Casing Drill Procedure Saves Operator up to $60,000 on Setting Conductor Pipe

Operator's Challenge

A Gulf of Mexico operator needed to insure that over 200 ft of 30-in casing would be set in an unconsolidated soil to its maximum depth and be able to help support the entire casing string. Normally, the 30-in casing was washed into place leaving a hole so big that the casing would have to be held in place until the alluvial soil would fill in around the pipe. This took 6 to 12 hours. Even then, the casing sometimes started to sink below the mud line and had to be pulled back up and held until the formation filled in again. The procedure was repeated until the conductor pipe stayed in position. Well specifications included 961-ft water depth, gumbo formation, and 26-in bit.

Halliburton's Response

Halliburton implemented a solution in which a Dyna-Drill™ drilling assembly was suspended within the pre-assembled conductor pipe. The drilling assembly drilled the hole and the casing followed it down to the desired depth. A TV monitor run on guide lines relayed the progress of the drilling to the surface vessel. Seawater was used for drilling fluid. This procedure eliminated the need to pull the drilling assembly out of the hole to set the casing. Also, the Dyna-Drill method virtually eliminated the risk of losing the hole since the casing traveled with the drilling assembly. This was especially important in unconsolidated, alluvial deposits.

Economic Value Created

Using the Dyna-Drill casing drill procedure, the casing was drilled and set in three hours. This saved the operator 6 to 12 hours of rig time for a total economic value created of $30,000 to $60,000.

www.Halliburton.com