井间干扰对煤层气渗流规律影响的数值模拟

The numerical simulation of seepage rule of coal-bed gas under the condition of inter-well interference

多井开采煤层气在我国尚处于起步阶段,该技术涉及的数学理论较为复杂,不易获得解析解,而数值模拟方法可以较好地获得数值解,从而为煤层气的开采提供理论指导。在基本假设条件下,建立了多井煤层气渗流数学模型;在一定的边界条件及初始条件下,利用数值模拟软件进行编程计算后,得到单井及多井开采100d后的压力场、压力漏斗降和速度场。数值模拟结果显示,在一定的生产区域和开采时间,随着井筒数目的增加,井间压力场和流速场干扰加强,压力漏斗降大面积扩展,煤层气供气区及解吸面积大幅增长,煤层气解吸能力及稳产能力加强。

It＇s a beginning stage for application of the multi-well in coalbed methane extraction in China. It＇s so complicated to the mathematic theory of this technology that the resolve resolution can be gained hardly. But the numerical value can be obtained by the numerical simulation easily. And then the theory guidance of exploring cola-bed gas is supplied by numerical result. On the basis of hypothesis conditions, the mathematical model of seepage considering multi-well extraction condition is set up. Considering certain boundary and initial conditions, the mathematic software is used to calculate the pressure field, the funneled drop of pressure and velocity field after 100 day production of single well and multi-wells.The simulation result shows that the inter-well interference of pressure field and velocity field is strengthened, the area of funneled drop of pressure is expanded, the area of supplying and desorption is increased dramatically, the ability of desorption and steady production is improved as the number of well increases in certain production area and mining time. The advantage of inter-well interference extraction technology is showed through the simulation result. The theoretical basis is provided for coal-bed gas industrial extraction with multi-production wells.