STUDY OF THE HOISTING CAPACITY OF THE MAGNETIC FISHING TOOLS

Accidents which happen during the construction of oil and gas wells causes the widespread use of magnetic fishing tools. One of the main drawbacks of existing tools based on permanent magnets is the flat working surface of the magnetic system, which limits effective interaction with objects of complex geometry and reduces the lifting force. To improve the efficiency of extracting ferromagnetic objects with irregular shapes from wells, a new design of a fishing tool with the moving magnetic systems has been proposed. In order to determine the working capacity of the designed tool, theoretical studies were carried out using the finite element method. The calculated hoisting capacity during interaction between the magnetic systems and both the roller cone bit and the drill bit confirmed the effectiveness of the tool in fishing irregularly shaped objects. The application of the developed fishing tool allows to remove the ferromagnetic objects from the well regardless of their weight and shape.