To further reduce backpressure on low-pressure gas wells and increase reserves in a mature gas field, a gas-ejector project was evaluated and proposed. Following on-site tests on several gas wells, the gas ejector was put into service successfully. Reservoir simulation estimates that 6.4 Bcf of incremental reserves will be achieved through gas-ejector installation by decreasing inlet pressure to 50 from 100 psi. The application of the gas ejector during a 2-year period to reduce backpressure has helped to improve economics in a mature gas field.
Introduction
The YC13-1 gas field commenced sales from offshore platforms to Hong Kong and Hainan Island in 1996. Following 22 years of continued production, the field depleted naturally to approximately 10% of the original reservoir pressure, with most wells producing with tubing pressure varying from 150 to 200 psi.