Abstract: Methods and computer program products for evaluating the performance of a gas lift well. The method includes measuring key gas lift well parameter data and concentration of a tracer present in a substance retrieved from the gas lift well which was injected into the annulus formed between a well casing and a production tubing of the gas lift well. The actual travel time of the tracer which corresponds to a time duration required for injected tracer and lift gas to travel from the injection point, down the annulus, through one or more points of entry of the lift gas into the production tubing is then determined based on a deviation in the concentration of the tracer measured by accounting for variations in a fractal obtained by plotting multiple key well parameter data and a concentration of the tracer in a multi-dimensional time dependent plot.

Abstract: Apparatuses, methods, and computer program products for evaluating the performance of a gas lift well are disclosed. A gas lift well surveillance kit is disclosed. A method for evaluating the performance of a gas lift well includes injecting a tracer into an annulus, measuring a concentration of the tracer present in a substance retrieved from the well, determining actual travel times of the tracer, segmenting the gas lift well into a plurality of ranges of well depth, determining lift gas loss parameters, calculating lift gas velocities in the annulus and in the production tubing for each of the plurality of ranges of well depth based on the lift gas loss parameters, and determining points of entry of the lift gas into the production tubing based on: (i) the actual travel times of the tracer, and (ii) the lift gas velocities in the annulus and in the production tubing.