特低渗透油田经济开发差异化井网调整方法

低渗透油藏存在启动压力梯度,只有建立有效驱替压力系统,才能有效开发油田。而技术极限井距一般小于经济合理井距,甚至小于经济极限井距。分析认为,国外特低渗透C油田原来井距为400 m的反七点井网不能建立有效驱替,是注水效果差的直接原因。通过技术极限井距和经济极限井距,论述注水经济开发的有效厚度下限。根据不同区域油层分布情况,采用不同的注采井网调整方法和储层改造对策。结果表明菱形反五点差异化井网加密调整方法适用于国外此类油藏注水开发,实现了该类特低渗透油田的经济开发。

Different area with different well spacing adjustment method for an Extra-low Permeability Oilfield

For the starting pressure gradient in low permeability reservoir, only the efficiency water flooding pressure system established the oilfield can developed efficiently. But the technology critical well spacing is generally less than economic reasonable well spacing even less than the economic critical well spacing. The well pattern of C oilfield is inverse seven-point with 400 m of well spacing. The development result by water flooding is very bad. After evaluation of the technology critical well spacing, the relationship of the economic critical well spacing with net-pay, adjust the different well spacing and select fracturing parameters in different area by the oil-bearing distribution. The development result by water flooding is improved obviously and obtained high economic returns.