西湖凹陷白垩系石门潭组火山岩储层特征  

Characteristics of volcanic reservoirs in Cretaceous Shimentan Formation in Xihu Sag

作　　者：王辉 赵洪 唐华风[2] 王璞珺[2] 许垣寅 赵鹏九 WANG Hui;ZHAO Hong;TANG Huafeng;WANG Pujun;XU Yuanyin;ZHAO Pengjiu(CNOOC China Limiled,Shanghai Branch,Shanghai 200335,China;College of Earth S ciences,Jilin University,Changchun,Jilin 130061,China)

机构地区：[1]中海石油(中国)有限公司上海分公司,上海200335 [2]吉林大学地球科学学院,吉林长春130061

出　　处：《中国海上油气》2025年第1期57-66,共10页China Offshore Oil and Gas

基　　金：“十三五”国家科技重大专项课题“东海深层大型气田勘探评价技术(编号:2016ZX05027-002)”;中国海洋石油有限公司“十四五”重大科技项目“弧后盆地深层/超深层油气成藏条件与成藏机制研究—西湖凹陷(编号:KJGG2022-0402)”部分研究成果。

摘　　要：东海陆架盆地西湖凹陷平北区石门潭组火山岩勘探取得了突破,但限于钻井数和实物资料的稀少,对火山岩储层特征揭示不完整,导致储层分布规律认识不清,阻碍了勘探潜力的分析。充分利用岩心、岩屑、测井和地震资料对平北地区火山岩岩性岩相、储集空间类型和储层物性特征进行分析。落实了岩性以流纹质/英安质凝灰岩、流纹质/英安质凝灰熔岩、流纹岩、安山岩和安山质隐爆角砾岩等为主;识别出4相10亚相,主要为爆发相热基浪亚相和热碎屑流亚相、溢流相中部亚相和下部亚相、火山通道相隐爆角砾岩亚相和火山沉积相等岩相;识别出3类7种储集空间类型,其中气孔和脱玻化孔可具有较高的孔隙度。储层物性与岩性、岩相等相关性研究结果表明,爆发相热基浪亚相远源相带-近源相带具有良好的储集能力,在火山口-近火山口相带应该具有更好的储层;爆发相热碎屑流亚相应该具有优于热基浪亚相储层的潜力;该区可能发育溢流相(流纹岩)为主的火山机构,也应具有良好的潜力。Breakthroughs have been made in exploration within volcanic rocks of the Shimentan Formation in the Pingbei area of the Xihu Sag in the East China Sea Shelf Basin. However, the characteristics and distribution patterns of the Shimentan volcanic reservoirs are not fully revealed due to limited wells and collected data, which hinders exploration potential analysis. This study, by fully utilizing cores, cuttings, logging, and seismic data, analyzed the lithological facies, reservoir space types, and reservoir physical properties in volcanic rocks in the Pingbei area. The recognized lithologies are mainly composed of rhyolite/andesitic tuff, rhyolite/andesitic tuffaceous lava, rhyolite, andesite, and andesitic cryptoexplosive breccia. Four types of facies and ten types of subfacies were identified, which are predominantly base surge subfacies and pyroclastic flow subfacies of eruptive facies, middle-lower subfacies of effusion facies, cryptoexplosive breccia subfacies of volcanic conduit facies, and volcanic sedimentary facies. Three categories and seven types of reservoir spaces were also distinguished, among which pores and devitrification pores own relatively high porosity. Based on the correlation between reservoir physical properties and lithologies/facies, a better reservoir capacity should be expected in the distal facies belt-proximal facies belt of base surge subfacies of eruptive facies, and better reservoirs should be expected in the crater-near-crater facies belt. The pyroclastic flow subfacies of eruptive facies should have better reservoir potential than the base surge subfacies. This study also indicates that the volcanic structures of effusion facies (rhyolite) may develop in the study area and should also have good reservoir potential.

关 键 词：西湖凹陷 白垩系 石门潭组 火山岩 储层特征 

分 类 号：TE122.2[石油与天然气工程—油气勘探]