塔里木盆地三叠系沉积特征及生烃潜力

SEDIMENTARY FEATURES AND HYDROCARBON POTENTIAL IN THE TRIASSIC SYSTEM OF THE TARIM BASIN

唐开疆

Tang Kaijiang

地质矿产部石油地质综合大队, 湖北江陵 434100

Research Party of Petroleum Geology, MGMR

塔里木盆地三叠系以河、湖相含煤碎屑岩为主,夹有海泛相碳酸盐岩及砂、泥岩,厚500～1900m,分布面积约34×104km2.烃源岩主要发育于深、浅湖亚相、三角洲相及海泛相,岩性以暗色泥、页岩、炭质泥岩为主,夹灰色碳酸盐岩、煤层及油页岩,累计厚200～800m.满加尔拗陷带及唐古孜巴斯拗陷带是盆内两大烃源岩分布区,面积约13×104km2.有机质类型以ⅡB～Ⅲ型为主,次为ⅡA～Ⅰ型.R°为0.6～1.2％.具有良好的生烃潜力.近年来塔东北地区已在三叠系连续获得重大油气突破,塔里木盆地三叠系具有广阔的油气前景.

The Triassic system of the Tarim Basin mainly consists of the coal-bearing clastic rocks of fluvial-lacustrine facies,intercalated with pan-marine carbonates,sands and mudstones;the thickness of the system ranges 500-1900m,and the distributing area reaches to about 30×104km2.In the system the source rocks mainly developed in deep-shallow lake subfacies,delta facies and pan-marine facies,lithologically it is characterized by dark mud,shales,carbonaceous mudstones intercalated with grey carbonate rocks,coals and oil shales.The accumulated thickness is up to 200-800m.The Majiar and Tangguzibasi depressions in the basin are the two major source rock areas totalling to about 13 ×104km2.The organics are predominately attributed to types ⅡB~Ⅱ,then to types Ⅱ~Ⅰ,with the R°values ranging 0.6~1.2%,therefore,they have a good hydrocarbon potential.In recent years,the several significant break-throughs of oil/gas exloration have been made in the Triassic system of the Northeast Tarim Basin,suggesting there is an extensive prospect for the petroleum exploration in the Triassic system of the basin.

https://doi.org/10.11781/sysydz199302128