Abstract
With soaring global demand, depleting supplies of crude oil coupled with the collapse in the oil prices, maximizing oil production in mature fields has become a priority. Such fields account for over 70% of the world's oil and gas production, with a worldwide average recovery factor of 35% for oil. Main challenge encountered by mature oil fields is the well pressure depletion over time, sand production and increased water-cut. Since pressure depletion is inevitable, it is particularly challenging to continue to produce as there is insufficient reservoir pressure to push the well fluids to the main processing facilities. As the reservoirs starts to deplete, other issues such as sand production and high water cut also becomes more prominent.
The system discussed in this paper is an effective engineering solution designed for topside receiving facilities. The Multi Production Unit (MPU) is a low pressure production unit with integral desanding and dewatering. MPU is a system tailored to boost the pressure of production fluids from low pressure wells, while handling common challenges in mature fields such as high water cut and high sand production. The system is ideally suited for remote wellhead platforms where wells have insufficient pressure to deliver well fluids to production header in addition to flow assurance issues related to high sand and water production.
Conceptual design of this system is based on the very low, almost atmospheric, operating pressure of the system, wherein the elements. The system is designed in such a way that it can receive continuous full flow from the well, and still manages–through intricate isolation methodology-to operate in batches. This batch operation arrangement allows for liquid accumulation which is then discharged to the production header after being pressurized. The integral desander enables sand removal from the production fluid before discharging the liquids to the production header. The accumulated sand can be discharged in batches whilst the system continues to produce. The dewatering feature of the system allows for removal of water prior to discharging the oilflow from the well to topside becomes easier without the need to inject the well itself with any foreign, resulting in reduced induced backpressure due to reduction in flow to the downstream system.
Features of the system include:
Compact design;
Light weight;
Self-contained system – no external utilities required except for HP gas source for motive gas and instrument gas/air supply;
No pumps and power generation;
Low system complexity and controls;
Fully automated system
No manning requirement;
Sand handling; and
Bulk water handling.
