| Preformed particle gels (PPGs) serve as a conformance control agent and have been used widely to control excess water production through conduits, fractures or fracture-like features. This research ranks the parameters that impact PPG resistance to water flow in partially opened conduits. Experiments were conducted to examine the effect of brine concentration, PPG injection pressure, back pressure, reducing water salinity and matrix permeability on PPG resistance to water flow through conduits, PPG penetration to the matrix. PPGs were swelled in different concentration brines and were injected into the conduits at a few designed injection pressures. PPG swollen in high brine concentration took a longer time to reach the target placement pressure than those swollen in low brine concentration. The injected PPGs swollen in low brine concentration caused more damage to the matrix permeability than PPGs swollen in high brine concentration. Results show PPG resistance to water flow may have been the result of gel particle accumulation into conduits/fractures or gel filter cake formation in rock matrix or both. Their resistance increased when they were injected at high pressure. However, PPGs formed a filter cake on the surface of the matrix. Gel particles penetration into the matrix were only a few millimeters deep, and their penetration into to the matrix depended on matrix permeability, gel strength, and injection pressure drop across the core. |
