Connections of oil casing 1. External upset direct connection method: pipe with an inner threaded section and thickened, and the other side external threading. Phase coupled together, the sleeve has a smooth inner surface, 2. Direct connection method: both ends of the tube is threaded inside and outside, is directly connected to the pipe smooth inside and outside surfaces. 3. Took over the connection method: threaded inner ends of the tubes are used to take over the connection. Outside the connection is smooth. 4. The coupling connection method: threaded outer ends of the tubes are connected with external hoop. Late into the internal connection smooth surface In addition, recently, the method of welding the sleeve junction can make the tube surface smooth  after welding.

1, To reduce tripping time. By using wireline replacement than traditional drill with drill rod from about 5-10 times faster; 2, Save the drill pipe and drill collars related procurement, transportation, inspection, maintenance and replacement costs; 3, Because there is always the wellbore casing, no longer have the time to drill down from the pumping action within the wellbore, the well control situation has improved; 4, Due to the elimination of the drill pipe from the pumping action and bring pressure pulsation; 5, Maintained when the wire rope from under the continuous circulation drill mud, cuttings prevents aggregation also reduces the occurrence of a kick; 6, To improve the return on annular velocity and cleaning the wellbore conditions. When the sleeve is pumped into the mud because of an inner diameter larger than the drill pipe, reducing the hydraulic losses, which can reduce the drilling rig mud pump with power. Mud returns from the annular space between the casing and the borehole wall, since the annulus area is reduced, improving the return on the speed and improve the drill cuttings taken out of the situation; 7, The size can be reduced rig, the rig structure to simplify and reduce the cost of drilling rig; 8, Rig more lightweight, easy to move and operate. Manual labor and costs are reduced.

Tubing & casing compared with mechanical transmission, electric drive, hydraulic drive has the following advantages: 1, The various components of the hydraulic drive, can easily and flexibly be arranged as needed. 2, Light weight, small size, low inertia, fast response. 3, Easy operation control, can achieve a wide range of variable speed (speed range up to 2000: 1). 4, Automatic overload protection. 5, Generally use mineral oil as the working medium, the relative movement surface can be self-lubricating, long life; 6, It is easy to achieve linear motion / 7, It is easy to automate the machine, when the electro-hydraulic joint control, not only to achieve a higher degree of process automation, and remote control can be achieved.

First: spiral steel pipe end degaussing method 1, with a coil wound outside the steel pipe, to pass on the exchange electric coil, and gradually reducing the current exchange of electricity, until the phase-out to zero. Degaussing effect: do not change the physical properties of spiral steel pipe, however, in the event of an external magnetic field again, spiral steel pipe will be magnetized. 2, through the heat treatment process punishment, can probably complete demagnetization than the force, but, after degaussing, spiral steel hardness and rigidity will be change, and then when the next encounter magnetic field, after the external magnetic field dissipates, steel will fundamentally no residual magnetism. 3, the heat treatment process of punishment, probably is: anaerobic heated to a certain temperature, and then, with 72 hours and gradually cooled to room temperature. Second: spiral steel pipe produce a magnetic field reasons In the welding process, welding satisfied within DC welding, internal welding line and large horn positions due to a large current produce a strong magnetic field, the steel tube in the magnetic field, the magnetic moment or tendency to give in and get an external magnetic field similar bias breakdown. When welding then ended, the magnetic field gradually eliminated until dissipated, because of hysteresis phenomenon, otherwise the tubular body residual magnetic flux density exists, which is what we usually refer to the remanence phenomenon. Third: Hazard spiral steel field The existence of residual magnetism, image enhancer deflecting an electron beam deflection, X-ray industrial TV system image produce "S" type distortion, affecting the pores, slag and other natural defects, particularly a lack of penetration, cracks and other linear natural defect detection rate. With the progress of pipeline stage and television system to strengthen the X-ray image transducer type, especially the impact of residual magnetism. The existence of residual magnetism when the pipeline butt welding ring, will produce signs of partial arc, affecting the quality of welding.

From 15th to 17th July, Mexico customer visit and study Husteel Group for three days. The deputy general manager Mr.Zeng, deputy general manager Mrs.Chen, and the person in charge from electronic commerce department accompanied the visit. The customer visited the production workshops of seamless steel pipe and welded steel pipe. After seeing the working performance, the customer spoke highly of the products; and then makes a deep discussion with the related department officer. The customer was deeply impressed by advanced technology, convenient operation, high efficiency and comfortable operating environment.Previously, the client also examined other well-known manufacturers of the industry.