Screw drill stator made of PTFE (Polytetrafluoroethylene) and PTFE applied to stator

Abstract

The invention relates to a screw drill stator made of PTFE (Polytetrafluoroethylene) and the PTFE applied to the stator. The stator mainly comprises a stator shell and a polymer layer in sequence from outside to inside, wherein the polymer layer is made of the PTFE. The PTFE applied to the drill screw stator comprises PTFE powder and an additive, wherein the additive comprises the following components: 1-10 percent of polyether-ether-ketone powder, 0.5-10 percent of carbon fiber, 0.5-20 percent of glass fiber and 0.5-10 percent of graphite, and the balance is the PTFE powder. The screw drill stator made of the PTFE with reasonable compatibility has favorable toughness at about 170 DEG C, and can withstand long-term corrosion of drilling fluid as well as strong acids and strong alkali, the service life is prolonged to over 250h, the maintenance period is prolonged, and further, the production cost and the maintenance cost of equipment are reduced.

Description

technical field [0001] The invention relates to a screw drilling tool stator made of PTFE and the PTFE applied to the stator. Background technique [0002] Polytetrafluoroethylene (PTFE) resin has excellent properties such as high and low temperature resistance, corrosion resistance, aging resistance, high insulation, and non-stickiness. However, due to its poor dimensional stability, poor thermal conductivity, large creep, and low hardness, especially in It is easy to wear under load, which limits its application in the fields of mechanical bearing, friction and wear, and seal lubrication. Therefore, in order to expand the application field of PTFE, it is necessary to modify its filling, that is, to use the advantages of filling particles such as high hardness, wear resistance, stable size, and good thermal conductivity to improve the defects of PTFE. [0003] The screw drilling tool is a volumetric downhole power drilling tool that uses drilling fluid as power and convert...

AI Technical Summary

Problems solved by technology

[0004] Since the inner wall of the tubular casing of the stator in the prior art is provided with concave thread grooves, the processing technology of the tubular casing is difficult, the molding process is complicated, and more processing residues are generated, which greatly increases the processing cost

In addition, the rubber bushing is injected on the inner wall of the housing by high pressure, and the molding process is also very complicated, with high processing costs and low labor efficiency

In the prior art, the rubber bushing materials of screw drilling tools are generally NBR and HNBR. Among them, the limit temperature (static) of HNBR is 176°C, but the long-term temperature of high-temperature wells is close to 170°C. According to the working characteristics of screw drilling tools, The temperature is easy to concentrate on the part where the rubber bush and the rotor are in contact, and the dynamic heat generated by mutual extrusion and torsion between the stator and the rotor

When the temperature is high and concentrated in the above area for a long time, it will cause the aging of the rubber bushing, which will cause rubber damage

Therefore, the service life of screw drilling tools for high-temperature wells in the prior art is short, generally only more than 100 hours, the service life is short, and the maintenance requirements are high, which seriously affects the efficiency and progress of drilling work and increases drilling costs.

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