Between cycles, the pump rests on the catch mechanism of the lubricator at surface.
As the cycle begins, the pump is released from the surface lubricator with the internal valve open. The pump free falls in the casing allowing gas and liquids to pass through the open valve. Gas production is uninterrupted.
The pumpís internal valve closes upon contact with the downhole stop. The formation liquids, which have accumulated in the casing above the perforations, are effectively trapped and isolated from the gas in the reservoir by the positive sealing swab cups.
As formation gas enters the casing, the pump and column of trapped fluid ascend to the surface due to the differential pressure produced by the reservoir.
The pump reaches the surface, enters the surface lubricator and is captured by the catch mechanism. The internal valve opens which allows continuous uninterrupted gas production to the sales line until the pump is released to start the next cycle.