drill pipes and drill rig

Introduction of commonly used pipe equipment

Table of Contents

1. Casing pipe

For an oil and gas well, during the drilling process or after drilling, according to the design requirements which to run down one or several columns of steel pipes are to prevent the collapse of the well wall, separate the fluids in each layer, and form oil and gas production channels, etc. This kind of steel pipe called a casing.oil and gas pipe.

api pipe
api pipe

2. Oil pipe

Oil pipe is a special pipe for oil wells. According to the thickening situation, the oil pipes with thickened oil pipes at both ends and flat oil pipes. To use Thickened tubing at both ends when deep well completion work. The length of tubing is generally 6 to 10 meters, and its specifications pls check in Table 2-3.

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api pipe
api pipe

3. Sucker rod pippe

1) Technical specification of sucker rod

The main body of the sucker rod is a solid rod body with a circular section, with thick forging heads at both ends, and the forging heads are provided with connecting threads and square sections for wrench. Nominal sucker rod diameters are 16 mm (5/8 inch), 19 mm (3/4 inch), 22 mm (7/8 inch) and 25 mm (1 inch). In addition to the most common 8-meter-long sucker rod, there are five lengths of 1.0m, 1.5m, 2.5m, 3.0m and 4.0m specially processed for combination.

2) Material of sucker rod

There are two kinds of domestic sucker rods, one is carbon steel sucker rod, the other is alloy steel sucker rod, carbon steel sucker rod is generally made of 40# high-quality carbon steel, alloy steel sucker rod is generally Made of 20-gauge chrome-molybdenum steel or 15-gauge nickel-molybdenum steel.

3) The grade of the sucker rod

C, D, K three grades

(1) Grade C tensile strength is low (620-794MPa), suitable for light and medium loads, shallow wells and medium-deep wells with slight salt water corrosion;

(2) D-grade tensile strength is high (794-965MPa), suitable for medium and heavy loads with slight salt water corrosion in medium and deep wells and deep wells;

(3) K-grade tensile strength is the lowest (588-794MPa), which is suitable for light and medium load wells with corrosive media of hydrogen sulfide and carbon dioxide.

4. Drill pipe

drill pipe
drill pipe
api drill pipe
api pipe

The drill pipe is one of parts of the drill string. It mainly transmits the torque and load of the turntable and establishes the working fluid circulation channel. It is the basic supporting special pipe material for completing the workover process. The joints provided with the drill pipe itself are collectively called drill pipe joints, which are used in pairs, that is, the two ends of a drill pipe are respectively equipped with male and female joints, and their function is to connect and protect the drill pipe and facilitate the buckle. Feature parameters pls check Figure 2-2.

The oil drill pipe joint have the clamping part of the tongs, the welding part, the joint thread and the sealing shoulder, etc. It has an internal threaded joint and an external threaded joint.

The drill pipe is the basic part of the drill string. It is made of seamless steel pipe (the wall thickness is generally 9~11mm). Its main function is to transmit torque and transport drilling fluid. deepen. Therefore, drill pipe occupies a very important position in oil drilling.

Drill pipe structure and specification

The drill pipe is composed of seamless steel pipe, the wall thickness is generally 9~11mm, and it is composed of two parts: the drill pipe body and the pipe joint. There are two ways to connect the pipe body joint of the drill pipe: one is to connect with a thin thread button, that is, there are thin male buttons at both ends of the pipe body, which are connected with the female thin button at one end of the joint, which is called a thin thread. The drill pipe is buckled; the other is that the pipe body and the joint are butt welded together by friction welding, which is called the butt welding pipe. Drill pipes with fine buckles have been basically eliminated at present, and all drill pipes produced or imported in my country are butt welded drill pipes (pipes without fine buckles).

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Both ends of the pipe body need upset to enhance the connection strength during the pipe body and the joint. Commonly used thickening forms are internal thickening, external thickening, and internal and external thickening. According to the regulations of the American Petroleum Institute (API-American Petroleum Institute), drill pipe is divided into three categories by length:

The first category, 5.486~6.706m (18~22ft);

The second category, 8.230~9.144m (27~30ft);

The third category, 11.582~13.716m (38~45ft);

The most commonly used drill pipe sizes are 88.9 (3.5in), 114.3 (4.5in), and 127.0mm (5in).

The outer diameter of the drill pipe joint is larger than the outer diameter of the pipe. During the drilling process, it is constantly in contact and friction with the well wall or casing, resulting in wear. Equipped with pipe joint wear belt.


Steel grade and strength of drill pipe

The minimum yield strength of the pipe will determined the grade. API stipulates that the grades of pipe include D, E, 95(X), 105(G), and 135(S) grades. The higher the grade , the greater the yield strength , so are various strengths of the drill pipe. In the strength design of the drill string, we recommend to increase the strength of the drill string by increasing the steel grade, rather than increasing the wall thickness.


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