The oil drill collar is a key tool in the oil drilling process. It is used to cut and drill rocks, soil layers, and oil and gas reservoirs in the formation. It is one of the core components for drilling operations. The design, selection and use of drill collars have an important impact on drilling efficiency, drilling quality and safety. Below I will conduct a detailed analysis of oil drill collars in terms of structure, type, working principle, material selection and performance.
Structure and type
The basic structure of a petroleum drill collar usually includes a cutter, a cutter body, a cutter arm and a connecting part. The cutter is the cutting part at the bottom of the drill collar, which is cut by rotating and pressing down; the cutter body is the support structure of the cutter, which can withstand the rotational force and downward pressure from the drill; the cutter arm connects the cutter and the cutter body. The part plays the role of transmitting force and supporting the tool; the connecting part is the part that connects the drill collar to the drill pipe.
Petroleum drill collars can be divided into many types based on the shape and structure of the tool, including:
Drill bit collar: Commonly used in soft rock formations and general drilling operations. The cutting tools are mostly made of carbide materials, with shapes such as round heads, ball heads, cone heads, etc., and are suitable for different formation types.
Cutting structure drill collar: The cutting structure can be divided into gear type, hob type, spiral type, etc. The drilling operation is realized through the cutting structure, which is suitable for harder formations or special operation requirements.
Drill bit guide drill collar: It has a guiding function and can control the direction of the drill collar. It is often used in drilling operations of horizontal wells and directional wells.
working principle
The working principle of the oil drill collar is mainly to use the rotational power and downforce provided by the drilling rig, and under the cooling and impact of the drilling fluid (mud), to bring the tool part into the formation for cutting and drilling. When the drill collar rotates, the tool comes into contact with the formation. Through rotational friction and cutting action, the formation rocks and soil are cut away. At the same time, the impact of the drilling fluid takes away the cut cuttings to complete the drilling operation.
Material selection
The manufacturing materials of petroleum drill collars have an important impact on their performance and life. Commonly used drill collar materials include:
Carbide: Carbide cutting tools have high hardness, wear resistance and high temperature resistance. They are often used in the manufacture of drill collars and are suitable for soft rock formations and general drilling operations.
Petroleum drill collars need to have the following performance requirements:
Wear resistance: When the drill collar rotates at high speed for a long time, it needs to have high wear resistance to maintain the cutting efficiency and life of the tool.
High temperature resistance: Drill collars will be affected by high temperatures during the drilling process and need to be high temperature resistant to avoid tool failure or deformation.
Cutting efficiency: The cutting efficiency of the drill collar directly affects the speed and effect of drilling operations, and it requires good cutting performance.
Steering performance: For some operations that require controlling the drilling direction, the drill collar needs to have good steering performance and be able to accurately control the drilling direction.
Safety: Drill collars need to have good safety during use to avoid accidents caused by tool failure or other reasons.
In general, as the core tool in the oil drilling process, the design, manufacturing and selection of oil drill collars need to comprehensively consider factors such as formation characteristics, drilling operation requirements and working environment to ensure efficient, safe and reliable drilling operations.
（To learn more, please visit the website:
www.baowi-steel.com）