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CN-121993393-A - End upsetting oil-well pump pull rod and processing method thereof

CN121993393ACN 121993393 ACN121993393 ACN 121993393ACN-121993393-A

Abstract

The invention belongs to the technical field of oil pumps of a sucker rod oil extraction system, and particularly relates to a pull rod of an end upsetting oil pump and a processing method thereof. The utility model provides an tip upset oil-well pump pull rod, including the body of rod, connect the oil-well pump link and the sucker rod link in the body of rod both sides, the oil-well pump link includes the upset section, upset section diameter is greater than the body of rod diameter, upset section and body of rod junction are equipped with first transition circular arc, the end of upset section is equipped with metric screw thread section, be equipped with metric screw thread on the metric screw thread section for connect the oil-well pump, sucker rod link tip is equipped with the sucker rod link, the diameter of sucker rod link is greater than the body of rod diameter, sucker rod link and body of rod junction are equipped with the second transition circular arc, the end of sucker rod link is equipped with the sucker rod screw thread for connect the sucker rod coupling. According to the invention, through the end upsetting structure, the stress condition of the tail end of the thread is improved, the toughness and fatigue resistance of the pull rod are improved, and the fracture frequency of the pull rod is reduced.

Inventors

  • WANG WEISHENG
  • TANG LIANGWEN
  • JIANG CHAO
  • MA GUANGHE
  • ZHANG ZHONGQIN
  • SUN XIANFA
  • ZHANG ZHENGPING
  • LAN FANG
  • HU RUJUN

Assignees

  • 中国石油天然气股份有限公司

Dates

Publication Date
20260508
Application Date
20241107

Claims (7)

  1. 1. The end upsetting oil-well pump pull rod is characterized by comprising a rod body (5), oil-well pump connecting ends and sucker rod connecting ends, wherein the oil-well pump connecting ends are connected to two sides of the rod body (5), the oil-well pump connecting ends comprise upsetting sections (3), the diameter of each upsetting section (3) is larger than that of the rod body (5), a first transition arc (4) is arranged at the joint of each upsetting section (3) and the rod body (5), a metric thread section is arranged at the tail end of each upsetting section (3), metric threads (1) are arranged on the metric thread sections and are used for connecting an oil-well pump, sucker rod connecting ends are provided with sucker rod connecting sections, the diameter of each sucker rod connecting section is larger than that of the rod body (5), a second transition arc (9) is arranged at the joint of each sucker rod connecting section and the rod body (5), and sucker rod threads (8) are arranged at the tail end of each sucker rod connecting section and are used for connecting sucker rod couplings.
  2. 2. The end upsetting oil pump pull rod according to claim 1, wherein a spanner square (6) is arranged on one side of the sucker rod connecting section close to the second transition circular arc (9), and a sucker rod head pushing bearing surface (7) is arranged on one side of the sucker rod connecting section close to the sucker rod thread (8).
  3. 3. The end upsetting oil pump pull rod according to claim 1, wherein a step surface (2) is arranged at the joint of the metric thread section and the upsetting section (3).
  4. 4. The end upsetting oil well pump pull rod according to claim 1, wherein the thread diameter of the metric thread (1) is smaller than the diameter of the upsetting section (3), the arc radius R of the first transition arc (4) and the second transition arc (9) is R57.15+/-3.175 mm, the length ratio of the upsetting section (3) to the end of the metric thread (1) is 1:1, and the diameter of the upsetting section (3) is larger than the diameter ratio of the rod body (5) by 17.06% -20.26%.
  5. 5. The method for processing the end upsetting oil-well pump pull rod according to claim 1, which is characterized by comprising the following steps: S1, straightening a rod body; straightening the rod body (5) by using a straightening machine, and improving the straightness of the rod body (5), wherein the straightness of the rod body after straightening reaches 304.8mm to 1.65mm; S2, forging upsetting; upsetting forging is carried out on the end part of the rod body by adopting a horizontal parting die and a punch, and the concrete process is as follows: S21, performing appearance inspection on the straightened rod body (5) to remove surface cracks and inclusion defects, determining the shape, the size and the tolerance of a die according to a drawing of a pull rod, mounting the die at a designated position of a flat forging machine, performing pressure test and debugging for a plurality of times, ensuring that the die is tightly closed and has no dislocation, and adjusting punching force and speed parameters; S22, heating the rod body (5) in an intermediate frequency heating furnace, wherein the intermediate frequency voltage is 660+/-20V, the intermediate frequency power is 750+/-20 KW, the intermediate frequency is 6.0+/-0.2 KHZ, the temperature of cooling water in the intermediate frequency heating furnace is less than or equal to 38 ℃, and then, the rod body is sent into a working area of a horizontal forging machine by a mechanical arm to be gradually forged into a pull rod shape meeting the design requirement; s3, integral heat treatment; the whole heat treatment is carried out by adopting a quenching and tempering mode, and the specific process is as follows: s31, before the heat treatment is started, thoroughly cleaning and degreasing the rod body (5) to remove impurities and greasy dirt on the surface, and meanwhile, performing preliminary inspection on the sucker rod to confirm that the sucker rod has no obvious cracks, deformation or damage; S32, a heating process, namely loading the rod bodies (5) subjected to the pretreatment into a box-type passing electric furnace one by one, uniformly distributing the rod bodies (5) in a hearth, wherein the heating temperature range of the box-type passing electric furnace is 800-850 ℃, and the heating and heat preservation time is 40-50 min, so that the internal tissues of the rod bodies (5) are subjected to full phase change and recrystallization; S33, after heating, the rod body (5) rapidly enters a quenching medium for cooling, and in the quenching process, water is selected as a cooling medium, and a layer of compact martensitic structure is formed on the surface of the quenched pull rod; s34, tempering, namely putting the rod body (5) into a box-type passing electric furnace again, and performing high-temperature tempering treatment, wherein the tempering temperature range is 500-550 ℃ and the tempering time is 30-50 min; S35, performance detection, namely after tempering is finished, performance detection is required to be carried out on the rod body (5), wherein the tensile strength is more than or equal to 800MPa, the elongation is more than or equal to 10%, the area shrinkage is more than or equal to 45%, the fatigue performance sigma 0.1 540MPa≥10 6 times, and the impact toughness (U type) is more than or equal to 60J; S4, shot blasting Performing cold work hardening on the surface of the rod body (5) in a shot blasting mode, starting a shot blasting machine, after the shot is accelerated to an extremely high speed in the shot blasting machine, performing directional projection by a shot blasting wheel, impacting the surface of the rod body at a high speed, wherein the impeller speed of the shot blasting machine is 2250 revolutions per minute, the axial scattering angle is 0-55 degrees, the radial scattering angle is 0-12 degrees, the shot blasting amount is 150-200 kg/min, the steel shot specification is 1.0-1.8 mm, and the working speed is 0.50-2.00 m/min; s5, processing threads; machining sucker rod threads (8) and metric threads (1) at two ends of a rod body (5) respectively; And S6, surface corrosion prevention, and finishing processing.
  6. 6. The method of claim 5, wherein during the upsetting step S2, the initial forging temperature of the flat forging machine is 1100-1250 ℃ and the final forging temperature is not lower than 750 ℃.
  7. 7. The method for processing the pull rod of the end upsetting oil pump according to claim 5, wherein the surface corrosion prevention in the step S6 is one of spraying, brushing or electroplating, and the specific process is as follows: S61, pre-preparing, namely checking a paint dipping tank, a stirrer and water removing equipment, keeping the operation area dry and ventilating, and controlling the room temperature to be-10 ℃ to 20 ℃ and the humidity to be more than 20%; S62, dip coating pretreatment, namely thoroughly removing greasy dirt, rust and old coating impurities on the surface of the rod body (5) by using a high-pressure water gun or a chemical cleaning agent, ensuring that the surface is clean and has no residue, and drying the cleaned rod body (5); S63, paint dipping operation, namely uniformly mixing a water paint main agent, a curing agent and a diluent according to the proportion provided by manufacturers, preparing paint liquid suitable for dip coating, slowly dipping the treated rod body (5) into the prepared paint liquid, wherein the paint dipping time is 5min, S64, leveling and removing redundant paint, namely standing the immersed rod body (5) for a period of time, naturally leveling paint liquid under the action of gravity, reducing surface bubbles and uneven phenomena, and gently scraping off the two ends of the rod body and the redundant paint liquid possibly accumulated by using a scraper or cloth strip; And S65, drying the rod body (5) after leveling, removing moisture and volatile substances in a paint film, and improving the hardness and wear resistance of the coating.

Description

End upsetting oil-well pump pull rod and processing method thereof Technical Field The invention belongs to the technical field of oil pumps of a sucker rod oil extraction system, and particularly relates to a pull rod of an end upsetting oil pump and a processing method thereof. Background In the petroleum exploitation process, the oil pump plays a critical role and is a key device for mechanical oil exploitation of the sucker-rod pump in the oil field. As a key component for connecting the pump body and the driving device, the pull rod of the oil pump continuously transmits and bears alternating stress between the sucker rod and the piston of the oil pump, and the performance of the pull rod directly influences the stable operation and the efficiency of the whole sucker rod pumping system. The upper and lower diameters of the pull rod body of the existing oil pump are the same, metric threads are processed at the two ends, one end is connected with the sucker rod through a reducing coupling, and the other end is connected with a plunger oil outlet valve cover of the oil pump and is locked by a cap; or one end of the sucker rod is threaded, the sucker rod is connected with the sucker rod through a coupling, and the other end of the sucker rod is connected with the oil outlet valve cover of the plunger of the oil pump through metric threads and is locked by adopting a cap. At present, most oil fields enter the later development stage, pump hanging is deepened continuously, the stroke frequency and the pump diameter are gradually increased in face of the requirement of increasing the drainage amount, the pull rod bears alternating load in the working process to be increased, the frequent disconnection of the pull rod is easy to cause, and the frequent disconnection of the pull rod occurs in the metric screw thread tail vanishing section. Disclosure of Invention Aiming at the problem that the pull rod is easy to break and fall off when the stroke, the stroke frequency and the pump diameter of the existing pull rod of the oil pump are increased and the stress is increased, the invention aims to provide the end upsetting pull rod of the oil pump and the processing method thereof. The technical scheme includes that the end upsetting oil pump pull rod comprises a rod body, oil pump connecting ends and sucker rod connecting ends, wherein the oil pump connecting ends are connected to two sides of the rod body, each oil pump connecting end comprises an upsetting section, the diameter of each upsetting section is larger than that of the rod body, a first transition arc is arranged at the joint of each upsetting section and the rod body, a metric thread section is arranged at the tail end of each upsetting section and is used for connecting an oil pump, a sucker rod connecting section is arranged at the end of each sucker rod connecting end and is larger than that of the rod body, a second transition arc is arranged at the joint of each sucker rod connecting section and the rod body, and sucker rod threads are arranged at the tail end of each sucker rod connecting section and are used for connecting sucker rod couplings. The side of the sucker rod connecting section, which is close to the second transition arc, is provided with a spanner side, and one side of the sucker rod connecting section, which is close to the sucker rod thread, is provided with a sucker rod head pushing surface. The joint of the metric thread section and the upsetting section is provided with a step surface. The diameter of the metric thread is smaller than that of an upsetting section, the arc radius R of the first transition arc and the second transition arc is R57.15+/-3.175 mm, the length ratio of the upsetting section to the metric thread end is 1:1, and the diameter of the upsetting section is larger than that of the rod body in a range of 17.06% -20.26%. A processing method of an end upsetting oil-well pump pull rod is provided, which processes the end upsetting oil-well pump pull rod, and comprises the following steps: S1, straightening a rod body; Straightening the rod body by using a straightening machine, and improving the straightness of the rod body, wherein the straightness of the rod body after straightening reaches 304.8mm to 1.65mm; S2, forging upsetting; upsetting forging is carried out on the end part of the rod body by adopting a horizontal parting die and a punch, and the concrete process is as follows: s21, performing appearance inspection on the straightened rod body to remove surface cracks and inclusion defects, determining the shape, the size and the tolerance of a die according to a design drawing of the pull rod, mounting the die at a designated position of a horizontal forging machine, performing pressure test and debugging for a plurality of times to ensure that the die is tightly closed and has no dislocation, and adjusting stamping force and speed parameters; S22, heating the rod body in an intermediate frequency