Design and analysis of downhole completion of Adelaide University Test Well
Aziz, Mohd Azam
Engineering Honours Degree 2009
University of Adelaide
Adelaide University Test Well is a shallow well that has been specifically drilled for teaching and research purposes. With a measured true vertical depth of 154m (505 ft) only, this 12 inch hole is also cased with 9-5/8” (8.835 ID) heavy PVC pipe and cemented to surface. Prior to the start of this honours project, the test well has been recognized as having several potential applications for research, undergraduate and postgraduate teaching, training and service to the industry.
In this honours project, the main objective would be to consider several possible completion configurations for the well and propose an option for final completion design with details. As part of the design considerations, this project also concentrates on liquid loading occurrence in gas wells. At the same time, multiphase flow gradients in tubing will be taken into consideration as well. Apart from that, possible design of artificial lift option for gas well particularly installation of gas lift valves are also studied. Three main options are recognized to be suitable for this well – single, dual, and concentric completion options, considering the potential applications of the well as a simulator for gas wells with liquid production.
Since liquid loading is a common phenomenon in gas wells, the study of liquid loading in gas wells is vital in order to determine the critical flow rates of gas required to carry out liquid to the surface. This project analyses the effects of tubing sizes on the critical gas flow rates. As a result, determination of suitable tubing sizes can be made so that liquid loading problem can be prevented. Selection of tubing size is mainly based on the well ability to flow gas and water at the rates of 90000 scf/day and 1000 bbl/d respectively.