地面井预抽瓦斯运移规律数值模拟研究

发布时间：2018-08-09 17:43

【摘要】：基于气固耦合理论,建立了地面井预抽瓦斯的气固耦合力学模型和数值计算模型,并分析了地应力、储层压力等因素对地面井预抽瓦斯效果的影响。计算结果表明:地应力与煤层产气率之间呈现非线性负相关关系。抽采前期瓦斯的产出速率随地应力的增大而显著变小,随着抽采的进行,地应力对产出速率控制性逐渐减弱;储层压力与瓦斯产气率呈正相关关系。煤层瓦斯压力越大,初始瓦斯抽采效率越高,抽采产量越大,随着抽采时间的增加,煤层瓦斯压力下降,瓦斯抽采效率迅速降低;瓦斯产出速率由煤体渗透率和储层瓦斯压力梯度两者共同决定,抽采初期前者对瓦斯产出速率的控制性占主导地位,随着抽采的进行前者对其控制性要逐渐小于后者。
[Abstract]:Based on the gas-solid coupling theory, the gas-solid coupling mechanical model and numerical calculation model of gas pre-drainage in surface wells are established, and the effects of in-situ stress and reservoir pressure on the pre-drainage effect of surface wells are analyzed. The results show that there is a nonlinear negative correlation between in-situ stress and coal seam gas production rate. In the early stage of gas extraction, the gas production rate decreases significantly with the increase of in-situ stress, and with the development of extraction, the controlling effect of in-situ stress on the output rate decreases gradually, and the reservoir pressure has a positive correlation with the gas production rate. The higher the gas pressure in coal seam, the higher the initial gas extraction efficiency and the greater the output. With the increase of extraction time, the gas pressure in coal seam decreases and the gas extraction efficiency decreases rapidly. The gas production rate is determined by both coal permeability and reservoir gas pressure gradient. In the early stage of drainage, the control of gas production rate is dominated by the former, and the latter is gradually smaller than the latter.
【作者单位】：河南理工大学河南省瓦斯地质与瓦斯治理重点实验室省部共建国家重点实验室培育基地;河南理工大学安全科学与工程学院;煤炭安全生产河南省协同创新中心;
【基金】：教育部科学技术研究资助项目(213022A) 国家自然科学基金资助项目(51574112,51304072,51404100) 高等学校重点科研资助项目(15A440010)
【分类号】：TD712.6

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