Improve hydrocarbon recovery and sweep efficiency by balancing flow across intervals with permeability variations.
To prevent or minimize problems associated with water coning in horizontal oil producers, inflow control devices (ICDs) are installed along the wellbore to better equalize the toe-to-heel flux. Nozzle-based ICDs are popular because they are: 1) easy to model accurately, 2) virtually viscosity independent, and 3) easy to install at the wellsite with many unique settings. Nozzles can be installed either in the wall of the base pipe (radial orientation) or in the annulus between the base pipe and housing (axial orientation). The advantages of the former are: 1) smaller max running OD, and 2) no need for a leak-tight, pressure-rated housing. One disadvantage is the high exit velocity that raises concern of erosion or erosion-corrosion of the basepipe.
To overcome this disadvantage, a new nozzle had been developed with a novel geometry that reduces the exit velocity about ten-fold compared to a conventional nozzle for the same pressure drop and flow rate. Computational fluid dynamics (CFD) was used to first fine tune the design to meet strict erosion-corrosion prevention requirements on the wall shear stress downstream of the nozzle for both production and (acid) injection directions, and then to develop flow performance curves for four different nozzles "sizes" that vary in their choking ability, thereby allowing many unique settings per joint at the wellsite.
Full scale prototype manufacturing and flow loop testing were then performed to validate the CFD flow performance predictions and to demonstrate mechanical integrity and erosion resistance for high rate production and injection. The results, as presented herein, demonstrate a robust and commercially viable ICD design that: 1) has predictable flow performance using CFD, 2) minimizes erosion and erosion-corrosion in either direction, 3) minimizes running OD, 4) simplifies the housing design, and 5) allows easy installation at the wellsite with 34 unique settings per joint. Also discussed are two new advantages over other ICDs that were not anticipated in the original development.