Abstract
Production separators require increased sand handling capability as watercut grows due to field maturation and EOR use. A compact cyclonic jetting device allows on-line fluidization and removal of sand and solids from production vessels and tanks. The cyclonic transporter combines the jetting and evacuation functions into a single device for integration into new build or retrofit separation vessels. Using an optimized hydrocyclonic platform this technology converts jetting spray water into shielded vortex flow that affects sand in a circular zone with no disturbance of the oil-water interface. The area of influence for the device is a function of set height, spray flow, and spacing. The optimum placement of a single unit was determined at 10 cm (4") set height with 0.7 barg (10 psig) spray pressure. At 28 cm (11") sand bed depth in an atmospheric tank, the device has a circular area of influence of 1.1 m² (11.7 ft²).
Placing two units in parallel with overlap of their affected zones does reduce the egg-carton effect. Optimum operation, in terms of total sand removed, occurs when the units do not overlap. The discharge slurry concentration has a peak of up to 60 wt.% solids which follows an exponential decay profile as the sand is evacuated. The concentration decreases to negligible sand at 10-15 minutes of operation which validates the process jetting time. The design of the cyclonic jetting device allows on-line solids removal using less water than conventional spray jetting with no disturbance of the oil-water interface during operation and elimination of mechanical wear.
