临兴区块深部煤层气井生产特征及影响因素

Production feature and influencing factors of deep coalbed methane In Linxing Block

  • 摘要: 【目的】深部煤层气生产特征与中浅部煤层气生产特征具有明显区别,且同一区块内深部煤层气排采井也存在差异性。相关研究尚处于探索阶段,深入分析深部煤层气生产特征差异的影响因素对后续大规模开发阶段的产能预测与生产管理具有重要意义。【方法】为明确临兴区块深部煤层气生产特征及其影响因素,基于含气性、煤厚、埋深、水化学特征及压裂工艺等地质工程因素开展研究。【结果和结论】结果表明:(1)临兴区块深部煤层气井分为过饱和气藏自喷井、过饱和气藏排采井和欠饱和气藏排采井三类。(2)含气性是三种生产特征的主控因素,工区内1 800~2 000 m埋深的煤层气井含气量与稳产气量均相对较高。(3)欠饱和气藏排采井储层保存条件较差,水化学特征与其他两类井存在明显差异,导致其生产效果相对较差,且由于高矿化度和高碳酸氢根离子产生的管柱结垢与腐蚀导致排采不连续。(4)大规模压裂是提高气井产量的有效储层改造措施,压裂砂对裂缝的有效支撑是保障深部煤层井高气量稳产的关键因素。上述成果明确了临兴区块深部煤层气生产特征差异影响因素,对研究区和邻近地区深部煤层气生产具有参考意义。

     

    Abstract: The production characteristics of deep coalbed methane are significantly different from those of medium and shallow coalbed methane, and there are also differences in the drainage wells within the same block.Due to the fact that relevant research is still in the exploratory stage, the analysis of factors affecting the production characteristics of deep coalbed methane is of great significance for the production capacity research and production management in the subsequent large-scale development stage of this field.Deep coalbed methane wells in the Linxing block can be divided into three types based on production characteristics: self flowing wells in supersaturated gas reservoirs, drainage wells in supersaturated gas reservoirs, and drainage wells in undersaturated gas reservoirs.To clarify the influencing factors of deep coalbed methane production characteristics in the Linxing block, this article conducts research based on geological engineering factors such as gas content, coal thickness, burial depth, hydrochemical characteristics, and fracturing technology.The results show that: (1) Gas content is the main controlling factor for the three production characteristics, and the gas content and stable production of coalbed methane wells buried at depths of 1 800-2 000 meters in the work area are relatively high; (2) The storage conditions of undersaturated gas reservoir drainage wells are poor, and there are significant differences in hydrochemical characteristics compared to the other two types of wells, resulting in relatively poor production efficiency.Moreover, due to high salinity and high bicarbonate ions, the scaling and corrosion of the pipe columns can cause discontinuous drainage; (3) Large scale fracturing is an effective reservoir transformation measure to increase gas well production, and the effective support of fracturing sand on fractures is a key factor in ensuring high gas production and stable production in deep coal seam wells.The above achievements have clarified the influencing factors of the differences in the production characteristics of deep coalbed methane in the Linxing block, and have guiding significance for the production of deep coalbed methane in the research area and adjacent areas.

     

/

返回文章
返回