Short Bolting Issues John Newhouse Mid Con Arkoma

Short Bolting Issues John Newhouse Mid. Con - Arkoma

API RP 54 Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations 6. 4. 10 - All pipe fittings, valves, and unions placed on or connected with blowout prevention equipment, well casing, casinghead, drill pipe, or tubing and exposed to well pressure shall have a working pressure rating equal to or greater than the maximum anticipated well surface pressure. The BOP stack and related riser connections should not be short bolted (not less than three threads showing) and should be checked for properly torqued bolts. Arkoma May 7, 2008

Basis of Standard • Bolt thread must protrude through entire nut for full strength to be realized • Short bolting increases risk of failure by way of thread stripping • First 1 or 2 pitches of the thread are typically partially formed because of a chamfer • Extra three threads allows for only full-strength threads to be engaged with nut • API’s recommendation of three threads is conservative − Allows sloppiness in makeup Arkoma May 7, 2008

Effect of Chamfer Full thread profile Chamfer reduces integrity of first thread Arkoma Images: www. colorado. edu May 7, 2008

BOP Bonnet Bolts on the rams on BOP Stack Bolts below the double rams on BOP Stack Arkoma May 7, 2008

Choke 3 2 1 Arkoma May 7, 2008

Choke Arkoma May 7, 2008

API RP 54 Arkoma May 7, 2008

High Pressure Non-BOP Arkoma May 7, 2008

High Pressure Non-BOP Arkoma May 7, 2008

Low Pressure Arkoma May 7, 2008