产量递减曲线参数最优化分析方法

认为拟合油气井产量递减规律的指数递减和调和递减是双曲递减的特例。但双曲递减曲线表达式无法变换成线性形式，常用方法（试凑法，曲线移位法，典型曲线分析法）既费时，又难以达到较高的拟合精度。对于实际油气井或油气藏产量递减分析来说，如果确定了递减阶段的初始产量、初始递减率和递减指数，就唯一地确定了其双曲递减曲线表达式。提出采用最优化理论优化求解这３项参数的计算方法，编制了应用程序。用该方法拟合某气井递减阶段的生产数据，拟合值的最大相对误差约为０．３３１％，平均相对误差约为０．０３９％。用该方法求解产量递减曲线参数，不受人为因素干扰，计算速度快，对指数递减、调和递减和双曲递减曲线都能精确地拟合。表１参２（陈志宏摘）

Optimization of parameters in production declining curves.

Exponential declining and harmonic declining are considered as special forms of hyperbolic declining in matching the declining regularities of oil and gas wells. However, hyperbolic declining expression cannot be transformed to a linear expression. Conventional methods (trial and error technique, curve movement technique, type curve analysis technique) are time consuming and high matching accuracy cannot be obtained moreover. For the declining analysis of an oil (gas) well or that of an oil (gas) reservoir in a practical case, if the initial production rate, initial declining rate and declining exponent are determined, the hyperbolic declining expression is determined uniquely. A calculation technique to derive three parameters by optimization theory is suggested and applied programs are given. The production record of a gas well in certain declining period is matched by the suggested technique, with a maximum relative error of about 0.331% and an average relative error of about 0.039%. To derive the parameters in the production declining curve by such a technique will not be affected by any man made factors, and is rather fast in the matching program. Exponential declining, harmonic declining and hyperbolic declining curves can be matched accurately. Subject