O. Lynn Rowlan and Jim McCoy, Echometer Company, A.L. Podio, University of Texas at Austin
To efficiently and economically operate a plunger lift well one of the most important requirements is to: KNOW THE PLUNGER LOCATION AT ALL TIMES, otherwise the operator has to guess, even when using electronic controllers. Except for when the plunger is at the surface, detected electronically or by ear, it has been difficult to determine the position of the plunger inside the tubing during the plunger fall and when it reaches the bottom of the tubing through the liquid column that has accumulated during the flow period. This new portable system can be used on plunger lifted wells to record the acoustic and pressure signal produced by the plunger during the operating cycle. The very sensitive acoustic monitoring system coupled with a user-friendly graphical software application, it is possible to virtually "see" the plunger at all times during a cycle, determine its precise fall velocity, and determine the volume of liquid accumulated at the bottom of the tubing. Software processes this plunger acoustic data along with the tubing and casing pressure data to display plunger depth, plunger velocity and well pressures vs. time. Plunger arrival at the liquid level in the tubing, and plunger arrival at the bottom of the tubing are identified on the data plots. Well inflow performance is calculated and plotted. Software displays the data and analysis in several formats including a well bore picture representation showing the tubing and casing pressures, plunger location, gas and liquid flow rates in the tubing and annulus, and inflow performance relationship at operator selected intervals throughout the cycle. Field data collected from various plunger lifted wells are presented to show how to identify operational problems such as holes in the tubing, fast or slow plungers and plungers sticking not getting to bottom. Field cases are presented to show how this recorded information can be used to optimization, analysis and trouble shooting of Plunger Lift operations.