Biopolymer Injection in Offshore Single-Well Test

Abstract A single well biopolymer injection test has been performed to investigate the stability of the biopolymer Schizophyllan under reservoir conditions. Laboratory tests of the Schizophyllan biopolymer prior to field test did show microbial degradation, and an environmentally qualified biocide was selected to be injected together with the biopolymer. The objective of this paper is to focus on the microbial aspects of using biopolymers for EOR (Enhanced Oil Recovery) by performing an extensive microbial analysis program of injected and produced water samples both prior to and after injection of the biopolymer into the reservoir. Multiple samples at different stages during the field test were collected using sterile and anaerobic methods to investigate any change in microbial community and evaluate any microbial degradation of the biopolymer. Analyses show that the biopolymer was not biodegraded during the shut-in period due to presence of biocide. However, microbes able to degrade the biopolymer Schizophyllan were present and could have biodegraded the biopolymer in the absence of active biocide. The microbial community changed in the area affected by biopolymer injection during the field test.