I. Introduction

Drilling is an important part of oil exploration and development. Drill pipe, drill string and drill collar are the three most commonly used drilling tools in drilling. They have obvious differences in structure, purpose and material. Let's take a closer look at the differences between these three drilling tools.

II. Structure

The drill pipe is composed of a group of long round rods, each of which is tightly stacked together to form a drill pipe that is hundreds of meters long. The drill string is a long rod body similar to the drill pipe. Depending on the specifications of the drill string, it can also be very long, but it is relatively not as long as the drill pipe. The drill collar looks shorter, but it has a large diameter and is generally used in the early stage of drilling. In addition, there are many ways to connect the drill pipe and the drill string. The drill pipe is generally connected by a lock or thread, while the drill string is mostly connected by a buckle.

III. Use

The drill pipe is used to transmit rotational force transmission. It fixes the drill bit in the well and rotates the drill bit to drill. The drill string is used to bear force at the bottom of the drill pipe, and its function is to transmit heavy load and torque. The meaning of drill collar is relatively broad. It is generally used to open the sludge accumulated in the well, or encounter hard rock layers, and drill collars are needed to cut and break the rock layers.

4. Material

Drill pipes are generally made of medium carbon steel or alloy steel, while drill strings can use high-strength medium carbon steel or alloy steel. The material required for drill collars is generally high carbon steel or special alloys. It is subjected to huge impact and wear during the drilling process, so the material requirements for drill collars are higher.

5. Summary

In summary, drill pipes, drill strings, and drill collars have obvious differences in structure, use, and material. The drill pipe is responsible for the rotation of drilling, the drill string transmits the heavy load and torque of the drill pipe, and the drill collar is used in the early stage of drilling or to deal with problems encountered. Different drilling tools have specific functions, and drillers need to choose appropriate drilling tools to complete the work according to different needs during operation.
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