An Improved Continuous Gas Lift Design Method with Variable Pressure Drop

As to three kinds of continuous gas lift design methods commonly used using surface casing pressure control all have several disadvantages when the pressure drop between the valves is small, and they have some deficiency when gas injection pressure is relatively inadequate on ground or want to play the affection of the gas injection pressure on ground as much as possible, therefore, the applied study is made in this regard. First, the precise calculation method of the top valve depth under different conditions was achieved based on the principle of U type tube, then an improved variable pressure drop design method was derived based on the basic principle of gas lift unloading and by using another set of gas injection pressure system on ground independently for designing the valve depth. The obvious advantages of the improved method were found by comparing the available maximum of the gas injection depth and the production rate of the existing methods and the improved method in the same condition of gas injection on ground and on the basis of ensuring the safety design principle.