滇东宣威地区宣威组“三气兼探”储层地质条件初步分析

Preliminary analysis of geological conditions of "three gas and exploration" reservoir of Xuanwei Formation in Xuanwei area

以煤层气、页岩气、致密砂岩气为主的煤系"三气"在非常规油气资源中具有重要的地位。通过滇东宣威地区野外地质调查,发现宣威组煤系地层以河流及三角洲相煤、泥页岩、粉砂岩等岩性为主,地层厚100～270 m,含煤25～60层。结合钻井地震资料,岩性及岩相分析,优选出四个"三气"连续储层;储层煤层气含量较大,泥页岩瓦斯含量最高可达4 m3/t,具备较好的地质和资源潜力。通过分析煤层气、页岩气、致密砂岩气勘探开发特点,结合滇东宣威地区煤炭开发现状,认为在本区进行"三气共探共采",能够实现地质资源的最大价值,大大提高生产效益,成为云南省非常规天然气勘探开发的新突破口。

The "three gas" dominated by coalbed methane,shale gas and tight sandstone gas plays an important role in unconventional oil and gas resources. In Xuanwei Yunnan,The coal measures in Xuanwei Formation is made of mainly fluvial and delta facies,such as coal,shale,siltstone and so on. This set of strata has 100~270 m thick and contains 25~60 layers of coal. According to lithology and lithofacies characteristics,four "three gas" continuous reservoirs are selected. The coalbed methane content is large,the shale gas content up to 4 m^3/t, It has good geological and potential resources. Analysed the characteristics of coalbed methane,shale gas,tight sandstone gas exploration and development,combined with the status quo of coal exploitation in Xuanwei Yunnan. It is suggested that carry on the "three gas extraction" combined with the characteristics of reservoir system,it can realize the maximum value of geological resources and form a better production benefit,at the same time,it provides a new breakthrough for unconventional gas exploration in Yunnan province.