Gas withdrawal from low pressure wells is stopped when wellhead pressure in them reaches the pressure in the collection manifold. At the same time, the gas flow from high-pressure wells is simply throttled to the pressure in the collection manifold by means of a fitting installed at the wellhead.
Smart manifold of the inlet manifold, the main elements of which are ejectors and in-line separators.
The absence of liquid in ejectors promotes the most efficient use of high-pressure gas energy for the low-pressure gas compression. At high liquid fraction content in gases, it is possible to use inline separators in smart manifolds. The configuration of smart manifold is selected individually for each specific case, depending on the pressure profile in the connected wells, gases flow rates and compositions.
Smart manifold centers use several jet pumps simultaneously, providing the highest possible level of gas extraction from the low pressure wells. The direct application of jet pump systems is impossible at the gas condensate wells, since condensate and water contained in the gas prevent effective acceleration of gas in the jet pump nozzles, which leads to low efficiency of ejection. In such cases jet pumps are used in combination with in-line separators. In-line separators are axial cyclones where all gas-dynamic elements are mounted inside the pipeline elements. Gas-liquid flow separation in such separators is achieved by separation of gas stream droplets by centrifugal forces generated by swirling gas flow. Inline separators are installed in the smart manifold center to separate liquid from the gas streams directed to jet pumps. Lack of fluid in jet pumps helps to maximize the effective use of energy to compress the low-pressure gas.
Unique inline ejector-separation system for increasing low pressuregas wells productivity. Wells that are the part of one well cluster or different gas and gas condensate well clusters, usually differ by their wellhead gas pressure. Traditional connection of such wells to a single pipeline causes low pressure wells gas and gas condensate production drop to minimal. As soon as wellhead pressure in low pressure wells become equal to the pressure in the gathering main, gas extraction from low-pressure wells will cease.
At the same time the gas flow from high pressure wells is simply choked to the pressure level in the gathering main by the flow orifice installed on the wellhead. Jet pumps that use the energy of gas from high-pressure wells to compress the gas from low-pressure wells can be used to increase the gas extraction from low-pressure wells. In this case the jet pump is acting as a compressor. If one jet pump is used, gas from high pressure wells goes to high-pressure nozzle of the jet pump, and gas from low-pressure wells is directed to low-pressure nozzle of jet pump.