鱼骨型分支井稳态产能公式

Productivity Equation of fishbone shaped wells in steady state

鱼骨型分支井与地层接触面积大,但其井身结构复杂,目前还没有鱼骨型分支井产能计算的解析和半解析公式,难以预测鱼骨型分支井产能.采用渗流场剖分的方法,将渗流区域划分为外部渗流和局部渗流,简化渗流问题;采用保角变换和等值渗流阻力理论,推导鱼骨型分支井稳态产能近似公式;利用水电模拟实验对产能近似公式进行检验,最大误差为11.88%.将计算结果与实际油田鱼骨井参数进行对比,相对误差为11.56%,表明该产能近似公式精度能够满足工程需要.

Fishbone shaped multilateral wells are widely used in oilfield operations due to large contact area of multilateral wells with productive formation.But because of its complex structure,there isn't any analytical or semi-analytical formula for calculating fishbone well's productivity published.So it is difficult to evaluate productivity of multilateral fishbone wells.This paper makes a reasonable simplification to flow region.The flow region is reasonably divided into two parts:the inner flow region and the external flow region.Based on conformal mapping method and hydro-electrical equivalent flow resistance method,derived the approximately formula for calculating productivity of a fishbone multilateral well in steady state.The formula has been tested by using of the hydroelectrically simulation experiment,which has the results of 11.88% as maximum error.And compared with the productivity of a fishbone multilateral well,relative error is 11.56%.So the formula can be used to forecast the productivity of a fishbone multilateral wells.