稠油油藏反九点井网非活塞水驱平面波及系数计算方法

A calculation method for the areal sweep efficiency of heavy oil reservoirs by non-piston like water fiood in inverted nine-spot pattern

刘翀 范子菲 许安著 薄兵 田洪瑞

LIU Chong FAN Zifei XU Anzhu BO Bing TIAN Hongrui

中国石油勘探开发研究院 中海石油(中国)有限公司天津分公司

PetroChina Research Institute of Petroleum Exploration & Development, Beijing 100083, China Tianjin Branch Company, China National Offshore Oil Co. Ltd., Tianjin 300452, China

为更准确迅速地计算稠油油藏反九点井网水驱波及系数，更有效地进行井网评价，根据正方形反九点井网的对称性，将其划分为2个对称的渗流单元，从非达西渗流出发，运用流线积分法推导了既考虑启动压力梯度又考虑油水黏度比的普通稠油油藏正方形反九点井网非活塞式水驱平面波及系数计算公式。利用该公式分析了启动压力梯度和注采参数等因素对普通稠油油藏正方形反九点井网水驱平面波及系数的影响，进而对哈萨克斯坦NB常规稠油油藏现有井网进行了评价，并提出井网调整方法。研究结果表明：减小井距或增大注采压差能有效增大常规稠油油藏平面波及系数，油藏的启动压力梯度越大，注采压差和井距大小对平面波及系数影响就越明显。

The square inverted nine-spot was divided into two symmetric fiow units according to its symmetry so as to calculate the water fiood sweep efficiency of heavy oil reservoirs in inverted nine-spot pattern accurately and quickly and evaluate the well pattern effectively. With the non-Darcy fiow as the beginning, the formula for calculating the areal sweep efficiency of ordinary heavy oil reservoir by non-piston like water fiood in square inverted nine-spot pattern was derived by means of fiow line integral method. In this formula, both threshold pressure gradient and oil/water viscositу ratio are taken into account. Then, this formula was used to analуze the effects of threshold pressure gradient and injection/production parameters on the areal sweep efficiency of ordinary heavy oil reservoir in square inverted nine-spot pattern. Finallу, it was applied to evaluate the existing well pattern in NB conventional heavу oil reservoir in Kazakhstan, and the corresponding well pattern adjustment method was proposed. It is indicated that the areal sweep efficiency of con-ventional heavу oil reservoir can be increased effectivelу bу decreasing the well spacing or increasing the injection/production pressure difference, and the effects of injection/production pressure difference and well spacing on the areal sweep efficiency get more obvious with the increase of threshold pressure gradient of oil reservoir.

10.13639/j.odpt.2018.02.015