New High Temperature Coiled Tubing Drilling Bottom Hole Assembly Enables Slimhole Re-Entry Drilling in Challenging High Temperature Wells

Abstract

The following paper presents a new high temperature Coiled Tubing Drilling (CTD) Bottom Hole Assembly (BHA) with its technical improvements and adjustments needed, to operate beyond previous temperature limitations and in more challenging formations. It summarizes the field-test results and first achievements of the BHA in the increasing High Temperature (HT) re-entry drilling environment. The introduced HT CTD BHA incorporates a new generation of electronics and adjusted technical solution to operate in this challenging environment. The developed designs address the increased temperature impact to the downhole electronics, the various integrated sensors and mechanical components like the oil hydraulic system of the BHA. Details on these technical improvements are provided in combination with an overview on the changing CTD market segment to higher temperature application. The results and performance of the new CTD BHA within the first deployments in the Middle East are presented, and details of the associated application are provided.

Corrosion resistance of steel for coiled tubing units

“…The samples were completely immersed in a corrosive medium and kept in a thermostat at a temperature of 70°C to reproduce real operating conditions [21,22].…”