common API– 5CT casing steel grades in Oil fields include J55, K55, N80-1, N80Q, P110, etc. Casing is mainly used in oil well drilling. According to API-5CT and ISO11960 standards, Pipes and their joints can be divided into STC (short Thread), ltc (long thread) and BTC (partial trapezoidal thread).
oilfield casing is placed in the wellbore and cemented in place to secure the underground formations and wellbore from collapse while also allowing drilling mud to circulate and be extracted. Casings are typically manufactured using external dimensions from 114.3 mm to 508.0 mm. Due to the harsh working conditions of the casing, the quality requirements for the steel are very strict. Steel should be produced and inspected in accordance with special standards or specifications. ISO 11960 and api spec 5ct specify steel product standards for casings.
L80 bushing
L80 belongs to the corrosion-resistant casing steel grade group. L80 API oilfield casing includes l80-1, L80-9Cr, and l80-13cr. L80-1 is used in H2S environment, while L80-9Cr and L80-13Cr are used in CO2 environment. In corrosive environments dominated by carbon dioxide, Super 13Cr has higher Corrosion resistance than L80-13Cr. This product has a higher Price, is suitable for complex geological conditions, and can be drilled into deeper wells. In Oil and gas extraction, the frequency of use of L80 is lower than that of materials such as J55 and N80.
J55 bushing
J55 API-5CT casing is the lower grade of steel used in oil drilling. Widely used in shallow oil and gas exploration. Because its cost is lower than other steel types, it has a wide range of applications and can generally be used in shallow wells, geothermal wells, and water wells.
N80 bushing
API-5CT N80 oilfield casing includes two types: N80-1 and N80-Q. The chemical composition and mechanical properties of the two materials are exactly the same, but the heat treatment is different. During the heat treatment process, N80-1 steel is normalized and tempered, while N80Q steel is quenched and tempered. Therefore, the collapse strength and internal pressure strength of N80Q are higher than N80-1. Designers should clearly indicate N80-1 or N80Q when selecting n80 casing. Because its mechanical properties are higher than J55 and K55 types, it is well suited for use in some more challenging formations. It is deeper than the J55 and K55 types, and can be suitable for the exploration of middle-layer oil and gas. Due to the high performance of N80 material, API-5CT casing is widely used in natural gas as well as coalbed methane mining and geothermal wells.
P110bushing
P110 API-5CT steel casing is an advanced steel grade among other steel grades. The finished shell is marked with a white band to identify the material. In the process of oil drilling and production, this kind of pipe is widely used in various complex areas due to its high tensile strength and high output. It is the deepest pipe entering the well among other pipes. But the price is higher and the usage is less. P110 casing is mainly used in specific environments and when the drilling depth extends to a specific level.
Mechanical Properties of api 5ct Material Grades
Group grade type Total elongation under load % Yield strength MPa Minimum tensile strength Maximum hardness MPa Specified Wall thickness mm Allowed hardness change b HRC
minute. maximum.hot rolled High strength steel
ied, but maximum variation is limited as a manufacturing control in accordance with API Specifications 7.8 and 7.9. 5CT.
