塔里木盆地奥陶系古潜山碳酸盐岩岩溶储层评价与预测——以轮古7井区以东为例

摘要

The Ordovician carbonate karst reservoirs are characterized by deep burial and strong heterogeneity in Tarim basin.The karst reservoir space is primarily the later dissolution pores,karst caves and solution fissures.The study on paleogeomorphology restoration and karst vertical zonation,combined with the reservoir production performance permits to evaluate and predict the Ordovician carbonate karst reservoirs east of the Lungu7 well block.The research suggests that high-production and high-efficiency wells are mainly located in karst graves,karst crests,and karst slopes of peak-hill depressions,hill-peak depressions and karst peak cluster valleys.In the vertical direction,surface karst belts and the upper part of vertical infiltration belts are localities with good exploitation effects,where developed crack-hole reservoirs and karst cave reservoirs.In the runoff karst belts and undercurrent karst belts developed weak karst,where small-scale karst caves and karst pipelines are present,and the karst reservoirs are of the fractured-or hole-type.At last,the research predicts five high-efficient oil and gas reservoir areas,which provide the evidence for planning exploration and development of oil and gas in this area.%塔里木盆地奥陶系古潜山碳酸盐岩岩溶储层具有埋藏深、非均质性强的特点.岩溶储集空间主要为后期溶蚀孔、溶洞和溶缝为主.通过古地貌恢复及岩溶垂向分带研究,结合油藏开采动态,对轮古7井区以东地区奥陶系碳酸盐岩岩溶储层评价与预测.研究认为:高产高效井主要位于岩溶缓坡地的峰丘洼地、丘峰洼地及岩溶峰丛谷地的溶丘、溶峰及其边坡部位.垂向上表层岩溶带和垂向渗滤带的上部,开发效果较好,多发育裂缝—孔洞型、洞穴型储层;径流溶蚀带、潜流溶蚀带岩溶发育相对较弱,局部发育小规模溶洞或岩溶管道,岩溶储层以裂缝型或孔洞型为主.在此基础上预测出五个高产高效油气储层岩溶区,为油气勘探与开发提供依据.