PVC U-tube Drilling and Completion Technology in Shallow Geothermal Development

Abstract

Steel tubing is the traditional well tube material used in production and reinjection wells in shallow geothermal development but has some problems when used in GWHP’s (Ground Water Source Heat Pumps) like corrosion and scaling. PVC-U tubing has several advantages over steel tubing: it is light weight, non-corrodible, and has a longer life time,. Because of the difference in physical properties between PVC-U and steel tubing, different drilling and completion technologies are used for each. Two PVC-U tube wells have been successfully completed to depths of 400 m and 437 m. This project broadens the application of PCV-U tubing and contributes to some key areas of interest in drilling and completion technology, including well structure design, “balance pressure” completion well technology, and accident solutions.