天津西部地区山西组页岩气富集条件及勘探方向

Enrichment condition and exploration direction of shale gas in Shanxi Formation in Western Tianjin

为了研究天津市西部地区二叠系山西组页岩气的富集特征,在结合以往石油、煤炭和地矿各系统资料和本次所采集样品试验数据基础上,对天津西部地区二叠系山西组炭质泥页岩的沉积分布规律进行了综合研究,并通过GIS手段运用多层次模糊综合评判方法,对该地区进行了页岩气富集评价。研究结果表明:区内二叠系山西组炭质泥页岩较厚,有机质类型为Ⅲ型,丰度较高,孔隙较发育,但渗透率较差;石英和长石类等脆性矿物含量大于30%,但与海相以石英为主的炭质泥页岩相比,脆性矿物含量较少,不太利于压裂;页岩气有利勘探区位于王口镇—梁头镇—静海镇一线以南区域,综合评价值在0.61以上,为优等有利开发区。

In order to study the enrichment characteristics of shale gas in Permian Shanxi Formation at the west area of Tianjin,in combination with the previous information from each system of petroleum oil,coal and local mine industry and based on the test data of collected sample test,a comprehensive study was conducted on sediment distribution law of carbonaceous shale in Permian Shanxi Formation in the southwest area of Tianjin. The GIS means and the multi layer fuzzy comprehensive judgement method were applied to evaluation on the study region. The study results showed that within the study region,the carbonaceous shale in Permian Shanxi Formation was thick,the organic matters type was Type Ⅲ,the abundance was high,the pore was well developed,but the permeability was poor. The contents of quartz,feldspar and other brittle minerals were over 30%. In comparison with the marine phase carbonaceous shale mainly with quartz,the contents of brittle minerals was low and was not favorable to fracturing. The shale gas favorable exploration area was located in the south area of Wangkouzhen-Liangtouzhen-Jinghaizhen line and the comprehensive evaluation value was over 0.61 and could be the excellent favorable development zone.