An Effective Foamed Polymer Resin Diverter System for Sand Control
Authors: Madasu Srinath , Vo Loan 
Published: November 2016

Billions of dollars are spent annually to remediate issues of unwanted solids flowback during production. These solids, whether formation sand, fines, or proppant produced from propped fractures, restrict well production by plugging sand screens, perforations, or wellbore fill. They often cause damage to downhole equipment, surface equipment, and storage facilities. Solids production is intolerable, especially for offshore operations. Both chemical and mechanical solutions have been applied to remediate solids flowback problems. Chemical treatment often involves pumping a chemical system down hole to treat the solids in the formation or in the proppant pack to keep them together and in place. However, effective and uniform placement of treatment fluid across multiple zones can be challenging during stimulation or remedial treatments for formation sand control treatments. Such challenges can be greatly enhanced when a long interval sand formation is largely heterogeneous. Good diversion technology dictates the treatment success. The purpose of this paper is to present a series of laboratory studies to demonstrate effective diversion on up to six treatment zones using a new foamed diverter system.

This study is unique in that it uses a new chemical diverter system based on a combination of foam and a polymer and simulates a mathematical model. The novel foamed polymer diverter flows to the high flowing perforation clusters to plug the fluid flow, diverting the fluid to the remaining perforation clusters to increase the reservoir drainage area. This is demonstrated using a newly developed mathematical model and numerical simulations.

Existing models are applicable to using foam diverter only, but this study uses a new foam resin model for the combined foamed polymer system. The novel features of this study are (1) a new foamed polymer diverter system is presented, (2) a new mathematical model is developed for this diverter system, and (3) the combined effect of the foam and the polymer are coupled to the flow using a new placement skin model.

The simulations are performed on a completion zone with six perforation clusters coupled to a vertical wellbore in a high-permeability reservoir. Usually, most of the fluid flows only in the highest- permeability reservoir layer without any diverter because of a high pressure drop as fluid attempts to flow into the lower-permeability areas. The chemical diverter injection diverts the fluid to the lower-permeability reservoir layers as a result of the increased skin near the top perforation cluster, a decrease in the rock permeability caused by gas blockage, and the increase in fluid viscosity caused by the presence of foam. The diversion effectiveness of the three chemical diverters, namely foam, polymer, and foamed polymer, are demonstrated in this study. The results from this simulation demonstrate that the new foamed polymer diverter system is the most effective of all three diverter systems studied, and previous testing indicated this foamed resin system provides adequate regained permeability.