Acoustic Oil-Water-Fines Separation for Sustainable Oil Production Operation

Summary A novel three-phase acoustic separation technology is introduced- the Acoustic Oil-Water-Fines Separation, AOWFS. The low-energy, intervention-less separation technique can be used downhole or on the surface. It utilizes a sequence of acoustic standing wave patterns along a flow conduit with a decreasing number of loops in the direction of flow. It is capable of simultaneously separating oil droplets and solid fines from water streams in the flow conduit: oil droplets are directed and coalesced in the bulk of the conduit while solid fines are directed and concentrated near the its walls. The oil/solids-free water can then be reused for waterflood-assisted oil recovery or other high-water-demand operations. A set of proof-of-concept experiments using direct microscopic visualization in a microfluidic channel demonstrated the instantaneous separation of micron-sized oil droplets and solid fines from water by exciting the proper acoustic standing wave fields in the flow channel. Another set of static, quantitative macroscopic scale experiments was subsequently conducted which employed a 3-ft long conduit with a 4-in × 4-in cross section to demonstrate the scalability of the technique.