CN202165025U

CN202165025U - Antifatigue drill collar threads

Info

Publication number: CN202165025U
Application number: CN2011202056681U
Authority: CN
Inventors: 李方坡; 刘永刚
Original assignee: China National Petroleum Corp; CNPC Tubular Goods Research Institute
Current assignee: China National Petroleum Corp; CNPC Tubular Goods Research Institute
Priority date: 2011-06-17
Filing date: 2011-06-17
Publication date: 2012-03-14
Anticipated expiration: 2021-06-17

Abstract

The utility model relates to antifatigue drill collar threads comprising an inner thread end and an outer thread end, wherein the outer thread end comprises a torque shoulder and tapered outer threads; the outer diameter of the torque shoulder is the outer diameter of the drill collar and is 165-175mm; the diameter of a shoulder chamfer is 154-164mm, the taper degree is 1/6mm/mm, and the thread pitch is 4 teeth/25.4mm; the form of the threads is V-038R; the pitch diameter of threads at a datum point is 120-125mm; the inner threads at the inner thread end are matched with tapered outer threads; the diameter of the reamed tapered hole of the inner threads is 124-134mm and the inner diameter of the reamed tapered hole of the inner threads is the inner diameter of the drill collar and is 55-72mm; and the peripheral shoulder of the reamed tapered hole of the inner threads is matched with the torque shoulder. The distribution state of the stress on the drill collar threads is ensured by the outer diameter and the inner diameter of the drill collar as welll as the diameter at the datum point; and the bearing capacity of the torque shoulder of the threads and the fatigue life of the drill collar threads are ensured by the diameter of the shoulder chamfer and the diameter of the reamed tapered hole of the inner threads.

Description

A kind of antifatigue drill collar threads

Technical field

The utility model relates to a kind of drilling tool screw thread of oil and gas well drilling technical field, is specifically related to a kind of screw thread of drill collar.

Background technology

Drill collar is one of main tool of oil and gas well drilling, and main effect is that drill bit is applied the pressure of the drill, guarantees carrying out smoothly of drilling process, between the drill collar through being threaded.The drill collar of extensive use at present is 165.1mm drill collar and 171.4mm drill collar, and the screw thread model of 165.1mm drill collar is NC46-65, and the screw thread model of 171.4mm drill collar is NC46-67.The field for many years finds that fatigue failure very easily takes place at the internal thread position of 165.1mm drill collar and 171.4mm drill collar.The fatigue failure of drill collar threads, especially fracture failure have a strong impact on drilling progress, even can cause whole mouthful of well to be scrapped, cause enormous economic loss.

For the fatigue life at the screw thread position of improving 165.1mm drill collar and 171.4mm drill collar, the many units in home and abroad have developed various forms of stress-relief groove structures in succession.Yet field practice shows that the effect of drill collar internal thread stress-relief groove is also not obvious.Improve the drill collar threads structure, improve screw thread fatigue life, the generation that reduces failure accidents has become the problem that presses for solution in the present drill collar Design and Machining.

The utility model content

The purpose of the utility model is through improving the size at drill collar threads position, a kind of drill collar threads structure of anti-fatigue performance is provided, prolong the application life of drill collar, improve rate of penetration, reducing drilling cost.

The described highly anti-fatigue drill collar threads of the utility model is made up of female end and male end; Male end is made up of torque shoulder and conical external screw thread; The external diameter of torque shoulder is the external diameter of drill collar, is 165-175mm, and the shoulder bevel diameter is 154-164mm; Tapering is 1/6mm/mm; Pitch is 4 teeth/25.4mm, and the tooth form of screw thread is V-038R, and the pitch diameter of thread of datum is 120-125mm; The internal thread and the conical external screw thread of female end are complementary, and internal thread reamer bore dia is 124-134mm, and internal diameter is the internal diameter of drill collar, is 55-72mm, and internal thread reamer hole periphery shoulder and torque shoulder are complementary.

The present invention is through the external diameter of drill collar, and the diameter of internal diameter and datum guarantees the stress distribution of drill collar threads; Guarantee the supporting capacity of screw thread torque shoulder through shoulder bevel diameter and internal thread reamer bore dia, guarantee the fatigue life of drill collar threads through above two aspects.Because the tooth form of drill collar threads adopts the existing form of thread V-038R of API,, be convenient to screw thread processing and detection so do not need the specialized designs processing tool.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Wherein: 1, footpath Qc, internal thread reamer bore dia D in the internal diameter C of the outside diameter d of torque shoulder 2, conical external screw thread 3, female end 4, male end D, drill collar, drill collar, the screw thread datum _F, the shoulder bevel diameter

The specific embodiment

With reference to Fig. 1, the described highly anti-fatigue drill collar threads of the utility model is made up of female end 3 and male end 4; Male end 4 is made up of torque shoulder 1 and conical external screw thread 2, and the external diameter of torque shoulder 1 is the D outer diameter of drill collar, is 165-175mm, shoulder bevel diameter D _FBe 154-164mm, tapering is 1/6mm/mm, and pitch is 4 teeth/25.4mm, and the tooth form of screw thread is V-038R, and the pitch diameter of thread C of datum is 120-125mm; The internal thread of female end 4 and conical external screw thread 2 are complementary, and internal thread reamer bore dia Qc is 124-134mm, and internal diameter is the inner diameter d of drill collar, is 55-72mm, and internal thread reamer hole periphery shoulder and torque shoulder 1 are complementary.

Claims

1. an antifatigue drill collar threads is made up of female end and male end; It is characterized in that: male end is made up of torque shoulder and conical external screw thread; The external diameter of torque shoulder is the external diameter of drill collar, is 165-175mm, and the shoulder bevel diameter is 154-164mm; Tapering is 1/6mm/mm; Pitch is 4 teeth/25.4mm, and the tooth form of screw thread is V-038R, and the pitch diameter of thread of datum is 120-125mm; The internal thread and the conical external screw thread of female end are complementary, and internal thread reamer bore dia is 124-134mm, and internal diameter is the internal diameter of drill collar, is 55-72mm, and internal thread reamer hole periphery shoulder and torque shoulder are complementary.