Statistic Analysis on Drilling Tools Failure in One Oil Field

A thorough investigation of failure state of different drilling tools in 2002-2004 in one oil field was made, and failure model and quantity of different drilling tools were obtained. Through statistic analysis it is found out that the drill collar fracture quantity and proportion are most. It is considered that drill collar fractures are most early fatigue failure based on analysis on fracture mechanism and loading conditions of the drill collars. It is chased down that there are some deficiencies in drill collar standard by failure analysis. The product quality problems are pointed based on the fracture cause analysis on configuration stress, remains stress, and material toughness of the drill collars. The main factors of operation affecting on drill collar fracture are indicated through analysis on drill condition and drill parameters. It is found that the drill collar failure accident decreased obviously in 2009-2011 by carrying out prevention from above drilling tool failure in accordance with failure conclusion.