Ensayo de Barrido para Mejorar la Recuperacion de Petroleo con un Fluido Multiproposito

GONZALEZ, ESTEBAN; FERNANDEZ, LAURA; ABRIGO, SERGIO; PIZARRO, AGUSTIN; PRIETO, JOSE;

Mendoza

Congreso; 10° Congreso de Exploracion y Desarrollo de Hidrocarburos; 2018

Instituto Argentino del Petroleo y el Gas

The recovery of heavy crude oil with high reservoir temperatures represents a challenge for improved oil recovery (EOR) with the application of chemical products (CEOR) as it is necessary to develop new polymers and / or their byproducts that will provide greater resistance to thermal degradation. This work focuses on the development of a multipurpose fluid consisting of a polyacrylamide (P), a mixture of surfactants (S) and an additive (A), resulting in a PSA fluid whose objective is to become a viscosifying agent, with ability to decrease the interfacial tension oil-brine and with the distinctive feature of decreasing the viscosity of the crude stored in the reservoir rock. The first step was to analyze the effect of the additive (A) on the rheology of the polymer-surfactant (SP) with an Anton Paar rheometer and on the interfacial tension-water with a Spinning Drop. The effect of the additive in individual form was analyzed on two heavy crudes, analyzing the rheological behavior in a wide range of cut-off rates (1 to 1000 s-1) and in a temperature range (35 °C to 80 °C). From the results, a crude oil was selected and a dynamic laboratory-scale sweep test was carried out in a Triaxial cell, using a sandstone core as rock, under conditions of confining pressure and reservoir temperature. Petrophysical determinations carried out in the laboratory allow to have the characteristics of the porous medium, such as porosity (Ö), pore volume (VP) and absolute permeability (kabsw). As a strategy of the sweep, it was established to inject different displacing fluids having conditioned the porous medium to the residual oil saturation (Sor). The sequential injection for this test was 0.35 VP of the Polymer-Surfactant-Additive (PSA) formulation, 4 VP of the Polymer-Additive (PA) formulation and 10 VP of brine. With this injection strategy in the application of the CEOR process it was possible to recover 66.40% of Sor. With reference to the POIS, the total recovery achieved by secondary and sequentially by tertiary was 81.50%.Resistance factors of the order of 2 are usual values for these processes and the retention of the polymer in the rock of 0.034 mg / g is within the economic margin.