Study of water wetting in oil-water flow in a small-scale annular flume

摘要

Proper characterization of the phase wetting regime (water wet or oil wet) in two-phase oil-water flow can lead to optimized measures for pipe integrity management and save cost. In previous work it was demonstrated that not only the physicochemical properties of the produced oil and water have an important impact on flow patterns, but also the wettability of the pipe surface can favor or hamper the contact with water. Since the wettability of steel pipes can be altered by the chemical composition of the oil and water phases, and due to the wide diversity of the chemical composition of produced crude oils and water, as well as different chemicals injected in production systems (e.g., corrosion inhibitors, scale inhibitors, de-emulsifiers), it is important to perform phase wetting experiments in dynamic conditions using representative fluids and pipe material. This study presents an experimental assessment of the phase wetting regime of oil-water flow using a small-scale annular flume of 51 capacity, which is advantageous as a potential testing tool for crude oil-water flows compared to regular multiphase flow loops. A model oil and brine were used as experimental fluids and three different materials (carbon steel, stainless steel and a polyester plastic) were used to analyze the effect of flume surface wettability on the phase wetting regime. The results indicate that the annular flume is a promising low-cost tool to test dynamic phase wetting and dispersed flow of petroleum-water systems qualitatively as well as quantitatively. Moreover, basic hydrodynamic assessment of the annular flume flow was performed to evaluate available criteria to predict the stability of fully dispersed flow.