Novel sucker rod coupling and production process thereof

Abstract

The invention relates to the field of oil equipment, particularly to a novel sucker rod coupling and a production process thereof. The novel sucker rod coupling comprises a main body, the main body is a hollow cylinder, the middle of the hollow cylinder is provided with square-neck surfaces matched with a double-edge wrench, the two square-neck surfaces are parallel, and the middle of the main body is provided with an axial internal threaded hole. The novel sucker rod coupling is characterized in that the outer surface of the main body is partially or totally covered with copper-based alloy composite coating, which is composed of, by weight percentage, 10-50% of hard tungsten carbide (WC) particles and 50-90% of copper-based alloy powder. According to the novel sucker rod coupling, the copper-based alloy composite coating and nickel-based alloy coating at both ends of the outer surface of the coupling are connected through transitional sections to ensure continuity and high quality and further to achieve obvious prolonging of the service life and long-term protection on the inner wall of a sucker rod.

Description

technical field [0001] The invention relates to the field of petroleum equipment, in particular to a novel sucker rod coupling and a preparation process thereof. Background technique [0002] The sucker rod coupling is a very widely used part in the oil production system of the rod pump in the oil field. Through it, the connection between the sucker rods can be realized, so that the total length of the sucker rod can reach hundreds of meters or even thousands of meters underground. Crude layer. When the pumping unit in the oil field is working, the sucker rod moves up and down in the oil pipe, and the diameter of the sucker rod coupling is larger than that of the sucker rod, so the sucker rod coupling inevitably rubs and collides with the inner wall of the oil pipe. It is easy to cause the wear of the sucker rod coupling and the inner wall of the tubing and the long-term corrosion of the well fluid, and the most direct impact of corrosion and wear is the eccentric wear of t...

AI Technical Summary

Problems solved by technology

When the pumping unit in the oil field is working, the sucker rod moves up and down in the oil pipe, and the diameter of the sucker rod coupling is larger than that of the sucker rod, so the sucker rod coupling inevitably rubs and collides with the inner wall of the oil pipe. It is easy to cause the wear of the sucker rod coupling and the inner wall of the tubing and the long-term corrosion of the well fluid, and the most direct impact of corrosion and wear is the eccentric wear of the coupling and the thinning of the inner wall of the tubing, and even cause the sucker rod Shedding and abrasion of tubing

[0003] At present, the conventional method to solve the above problems is to adopt: 1) The outer layer of the coupling is sprayed with nickel alloy coating. Although this method significantly prolongs the inspection period of the pump, it still causes wear on the inner wall of the tubing by the alloy coating coupling, and sometimes The oil pipe is perforated, resulting in the shutdown of the oil well, which brings great economic losses to the oil field

2) Add solid lubricant directly to the nickel-based alloy coating. Although this method can effectively solve the problem of coupling lubrication and oil pipe wear of the nickel-based alloy coating, the addition of several types of solid lubricating particles such as molybdenum disulfide and organic lubricating particles It will lead to defects such as holes in the coating, and the actual preparation is difficult and limited. The field application of this type of product is seldom

3) Metal anti-friction elements are added to the nickel-based alloy coating, such as Cu and Mo are used as anti-friction elements, or Cu, Mo and Sn are used as anti-friction elements, but due to the characteristics of the nickel-based alloy powder itself, the friction-reducing elements The amount of addition is very limited, otherwise the hardness of the coating will be reduced too much, and even the coating quality will be significantly reduced such as holes; therefore, from the results of field use, it is found that there is still a certain proportion of such alloy coating couplings that wear through the tubing problems, especially in the build-up section in the wellbore, etc.

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