EXPERIMENTAL STUDIES OF HIGH VISCOSITY OIL-WATER (WATER-ASSIST) FLOW BEHAVIOR IN HORIZONTAL PIPE

Abstract

The challenges of low oil production due to the flow assurance problems associated with transportation of high viscosity oil in pipes has attracted attentions for more than two decades. Laboratory scale studies were conducted on co-current flow of high viscosity oil and water in a horizontal perspex pipe 1-in ID 5m long. Two oil brand, CYL680 and CYL1000, 917 and 916.2kg/m³ densities and viscosities 1.830 and 3.149Pa.s at 25^oC respectively were used. The interfacial tension of high viscosity oil/water is 0.026N/m at 19^oC. The results show the reduction pressure gradient by one order of magnitude. The flow patterns identified from the trend plot of the downstream pressure signals, its probability density function (PDF) and statistical moments as well as visualisation of the flow are  Water Assist- Annular (WA-ANN), Dispersed Oil in Water (DOW/OF), Oil Plug in Water (OPW/OF) with oil film on the wall and Water Plug in Oil (WPO). Thin layer of wavy oil film was on the pipe wall forming an envelope for water in all the flow patterns where water was the continuous phase.