底水气藏打开不完善井二项式产能公式

底水打开不完善气井的渗流是由井附近区域遵循二项式径向流规律的非达西流动及此区域外遵循由底水驱动向不完善井三维达西流动两部分组成。由于底水气藏的产气主要由底水驱动而得，侧边边界影响可忽略，故假定气藏由上边界封闭和下边界定压的无限大区域所导出的产能公式便具有普遍意义。文章首先导出底水气藏打开不完善井在达西区域的压降公式，再结合非达西区域的二项式产能公式最终得到底水气藏向打开不完善井流动的二项式产能公式。目前仍使用改进的上下封闭边界的裘比公式，未能充分地反映底水驱动特点，而该公式能准确地描述底水驱动的打开不完善井非达西流动规律下的产能。

BINOMIAL DELIVERABILITY EQUATION OF PARTIAL PENETRATING GAS WELL IN RESERVOIR WITH BOTTOM WATER

Drainage domain of partial penetration gas well in bottom water reservoirs consists of the following two parts: (1) Non-Darcy binomial radial flow near the well; (2) three dimensional Darcy flow in areas far away from the partial penetration gas well due to bottom water drive. Because the main drive mechanism is bottom water drive and the effects of lateral boundaries are negligible, it is assumed the gas reservoir is infinite with an impermeable upper boundary and a constant pressure lower boundary, without losing generality. A pressure draw-down equation is first established for partial penetration gas well in Darcy-flow dominated domain in bottom water reservoir, and then a binomial deliverability equation is obtained by combining with Non-Darcy binomial radial flow equation. In the literature, the flow equations for partial penetrating wells are based on two-dimensional model with impermeable upper and lower boundaries, and they cannot reflect the characteristics of bottom water drive mechanism, while the new equations presented in this paper can accurately describe the deliverability of partial penetrating gas wells with Non-Darcy flow pattern in gas reservoirs with bottom water.