煤层气多分支井形态分析

ANALYSIS ON CONFIGURATION OF MULTI-LATERAL WELL FOR COALBED METHANE

煤层气井开采的第三阶段是煤层气井开采期限的主要部分,前人研究表明可用真实气体拟压力法来精确描述这一阶段的渗流规律。因此,根据镜像反映和压力叠加原理,建立了上下封闭煤层气藏中煤层气多分支井压力分布方程。考虑多分支井沿程流动压降对产能的影响,建立煤层气多分支井稳定渗流时的产能计算耦合模型,给出了模型的求解方法,分析了多分支井形态参数对煤层气多分支井产能的影响规律。

The third phase of coal-bed gas exploitation lasts long time,so stable seepage laws of this phase should be studied. Pseudo pressure function is adopted to resolve this problem by J. P. Seidle. The pressure distribution equations in the formation of multi-lateral well for coalbed methane are constructed on the basis of pressure superposition and mirror image reflection theory. Pressure drop influence on the deliverability is considered. By coupling wellbore flow and reservoir stable seepage flow,the deliverability calculation model and its solution method for multi-lateral well are established. Rules of influence on deliverability of multi-lateral well for coalbed methane is analyzed.