Fluid is produced from a well that is equipped with a plunger lift system. The plunger lift system includes a plunger that is inserted into production tubing that is installed in the well. Liquid from a surrounding formation accumulates on top of the plunger. The liquid accumulation on the plunger is monitored. Lift gas is injected into the production tubing below the plunger to lift the plunger and accumulated liquid to surface. A wellhead assembly at surface directs the accumulated liquid away from the well, and injection of the lift gas is suspended to allow the plunger to drop back to its initial position. The timing of the lift gas injection is based on monitoring liquid accumulation, and also to maximize production from the well.

Fluid is produced from a well that is equipped with a plunger lift system. The plunger lift system includes a plunger that is inserted into production tubing that is installed in the well. Liquid from a surrounding formation accumulates on top of the plunger. The liquid accumulation on the plunger is monitored. Lift gas is injected into the production tubing below the plunger to lift the plunger and accumulated liquid to surface. A wellhead assembly at surface directs the accumulated liquid away from the well, and injection of the lift gas is suspended to allow the plunger to drop back to its initial position. The timing of the lift gas injection is based on monitoring liquid accumulation, and also to maximize production from the well.

The invention relates to a fluid pump that has an electric motor with a shaft and an impeller with an outer diameter, that is connected to the shaft for conjoint rotation. A maximum volumetric flow and a maximum pressure difference (dp) can be generated in the fluid pump by the rotating impeller. A characteristic index number (K) for the fluid pump is greater than 350 kW/m.sup.2. The index number (K) corresponds to the product of the maximum volumetric flow and the maximum pressure difference in the fluid pump divided by the square of the outer diameter of the impeller.