Abstract
When performing multiple fracture treatments in horizontal Barnett Shale wells, many operators choose to utilize artificial lift to remove fracture fluids rather than incur the expense of energized fluids that may not be effective. Gas lift has been a popular artificial lift method to remove fracture fluids, as it allows for high liquid flowrates and is excellent at handling flowback sand. Its disadvantage is that a source of lift gas is required to initiate gas lift, with this source typically being other nearby gas wells or a third party gas pipeline. In new exploration areas such as the Barnett, often neither are available. Operators resort to costly nitrogen membrane units to provide lift gas, but are left with questions about the net gas being produced (since returning nitrogen and produced natural gas are combined downhole then vented to the atmosphere). A new system (patent pending) has been developed that addresses gas lift's issues of initially filling the system with lift gas, as well as maintaining this gas so that additional gas is not required. Being a closed loop system, it also provides for very accurate measurement of net gas production by measuring any gas in excess of that needed for lift, and discharging the same to a flare stack. The paper will describe the major components used in this system, present a case history, and address the significant cost reductions and other benefits realized.
