Lessons Learned from the Implementation of Two Thermally Active Polymer Campaigns as an In-Depth Conformance Technology: Yariguí Field, Colombia

Abstract

The Yariguí-Cantagallo oil field, located in Colombia's western flank of the Middle Magdalena Valley basin, is a well-established and mature oil-producing field. Oil extraction operations started in 1941 and have been accompanied with water injection since 2008. However, due to the challenge of water channeling, certain wells have experienced a significant increase in water cuts, exceeding 90%. For this reason, ECOPETROL S.A. initiated its first in-depth conformance treatment endeavor in Colombia in 2020, targeting two wells. It was followed by a second campaign in 2022, which included five wells. The chosen solution for these conformance projects is known as Thermally Active Polymer (TAP). This technology is employed in reservoirs undergoing waterflooding and facing complications such as thief zones and preferential flow channels. TAP relies on the deployment of expandable submicron particles that are injected downhole using a surfactant as dispersant, with the injection water as the carrier fluid. The selection of injection patterns and the estimation of treatment volume were carried out through the analysis of diagnostic plots and analytical pattern simulations. The injection process for the first pattern started on December 14, 2020, entailing a cumulative injection of 6,344 barrels of water containing TAP at an injection rate of 700 barrels per day. The TAP concentration gradually increased from 3,500 ppm to 12,000 ppm. Subsequently, the second injection pattern was executed on December 23, 2020. In this case, 9,152 barrels of water containing TAP were injected at an injection rate of 700 barrels per day, with TAP concentrations ranging from 3,500 ppm to 8,000 ppm. The five injectors of the second campaign were intervened with slightly different strategies. Some of the wells were treated with two grades of TAP with different activation kinetics. This paper provides a comprehensive overview of the implementation of TAP technology as a pilot project in Colombia. It outlines the methodology employed and offers insights into the project's QAQC monitoring and injection-production results. The two years monitoring of the first campaign have showed water cuts reduction by up to 5%, resulting in a remarkable increase in oil recovery of 39KBO (Barrels of oil). As for the second campaign, the additional oil recovery is up to now of 26KBO.