Liquid Fall-Back Measurements in Intermittent Gas Lift with Plunger

Abstract

Abstract This work represents the first part of a three - stage research program that consists of: a) lab scale test; b) Held scale test in an experimental well and c) adjustment of existing mathematical models based on experimental test and actual oil wells. The objective of this first stage was not to develop mathematical correlations that can be applied in the field, but to gather well controlled data that can be used to look for trends and test simple theoretical models. The experimental results of liquid fall-back measurements in intermittent gas lift are presented. The variation of liquid fall-back with changing injection pressures, amount of gas injected and initial liquid column above the plunger are described. The plunger velocity is measured by means of proximity sensors able to detect the metallic plunger. The amount of liquid produced is determined in two ways: a) by using a weighting tank separator at the tubing outlet and b) by using pressure transducers in the bottom of the production tubing which measure liquid column height, before and after the gas injection. The experimental work was carried out using 2 3/8" tubing of 63 ft in length. The liquid being lifted was water and compressed air was used to lift the water.