data of drilling,core,logging and seismic sections in this area,which are cave type,pore-hole type and fracture-cavity type.The major reservoir sections in vertical are the upper fracture-cavity karst reservoir in Yijianfang formation,which distributes beneath shallow coverage area and the lower cave karst reservoir in Yingshan formation.which extends to Sangtamu formation coverage area.With a comprehensive analysis of the karst reservoir genesis mechanism in this shallow coverage zone,we thought that the lower karst reservoir developed in runoff belt and the southern rivers control the size and direction of the reservoir’s development during Lianglitage paleokarst period while the upper karst reservoir developed in runoff belt during the pre-Silurian paleokarst period.Moreover,the karst lake is a karst runoff drainage area,which controls the development of karst reservoir in the southern shallow coverage area.Combined with the characteristics of modern American Mammoth Cave system,two kinds of carbonate karst model in Halahatang shallow coverage zone are proposed,which provides a theoretical reference for further reservoir prediction and exploration practice.更多还原