Abstract
This paper presents results of laboratory and field testing performed to investigate the feasibility and effectiveness of applying a one-component, low-viscosity consolidation material to stabilize or strengthen the unconsolidated formation sand surrounding a wellbore and overcome the effects of cyclic loading, while minimizing any reduction of its original permeability. Treatment fluid volumes, overflush fluid, and the chemical composition of the consolidation material were found to directly impact the consolidation performance and the retained permeability of the treated formation sand. The treatment renders formation fines immobile so that migration and plugging do not occur.
This study has determined that application of a consolidation material containing a specific solvent chemistry for clay-laden sands has resulted in excellent strengths even at high clay contents. This new finding indicates that the new approach allows the consolidation material to be drawn onto the mineral surfaces, resulting in very minimal loss in effective porosity. Scanning electron micrographs of the consolidated core material clearly reveal the entrapment of fines as the consolidation material formed a thin film on the mineral surfaces, resulting in very little damage to the porosity and permeability of the formation.
Results of field testing indicate that the consolidation treatment effectively stops the production of formation sand and fines while maintaining the production of the wells at desirable flow rates. The technique provides a very attractive alternative to conventional sand control completions in lower quality reservoirs as well as an effective thru-tubing completion alternative.
