| dc.description.abstract | With the demand for oil and gas increased, and the development of oil and gas drilling technology so fast, the development of global oil and gas exploration has entered a deep well, ultra deep well and offshore deep water exploration and development era. Land and shallow sea oil and gas exploration degree now is high, oil and gas production has been close to the peak, therefore many country and big oil and gas multinational companies have turned to deep water search for oil and gas resources, and have got a series of major discovery and development.
Due to the restriction and impact of the ocean drilling platform arrangement and cost, Offshore drilling widely used cluster well, directional well, horizontal well and large displacement technology, all these lead to drill stem under cyclic loading, and the working condition of drill stem become more and more bad. Due to the high cost of offshore drilling industry, the failure accident of drill stem will cause huge economic losses.
Oil drill stems is the main tool for exploration and development of oil and gas, the failure accident of drill stem in oil and gas exploration will not only hindered the drilling speed and production, but also caused huge economic loss.
The failure type of drill stem is given priority to fatigue failure, according to the research of the drilling contractor, there are about 50~60% fatigue failure in the total failure of drill stem. Therefore, the research of tool fatigue prediction will bring great significance for enhance drill stem management standards, establish a whole life cycle of drill stem, monitoring, evaluation and query, ensure the safety of drill stem quality and drill string, and reduce drilling cost. | nb_NO |
