Most wells will flow naturally as the natural pressure from the reservoir and the formation gas force the fluid to the surface. Over time as the reserves diminish so too does the energy used to transport the oil to the surface. When this occurs it is necessary to introduce an artificial aid to maintain the flow. Gas Lifts are one such method. As an example in the late 1960’s the DPE reservoir began production, this flowed naturally through until the early 1980’s. At such time the Fateh Gas Lift Facility was commissioned to oversee the secondary oil recovery in this field. This is an ongoing process throughout our fields, to put this requirement into perspective 96% of our wells lift oil using gas lifts.
DPE reservoir was discovered in 1967. After producing naturally for almost 10 years in July 1981, the Fateh Gas Lift facility was commissioned as part of the ongoing secondary oil recovery plans. During 1988, the Fateh Central Compressor Platforms (CCP) #3 and #4 were commissioned for providing additional gas lift facilities. Currently, 96% of DPE wells are lifted via gas lift.
DPE central complex receives associated gas and lifts gas from producing wells across the various fields. The associated and lift gas is separated from liquid production in the separators. The HP separator outlet gas is sent to the lift gas compression facilities and distributed to producing wells. The lift gas system is essentially a closed-loop.
The DPE total gas lift compression capacity is ~ 1000 MMCFD, distributed by platform and trains. Lift gas compression facilities include two trains of 2-stage turbine-driven centrifugal units on each CCP, except for CCP-3 which has an additional compression train for the EOR pilot. Each compressor train is complete with suction and interstage gas scrubbers and interstage/discharge gas coolers. The compressors take suction gas from the HP separators at 110 psig and discharge at 1600 psig. The EOR pilot compressor is fed from this discharge and is capable of further compressing the gas to 5200 psi.
Fig. Typical Schematic of Gas Lifted Well