中国海陆交互相页岩气研究现状与展望

Research status and prospects for marine-continental shale gases in China

国内外对于海陆交互相页岩气的勘探开发与研究工作尚处于起步阶段。海陆交互相富有机质泥页岩在中国主要分布在北方鄂尔多斯盆地、沁水盆地、南华北盆地的石炭—二叠系本溪、太原和山西组地层中,以及南方四川盆地西南部、贵州西部和湘中—湘南坳陷的二叠系龙潭组地层中。该文总结了中国海陆交互相页岩气研究的成果,认为中国海陆交互相泥页岩干酪根类型以Ⅱ-Ⅲ型为主,除南华北盆地南部和东部外,有机质成熟度普遍较高,一般大于1.5%,处于高成熟—过成熟阶段。海陆交互相泥页岩地层岩相变化快,单层厚度薄,常与煤和致密砂岩甚至灰岩互层,单独开发这套薄层煤系页岩气在开发成本和技术上将面临很大的挑战,进行页岩气、致密气、煤层气等多目的层联合开发将是有效的新途径。

Shale gas has become one of the hot spots of unconventional natural gas exploration. At present,domestic and overseas research for shale gases is carried out mostly on marine formations; however,research for marinecontinental shale gases is still at the initial stage. In China,marine-continental shales rich in organic matter are mainly distributed in the Benxi,Taiyuan and Shanxi formations of Carboniferous and Permian age in the Ordos,Qinshui and southern North China basins in the north,and the Longtan Formation of Permian age in the southwestern Sichuan Basin,the western Guizhou province,and the central Hunan and southern Hunan depressions in the south.This paper summarizes present research results for marine-continental shale gases in China,and shows that the kerogen types of marine-continental shales are mainly II and III. Except for the south and east of the southern North China Basin,organic matter maturity is generally high,commonly greater than 1.5 %Ro and is in the high mature and over-mature stages. The lithofacies of marine-continental shales change rapidly and the thickness of a single layer is typically thin,often interbedded with coals,tight sandstones,and even limestones. As a result,separately developing shale gases from such thin layers will face a great challenge in development costs and technology. The joint development of shale gases,tight gases and coal bed gases from multiple target layers will be an effective new strategy.