Oil casing is a steel pipe used to support the well wall of oil and gas wells to ensure that the drilling process is carried out and that the entire well operates properly after completion. Several layers of casing are used in each well depending on the drilling depth and geological conditions. The casing is cemented after the well is drilled, and unlike tubing and drill pipe, it is not reusable and is a one-time consumable material. Therefore, the consumption of casing accounts for more than 70% of all oil well tubing.

Oil special pipe is mainly used for drilling of oil and gas wells and transmission of oil and gas. It includes oil drilling pipe, oil casing and oil 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 the drilling process and after completion to ensure the drilling process and the normal operation of the whole well after completion. The pumping tubing is mainly used to transport oil and gas from the bottom of the well to the surface.
Oil casing is the lifeline that keeps the well running. Due to the different geological conditions, the downhole stress state is complex, with tensile, compressive, bending and torsional stresses acting on the tubing body in an integrated manner, which places high demands on the quality of the casing itself. Once the casing itself is damaged for some reason, it may lead to production reduction of the whole well or even scrapping.
According to the strength of the steel itself, the casing can be divided into different steel grades, i.e. J55, K55, N80, L80, C90, T95, P110, Q125, V150, etc. Different well conditions and depths require different steel grades. In corrosive environments, the casing itself is required to have corrosion resistance. In places with complex geological conditions, the casing is also required to have anti-crushing properties.

27MnCrV is a new steel grade for the production of TP110T steel grade casing. 29CrMo44 and 26CrMo4 are the conventional steel grades for the production of TP110T steel grade casing. 27MnCrV contains less Mo elements than the latter two, which can greatly reduce the production cost. However, the normal austenitizing quenching process is used to produce 27MnCrV with significant high-temperature temper brittleness, resulting in low and unstable impact toughness.
To solve such problems are usually used in two ways: one is the use of tempering after rapid cooling method to avoid high-temperature brittleness, to obtain toughness. The second is the sub-temperature quenching method through the incomplete austenitization of steel to effectively improve the harmful elements and impurities, improve toughness. The first method, relatively strict requirements for heat treatment equipment, requires the addition of additional costs.
AC1=736°C and AC3=810°C for 27MnCrV steel, the heating temperature during sub-temperature quenching is selected between 740-810°C. Sub-temperature quenching selected heating temperature 780 ℃, quenching heating holding time of 15min; quenching and tempering selected temperature 630 ℃, tempering heating holding time of 50min. due to sub-temperature quenching in the α + γ two-phase zone heating, quenching in the retention of part of the undissolved ferrite state, while maintaining a higher strength, toughness is improved.
At the same time, low-temperature quenching is lower than the conventional temperature, reducing the stress of quenching, thus reducing the deformation of quenching, which ensures the smooth operation of the production of heat treatment, and provides a good raw material for the subsequent wire turning process.
The process has been applied in the processing plant, quality assurance data show that the yield strength Rt0.6 in 820-860MPa, tensile strength Rm in 910-940MPa, impact toughness Akv in 65-85J between the steel pipe after heat treatment, 100% of the destruction resistance qualified. The data show that 27MnCrV steel pipe has been quite high quality high steel grade petroleum casing, on the other hand, also shows that the sub-temperature quenching process is a way to avoid high temperature brittleness in the production of steel products.

1. Petroleum casing is a large diameter tubing that serves to hold the wall or well bore of oil and gas wells in place. The casing is inserted into the borehole and secured with cement to help isolate the borehole from rock formations and prevent collapse of the borehole, as well as to ensure the circulation of drilling mud for drilling and extraction.
2. Steel grade of oil casing: H40, J55, K55, N80, L80, C90, T95, P110, Q125, V150, etc. Casing end processing forms: short round thread, long round thread, partial trapezoidal thread, special buckle, etc. It is mainly used for oil well drilling to support the well wall during the drilling process and after the completion of the well to ensure the normal operation of the entire well after the completion of the well.
3. The important position of oil pipe
4. The petroleum industry is an industry that uses a large amount of petroleum tubing, and petroleum tubing occupies a very important position in the petroleum industry.
5. 1, oil tubing usage, spending a lot of money, saving money, cost reduction potential is huge. The consumption of oil well pipe can be projected by the annual drilling footage. According to the specific situation in China, roughly 62kg of oil tubing is needed for every 1m of drilling, including 48kg of casing, 10kg of tubing. 3kg of drill pipe and 0.5kg of drill collar.
6. the mechanical and environmental behavior of oil tubing has an important impact on the adoption of advanced technology and increased production and efficiency in the oil industry.
7. The failure loss of oil pipe is huge, and its safety, reliability and service life are of great importance to the oil industry.

Generally speaking, the surface treatment of structural steel plates is needed to increase their anti-corrosion and durability. The quality of surface treatment directly affects the adhesion of the coating to the substrate of the coated workpiece and the corrosion resistance of the material. Oil, grease, dust and other contaminants will cause the paint film to fall off or produce a variety of appearance defects, anticorrosive coating can improve the anticorrosive protection of the paint layer on the steel plate and the smooth surface of the base steel. Common anticorrosive coatings require a substrate surface cleanliness of SA2.5 or above, and steel plate surface coatings provide excellent corrosion protection for the water treatment industry, pulp and paper mills, Bridges and offshore facilities.

According to the design and drawings, the anti-corrosion coating on the exposed part of the bridge support and the shock-absorbing steel plate is treated to prolong its service life. The main construction method is epoxy zinc-rich primer construction, according to the requirements of the design position of the steel plate to achieve protection purposes. The process includes base surface cleaning → primer coating (epoxy zinc-rich primer 50μm, 2 times) → finish coating (modified polyurethane topcoat 50μm, 2 times) → inspection and acceptance. The supporting plan of coating is as follows:

The base surface cleaning

Before the paint is brushed, the coating and rust of the exposed part of the steel plate of the support and the shock absorber plate are polished off with an Angle grinder. The quality standard for rust removal is SA2.5.

Primer coating (epoxy zinc-rich primer 50μm, 2 coats)

1) Epoxy zinc-rich primer, according to the ratio of 9∶1 and control the viscosity of the paint, the system should be fully stirred, so that the paint color and viscosity is uniform, curing 25 ~ 30 minutes, the paint needs to be used up within 4 ~ 6 hours.

2) Brush the first layer of primer brushing direction should be consistent, neat. Apply multiple times to prevent the brush from running too much paint.

3) Maintaining a certain time after the first brush, to prevent paint not dry paint flow drop. Brush the second time after the first drying. The direction should be perpendicular to the first time and the film thickness should be uniform.

Finish coating(modified polyurethane finish 50μm, 2 times)

1) Top paint is green. The finish coat should be made of a modified polyurethane finish of the same color, in accordance with the appropriate proportion. Full mixing before use and uniform color to ensure that the coating does not fall, do not show grain.

2) The method and direction should be the same as the above process.

3) The coating interval between top coat and primer should be more than 2 days.

Wldsteel produces welded steel line pipe, both spiralweld and rolled and welded, in lengths from 30’ to 60’ and wall thicknesses from .250 inches to 2.0 inches. These line pipes, often used to transfer liquid and air, meet the following standards: AWWA C200, ASTM 139, ASTM 134, and ASTM 135.

Steel pipe has many advantages to offer, including strength and weight, ease of installation, and cost.

Wldsteel is SPFA certified and produces 18” OD to 90” OD hydrotested line pipe using a double submerged arc weld process for a variety of applications, including but not limited to, water transmission pipelines, slurry pipelines, gravity sewer mains, sewer force mains, intake and outfall lines, and raw water lines. Recently, Wldsteel’s line pipe has been used for water pipelines in both New York City and Texas.

Wldsteel has the ability to machine bevel steel pipe ends, which produces a much cleaner edge on the finished product. Line pipe can also be coated and lined and undergoes UT testing, in addition to the hydrotesting.

With steel line pipe manufacturing and stocking locations across North America, Wldsteel has the ability to quickly and efficiently deliver line pipe by truck, rail, or barge to partners across the country.

Ecologically responsible, fiscally sound resource management is only possible with the right infrastructure. Unfortunately, you don’t have to look far to find examples that fall short of the ideal — many of which center around the use of substandard pipe.

Wldsteel is transforming how private entities and municipal stakeholders manage the critical resources that advance our shared quality of life. Our welded steel line pipe raises the standard, no matter whether you use it for sewer, water, slurry, or other applications.

Diverse Steel Pipe Products
Every job demands specialized hardware, and failing to use the right products yields disastrous results. We’ve developed an extensive tooling line that produces highly performant pipe.

Regardless of what your target use entails, we have a solution made to match. Our spiral-welded products permit the easy creation of line pipes in numerous diameters accepted for use in seismically active zones, and our rolled and welded products are ideal for applications that require incredibly thick walls. What’s more, we can

Produce a range of lengths from 30 feet (9.14 m) to 60 feet (18.29 m)

Create custom-cut ends for simplified on-site joining

Deliver pipe with 18-inch to 90-inch outer diameters

Fabricate spotless bevel ends that make installation and fitting more manageable

Offer precise-tolerance wall thicknesses from 0.250 inches (6.35 mm) to 2.0 inches (5.08 cm).

Quality Oversight Fit for Global Applications
With Wldsteel line pipe, builders can readily meet stringent code, environmental, and safety requirements. Simply let us know which industry standard your line pipe needs to meet, and we’ll comply with AWWA C200, ASTM 139, ASTM 134, or ASTM 135 products that fit the bill.

Need a coating or lining? Our in-house specialists can apply surface treatments and perform ultrasonic testing that ensures perfect results.

As an SPFA-certified enterprise, we’re qualified to serve the water market with pipe that government stakeholders and end-users can depend on. Our engineering is here to help you with your design needs. We take pride in knowing our products are keeping the water flowing to some of North America’s most demanding populations.

We take great pains to ensure the quality of our work. From maintaining stringent fabrication controls during the double-submerged arc weld process to hydro-testing every pipe that rolls off our production line, we’re committed to producing infrastructure components that won’t quit under harsh conditions.

When the Pressure Rises, Professionals Trust Wldsteel
Line pipe isn’t just for standard water transmission. It also has to beat the odds in gravity sewer mains, sewer force mains, intake and outfall lines, potentially hazardous raw water lines, and a host of other applications.

No project timeline is too sudden, and no requirement is too demanding. With steel line pipe manufacturing and stocking locations across North America, Wldsteel quickly and efficiently delivers to any job site. Whether it reaches you by truck, rail, or barge, you’re only a click away from the world’s leading line pipe, so reach out now.