When and Where Relative Permeability Modification Water Shutoff Treatments Can Be Successfully Applied

R. D. Sydansk; R.S. Seright – 2007

Abstract

This paper provides guidance on when and where RPM/DPR water-shutoff treatments can be successfully applied in oil or gas production wells. When properly designed, these treatments can address a limited range of excess water production problems using bullhead injection without mechanical zone isolation. However, substantial limitations exist. For unfractured wells with radial matrix flow, oil and water zones must not be in pressure communication, and oil-producing zones must be producing at 100% oil cut (dry oil) for full drawdown. For fractured wells, pore-filling gels in matrix rock adjacent to fractures offer an attractive application when oil and water are co-produced through the fracture. Transient RPM/DPR treatments with short-term water/oil ratio improvement are possible in many unfractured wells but require custom engineering and often have marginal economics.

Key Takeaways

  • RPM/DPR treatments without zone isolation are only reliably applicable to a limited set of excess water production problems — many operators overestimate the range of problems these treatments can solve, leading to failed applications.
  • For unfractured radial-matrix production wells at full drawdown, RPM/DPR requires oil and water zones to be in pressure isolation and oil zones to be producing dry oil (100% oil cut) — conditions rarely met in practice for most wells with high water cuts.
  • An attractive and reliable RPM/DPR application is treating matrix rock adjacent to fractures when oil and water are co-produced through the fracture — pore-filling gels in the fracture-face matrix can selectively reduce water inflow without damaging the oil-producing fracture.
  • Transient RPM/DPR treatments in unfractured production wells (not fully drawn down) can temporarily improve water/oil ratios but require well-by-well custom engineering and typically have marginal economics — making them a higher-risk application for inexperienced operators.
  • First-time application of RPM/DPR treatments by inexperienced operators should be considered a high-risk undertaking — this paper’s guidance on application conditions is designed to prevent the most common categories of treatment failure.
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