Casing pipe

Casing pipe Definition

Seamless steel pipe used to sustain the wall of oil or gas well, it belongs to disposable consumable material. Casing pipe consumption take up 70% of all oil well pipes. According to usage condition, casing pipe can be divided into conduit casing, skin layer casing, technical casing and oil rock layer casing.

There are five grade for casing pipe, which is J55, K55, N80, L80, P110. According to casing pipe end thread and coupling form, it consist of STC, LTC and BTC. STC means short thread coupling, LTC means long thread coupling, and BTC means buttress thread coupling. Usually length consist of R1, R2 and R3. R1 is range from 4.88 to 7.62m, R2 is range from 7.621 to 10.36m and R3 is range from 10.36 to 14.63m.

Casing pipe Parameter


Casing pipe Image

Characteristic of Casing Pipe

Petroleum industry is an industry that uses a large number of oil pipes, and oil pipes play an important role in the oil industry: 1. Oil pipes are used in large quantities and spend a lot of money, which has great potential for saving expenses and reducing costs. The consumption of oil well pipes can be calculated according to the annual drilling footage.
According to the specific situation in China, 62kg of oil well pipe is needed for every 1m of drilling, including 48kg of casing and 10kg of oil pipe. 3kg drill pipe and 0.5kg drill collar; 2. The mechanical and environmental behaviors of oil pipes have an important influence on the adoption of advanced technologies and the increase of production and efficiency in the oil industry. 3. The failure loss of oil pipe is huge, and its safety, reliability and service life are of great importance to the oil industry.


1Is there any Anti corrosive protection for steel pipes?
It is made of high-density polyethylene wrapped on the outer surface of steel pipe, which has high mechanical strength and excellent corrosion resistance, and can protect it from damage caused by external factors during transportation, installation and use.
2What is the difference between oil tubing and casing pipe?
The main difference between oil tubing and casing pipe is that oil tubing is used for oil production, gas production, water injection and acid fracturing in oil wells. Casing pipe refers to the reservoir casing used when drilling to the target layer (oil-bearing and gas-bearing horizon). It is mainly used for sealing all oil and gas layers and upper exposed strata. Inside the oil casing is an oil layer.
3What is Anti-corrosion measures of oil casing?
A, first of all, pay special attention to water quality standards, strict water quality testing and management. Implement separate injection of sewage, strengthen the cleaning of the main water pipeline, achieve the water quality in the station and at the bottom of the well up to standard, and reduce the introduction of corrosion sources into the annular space; B, for water injection wells that have been newly put into production, adopt the annular protective fluid mainly adding sterilization, and form a system to add it regularly; C, in view of the accelerating effect of mechanical abrasion on the corrosion of oil casing, it is suggested to add a rubber ring on the tubing coupling or a centralizer at the part with serious deviation to avoid the tubing scratching the casing and one side contacting the casing during operation and water injection; D, aiming at the serious corrosion of bacteria under scale and the slow growth and killing of SRB at high temperature, high temperature water or steam at 100℃ can be injected into the annulus regularly to kill SRB under scale; E. it is not recommended to popularize cathodic protection and coated casing before the corrosion in casing of water injection well is effectively controlled.