Oil casing is an important equipment for oil drilling, its main equipment also includes drill pipe, core pipe and casing, drill collar and small diameter drilling pipe, etc.

How can you tell the difference between good and bad casing?

Shoddy oil casing is prone to folding. Folding is a variety of broken lines formed on the surface of an oil casing. This defect is often found throughout the longitudinal length of the product. The reason for folding is that the shoddy manufacturers pursue high efficiency, the pressure is large, the ear is produced, the next rolling will be folded, the folded product will crack after bending, and the strength of the oil casing will decrease greatly

The appearance of fake oil casing is often pockmarked. A pockmarked surface is an irregular uneven defect on the surface of an oil casing caused by severe groove wear. Because the shoddy oil casing manufacturers want to pursue profit, there is often excessive groove rolling.

The surface of shoddy oil casing is prone to scarring. There are two reasons: 1. The material of fake and inferior oil casing is uneven and there are many impurities. 2, shoddy material manufacturers guide equipment is simple, easy to stick steel, these impurities bite the roll easily produce a scar.

The surface of shoddy materials is easy to crack, the reason is that its billet is adobe, adobe porosity, adobe in the process of cooling due to the action of thermal stress, crack, after rolling.

Shoddy oil casing is easy to scratch, the reason is that shoddy material manufacturers' simple equipment, easy to produce burrs, and scratches the surface of the oil casing. Deep scratching reduces the strength of the oil casing.

Shoddy oil casing has no metallic luster and is reddish or similar in color to pig iron for two reasons. Its blank is adobe. 2. The rolling temperature of fake and inferior materials is not standard. Their steel temperature is measured visually so that it can not be rolled according to the prescribed austenitic area, and the performance of the oil casing can not reach the standard naturally.

The transverse ribs of fake and inferior oil casing are thin and low, and the phenomenon of filling is often dissatisfied. The reason is that in order to achieve large negative tolerance, the manufacturers have large pressure on the first few passes of finished products, small iron shape, and dissatisfied hole shape filling.

The cross-section of fake and inferior oil casing is oval, because the manufacturer in order to save materials, the pressure of the first two rollers of the finished product too large, the strength of this kind of rebar is greatly reduced, and it not meet the standard of the overall size of the rebar.

The composition of high-quality oil casing is uniform, the tonnage of the cold shear machine is high, and the end face of the cutting head is smooth and neat. However, because of poor material quality, the end face of the cutting head often has the phenomenon of meat falling off, that is, uneven and no metallic luster. And because the products of fake and inferior materials manufacturers cut less, the head and tail will appear big ears.

The material of fake and inferior oil casing contains more impurities, the density of steel is small, and the size is out of tolerance seriously, so it can be weighed and checked without a vernier caliper. For example, for rebar steel 20, the maximum negative tolerance is 5% according to the national standard. When 9M is measured, its theoretical weight is 120X (l-5%) = 114kg, and its minimum weight should be 120x (L-5%) = 114kg. If the actual weight of a single bar is smaller than 114kg, it is a fake oil casing because its negative tolerance is more than 5%. In general, it is better to adjust the quantity, mainly because of the cumulative error and probability theory.

The inside diameter of shoddy oil casing fluctuates greatly due to the following reasons: 1, steel temperature instability has a Yin and Yang surface; 2, the composition of steel is not uniform; 3, due to simple equipment, low foundation strength, and rolling mill bounce. There will be a large change in the inner diameter within the same week, such reinforcement force is not uniform and easy to fracture.

The quality of the trademark and printing is standard.

Oil casing diameter 16 or more large thread, the spacing between the two marks is more than IM.

The longitudinal bars of shoddy oil casing is often wavy

Shoddy oil casing manufacturers because there is no truck, so the packaging is loose. Elliptic profile

Cangzhou Shenlong Pipe is a qualified supplier of PetroChina and BP Oil. Its products are widely used in oil and petrochemical projects all over the world. It is a reliable producer.