鄂尔多斯盆地中东部太原组石灰岩天然气勘探新突破及勘探方向  

New breakthrough in and direction of natural gas exploration in Taiyuan Formation limestone in the central and eastern Ordos Basin

作　　者：刘新社[1,2] 张涛[3] 黄道军[1,2] 董国栋 王康乐[1,2] 付勋勋 赵小会[1,2] 卢子兴[1,2] 于洲[4] 荆雪媛 张君莹[1,2] LIU Xinshe;ZHANG Tao;HUANG Daojun;DONG Guodong;WANG Kangle;FU Xunxun;ZHAO Xiaohui;LU Zixing;YU Zhou;JING Xueyuan;ZHANG Junying(Exploration and Development Research Institute,PetroChina Changqing Oilfield Company,Xi'an,Shaanxi 710018,China;National Engineering Laboratory of Low-permeability Oil&Gas Exploration and Development,Xi'an,Shaanxi 710018,China;Exploration Division,PetroChina Changqing Oilfield Company,Xi'an,Shaanxi 710018,China;PetroChina Hangzhou Research Institute of Geology,Hangzhou,Zhejiang 310023,China)

机构地区：[1]中国石油长庆油田公司勘探开发研究院 [2]低渗透油气田勘探开发国家工程实验室 [3]中国石油长庆油田公司勘探事业部 [4]中国石油杭州地质研究院

出　　处：《天然气工业》2023年第5期1-11,共11页Natural Gas Industry

基　　金：中国石油天然气股份有限公司科学研究与技术开发项目“鄂尔多斯盆地碳酸盐岩重点层系综合地质研究、目标评价、技术攻关与现场试验”(编号:2022KT0103)。

摘　　要：近年来,鄂尔多斯盆地中东部下二叠统太原组石灰岩天然气勘探先后有2口水平井测试获得高产气流,展示了该新领域良好的天然气勘探前景,但由于储层致密且相关勘探配套技术支撑不够,制约了该区天然气的勘探。为此,基于钻井岩心、微观薄片和地球化学特征等资料,系统研究了太原组石灰岩的烃源岩条件、储层特征、输导体系以及保存条件等天然气成藏地质条件,建立了太原组石灰岩天然气成藏模式,攻关形成了致密石灰岩微断层与流体地震预测、缝网体积压裂改造等关键配套技术,并预测了天然气勘探有利区带。研究结果表明:①太原组石灰岩天然气藏为源内气藏,上古生界石炭系—二叠系煤层和暗色泥岩是主要烃源岩;②受沉积微相控制,该区发育生屑滩和生物丘相2类石灰岩储层,其中生屑滩相石灰岩储层岩性为生屑石灰岩,储集空间类型主要为残余生屑体腔(溶)孔、晶间微孔,平均孔隙度为2.4%,生物丘相石灰岩储层岩性主要为藻黏结石灰岩,储集空间类型为残余生屑体腔(溶)孔和藻格架(溶)孔,平均孔隙度为2.2%;③断层和裂缝是煤系烃源岩油气向太原组石灰岩储层运移的通道,山西组二段泥岩是良好的盖层,太原组石灰岩天然气藏是具有“三明治”结构的源内气藏特征;④针对石灰岩储层致密、微断层及流体识别难度大、酸化效果不理想等问题,攻关形成了“导向滤波+人工智能+关键地震信息融合”相结合的微断层刻画技术、基于概率神经网络的含气饱和度地震定量预测技术以及“先成缝后成网”的缝网体积压裂改造技术。结论认为,乌审旗—横山—靖边和榆林—米脂—清涧是太原组石灰岩天然气勘探有利区,有利区面积约1.5×10^(4) km^(2),该领域的深化勘探有助于推动整个华北地块太原组石灰岩气藏的勘探进程。In recent years,two horizontal wells have been tested to obtain high-yield gas flow during natural gas exploration in the Taiyuan Formation of Lower Permian in the central and eastern Ordos Basin,which reveals the promising prospect of natural gas exploration in this new field,but the tight reservoirs and the insufficient supporting technological support restrict natural gas exploration in this area.Based on the data of drilling cores,microscopic thin sections and geochemical characteristics,this paper systematically studies the source rock conditions,reservoir characteristics,transport systems and preservation conditions of the Taiyuan Formation limestone,and establishes a natural gas accumulation model.The key supporting technologies are researched and developed,such as tight limestone microfault and fluid seismic prediction,and fracture network volume fracturing.In addition,favorable natural gas exploration areas are predicted.And the following research results are obtained.First,the Taiyuan Formation limestone natural gas reservoir is a gas reservoir inside the source rocks with the coal seams and dark mudstone of the Upper Paleozoic Carboniferous and Permian as the main source rocks.Second,under the control of sedimentary microfacies,two types of limestone reservoirs are developed in this area,namely bioclastic beach and bioherm facies.The lithology of the bioclastic beach facies limestone reservoir is bioclastic limestone,and the reservoir space is mainly composed of residual bioclastic cavity(dissolved)pores and intercrystalline micropores,with an average porosity of 2.4%.The lithology of the bioherm facies limestone reservoir is mainly algal clay limestone,and the reservoir space is acted by residual bioclastic cavity(dissolved)pores and algal framework(dissolved)pores,with an average porosity of 2.2%.Third,faults and fractures are the migration channels of oil and gas sourced from coal measures to the Taiyuan Formation limestone reservoir.The mudstone of the second Member of Shanxi Formation is a good ca

关 键 词：鄂尔多斯盆地 下二叠统 太原组 石灰岩 成藏地质条件 微断层及流体识别 缝网压裂技术 勘探方向 

分 类 号：P618.13[天文地球—矿床学]