Examination of Literature on Colloidal Dispersion Gels for Oil Recovery

Dongmei Wang, Randall S. Seright – 2021

Abstract

This paper critically examines literature that claims colloidal dispersion gels (CDGs) are superior to polymer floods for oil recovery. The central question is whether CDGs can propagate deep into porous rock while simultaneously providing resistance factors or residual resistance factors greater than the same polymer formulation without crosslinker. The answer from the review is unambiguous: there is no credible evidence that CDGs can do both. CDGs have been marketed using misleading arguments — particularly the use of Hall plots to claim in-situ resistance factors, when Hall plots cannot distinguish between face plugging, in-situ mobility changes, and fracture extension. Laboratory studies showing CDG propagation through short cores in 2–3 hours have been incorrectly extrapolated to deep reservoir propagation over months. Before gel aggregates grow to pore-throat size, CDG gelants flow like polymer solutions without crosslinker; after gelation, they no longer propagate. Money spent on crosslinker in CDG formulations was wasted, mobility reduction was under-designed, and reservoir performance may have been damaged.

Key Takeaways

  • There is no credible evidence in the published literature that colloidal dispersion gels (CDGs) can simultaneously propagate deep into reservoir rock and provide resistance factors greater than the same polymer formulation without crosslinker.
  • Hall plots — the most common tool cited to support CDG performance claims — cannot distinguish between face plugging, in-situ mobility changes, and fracture extension; they do not quantify in-situ resistance factors or residual resistance factors.
  • Laboratory CDG propagation studies using short cores over 2–3 hours have been incorrectly extrapolated to deep reservoir penetration over months — a fundamental misapplication of laboratory timescales to field conditions.
  • Before CDG gel aggregates grow to pore-throat size, the gelant flows identically to the polymer without crosslinker; after gelation, it no longer propagates — the same behavior as all other oilfield gel systems.
  • If CDG performance claims were accepted uncritically, operators would waste crosslinker cost, under-design mobility control, and potentially damage reservoir performance through face plugging and excessive fracture extension.
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