G. P. Willhite

Development of Correlations To Predict Biopolymer Mobility in Porous Media

This paper describes the flow and rheological behavior of biopolymer solutions in sandpacks over a wide range of permeability and frontal advance rates. Empirical correlations were developed to estimate polymer mobility in porous media. The correlations are based on porous medium properties, polymer concentration, and rheological parameters for the polymer derived from steady-shear measurements.

Mathematical Model of In-Situ Gelation of Polyacrylamide by a Redox Process

Recent displacement data conclusively show that the initial permeability reduction during in-situ gelation processes does not result from a bulk gelation of the injected fluid. This paper presents a filtration-based model that correctly accounts for all physical phenomena occurring during in-situ gelation displacements

The Effect of Flow Rate on the In-Situ Gelation of a Chrome/Redox/Polyacrylamide System

Presentation of experimental data on the gelation of a polyacrylamide/thiourea/Cr(4) gel system in unconsolidated sandpacks at flow rates typical of those encountered beyond the immediate vicinity of a wellbore

Permeability reduction by a xanthan/chromium(III) system in porous media

This paper presents an experimental study on gelation of a xanthan/chromium(III) system in unconsolidated sandpacks at frontal velocities between 3 and 120 ft/D. High flow resistance developed at specific locations in the sandpacks in experiment conducted at velocities up to 35 ft/D; the locations correlated with velocity. No significant flow resistance developed in the sandpacks at frontal velocities of 83 and 118 ft/D. The effects of flow and shear rates and permeability on development of high flow resistance in the sandpacks are discussed. A conceptual model of the gelation process that incorporates filtration of gel aggregation is presented.

Study of Intra-Molecular Crosslinking of Polyacrylamide in Cr(III)-Polyacrylamide Gelation by Size-Exclusion Chromatography, Low-Angle Laser Light Scattering, and Viscometry

The application of crosslinked-polymer systems for permeability modification of petroleum reservoirs has received increasing attention in recent years. A crosslinked-polymer treatment, in general, involves an injection of a polymer solution into high-permeability zones or fractures which have been previously swept by the displacing fluid1. The polymer solution reacts, either before or after injection, to form a three-dimensional gel network which reduces the effective permeability of the invaded portions of the reservoir. Fluid subsequently injected is diverted to other, tighter regions of the formation, thereby improving overall volumetric sweep efficiency.