万安盆地油气地质特征及其资源潜力新认识

利用最新掌握的地震及分析化验资料，系统分析了万安盆地地质条件、油气分布特征及富集规律，获得了对其油气地质特征和资源潜力的新认识。万安盆地总体上经历了断拗期和拗陷期2大构造演化阶段，发育近岸湖沼、扇三角洲、滨海三角洲、滨海—浅海、半深海相沉积，物源自西向东；主力烃源岩为渐新统、下中新统的泥岩、页岩、煤及含煤泥岩，分布于中部坳陷和北部坳陷；储层主要有三类，分别为渐新统到上新统砂岩、中—上中新统碳酸盐岩、前古近系基岩；盖层为上新统—第四系和上渐新统—下中新统2套区域性地层；发育西部油气带、中部油气带和南部气带3大有利油气聚集区。万安盆地油气资源潜力巨大，盆地地质资源量分别为石油29.38×108 t，天然气34 897×108 m3。 

New understanding of oil and gas geological characteristics and resource potential in Wan'an Basin

The geological conditions, hydrocarbon distribution and enrichment regularity in the Wan'an Basin were systematically analyzed based on the latest seismic and test data. Some new understanding of oil and gas geological characteristics and resource potential were obtained. The Wan'an Basin experienced two tectonic evolution stages: fault depression phase and depression phase. Inshore limnetic, shore delta, fan delta, coastal-shallow sea, and bathyal facies deposited. Sediments are from west to east. The major source rocks are mudstone, shale, coal and coal-bearing mudstone in the Oligocene and Miocene, which mainly distributed in the central and northern depressions. There are three kinds of reservoirs, respectively the sandstones of Oligocene to Pliocene, the carbonate rocks of Middle to Upper Miocene, and the bed rocks of pre-Tertiary. There are two sets of regional cap rocks, the Pliocene-Quaternary and the Upper Oligocene-Lower Miocene. There are three favorable oil-and-gas regions, the west, the central and the southern zones. Oil and gas potential of the Wan'an Basin is tremendous, and the geology resources of oil and gas are 29.38×108 t and 34 897×108 m3, respectively.