Screw drilling tool motor stator

Abstract

The invention relates to a motor stator which is used for the petroleum and natural gas well-drilling field and is matched with the screw drilling tool. The motor stator comprises a casing and a rubber bushing. The rubber bushing is bonded with the inner opening of the casing. The inner opening of the rubber bushing is of a continuous spiral type. The radial cross section is of a circumferential uniformly-distributed petal shape. The difference is that the wall thickness of the rubber bushing at the radial cross section is not even. The wall thickness of each petal of the rubber bushing at the radial cross section from the lowest part of the dent to the highest part of the projection gradually increases. The largest thickness is 1.2-2 times of the smallest thickness. The shape of each petal on the radial cross section is same,The motor stator of the invention not only can prevent the damage of the stator rubber caused by the easy blocking of the rotor in the stator and no easy discharge of the slurry pressure when an overgreat drilling pressure generates on the stator with same wall thickness, but also prevents the problem of over-early failure caused by the large wall thickness difference of the rubber bushing and easy heat accumulation to the part with thick rubber. Therefore the advantages of greatly increasing the efficiency of the motor stator and effectively prolonging the service lifetime are obtained.

Description

technical field [0001] The invention relates to a motor stator used in the field of oil and natural gas drilling and the configuration of screw drilling tools. Background technique [0002] Screw drilling motor is currently the most widely used downhole power drilling tool, mainly used for deflection and torsion azimuth construction in directional wells and horizontal wells, and partly used in reverse buckling or sidetracking operations in vertical wells. The United States began to develop screw drilling tools in the mid-1950s. It was used for production in 1962. Different manufacturers produced Dina drilling tools (Smith Company), Navier drilling tools (Christensen Company) and Persian drilling tools. The basic principles are based on volume type motor. The motor stator of traditional screw drilling tools, such as figure 1 As shown, the rubber is vulcanized in the steel pipe shell (1) to form a rubber bushing (2). The inner hole of the steel pipe shell is circular, and th...

AI Technical Summary

Problems solved by technology

This can avoid the heat failure of the over-thick part of the rubber bushing. However, from the application point of view, when the drilling pressure is too high, the deformation of the equal-wall rubber bushing is relatively small, and the rotor is easily stuck in the stator. Not easy to discharge will also cause damage to the stator rubber, affecting the working efficiency and service life of the screw drilling motor

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