Test Results of a Comparison between a Conventional and Low Shear Valve and Its Effect on Water/Oil Separation

Abstract

During the last years, a lot of work have been done focusing on development of low shear valves solutions to be applied on petroleum primary process plants. The main goal of the low shear valve is to generate water-in-oil (WiO) and oil-in-water (OiW) emulsions that can be easier treated by the separation process, when compared with emulsion generated by conventional valves. This paper presents experimental results of a comparison between a commercial low shear valve and a conventional valve. Both valves were installedin parallel on a test loop and the fluids used for all test matrix points were potable water mixed with Petrobras Marlim Crude Oil. The test matrix includes variation of differential pressure on valves, flowrates and concentration of water/oil. Samples were collected downstream of both valves and led to settle into several residence times. The degree of contamination of both phases were analyzed for all residence times. The benefit of the application of low shear valve was quantified for all test conditions and the results were very promissory. The pressure drops across valves were selected considering typical values observed at Petrobras choke valves and control level valves. For almost all test matrix's points the emulsion generated by the low shear valve showed at least a slight benefit, allowing have better water quality after settling. The low shear valve solution showed to be a promissory technology but the magnitude of the benefit is very influenced by valve process operation conditions.