Multisegment production profile models — A tool for enhanced total value chain analysis

In the development phase of an oil or gas field, it is crucial to have a satisfactory model for the production. Since the first attempts in the 1940ʹs, many different models have been developed for this purpose. Such a model typically incorporates knowledge about the properties of the reservoir. 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, uncertainty may be added to the framework using Monte Carlo simulation. The proposed framework constitutes an important building block in total value chain analysis, that may be incorporated in a full scale analysis of a project. In such an analysis revenues, costs and investments are modelled to obtain assessments of project profitability and different strategies. As the focus of the present paper is on production profile modelling, such a full scale analysis will not be done here.