A Methodology to Design Exploitation Plans through the Application of Thermal Process, Orocual Field, Venezuela

Abstract

Orocual is the most complex Field in Monagas, eastern Venezuela. Due to its complexity it has been divided vertically into two zones: shallow (heavy oil) and deep (light oil and condensate). The OOIP in shallow reservoirs is reported as 3500 MMSTB. The reservoir pressure is close to original conditions due to low historical production. Therefore, the current oil recovery factor is less than 1%. To date, cyclic steam injection pilot was applied to 5 wells and the initial oil rate showed to be as high as five times the cold production in vertical wells and six times the cold production for horizontal wells. According to the results of the pilot test, the future development of shallow Orocual will be mainly based on the application of thermal processes. This paper shows a methodology to design an exploitation plan through the application of thermal process. The first step involves analyzing the reservoir by sectors in order to determine which thermal process is appropriate to the reservoir; the second step is building sector models to simulate each process and optimize operational parameters. For the first time cyclic steam injection, steamflooding and steam assisted gravity drainage were simultaneously simulated in the same model. According to this study it is possible to maximize the production of these reservoirs, accelerate the exploitation of its reserves and optimize operational parameters in thermal recovery, as well as determine critical factors for each process. This study shows that numerical simulation of complex process can be efficiently carried out in FullField scale.