一种新型递减曲线

提出了一种新型递减曲线，基于该新型曲线和Ａｒｐｓ递减曲线间的产量与累积产量关系提出求取递减参数的重复线性回归法。对比表明，该新型递减曲线有以下２点优于Ａｒｐｓ曲线：①在任何情况下新型曲线都可以满足，当时间（ｔ）等于零时，ｔ时的瞬时产量（Ｑｔ）等于ｔ为零时的瞬时产量（Ｑｉ），累计产量（Ｎｐ）等于零，当ｔ趋于无穷时，有Ｑｔ等于零和Ｎｐ等于最大可采储量（ＮＲｍａｘ），而对于Ａｒｐｓ曲线，当求出的递减指数ｎ小于０和大于等于１时，不能满足上述边界条件；②描述递减规律比Ａｒｐｓ曲线更灵活和广泛，因此拟合实际递减数据时，该型曲线的相关系数一般比Ａｒｐｓ曲线高。该型曲线预测开发指标时，一般表示不采取任何调整增产措施的情况；而Ａｒｐｓ曲线反映在一定条件下持续采取与预测前相同强度的调整增产措施的情况。图３表２参３（陈志宏摘

A new decline curve.

new decline curve has been proposed. The repeated linear regression method for obtaining decline parameters of the new decline curve and Arps decline curve on the basis of their Qt vs. Np has been proposed. A comparison between the new decline curve and Arps decline curve shows that the new decline curve is better than Arps decline curve at following 2 points: Under the boundary conditions: when t=0, Qt=Qi and Np=0; when t, Qt=0 and Np=NRmax; in any case the new decline curve is reasonable. But when Arps decline indexes n<0 and n1,Arps decline does not satisfy abovementioned boundary conditions, so it is unreasonable; In describing decline pattern the new decline curve is more nimble than Arps decline curve, so when matching actual data, the correlation coefficient of the new decline curve is bigger than that of Arps decline curve usually. In predicting indexes of oilfield development, results of the new decline curve usually show that no measure is necessary, but results of Arps decline curve usually show that it needs to continuously take the measure with same intensity before prediction under certain condition.