Paper: Flow Valve Selection for Gas Lifting Duals

Increased drilling and operating costs have resulted in a greater number of dually completed wells. Most operators prefer two parallel tubing strings over concentric installations, since the development of detachable two-string packers and split wellhead equipment for parallel strings. This paper discusses in detail the flow valve selection for gas lifting both zones of dual with a common injection gas source. The material is presented in a manner which permits an operator to choose the proper valve design for a dual without a previous thorough knowledge of gas lift principles. The design considerations using fluid operated, intermittent and continuous flow gas lift valves for dual installations are discussed. An efficient installation is based on the combination of producing characteristics of the two zones. Proposed valve installations are outlined for the following combinations: 1. Both zones continuous flow. 2. One zone continuous flow and the other zone intermittent flow. 3. Both zones intermittent flow. 4. Producing characteristics of either or both zones unknown.