Experimental investigation of plugging and fracturing mechanisms in unconsolidated sand reservoirs under injection of water containing suspended fine particles - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Geoenergy Science and Engineering Année : 2023

Experimental investigation of plugging and fracturing mechanisms in unconsolidated sand reservoirs under injection of water containing suspended fine particles

Résumé

Progressive plugging of the medium due to filter cake formation is considered as a major challenge during Produced Water Re-Injection (PWRI), leading decreased well injectivity during production. Field operations have shown that injectivity can be at least partially restored by fracturing the clogged medium when injecting in the frac-regime. An experimental investigation is performed to explore the effect of the injection of a suspension on the plugging and fracturing processes in an unconsolidated sand formation. The tests are performed by injecting water containing fine particles at a constant low flow rate to first clog a sand specimen (phase 1), then by increasing the flow rate until fracturing (phase 2). Experimental results exhibit a continuous increase of the injection pressure (decrease of injectivity) during phase 1 due to the formation of filter cake build-up caused by the deposition of injected solid particles. During phase 2 when the flow rate is increased, pressure drops are observed and attributed to the formation of fractures, resulting in the increase of the overall permeability of the medium. This is confirmed by post-mortem analysis of the specimens using X-ray Computed Tomography. Small radial fractures (“pseudo-cracks”) induced around the injection point are visible. They appear as localized zones of higher porosity. The effect of the confining pressure and of the suspended particles concentration on the clogging and fracturing of the medium is investigated. It is shown that the clogging process strongly depends on the concentration of particles in the injected fluid. A lower quantity of injected particles is needed to induce the same level of permeability impairment when a lower concentration is used. No significant effect of particle concentration is observed on the fracturing pressure. As with pure water injection, the fracturing pressure is proportional to the imposed confining stress. Moreover, it is observed that the clogged specimen requires a higher injection pressure to reach the frac-regime as compared to an injection scenario with pure water and no filter cake formation and that permeability recovery could be higher.
Fichier principal
Vignette du fichier
Manuscript-HAL version.pdf (3.09 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-04181688 , version 1 (16-08-2023)

Identifiants

Citer

Thanh Tung Nguyen, Jean Sulem, Rawaz Dlawar Muhammed, Jean-Claude Dupla, Jean Canou, et al.. Experimental investigation of plugging and fracturing mechanisms in unconsolidated sand reservoirs under injection of water containing suspended fine particles. Geoenergy Science and Engineering, 2023, 221, pp.211346. ⟨10.1016/j.geoen.2022.211346⟩. ⟨hal-04181688⟩
30 Consultations
22 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More