A customer operating an oil field offshore Ivory Coast was encountering paraffin deposition in the production flowline between a wellhead tower and the FPSO. Despite the wax inhibitor program in place, wax particles were found in the lower chambers of the test separator vessels, and a wax pad was forming at the oil/water interface. Increased pressure drop (ΔP) across the flowline also indicated wax buildup.
Following a system review that included sampling the interface and debris collected from the vessels, SLB recommended its proprietary paraffin dispersant PI-7259. Laboratory solvency tests performed on a deposit sample indicated that the selected product was the optimal choice. To trial the solution, the dispersant was injected at the wellhead tower at a dose rate of 300 ppm to prevent paraffin wax deposits in the flowline and allied downstream equipment.
An average 22% reduction was observed in the ΔP between the tower and FPSO, and steam flushing of the test separator was required less frequently. Pleased with the results, the operator initiated long-term injection of PI-7259. Daily operations have improved, with significant reduction in wax deposits aboard the FPSO. The operator also decided to start injecting the paraffin dispersant at a second wellhead tower supplying the FPSO after a wax-producing well was identified there. This measure has further reduced the likelihood of process shutdown and eliminated steam flushing, thereby enhancing safety and uptime.
