塔河地区奥陶系岩溶斜坡峰丘高地的形成及油气地质意义  

Formation of hoodoo-upland on Ordovician karst slope and its significance in petroleum geology in Tahe area,Tarim Basin,NW China

作　　者：张三 金强[1] 孙建芳[2] 魏荷花[2] 程付启[1] 张旭栋 ZHANG San;JIN Qiang;SUN Jianfang;WEI Hehua;CHENG Fuqi;ZHANG Xudong(School of Geosciences,China University of Petroleum,Qingdao 266580,China;Petroleum Exploration and Development Institute,Sinopec,Beijing 100083,China)

机构地区：[1]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [2]中国石化石油勘探开发研究院,北京100083

出　　处：《石油勘探与开发》2021年第2期303-313,共11页Petroleum Exploration and Development

基　　金：国家自然科学基金:-中国石化联合基金:项目(U1663204);国家油气重大专项(2016ZX05014-002-007)。

摘　　要：基于大量地质、地球物理资料,从断裂特征和地层厚度分析入手,探讨塔河地区奥陶系岩溶斜坡上峰丘高地的成因,并对其缝洞类型与油气分布进行深入剖析。结果表明,海西早期,岩溶斜坡上发育由高耸丘峰与狭长丘谷组成的带状峰丘高地,其与北北东向正花状构造空间展布一致,具继承性演化特征。峰丘高地奥陶系鹰山组残余厚度大于其间残丘谷地,断层-裂缝及缝洞复合体密集发育,厚度可达百米,60%的油井单井累计产油量可达20×10^(4) t,在其丘谷处发现崩塌角砾无序堆积搭建"洞穴",洞高为1.6~13.5 m,充填率为51.6%。研究认为,走滑挤压背景下的正花状构造形成了岩溶斜坡上峰丘高地的雏形,导致了水系差异分布和岩溶作用差异;相对于富水残丘谷地,贫水的峰丘高地岩溶作用弱,残余地层厚,地貌相对抬高;每逢雨季,大气降水沿其中密集分布的缝隙扩散、渗滤溶蚀,形成错综复杂的网络状缝洞群;加之岩溶斜坡继承性隆升以及北北东向通源断裂的有效配置,油气持续不断向缝洞空间充注、运聚,形成纵向准连续分布、横向片状富集的峰丘体型缝洞油藏,油气丰度大,油井产量高。Based on a large number of geological and geophysical data,the formation,fracture-caves types and hydrocarbon distribution of hoodoo-upland on the Ordovician karst slope in the Tahe area,Tarim Basin,are discussed by analyzing faults and strata thickness.The hoodoo-upland was made of high peaks and narrow valleys in the Ordovician karst slope during the Early Hercynian karst period,which were distributed along the NNE positive flower structure and had inherited evolution.The fault-fractures and fracture-vugs complex were extremely developed,with a thickness of 100 m.The cumulative oil production of 60%oil wells was more than 20×10^(4) t per well in the hoodoo-upland,where the residual thickness of the Ordovician Yingshan Formation was greater than karst depressions.Caves formed by the shelter of collapsed breccias were developed in the valleys.They were 1.6 to 13.5 m high,with a filling rate of 51.6%.The positive flower structure under the settings of strike-slip compression controlled the early formation of the hoodoo-upland on the karst slope,resulting in the differences of drainage distribution and karstification.Compared with the water-rich karst valley,the hoodoo-upland with lean water suffered weaker karstification,had thicker residual stratum,and was higher in terrain.In rainy season,the meteoric water flew and corrode along the cracks,forming a complex network of fractures and caves.Combined with inherited uplift and the effective match of the NNE deep faults,oil and gas continuously charged into the reservoir space in the upland,forming the hoodoo fracture-cave reservoir with vertically quasi continuous distribution,high hydrocarbon abundance and high production.

关 键 词：塔河油田 奥陶系 岩溶斜坡 峰丘高地 花状构造 缝洞油藏 深层勘探 塔里木盆地 

分 类 号：TE122.1[石油与天然气工程—油气勘探]