火山岩岩性地层油藏成藏条件与富集规律——以准噶尔盆地克—百断裂带上盘石炭系为例

为了进一步扩展准噶尔盆地西北缘克（克拉玛依）-百（百口泉）断裂带上盘石炭系火山岩油气勘探开发工作，经过仔细研究和实际勘探，揭示了石炭系火山岩油气成藏机理、主控因素和油气富集高产规律。克-百断裂带上盘石炭系油气源于断裂带下盘二叠系烃源岩，生成的原油由主断裂下盘沿断裂、不整合面、石炭系储集层逐级向上盘运移，形成上盘石炭系油藏，受断裂、老山边缘稠油封堵、上覆三叠系油藏及白碱滩组盖层遮挡，形成平面上满带含油、纵向多段含油的大规模岩性地层油藏。克-百断裂带上盘石炭系油藏为裂缝-孔隙双重介质，非均质性强，断裂发育的爆发相、溢流相火山岩分布区是油气富集高产的主要区域。该区2005年探明石油地质储量超过5000万t，三级石油地质储量超过1．8亿t，展现了上盘石炭系火山岩良好的油气勘探前景。图6表1参17

Oil accumulation and concentration regularity of volcanic lithostratigraphic oil reservoir: A case from upper-plate Carboniferous of KA-BAI fracture zone, Junggar Basin

The controlling factors and the regularity of accumulation and enrichment are revealed in the upper-plate Carboniferous volcanics in Karamay-Baikouquan(KA-BAI)fracture zone,Junggar Basin.The oil derived from the lower-plate Permian accumulates to the upper-plate via faults,unconformities and Carboniferous reservoirs,and is trapped by heavy-oil,faults and the Baijiantan mud-belt,thus forming the upper-plate lithostratigraphic reservoir.This upper-plate Carboniferous reservoir is charged effectively on the flat,and shows a stair-pattern vertically.The reservoir has the fracture-pore double porosity,and strong heterogeneity.The volcanic eruption facies and effusion facies near faults are the major areas of oil/gas concentration and high production.In 2005,the proved oil in place is more than 50 million tons,and the 3rd order oil in place is more than 180 million tons in the area,showing a good prospect for oil exploration.