Drill pipe management extends drillstring life
- Global Marine Drilling Co., Houston, TX (US)
Better handling procedures and frequent drill pipe inspections prolong the life of a drillstring. Crews taught to make quick visual inspections during rig moves and tripping can spot problem pipe early, thus preventing downtime or extensive repairs. Because of escalating costs of drillstring repair and replacement, Global Marine Drilling Co. organized a task force in March 1989 to define problem areas and establish new handling and maintenance procedures. The task force estimated that one 20,000-ft drillstring costs abut $600,000 and has a 7-year life span. Assuming the average rig life is 21 years, each rig will wear out three strings, totaling $1.8 million. The addition of $30,000/year for full rack inspections, repairs and downhole loss brings the total to approximately $2.4 million/rig over the 21 years. A contractor with a fleet of 25 rigs could expend $60 million on drill pipe-the construction cost of a well-equipped, 300-ft jack up rig. The task force reported on in this paper identifies four basic caused of drill pipe failures: Tool joint and tube OD wear, Internal corrosion, Fatigue cracking in the slip and internal upset areas, Physical damage to the tool joint threads and shoulders, and the tube.
- OSTI ID:
- 5651510
- Journal Information:
- Oil and Gas Journal; (United States), Journal Name: Oil and Gas Journal; (United States) Vol. 89:43; ISSN 0030-1388; ISSN OIGJA
- Country of Publication:
- United States
- Language:
- English
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