摘要
根据砂岩薄片、铸体薄片、扫描电镜的分析,研究区内发育大量的粒间和粒内溶蚀孔。在大量实测物性参数统计分析的基础上,发现了白云凹陷第三系储层存在两个次生孔隙发育带,主要分布在2 750～3 500 m和4 100～4 600 m两个深度段。通过同位素示踪的方法,证实了形成次生孔隙的原因主要是有机质成熟时释放的有机酸和成岩过程中有机质脱羧作用产生的CO2形成的酸性水对长石、含长石火山岩屑、早期碳酸盐胶结物和生物化石等的溶解。影响次生孔隙的地质因素还有烃源岩的分布和类型,沉积相内砂体的分布和砂岩类型,构造活动产生的断裂。另外次生孔隙还受控于烃源岩成熟时间与断层、砂体和古构造脊组成的输导体系之间的匹配关系。综合各种地质因素分析后,将有机酸形成的次生孔隙模式概括为"生、运、匹、溶",该模式对研究区优质储层的预测具有一定的指导意义。
As the world＇s deep water oil and gas exploration continue to strengthen,the deep-water basin has increasingly become the new areas to gain growth in oil and gas reserves.The deep-sea oil and gas exploration has developed the inevitable challenges.Therefore,to make related research about the deep exploration and development in particular characteristic of the reservoir is a necessary requirement to find deep water oil and gas and also the direction of ocean exploration.Pearl River Mouth Basin is a major basin in China＇s offshore oil and gas basins with low level of exploration and the lacking comprehensive research on the variation law and influencing factors of reservoir properties.Deep reservoir with high porosity has been increasingly developed the concern problem with oil exploration performing to deep zone by petroleum geologists.The formation mechanism and controlling factors of the secondary porosity are reasonably explained or not,which directly impacts on the establishment of oil and gas basin clastic reservoir quality prediction model and serious impact on the objective evaluation of the reservoir.In this paper,the constraints of the factors of the secondary porosity in the study area are discussed systemically by isotope geochemistry,organic geochemistry methods combined with sedimentology.The study area contains a large number of grains and grain dissolution pore,according to sandstone sheet,cast thin sections,scanning electron microscopy analysis.Based on reservoir property data,two secondary porosity zones can be found in the Tertiary reservoirs,Baiyun Sag,mainly in the 2 750～3 800 m and 3 500～4 600 m.Mineral grains and carbonate cement are dissolved forming large of intergranular dissolution pores and dissolution pores.By isotope tracing method,it is found that the formation of secondary porosity is caused by the organic acid.Organic maturity and acidic water in which CO2 is released by decarboxylation of organic matter in the process of diagenesis were the main reason.The feldspar particle
出处
《沉积学报》
CAS
CSCD
北大核心
2011年第4期734-743,共10页
Acta Sedimentologica Sinica
基金
国土资源部全国油气资源战略调查与评价项目(编号:XQ-2004-05)
国家科技重大专项海洋深水区油气勘探关键技术(编号:2008ZX05000-025)
中国科学院"西部之光"联合学者项目资助
关键词
白云凹陷
次生孔隙
有机酸
包裹体
输导体系
优质储层
Baiyun Sag
secondary pores
organic acid
inclusion
migration pathway system
high-quality reservoir
