Determination of the possible point of wax deposition along flowlines: A case study of Seke-03s flowline, Niger Delta

ABSTRACT The demand for oil and gas is very high, as a result, oil and gas companies are now moving into challenging environments and deep-water areas for hydrocarbon exploration and production. These cold regions with very low temperatures lead to wax deposition in the oil production and transportation facilities. This condition leads to reduced production rates and larger pressure drops which posses a major challenge in flow assurance. The current practice of controlling wax deposition in oil flowline is either to inject chemicals to dissolve the deposited wax or to pig the flowline. These methods are very expensive and time consuming which often requires production shutdown, there is need to first locate the point of wax deposit before adopting appropriate mitigation measure. The focus of this study is to determine the possible point of wax deposition along a flowline using SEKE-03S oil flowline in Niger Delta as a case study and to recommend a cost effective method to prevent wax deposition in oil and gas flowlines. This research commenced with field studies to ascertain the flow line profile of SEKE-03S. The temperature profile along the flow line was determined using infra-red thermometer. Crude oil sample was taken from a total of 4 SEKE wells and laboratory analysis was carried out on the samples to determine the Wax Appearance Temperature (WAT) of crude and the amount of wax formed. The data obtained were analyzed and a plot of temperature drop along the flow line versus the flow line distance was made using excel spreadsheet. The results of the study showed that the wax appearance temperature of SEKE-03S is 20°C. It was also found that at well head temperature of 25°C the deposition point of wax is at distance of about 960m-980m from the well head. The study then recommends that wax inhibition tool should be placed at this point to dissolve any wax formed around this region without shutting down production. This method will be cheaper and less time consuming than the existing methods of controlling wax deposition problem in the petroleum industry.