An experimental simulator has been designed and constructed to model a gas reservoir performance during well-control operations. The simulator has been installed in a full-scale well in which a gas kick is simulated by injecting natural gas through a tubing string into the bottom of the well.

Basically, the system consists of a pressure sensor installed at the bottom of the well, a gas flow controller valve placed on the surface injection lines and a microcomputer that stores a gas reservoir inflow performance curve (flowing pressure at producing formation face vs. gas producing rate). A variation of flowing bottomhole pressure is sensed and electrically transmitted to the surface where it enters the microcomputer that processes the corresponding gas flow rate based on the previously defined inflow performance curve. This information is sent to the gas flow controller device that adjusts by itself to deliver the new injection gas flow rate.

Including the data acquisition and the gas meter systems, the simulator employs as many as four microcomputers.

The simulator performance is evaluated through graphical comparison between the gas flow rates calculated from the inflow reservoir performance curve and the actual gas flow rates delivered by the system. These data were obtained during well unloading experiments.

The overall performance of the simulator was satisfactory for the range of gas flow rates used in the experiments. Operational factors have limited the range of gas flow rates to be delivered, however. These limitations are discussed and recommendations are made to widen the range of utilization of the simulator.

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