Mathematical modeling of well performance in shared gas condensate reservoirs

Abstract

Shared reservoirs, in which typically contain internal and external regions, are under dominion of two or several operators (such as countries or companies). Therefore, some challenges (e.g., political issues for definition of border line) should be anticipated for the development of these fields. However, production data of external region is usually not available. Lack of knowledge regarding to external region production conditions has led to some challenges in forecasting of well deliverability and evaluation of gas migration. This is due to the assumption of constant drainage area in most of the well performance models which does not align with real cases. The aim of this study is to propose an analytical well performance and multi-phase flow methods for gas condensate reservoirs, accounting for the non-volumetric effect of the internal region wells in a shared pattern. In addition, the method can be used for estimation of gas migration and production rate of external region in such reservoirs. This could be achieved by the introducing a novel dynamic material balance and two phase pseudo-time function to calculate the average pressure through assessing the deliverability of internal wells. It is noted that the production information of the external region is not required here.Upon defining a shared pattern, we evaluated the proposed methodology through a commercial simulator using actual field data. The acquired results ensure the accuracy of its application in typical rock and fluid characteristics of gas condensare reservoirs. The proposed novel technique can be utilized for material balance calculation in shared reservoirs.