The Modelling of Multisegment Production Profiles Using Hybrid Systems and Ordinary Differential Equations

Abstract

fax 01-972-952-9435. AbstractWhen an oil-or gasfield project is evaluated, it is crucial to have a satisfactory model for the production. Knowledge about the properties of the reservoir should be included in such a model. When used in a total value chain analysis, however, also economic and strategic factors need to be taken into account. In order to do this, more flexible modelling tools are needed. In this paper we demonstrate how this can be done using hybrid system models. In such models the production is modelled using ordinary differential equations representing both the reservoir dynamics as well as strategic control variables. The approach also allows us to break the production model into a sequence of segments. Thus, it is possible to represent various discrete events affecting the production in different ways. The flexibility of the modelling framework makes it possible to obtain realistic approximations to real-life production profiles. As the calculations can be done very efficiently, the framework can be incorporated in a full scale uncertainty analysis based on Monte Carlo simulation.)

Procedure for calculating estimated ultimate recoveries of Bakken and Three Forks Formations horizontal wells in the Williston Basin

“…The modification of a hyperbolic decline by attaching an exponential tail when a certain rate of decline is reached is referred to as a hybrid-decline model. An overview of stochastic modeling techniques for well-level production using multiple segments of differently declining production data is outlined by Haavardsson and Huseby (2007). The exponential tail method is expected to more accurately reflect the reality of long-term production rates in horizontal Bakken and Three Forks wells in the Williston Basin.…”