Abstract

Characteristic of high pour point oil may cause problems in pipeline transportation if it is not handled carefully, especially in long and hilly terrain pipeline. It may form solid in ambient temperature, and further may cause pipe plugging along the line, especially in sloping pipe area. The pipeline is 20 inch diameter stretch 250 km from Tanjung oil field to oil refinery in Balikpapan, East Kalimantan Province of Indonesia.

Alternatives of transportation had been considered, such as insulation line, heating, chemical, etc. Alternative chosen was transportation of mix fluid of the high pour point oil and water. Transportation of mix liquid may prevent accumulation of solid oil particle at places along the line and avoid pipe plugging, and the method was also considered low cost of investment and operation. Such method of transportation has been conducted since 1963 and reached peak pumping of 44.000 BOPD oil production. At present time total oil production has declined to only 7800 BOPD, and transportation of the oil production is conducted periodically 12 times a year in oil-water mixture of 65% oil and 35% water, with total oil transported 250.000 Barrel per-pumping period.

On year 2002 it was experienced an operational failure, when the pipeline was plugged caused by solid oil particle accumulation, causing interruption of pumping. An effort to remove the plugging has succeeded by conducting “rocking” method and injection of light oil, and such method was able to bring transportation to normal operation in considerably short time.

A simple modelling approach of the high pour point crude oil transportation has been obtained using Multi Phase Flow Dynamic Model OLGA to study characteristic of the flow in pipeline through a hill, and predict critical operation conditions to avoid unexpected transportation failure in the future.

Introduction

Tanjung field is located in South Kalimantan province of Indonesia, it was discovered in 1937. Since the discovery it took some time to develop the field. Main problem was transportation of the oil production. At that time the field was located in the middle of Kalimantan deep forest, where no road access and infrastructure had been built. Other problem delaying the development of the field is the characteristic of the produced oil. Crude oil from the field was found have high wax content and high pour point. Pour point of the crude is about 100 °F, while the ambient temperature is about 85 oF that will change the crude into solid phase at ambient temperature.

Tanjung field is located about 240 km from the nearby Oil Refinery in Balikpapan, East Kalimantan Province. The refinery has enough capacity to process the oil production from Tanjung field. Transportation of the high pour point crude becomes a challenge, since it will solidify in ambient temperature, it may plug the line during transport. Other challenge is the characteristic of hilly terrain from the field location to the refinery. Alternatives of pipeline transport had been studied after field discovery such as insulation, heating the pipeline, and mix transport of crude and water.

After laboratory study and field test, it was decided to transport the crude by mixing with water. This method was considered the most effective way of transportation since no heating and insulation required. The critical thing is mixing composition of crude and water, and also how to maintain the mix remain in its form from pipeline inlet to the outlet. If somehow the mix has been broken, water may leave the oil behind or vice versa, that may cause plugging of pipeline. A combination right mixing of water and crude oil, and correct transportation procedure will be the key for the success of transportation.