Understanding China-made Oil Casing: A Comprehensive Guide

Contents

• What is oil casing
• Common sizes of oil casing
• Classification of oil casing
  • Conduit
  • Surface casing
  • Technical casing
  • Oil layer casing
• Steel grade of oil casing
• Application of oil casing

The oil industry is an industry that uses a large number of oil pipes. Oil pipes occupy a very important position in the oil industry: oil pipes are used in large quantities and cost a lot, so there is huge potential for saving expenses and reducing costs.

What is oil casing

Oil casing is a common pipe in oil drilling, which is used to fix and protect the wellbore wall and provide a channel for oil and gas to flow through.

Common sizes of oil casing

The common oil casing size is determined by two parameters: inner diameter (ID) and outer diameter (OD). Depending on the needs, its size can have various combinations.

Here are some common oil casing sizes:

1. 4 1/2 inches – 4 1/2 inches inside diameter, 5.000 inches outside diameter.
2. 5 inches – 5 inches inside diameter, 5.563 inches outside diameter.
3. 5 1/2 inches – 5 1/2 inches inside diameter, 6.050 inches outside diameter.
4. 7 inches – 7 inches inside diameter, 7.625 inches outside diameter.
5. 9 5/8 inches – 9 5/8 inches inside diameter, 10.750 inches outside diameter.
6. 13 3/8 inches – 13 3/8 inches inside diameter, 14.375 inches outside diameter.
7. 20 inches – 20 inches inside diameter, 20.750 inches outside diameter.

Classification of oil casing

Oil casing plays a vital role in the process of oil drilling and extraction. According to its functions and usage scenarios, it can be mainly divided into the following categories:

Conduit

The guide pipe is the first casing lowered into the well, usually used to isolate the shallow surface water layer, prevent drilling fluid backflow, and support the weight of subsequent casing.

It is usually located at a shallow position below the surface, mainly used for wellhead protection in the early stage of drilling and the establishment of drilling fluid circulation channels.

Surface casing

The surface casing is located below the guide tube and is used to isolate the unstable soft formations, formations prone to collapse and leakage, and water layers above.

It can support part of the weight of the subsequent technical casing and oil layer casing, and provide a stable working environment for subsequent drilling operations.

Technical casing

Technical casing, also known as intermediate casing, is used to isolate complex formations that are difficult to control, severe leakage layers, and oil, gas, and water layers with large pressure differences encountered during drilling.

It helps maintain wellbore stability, prevent wellbore expansion, and provide safety conditions for complex drilling operations such as directional wells.

Oil layer casing

The oil layer casing is also called the production casing, which is the casing with the deepest penetration and the smallest diameter.

It is used to separate the target layer from other formations, establish an oil and gas channel, and ensure that the oil and gas can be smoothly exported from the formation to the ground.

Steel grade of oil casing

Steel grades of oil casing: H40, J55, K55, N80, L80, C90, T95, P110, Q125, V150, etc.

Application of oil casing

Oil pipe is mainly used for drilling oil and gas wells and transporting oil and gas.

It includes oil drill pipe, oil casing and pumping pipe. Oil drill pipe is mainly used to connect drill collar and drill bit and transmit drilling power.

Oil casing is mainly used to support the well wall during drilling and after completion to ensure the normal operation of the drilling process and the entire oil well after completion.

Pumping pipe mainly transports oil and gas at the bottom of the oil well to the ground.