Test and First Results of an EOR Wettability Alteration Foam Injection Test in a Naturally Fractured Reservoir
Authors: Mondragón J. Salvador Flores , Huicochea César Andres Bernal , Rivera Luis Silvestre Zamudio , González Eduardo Buenrostro , Pérez Luis Manuel Perera , Campos Alfonso Olimpo García 
Published: October 2015

In mature fields, low oil production, increased gas production and water fractional flow of low pressure reservoir combined with the mobility ratio between the gas and oil feed contacts the w/o induced by the oil extraction process are accentuated in naturally fractured reservoirs (NFR) -. It is common N2 injection for pressure maintenance and decline of oil production; however N2 causes channeling towards producing wells. In various fields - NFR, closure of oil production by this mechanism loss value make unprofitable oil production and surface facilities for handling demanding high volume gas and / or water or gas production out of specification. In volumes estimated residual oil trapped in areas invaded by the gas cap and in areas of lower conductivity can be recovered if it has clearly identified enhanced recovery processes. Previous efforts to this work results showed potential benefits in terms of increased oil production and the significant reduction of Gas-Oil Ratio (GOR) and the technical and economic feasibility of using this type of process with surfactants developed specifically for the conditions of this area The technology tested and evaluated under methodological process is based on new supramolecular complexes wettability modifier, corrosion inhibitor and able to generate stable foams under high pressure, temperature and salinity, which penetrate and invade the channels of high conductivity formation cause decreased flow of gas by reducing gas mobility. The product in the liquid phase diffuses into the channels of lower conductivity which cannot penetrate the foam, and by spontaneous imbibition mechanism resulting from the change of wettability of the rock surface and reducing interfacial tension and favors an increase the oil recovery factor in naturally fractured reservoirs. The application of a methodological process allowed the parameters measurement and evaluation of test results, visualizing future opportunities for the new chemicals. This project was approved after evaluation from a process of allocation of federal funds.

With the purpose of defining the further steps in the search for the chemicals stability and risk mitigation stages of industrial upgrading for the complexity the NFR, the following discussion is presented.

In order to accelerate the knowledge of new technologies and its deployment on the field, PEMEX has diversified the efforts, to achieve the principal goals regarding new technologies. This will provide greater ability to assess best practices and technologies. To evaluate the efforts of companies a performance assessment model was designed and apply from 2008, which takes into account the integral complexity of each technology to attend the specific challenges from an Asset and to be fair in comparing the results obtained for the particular design of the test. The aim of this paper is to describe the results and the methodology used for developing the performance evaluation and identifying the new opportunities in the state of the art of these tests.