Validation of Fracture Lineaments with Dynamic Well Data, Improves History Matching of a Dual Porosity-Permeability Model

Abstract

Abstract Simulating fractured carbonate oil reservoirs using the conventional single-porosity/single-permeability (SPSP) model does not normally capture the whole fluid flow mechanism in the system. A dual-porosity/dual-permeability model (DPDP) conditioned by field dynamic data can lead to better fluid saturation matches. This paper presents a new approach to history matching of naturally fractured reservoirs using a DPDP model that incorporates integrating production field performance data into the geological fracture model. A case example from a carbonate reservoir model will be used to illustrate this approach. The construction of the fracture model was done by emplying structural lineaments from 3D seismic data, and then enhanced by integrating engineering data into the model. The engineering data included mud losses during drilling, flowmeter surveys, transient well test analysis and water production data. The upscaled 3D fracture model was then used for history matching. With only minor modifications to the fracture model, a simulation model yielded a reliable match for water production. Furthermore, eighty percent of mud loss occurrences were in agreement with the 3D seismic lineaments mapping. Introduction The area under study is part of a carbonate reservoir that has been on stream for the last 30 years. The area of interest has been produced at a limited rate under fluid expansion augmented by a weak aquifer drive before a peripheral waterflooding project was put in place. Characterization work was made to obtain an improved model of the three main heterogeneities: matrix, stratiform Super-K intervals and fractures. The natural fractures were modeled using a few image logs run on vertical wells and from curvature analysis made on the top structure seismic map. Consentino et al. 1 described the modeling and simulation work of a sector model located in the northern part of the studied reservoir. The authors showed how dual media simulation model was used to match the localized water breakthrough experienced in few up-dip wells. Since then, numerous horizontal wells were drilled. Additional data, both static and dynamic were gathered from these wells and were used to improve the fracture model.