Visualization of Fines Migration in the Flow Entering Apertures through the Near-Wellbore Porous Media

Abstract

Various slotted liners geometries are used to control the sand production in SAGD operations. The geometry of a slot (shape and size) not only affect sand production but it may also influence fine deposition and scaling at the slot entrance. Failure of SAGD wells due to the deposition of particles is an important issue that needs to be investigated at the pore scale. This study provides a fundamental understanding of fines transport and the plugging potential at the entrance of the slots on slotted liners. Three slot profiles including straight shape, keystone shape and seamed (rolled top) shape are examined experimentally in relation to the preceding conditions of pore spaces in porous media. The potential of slot plugging is also studied from the fluid flow motion perspective. This task is achieved by visualization of the flow passing through the near well bore region of different slot geometries using an optical technique, namely, particle image velocimetry. Motion of small particles (D = 20μm) in the oil flow are captured before entering the slot, at the entrance and after leaving the slot entrance. The changes in the streamlines and velocities are analyzed to estimate the potential plugging locations. The results highlights how changing the entrance geometry of the slots may increase the deposition potential in and around a slot. The flow of the oil within the near wellbore porous media have also indicated that depending on the locations of the porous media within the flow structure, different deposition pattern may take place. Based on the result of this study it can be concluded that among the slots, keystone has the highest potential for the particle build up within and at the entrance of the slot.