A well is drilled with limber BHA. When the limber BHA is pulled out and the stiffer BHA is used as the next BHA, the stiff BHA is unable to pass into the existing hole due to excessive dog leg and finally the BHA gets stuck.
Warning signs when you get stuck due to Stiff BHA
- Excessive dog leg severity is drilled.
- The pulled BHA is under gauge.
- While tripping in a hole with new BHA, sudden sit down weight is seen.
Stuck identification for Stiff BHA
- The BHA has a possibility of getting stuck at high dog leg areas.
- It is most likely to occur while running in a hole.
- Circulation is not restricted.
What should you do for this situation?
- If you get stuck while moving up, jar down with the maximum trip load. Torque may be applied with caution.
- If you get stuck while moving down, jar up without any toque applied in the drill string.
- Do not drill with a lot of dog leg severity
- Minimize changes in BHA configuration
- If the stiffer is used, you may need to ream in a hole while passing through high dog leg areas. Moreover, tripping/reaming speed must be limited prior to entering high risk zones.
- Do not create a lot of sit down weight to minimize BHA jammed areas.
John Mitchell Drilbert Engineering, 2002. Trouble-Free Drilling Volume 1: Stuck Pipe Prevention. Edition. Drilbert Engineering Inc.
Fanarco.net. 1999. Stuck Pipe Prevention Self-Learning Course. [ONLINE] Available at: http://www.fanarco.net/books/drilling/stuck-pipe.pdf. [Accessed 21 June 2016
Steve Devereux, 2012. Drilling Technology in Nontechnical Language, 2d Ed.. 2 Edition. PennWell Corp.