Lessons Learned From Relative Permeability Modifications in Colombia, South America

Abstract

Description This paper discusses well-interventions in Colombia that use a new generation of polymeric selective-water-reduction (SWR) product for selected candidates, treatment definition, differences of composition, radius of penetration, stages according to formation petro-physical properties, and well-productivity response in the short and long term. The evolution and improvements in technology over the past five years and its application in Colombia will also be discussed. Previous papers have presented databases with information from interventions around the world, including case histories from Colombia (Dalrymple et al. 2007). This paper will focus on more detailed information for selection, treatment, and operational procedures in Colombian fields. Application There are hydrocarbon-producing formations in Colombia that have productivity limitations because of their high relative-permeability to water. This condition has generated increased tendencies to water-coning, historical and gradual water cut increases, and promoted a negative impact during the productive well life. This technological application includes new perforated wells (which are characterized for a potential rapid water-coning based on the geographical area or the formation) or producing wells in mature fields where the intervention still presents economical benefits. Information will be presented from wells with zones covering mid-to-high permeability, clean sandstones, and argillaceous sandstones at temperatures ranging from 125 to 250°F. Results, Observations, and Conclusions There are records of successful treatments, allowing for a reduction in the water to oil ratio, with increased productivity which has been maintained for more than three years. It has been possible to identify benefits from the technology, its evolution, and improvements during recent years. However, candidate-selection criteria have been continuously adjusted, which has generated more successful cases. Significance of Subject Matter Selective water reduction (SWR) is a viable technology with an extensive history of applications worldwide, and its usage has increased during the last five years in the productive basins of Colombia. A strong, continuous improvement effort has been in place for better reservoir characterization, understanding of water-production mechanisms, laboratory protocols, candidate selection, treatment design (volume estimation, placement techniques), and treatment follow-up. Introduction The SWR treatment is a confirmed technical, operational, and economical water-management option because it can be bullheaded into open intervals without isolation of water zones from hydrocarbon zones. The productive lives of many wells have been extended, which has resulted in high potential-profitability value for mature fields with high water cut.