Installation of Wellhead Compressor
Another our achievement to increase gas production in 2008 was the operation of 19 Wellhead Compressor (WHC) units, which have been installed at Badak Field for 11 units since May 2008 and the rest at Nilam Field since June 2008. We should be proud of this achievement because we were recorded as the first oil and gas company who brought this new technology to Indonesian oil & gas industry. The technology was adapted from proven application of one of our mother company facilities in BP San Juan Basin, Colorado, USA.
Through study and field visit, the technology were deemed applicable for our facilities in East Kalimantan in order to extend economical utilization of gas wells that already in lower pressure state.
WHC is a moveable compressor unit that located near wellhead to decrease surface pressure as low as possible. The suction pressure is lower than 15 psi, to be compressed into equal with LP (Low Pressure) system around100 psi, and then sent to satellite. This characteristic allows gas from VLP (Very Low Pressure) wells flow continuously in such a low pressure, hence the entire gas inside their reservoir can be lift and increase gas production.
The election of potential wells began with test simulation of the wells candidates by performing direct parameter test on location i.e. decreased downstream pressure as low as possible by releasing gas to atmospheric pressure via local burn pit. The process was done in collaboration between BMT (Base Management Team) and Operations.
The prime mover of WHC is 200 HP gas engine. The compression capacity is 1 MMSCFD gas and 200 barrels liquid per day. Optimum condition can be reached by adjusting speed and capacity control to achieve an ideal compression ratio. Furthermore, the WHC is moveable to other wells if the existing wells were already depleted.
As security and safety facilities, the WHS is equipped with several accessories as follows:
- Surveillance system which can be monitored from Control Room as an early indication to operator. Besides operational parameter display (gas pressure and flow rate, and WHC on/shut down status), the surveillance can provide motion detector (if someone in close proximity), gas detection (if any gas leaks) and ultra violet (in case of fire).
- Lighting system will light up automatically by using solar cell during the night.
- SDV (Shut Down Valve) was installed at inlet and outlet.
The protection and surveillance system allows the compressor works unmanned, but only requires regular parameter reading each day. The safety system is also enable wells to continue flowing through check valve bypass during compressor shut down providing LP system has been switched to VLP system in the satellite.
As optimization of WHC utilization, currently we evaluate and try to increase WHC performance by adding additional gas feeding of relocating to other potential well, which has an adequate gas reservoir. We hope the installation of WHC will become a base program for future lower pressure well challenge in our company.