Pore-scale velocity measurements can be achieved by using micro particle shadow velocimetry (µ-PSV). Characteristic properties of a flow are, however, best investigated and described by the pressure distribution in the field. At the pore scale, applying direct pressure measurement techniques comes with significant challenges. By detailed measurement of velocity and applying theoretical relations that suit the flow field under study, the pressure field can be determined. This study demonstrates the application of image-based approaches to investigate the multi-phase flow of a single droplet. Experiments based on µ-PSV are used to determine the velocity field in the flow within the droplet as it passes through a single-pore geometry in the presence of a stationary continuous phase. The results are used to determine the pressure field calculated from a simplified Navier–Stokes expression of the flow, discretised using an Eulerian approach. For the dispersed phase, the theory of the Jamin effect allows the capillary pressure to be related to the observed change in radii of the leading and trailing edges of the droplet. To highlight this approach, two sizes of the glycerol droplets passing through a pore geometry in the presence of a stationary canola oil are investigated. The results show that the velocity and pressure distributions are dictated by the deformation properties of the droplet. The same trends are seen in the distribution of pressure and velocity gradients as a function of location along the channel. The larger of the two droplets showed increased levels of velocity and pressure gradients as it flows through the pore geometry. In general, this work demonstrates the use of the deformation behavior of a dispersed phase to determine the velocity and pressure distributions in a multi-phase flow field.

Summary Studies that investigate and attempt to model the process of steam-assisted gravity drainage (SAGD) for heavy-oil extraction often adopt the single-phase-flow assumption or relative permeability of the moving phases as a continuous phase in their analyses. Looking at the emulsification process and the likelihood of its prevalence in SAGD, however, indicates that it forms an important part of the entire physics of the process. To explore the validity of this assumption, a review of prior publications that are related to the SAGD process and the modeling approaches used, as well as works that studied the emulsification process at reservoir conditions, is presented. Reservoir conditions are assessed to identify whether the effect of the emulsion is strong enough to encourage using a multiphase instead of a single-phase assumption for the modeling of the process. The effect of operating conditions on the stability of emulsions in the formation is discussed. The review also covers the nature and extent of effects from emulsions on the flow mechanics through pore spaces and other flow passages that result from the well completion and downhole tubing, such as sand/flow-control devices. The primary outcome of this review strengthens the idea that a multiphase-flow scenario needs to be considered when studying all flow-related phenomena in enhanced-oil-recovery processes and, hence, in SAGD. The presence of emulsions significantly affects the bulk properties of the porous media, such as relative permeability, and properties that are related to the flow, such as viscosity, density, and ultimately pressure drop. It is asserted that the flow of emulsions strongly contributed to the transport of fines that might cause plugging of either the pore space or the screen on the sand-control device. The qualitative description of these influences and their extents found from the review of this large area of research is expected to guide activities during the conception stages of research questions and other investigations.

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.

The design of Flow Control Devices (FCDs) requires performance data of an FCD’s internal nozzle under a wide range of flow scenarios. The current study specifically considers the effect of nozzle diameter and wall profile on the induced pressure loss, and subsequently the recovery performance of an FCD. For this study, a flow measurement facility is developed to test the performance of different orifice/nozzle geometries. The flow of single- and two-phase fluid at various flow rates and mass fractions, is experimented. The pressure drop data from the experiments is used to produce performance curves that characterize pressure loss across the geometries. The pressure loss for two-phase flows are compared to their single-phase counterparts to characterize the performance of the tested geometries in the two scenarios. A detailed protocol for performance testing of FCDs is followed as per Advanced Well Equipment Standard (AWES: recommended practice3362). The testing protocol was utilized to characterize the performance of different FCDs geometries under single- and two-phase flow conditions. The results showed the pressure loss characteristic obtained from the flow loop experiments match the corresponding theories. The study has thus provided promising results for the successful application of direct flow loop testing to obtain reliable data which can be used in FCD design, performance investigation, and reservoir simulation.