四川盆地下志留统龙马溪组页岩气勘探前景
2015-10-21胡顺庆等
胡顺庆等
摘 要:利用野外露头、岩心、薄片及相关测试分析对四川盆地南部龙马溪组页岩气勘探前景分析。页岩厚度可达700m,有机碳丰度为0.15%~8.75%、生烃潜力大;页岩裂缝较发育,为页岩气提供了充足的储集空间。页岩其本身具有较强的抗破坏能力,是良好的盖层。四川盆地南部龙马溪组页岩层与美国成功开采的页岩气盆地的成藏条件相似,展示了该套页岩层具有良好的勘探潜力。
关键词:四川盆地 龙马溪组 页岩气 勘探潜力
中图分类号:P618.13 文献标识码:A 文章编号:1674-098X(2015)05(b)-0072-02
Exploration prospects of shale gas in Lower Silurian Longmaxi Formation, Sichuan Basin
Hu Shunqing1,2 Wang Xingzhi1 Pang Jiangping2 Li Xin3 Xiang Haiyang2 Yang Jialing2
(1.School of Geoscience and Technology, Southwest Petroleum University, Chengdu Sichuan, 610500;
2. Geological Exploration and Development Research Institute,Chuanqing Drilling Exploration Engineering,Chengdu Sichuan,610500;
3. Chengdu North Petroleum Exploration & Development Technology Company Limited, Chengdu Sichuan,610500,China)
Abstract:Based on the outcrop, core, thin section and test, the exploration prospects of shale gas in Lower Silurian Longmaxi Formation in Sichuan Basin are analysed. This shale has a great thickness about 700m, high organic content with 0.15~8.75%,. As the reservoir, according to analyses of rock core and logging, there exit s great quantity of cracks, which offers sufficient accumulated space for shale gas. As the reason of its strong damage resistance, shale can also be capping formation. Reservoir-forming conditions of shale gas is similar to several basins in USA, which had been successfully produced, indicating the great potential of shale gas.
Key Words:Sichuan Basin;Longmaxi Formation;Shale gas;Exploration prospects
頁岩气已成为重要的非常规油气资源,由于其特殊的成藏条件和较强的保存能力,开辟了油气资源勘探的新领域,成为国内外学者研究的重点领域[1]。古生代—中新生代,四川盆地是一个不断演化的海相和陆相复杂叠合盆地[2],下志留统龙马溪组的海相页岩具有巨大的勘探潜力[3],已成为四川盆地天然气勘探开发的一个重点领域。因此,该文利用野外露头、岩心、薄片及相关测试分析对四川盆地南部龙马溪组页岩气勘探前景进行分析。
1 区域概况
早志留世龙马溪期,盆地处于局限的深水陆棚环境,沉积了厚度大、范围广的黑色页岩。四川盆地南部是页岩气有利的发育地区,因此四川盆地南部成为了下志留统龙马溪组页岩气的重点研究区域(图1)。
四川盆地龙马溪组以黑色页岩为主,夹薄层灰黑色硅质页岩、深灰色灰岩。根据岩心和露头资料,自上而下,页岩砂质、硅质含量逐渐降低,生物化石逐渐增多。……
