Structural analysis in mast structure used in well servicing petroleum

Abstract

he world petroleum involves billions of dollars by year, being that failures and accidents in structures of mast of oil wells can result in severe economic and legal consequences to companies responsible for operation of these equipments. Currently in Brazil most onshore rigs are in operation more than three decades, and even so there isn´t survey or statistics monitoring of the operational accidents occurred during well servicing activity in well oil or gas with onshore rigs masts. However accidents with these equipments are frequents in Brazilian fields, but due absence of a rigid inspection, many of these accidents are ignored. This study has as propose evaluate the structural behavior of onshore rig mast after some years operation agreement requirements by safety established standard API SPEC 4F:3nd Edition: 2008. For this, was performed a survey of geometric, dimensional characteristics and type of material used in the structure fabrication, based on a study carried out in the field, to evaluate the static load capacity of the mast structure it was adopted the finite element methods. The results showed that rig analyzed require of the derating in original value design of the static lifting for attend the safety requirements established by standard API SPEC 4F.