天然气勘探与开发2026，Vol.49Issue(5)：46-59,14.DOI:10.12055/gaskk.issn.1673-3177.20260020
葡萄花边白云岩储层发育特征与主控因素
Development characteristics and key controlling factors of botryoidal-lace dolomite reservoirs:a case study of the second member of the Upper Sinian Dengying Formation,northern Sichuan Basin
摘要
Abstract
This paper investigates the development characteristics and key controlling factors of botryoidal-lace dolomite reservoirs in the second member of the Upper Sinian Dengying Formation(Deng-2 Member)in the northern Sichuan Basin.Based on data from field outcrop,core and thin-section observations,as well as physical property measurements and carbon-oxygen isotope geochemical analyses,the petrological characteristics,reservoir space types,physical properties,and distribution patterns of this dolomite type were studied,and the controlling effects of sedimentary environment,diagenesis,lithofacies,and tectonism on reservoir development were comprehensively evaluated.The following results are obtained.(ⅰ)Botryoidal-lace dolomites consist of fibrous laminae and crystalline cements,and can be classified into bedding-parallel,cross-bedding,circum-brecciform,dark-spotted,and isolated types according to morphology and occurrence.(ⅱ)Reservoir spaces are predominantly intercrystalline residual vugs and dissolution vugs,generally exhibiting the characteristics of vug to dissolution vug.Overall,the reservoirs indicate medium porosity(0.6%-11.7%)and low permeability(0.001 1-65 mD).(ⅲ)Vertically,the reservoirs are mainly developed in the middle-lower to middle-upper parts of the Deng-2 Member,with considerable cumulative thickness.Laterally,the reservoirs are widespread across restricted platform and platform margin facies belts within the basin,but absent in deep-water areas of the rift trough.(ⅳ)Different types of botryoidal-lace dolomites exhibit varying vug development.Specifically,the bedding-parallel,isolated,and circum-brecciform dolomites are characterized by well-developed vugs,whereas the cross-bedding and dark-spotted ones show underdeveloped vugs.Furthermore,the average permeability of samples with developed fractures is significantly higher than that of samples with underdeveloped fractures.It is concluded that,sedimentation-sea-level cycles and restricted platform-platform margin facies belts provide the material basis and pre-existing dissolution spaces;penecontemporaneous cementation controls the development of the dolomites and intercrystalline residual vugs,epigenic karstification during the Tongwan Movement Episode I effectively enhances porosity,while multi-phase tectonic fracturing significantly improves permeability.Given their wide distribution,large thickness,and favorable physical properties,such reservoirs hold considerable hydrocarbon exploration potential.关键词
葡萄花边白云岩储层/岩石学特征/储集空间类型/物性特征/分布规律/主控因素/准同生成岩作用/震旦系上统灯影组Key words
Botryoidal-lace dolomite reservoir/Petrological characteristics/Reservoir space type/Physical property/Distribution pattern/Key controlling factor/Penecontemporaneous diagenesis/Upper Sinian Dengying Formation分类
能源科技引用本文复制引用
胡明毅,周刚,曾帆,夏郡锴,王文之,苏佳芮,巩鑫强,刘海月..葡萄花边白云岩储层发育特征与主控因素[J].天然气勘探与开发,2026,49(5):46-59,14.基金项目
国家自然科学基金项目"川中地区埃迪卡拉系微生物白云岩成岩作用及储层孔隙定量演化"(编号:42072171). （编号:42072171）
