济阳坳陷古近系存在页岩气资源的可能性

RESOURCE POTENTIAL OF SHALE GAS IN PALEOGENE IN JIYANG DEPRESSION

北美的勘探实践证实,页岩气作为非常规天然气资源,是现实的接替能源。通过对大量地震、钻井、矿物、地球化学资料的分析,认为渤海湾盆地济阳坳陷古近系沙河街组普遍发育泥页岩,有机质丰度高,有机质类型以腐泥型—混合型为主,有机质成熟度分布范围宽,具备大量形成页岩气的物质基础;其具体地质条件与北美具有可比性,且各凹陷泥页岩发育大量的顺层、低角度和垂向、高角度裂缝,页岩层段普遍出现气测异常,可能存在着巨大的页岩气资源量,是值得关注的天然气勘探新领域。

The history of shale gas exploration and production in North America shows that shale gas,as one of unconventional natural gas resources,is a kind of realistic alternative energy resource. Based on analyses of numerous seismic,drilling,mineral and geochemical data,it is believed that shale is extensively developed in the Palaeogene Shahejie formation in Jiyang depression,the Baohai Bay basin. The shale in this area is characterized by high abundance of organic matter with main type Ⅰ-Ⅱ1,and wide range of maturity of organic matter,thus has already possessed good conditions for the generation of large amount of shale gas. The geological conditions in this area are comparable to that of North America. In addition,many low angle and high angle fractures are well developed in the shale. Abnormalities are commonly appeared on gas logs in the shale intervals,indicating the possibility of existence of large shale gas volume,thus shale gas will be a new frontier of gas exploration.