木里盆地中侏罗统烃源岩生烃潜力评价

Hydrocarbon potential evaluation of Mid-Jurassic source rocks,Muli Basin

为勘探木里盆地常规油气和非常规油气,在柴达尔剖面采集了泥岩、高碳泥岩和煤共65块样品,进行有机质丰度、类型和成熟度测试。结果表明:煤系泥岩的有机质丰度较低,属于中等偏差的烃源岩;高碳泥岩的有机质丰度达到了中等偏好的等级;煤的有机质丰度较高,属于好的煤成烃源岩。泥岩和高碳泥岩的有机质类型主要为Ⅲ_1型,煤为Ⅲ_1-Ⅲ_2型,有良好的生油气能力。烃源岩的镜质组反射率介于0.63%~1.58%之间,处于低熟-高成熟的阶段,可大量生烃。木里盆地中侏罗统烃源岩的生油强度为1 181.88 kg/m^2,生气强度为3 181.17 m^3/m^2,具有较高的生油气潜力。

Abstract：This paper is concerned with investigating the source rock potential of the Mid-Jurassic coal-bearing strata in the Mull Basin. The investigation works towards testing TOC, organic-matter type, and maturity using a total of 65 samples of mudstone, high carbonaceous mudstone, and coal collected from Chaidaer outcrop. The study suggests that the mudstones with a lower TOC are classified as low-to medium-quality source rock; high-carbonaceous mudstones are classified as medium-to good-quality source rock and the coal is ranked as good-quality source rock with high TOC; mudstone and high-carbo- naceous mudstones consist mainly of type Ⅲ 1 kerogen and the coal are blessed with Ⅲ1 - Ⅲ2 type kerogens with a higher hydrocarbon-generating potential; the value of vitrinite reflectance （Ro ） of the studied source rocks varies from 0.63% to 1.58% , suggesting that the source rocks occurring within low to high maturity stages are more likely to develop into the main hydrocarbon-generating phase; and the oil and gas resource densities of Mid-Jurassic source rocks of Mull Basin range between 1. 181 88 Mt/km^2 and 3. 181 17 km^3/km^2, demonstrating a higher gas-generating potential.