High Viscosity Friction Reducer Enhanced Oil Production in Reservoirs with Moderate to High Permeability

Abstract Fracturing fluids have evolved through time due to various challenges present in the oil and gas industry. These challenges make it difficult to find one fluid that works for all type of formations. Some of the most important and determining parameters that dictates the type and properties of the fracturing fluid that will be used are the formation permeability, native fluids and desired geometry. Type of leak-off for fracture geometry generation, behavior of net pressure and viscosity for proppant transport are three major parameters to consider in the design of the fluid. This will ensure that the generated fracture provides high conductivity to maximize production or injection rate, while formation damage is minimized. Leak-off and viscosity requirements from a fracturing fluid vary for low and high permeability formations. The design of a fluid that meets the characteristics of both low and high permeability formation is challenging. Success applications of the next generation of high viscosity friction reducer technology as main fluid in propped Hydraulic fracturing jobs to improve oil production in mature fields located in Colombia is presented. It has been a major challenge because these reservoirs have permeabilities from 90 to 1500 milidarcies, very low reservoir pressure gradients of 0.23 to 0.25 psi/ft and their producer wells with BSW higher than 90%. The lithological logs show reservoirs with clean sandstones in the lower zone meanwhile in the upper zone shows intercalations of sand and shale. The next-generation HVFR technology was designed and proposed specifically for these projects. This HVFR was developed with the characteristics of a crosslinked fracturing fluid showing a viscosity in the range of 200-400 cP and can transport proppant concentrations up to 5ppa. Prior to field application, core-flooding tests showed a retained permeability to oil higher than 90% meanwhile compatibility of the system with the native fluids as was verified. The HVFR fluid was pumped in four wells (three producer and one injector wells). These wells were successfully completed, pumping proppant concentrations up to 6 ppg. Total fluid breakthrough (viscosities less than 10 cP) and optimal fracture geometries for production were obtained decreasing the average of well-testing along flowback stage. In all the producer wells their oil production improved, and their perdurability was observed by at least 6 months.