The 9 7/8 -diameter pilot bore was initiated with a jetting tool because of sandy conditions at the entry point.
"It (coquina) is composed of small seashells, compressed over time into a formation hard enough to make drilling with the jetting tool difficult," says Breunig.
At the very least the screens' large open areas would permit rapid and thorough cleaning with acids or the jetting tool. This project, however, did present the opportunity to examine the problems of incrustations and various cleaning techniques.
Using surge blocks or jetting tools are effective methods of agitating the well.
In addition, there are jetting tools
and mechanical rock systems available: one manufacturer has marketed a dual-pipe mechanical rock option on a 22,500-pound machine for several years, and percussive tools to hammer into hard rock have been also been introduced.