Research And Application On Calculation Methods Of Economic Reserves

Economic recoverable reserves refer to the petroleum cumulative production with economic value from underground in the border of the profit and loss curve. It is material basis of oilfield development and construction. So it is necessary to forecast and calculate accurately.This paper introduced several calculation methods of economic reserves. These are production decline method, mathematiocal model method, and Fractional-Flow curve method. Author collects various methods for calculating recoverable reserves.The principles of the input-output balance must be complied to corresponding the threshold value of equilibrium for oil production and investment no matter which kind of methods were used.Calculation method of economic reserves in oilfield vary with the information and production stages.In this paper, gray model method, time series method, trend extrapolation method, simple linear regression model, multiple linear regression model, and nonlinear regression model are turned into prediction models to calculate oilfield output, cumulative production, recoverable reserves and economic recoverable reserves. And the examples testify the feasibility of these methods.Analysised and Combined with the present economic recoverable reserves principles and methods, this paper develops a new estimation method for economic recoverable reserves, which based on fractional-flow technology. This fractional-flow technique applies the oil volume drained by existing producers that would continue producing in the same or close fashion as at the time of the estimate. It provides a relationship (curve) of average water saturation versus water fractional flow at bottomhold of all producers. From this curve, economical recoverable reserves can be estimated. It was indicated that the new model is practical and effective through the practical application on oilfields.It can help company to choose the better management to though the strdy of economic recoverable reserves and it can also provide a basis for management plan.