Many oil and gas wells may be producing at rates which appear to be optimum but which actually contain unnecessary restrictions to flow. These wells can be analyzed using modelling techniques to evaluate all components of a producing well system. Often this procedure will identify possible modifications in the well which if made will result in larger flow rates. This method described is often referred to as Nodal* Analysis. All components starting at the static reservoir pressure and ending at the separator are evaluated if present. This may include inflow performance, flow across the completion, flow up the tubing string including any downhole restrictions, safety valves, flow across the surface choke (if applicable) and flow through horizontal flow lines and into the separation facilities.

The objectives of well analysis are as follows:

  1. To determine the flow rate at which a well will produce with a given wellbore geometry and completion (first by natural flow).

  2. To determine under what flow conditions a well will cease to produce. This can be related to time as the reservoir depletes.

  3. To select the most economical time for the installation of artificial lift and to assist in the selection of the best artificial lift method.

  4. To optimize the well conditions and geometry system in order to most economically produce the objective flow rate.

  5. To analyze each component in the well system to determine if it is restricting the flow rate unnecessarily when compared to the flow capacities of the other system components.

  6. Overall, this permits quick recognition by the operator's management and engineering staff of ways and means to increase production rates. This is a very important feature of being able to graphically display the wells performance with "production optimization" or "Nodal* Analysis Techniques."

There are numerous oil and gas wells around the world that have not been optimized to achieve an objective rate in an efficient manner. In fact, many may have been routinely completed in a manner such that their maximum potential rate cannot be achieved. Also, many of the wells placed on artificial lift are not achieving the efficiency that may be possible.

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