冀中坳陷东北部石炭-二叠系烃源岩生烃潜力评价

冀中坳陷东北部石炭-二叠系煤系地层生、储、盖组合条件完备,上古生界自生自储煤成气藏勘探潜力巨大。笔者基于该层系"油井少、空井多"的勘探现实,通过烃源岩热解数据分析和热模拟实验工作,评价区内烃源岩的生烃潜力,以期减少勘探风险。数据分析表明,w(TOC)为10%和40%是区内煤系暗色泥岩、炭质泥岩和煤岩的有效划分界限。区内石炭-二叠系煤系烃源岩主要以Ⅲ型干酪根为主,为中等较差的油源岩和较好的气源岩。分别受岩浆热变质和深成变质作用影响,区内存在武清凹陷、苏4-苏8-苏23-文古4和葛8-大参1三个成熟度高值区,即生油气中心。结合热模拟实验结果,采用体积法算得该区石炭-二叠系地层生气总量约为4万亿m3。

Hydrocarbon Evaluation of Carboniferous Permian Source Rocks in Northeast Jizhong Depression

Carboniferous‐Permian coal measures strata possess the conditions of a good source‐reservoir‐seal assemblage and thus a huge exploration potential of the self‐generation and self‐storage coal gas in the Upper Paleozoic strata in the northeast of Jizhong depression . However , the reality demonstrates only a few successful wells but a lot of empty ones in the historic exploration . We evaluated the hydrocarbon potential of source rock based on the pyrolysis data analysis and thermal simulation experiment to reduce the exploration risk in this strata .The results show that the contents of TOC (10% and 40% ) is the effective demarcation of dark mudstone ,carbon mudstone and coal .The source rock of Carboniferous‐Permian coal measures strata are of mainly type III kerogen ,and belong to poor‐medium oil source rock and good gas source rock .Affected by magmatic thermal metamorphism and plutonic metamorphism respectively ,the maturity of the three areas i .e .Wuqing depression ,Su4 Su8 Su23 Wengu4 ,and Ge8 Dacan1 are relatively high .As hydrocarbon generation centers ,their hydrocarbon generation amount is calculated for 4 trillion cubic square meters of gas .