煤层气直井开发井网适应性优选

Optimization of well pattern in the development of coalbed methane through vertical wells

利用直井井网开发煤层气,优选合理的井网对于煤层气藏的高效开发关系重大,因此,有必要针对不同储层条件的煤层气藏研究优化井网类型。通过数值模拟方法,针对不同渗透率、不同各向异性的煤层气藏,进行了正方形、矩形和菱形3种不同井网的数值模拟,得出适合不同井网开发的储层渗透率和各向异性的范围。模拟研究表明:正方形井网不适合煤层气的开发;矩形井网适合于中渗、低渗至特低渗煤储层;菱形井网适合于中渗至高渗煤储层。

Optimization of well pattern in coalbed methane reservoir has very critical effect on its effective develop- ment through vertical wells.At present, in the form of areal development of several coalbed methane （CBM） reservoirs in China, the selection of vertical well pattern should be further investigated.For effective development and higher recovery, it is essential to optimize well pattern for coalbed methane reservoirs with different formation properties. In this work, for coalbed methane reservoirs with different face cleat permeability and heterogeneity coefficients, reser- voir simulation is used to simulate the production with three well patterns including square, rectangle and rhombus, the reasonable range of face cleat permeability and heterogeneity coefficient is obtained for each well pattern.The simulation results indicate that square well pattern is not applicable to the development of coalbed methane reservoir, rectangle well pattern is appropriate to the development of coalbed methane reservoirs with medium, low or ultralow permeability, rhombus well pattern is suitable to the development of coalbed methane reservoirs with medium or high permeability.