中扬子地区下古生界海相泥-页岩含气勘探远景

利用中扬子区下古生界页岩的野外露头地质剖面、有机地球化学分析数据和钻井显示资料，分析中扬子下古生界页岩气资源勘探远景。研究表明，中扬子区下古生界海相泥-页岩主要以下寒武统水井沱组(或牛蹄塘组)和上奥陶统五峰组—下志留统龙马溪组为主。上述2套泥质岩和页岩有机质含量丰富、有机质类型好、热演化程度高，多数已达到成熟—过成熟阶段，是有效页岩气气源岩。中扬子区自加里东以来经历了多期构造运动、构造隆升和挤压作用，改善了页岩储层的储集性能，提高页岩气聚集量。湘鄂西区和江汉平原区南部下寒武统泥-页岩可作为有利页岩气勘探选区，而鄂西渝东区钻井揭示志留系见工业性气流，表明该区志留系页岩气潜力较大。

Exploration prospect of gas-bearing marine mudstone-shale in Lower Palaeozoic in the central Yangtze area, China

Based on the data of geochemistry, gas show of drilling and outcrop of the Lower Paleozoic shale, this paper analyzed exploration prospects of Lower Paleozoic shale gas in the central Yangtze area. The analysis indicate that the Lower Paleozoic marine shale included Lower Cambrian Shuijingtuo Formation (or Niutitang Formation), Upper Ordovician Wufeng Formation and Lower Silurian Longmaxi Formation in the central Yangtze area, which have rich organic matter content, fine kerogen type, high thermal evolution(mature to over mature), were valid source rocks of shale gas. The central Yangtze area has experienced multiphase tectonic movements since Caledonian. The shale reservoirs property was improved by tectonic uplift and compression, and accumulation for shale gas was improved. Lower Cambrian shales and/or mudstones are prospect for shale gas exploration in western Hunan and Hubei and southern Jianghan plain. While the commercial gas flow in Silurian shales and/or mudstones was revealed by drilling, which indicated that the potential of exploration for shale gas is great in western Hubei and eastern Chongqing.