Wax Problem Management in Sucker Rod Pump Wells with Rig-less Hot Water through Annulus Method in Tanjung Field, South Kalimantan

Abstract

Tanjung Field is located in South Kalimantan province and was discovered in 1898. Currently operated by PT Pertamina EP since 2004. The production wells in the Tanjung Field have various reservoir problems, including scale, wax or paraffin, sand, and depleted reservoir. Wax problem is the one that has the most dominant influence on the lost production opportunity. The average pour point of the Tanjung crude is between 39-42°C. Reservoir fluids that have paraffinic characteristics experience a decrease in pressure and temperatureduring the production process from the reservoir to the oil storage tank. This change in conditions causes the formation of wax deposits at several points such as around the perforation or pump intake holes, in the tubing, and in the well flowline. This wax deposits cause resistance to fluid flow, causing a decrease in production in sucker rod pump wells. In addition, the negative impact of this problem is that it can increase the frequency of well services job and chemical costs for well stimulation work.

One of the efforts that can be done to overcome the problem of wax is the thermal method. Hot water is injected using a hot watering unit into the annular casing of sucker rod pump wells. Hot water injected with a temperature above the pour point is expected to clean the wax that forms around the perforation holes, pump intakes, downhole pumps, and tubing. During the work, the pumping unit continues to operate normally so that hot water can flow from the subsurface to the surface, and there is no loss of production time. This method is proved to reduce low production and even can provide a production gain compared to the potential of the well with minimum cost dan faster work duration.