Drill pipe connection method

What is drill pipe?

Drill pipe is a steel pipe with a thread at the end, used to connect the surface equipment of the drilling rig to the drilling and grinding equipment or bottom hole device at the bottom of the drilling well. The purpose of the drill pipe is to transport drilling mud to the drill bit and to raise, lower or rotate the bottom hole device together with the drill bit. Drill pipe must be able to withstand tremendous internal and external pressure, twisting, bending and vibration.

Drill pipe connection method:

Common drill pipe joint connection methods include the following:
1. Threaded connection
The upper and lower ends of the drill pipe are connected by threads. Its advantage is that it is easy to disassemble and assemble, and is suitable for drilling operations that require frequent replacement of drill bits.

2. Bayonet connection
This connection method uses snap rings and pins to connect the drill pipes. Its advantage is that it is not prone to breakage and is suitable for operations that require ultra-deep drilling.

3. Spline connection
There are multiple splines and female keys on the connector of the drill pipe, and the connection is achieved by socketing the splines and female keys.

The selection of the above three connection methods needs to be selected according to the specific operating environment and requirements.

The function of the connector:

As a key component for connecting drill pipes, joints play a very important role. The joints must not only be able to bear huge pressure and tension, but also have wear-resistant, corrosion-resistant properties.

There are many types of joints, among which the more common ones include threaded joints, reversible joints, non-torque joints, etc. These joints have their own characteristics and scope of application, and they need to be selected according to the operating conditions.

In addition to the function of the joint itself, the joint is often used for geological exploration and data collection, such as temperature measurement, pressure measurement, flow measurement, etc. These operations require the transmission of data through connectors and are critical to exploration and acquisition efforts.

How to connect kelly pipe and drill pipe?

1. Direct connection
Kelly pipe and drill pipe can be connected using direct connection. This method requires cleaning the surface of the kelly and drill pipe first to ensure the safety of the connection.
The advantage of direct connection is that it is simple and convenient to connect, avoids connection gaps, and can effectively reduce friction loss during rotation of the connection and resistance to sludge discharge. However, direct connection has shortcomings such as low connection strength and easy breakage. It is necessary to pay attention to the strength during connection and inspection after use.

2. Install interface connection
In addition to direct connection, you can also use the installation interface connection method. This method requires the drill pipe and kelly pipe to be installed with respective interfaces and connected through the interfaces.
The advantages of the installation interface connection are high connection strength, high efficiency, and easy replacement of connecting parts. However, installing interface connections requires more preparation work, including installing interfaces, inspecting interfaces, installing drill pipes, etc.

Whether it is direct connection or installation interface connection, you need to pay attention to the following usage precautions:
a. Before connection, the surface finish of the connecting parts and the circular runout error of the connecting parts should be checked.
b. When connecting, the drill pipe should be installed correctly and with appropriate strength, and should not be excessively loose or too tight.
c. Thorough cleaning should be carried out after connection to prevent mud from entering the connection holes.
d. During use, regularly check the wear degree of connecting parts and make necessary replacements.

In short, the connection method between kelly and drill pipe plays a vital role in the safe operation of drilling projects and drilling efficiency. According to actual needs and conditions, selecting appropriate connection methods and strengthening maintenance and inspection can effectively improve project efficiency and reduce risks.