高级检索

我国低煤阶煤煤层气地质研究综述

Summarization of geological study on low rank coalbed methane in China

  • 摘要: 针对当前我国低煤阶煤煤层气尚未实现区块、盆地层次上商业化开采的现状,为加深对以"可采性"为核心的低阶煤层气开采地质条件的认识,从低煤阶煤煤层气成因、煤储层特性、煤层气成藏模式等方面,系统总结了我国低煤阶煤煤层气基础地质特征研究的最新进展,并指出了研究过程中所存在的问题及今后的发展趋势。结果表明:低煤阶煤煤层气具有3类成因及多气源补充的特点;煤储层宏观裂隙张开程度及连通性好,基质孔隙度较大,具有吸附时间短、解吸效率高、扩散量低,扩散系数和扩散率较高,渗透率偏低的特征;气源补给与保存条件是控制低阶煤含气量的关键。目前低煤阶煤煤层气勘探开发仍需解决4个方面的地质问题:1以现有的工艺技术水平界定低煤阶煤煤层气形成工业气流的含气性参数下限;2通过储层敏感性评价及主控地质因素研究实现储层可改造性预测;3三相态时空分布规律及各相态的地质控制因素是探寻低煤阶煤煤层气富集规律及有利地质条件的核心问题;4建立以"可采性"为核心的低煤阶煤煤层气可采地质模式与地质选区评价体系。

     

    Abstract: According to the status that no commercial exploration of the low rank coalbed methane in a level of a exploration block or a basin in China,in order to d eepen the understanding the geological conditions of the low rank coalbed methane exploration with a "mineability" as a core,from the origin of the low rank coalbed me thane,the low rank coal reservoir features,the low rank coalbed methane formation mode and other aspects,the paper systematically summarized the update progress 0 n the basic geological feature study of the low rank coalbed methane in China and pointed out the existed problems in the study process and the future development te ndency.The results showed that the low rank coalbed methane would have three type origins and multi source supplement features.The macro crack open degree and t he connection of the coal reservoir were good and the matrix porosity was high.The low rank coalbed methane would have the features of a short adsorption time,a high desorption efficiency,a low diffusion volume,a high diffusion coefficient and a high diffusion rate and a low permeability. The gas recharge and storage condition were the key to control the gas content of the low rank coal.At present,the exploration and development of the low rank coalbed methane would have four geological problems to be solved.The first would be the available technique and technical level applied to define the gas content coefficient low limit of the industrial gas flow formed from the | ow rank coalbed methane.The second would be the reservoir sensitivity evaluation and the main controlled geological factors to study and realize the prediction of the r eservoir reconstructability.The third would be the three-phase time and space distribution and the each phase geological control factor would be the key problems to ex plore the low rank coalbed methane enrichment law and the favorable geological conditions.The forth would be the establishment of the low rank coalbed methane mine able geological mode and the geological selected block evaluation system based on the " mineability" as the core.

     

/

返回文章
返回