A 5-Year Survey of Applications and Results of Placing Solid Chemical Inhibitors in the Formation via Hydraulic Fracturing

Abstract

Abstract Solid chemical inhibitors placed in the formation during hydraulic fracturing have provided inhibition protection for up to five years. Deepwater operators, especially, desire longer inhibition periods. This paper provides a summary on treatment results over five years and over 1500 wells. It covers inhibition for scale, paraffin and asphaltene either as a single application or as a multiple product application. These applications have been in various formations including deepwater, tight gas and coal bed methane formations. The longest documented treatment has been in the ground for over five years. Placing a solid chemical inhibitor into the formation via the fracturing process requires a product that is compatible with the fracturing fluid, does not adversely affect conductivity and provides long term inhibition through the controlled release of the inhibitor into the produced fluid. The solid inhibitor is added to the fracturing proppant. Primarily this is a mass-balance process by which a finite amount of inhibitor desorbs over time. The goal is to maximize the inhibitor loading, minimize the chemical release rate without negatively impacting the stimulation. In the treated wells inorganic and organic deposition has been arrested for extended periods when compared to alternative liquid addition applications. Solid scale inhibitors have been the most common treatment and are monitored through residual analysis. The paraffin and asphaltene inhibitors are monitored through comparative testing. The paper details both the time and the cumulative production that has flowed through the respective proppant packs. Wells that are scheduled for hydraulic fracturing and that display tendencies for organic and/or inorganic deposition are candidates for solid chemical placement during the fracture. The results from over 1500 wells indicate that this method for deposition inhibition reduces intervention costs and lowers lifting costs.