XS区块煤层气勘探井排采规律分析

Analysis of Drainage and Production Rules of Coalbed Methane Exploration Wells in XS Block

通过对XS区块7口煤层气勘探井排采过程的定量化分析得到单井泄压漏斗半径在48.1~108.4 m,显示本区煤层对压裂的响应较好但压降漏斗的扩展相对偏缓慢。通过对排采初期理论临界降速与实际排采降速的对比发现,合理的临界降速介于5.7~16.7 kPa/d,本区煤层气井排采初期的流压降速可控制在11.2 kPa/d左右。目前单井储层拟合渗透率介于0.31~0.76 mD,平均约0.55 mD,低于邻区高产井的0.9 mD,显示勘探井的储层改造工艺及对应的产气潜力均有提升空间,建议适当增大压裂规模强化储层改造效果。

Through the quantitative analysis of the drainage and production process of seven CBM exploration wells in XS block,the radius of the pressure relief funnel of a single well is between 48.1 and 108.4 meters,indicating that the coal seams in this area respond well to fracturing,but the expansion of the pressure relief funnel is relatively slow,at.Through the comparison between the theoretical critical speed reduction at the initial stage of drainage and the actual rate reduction,it is found that the reasonable critical speed reduction is between 5.7 and 16.7 kPa/d,and the flow pressure drop rate at the initial stage of drainage of coalbed methane wells in this area can be controlled at about 11.2 kPa/d.At present,the matching permeability of single well reservoir is between 0.31 and 0.76 mD,with an average of about 0.55 mD,which is lower than 0.9 mD of high yield wells in the adjacent area.It shows that the reservoir reconstruction technology and corresponding gas production potential of exploration wells have room for improvement.It is recommended to appropriately increase the fracturing scale to strengthen the reservoir reconstruction effect.