塔中东部碳酸盐岩储集层特征对比及勘探开发有利区预测

Comparison of carbonate reservoir characteristics in Eastern Tazhong Block of Tarim Basin and prediction of favorable development zone

奥陶系和寒武系碳酸盐岩是塔里木盆地油气勘探开发的重要方向之一。以塔中东南部古生界碳酸盐岩储集层为主要研究对象,基于三维地震、测井和岩心资料,分析主要储集层地质特征,并预测勘探开发有利区。结果表明:两条逆冲断层形成的断背斜为寒武系—奥陶系的主要控藏构造,位于断背斜北部的圈闭更有利于成藏。经过改造的白云岩储集层溶蚀缝洞发育,具有更好的油气储存空间。勘探开发有利区是以白云岩储集层为主的岩溶残丘,研究区发育20个自成白云岩背斜圈闭,总面积为17.20 km^(2)。该结果为碳酸盐岩缝洞型储集层分布规律和勘探方向研究提供依据。

Ordovician and Cambrian carbonate rocks are one of the most important directions of oil and gas exploration as well as development in Tarim Basin.The distribution and main controlling factors of high-quality reservoirs need to be clarified.Based on 3D seismic data,logging imaging and core data,we analyze the geological characteristics of the main production layers.The favorable areas for exploration and development are predicted.The study shows that the fault anticline formed by two"offset"faults is the main reservoir controlling structure of Cambrian-Ordovician.According to the evaluation of reservoir cap combination,the traps located in the north of fault anticline are more favorable for reservoir formation;the imaging logging results show that the dolomite reservoir after transformation has developed dissolution fractures and cavities,which has better oil and gas storage space;the favorable development area predicted is mainly dolomite reservoir.There are many karst residual hills.There are 20 self-formed dolomite anticline traps in the study area,with a total area of 17.20 km^(2).The results provide a basis for the study of distribution and exploration direction of fractured vuggy carbonate reservoirs.