Abstract
Petrobras has implemented three polymer injection pilot projects during the last two decades, in the onshore fields of Canto do Amaro (Rio Grande do Norte state), Carmópolis (Sergipe state) and Buracica (Bahia state), all of them in Northeast of Brazil. The first one is in the middle of the operation and the last two are already finished.
Polymer flood in oil reservoirs has been performed for several decades around the world. The polymers act basically increasing the viscosity of the injected water and reducing the porous media permeability, allowing for an increase in the vertical and areal sweep efficiency of the water injection, and, consequently, increasing the oil recovery.
The main drive for the pilot projects in Petrobras was to gain practical knowledge of the process, for a possible future expansion for other reservoirs and even for offshore fields.
This paper describes the experience of Petrobras in implementing and managing those polymer flood pilot projects. The laboratory tests, the designing and programming of the field operation, as well as the analysis and interpretation of the results, were all carried out by Petrobras personnel and are covered in this paper. The tracer injection for reservoir characterization purposes, which preceded the polymer floods, is also described.
In this work we performed a technical evaluation of the whole polymer injection process, investigating the reservoir response in terms of oil recovery and time. The economical study will be made hereafter in another work.
