LSAW Steel Pipe

    In order to ensure the safe operation of submarine pipelines during the designed life, the pipeline system shall fully prevent internal and external corrosion caused by the transport medium and seawater.     (1) Outer coating     Engineering practice proves that in actual seawater environments, the outer coating can provide effective corrosion protection. The outer coatings for submarine pipelines include coal tar enamel, asphalt enamel, epoxy resin, polyethylene resin, polybutadiene rubber, and the like.     (2) cathodic protection     As a supplement and reinforcement to the outer coating, cathodic protection provides adequate protection during the design life of the submarine pipeline system. Cathodic protection systems for subsea pipelines are usually based on sacrificial anodes.     The material of the sacrificial anode may be an alloy of aluminum or zinc. The weight and number of anodes are related to the re...

    (1) The domestic casing pipe is in accordance with SY / T6194-96. The length of the casing is variable, and its range is 8-13m. However, casings no shorter than 6m can be provided, and the number must not exceed Over 20%.     (2) No folds, hair lines, delaminations, cracks, folds and scars on the inner and outer surfaces of the casing. These defects shall be completely removed, and the removal depth shall not exceed 12.5% of the nominal wall thickness.     (3) The outer surface of the coupling must not have defects such as folding, hairline, delamination, cracks, folds, scarring, etc.     (4) The thread surface of the casing and coupling should be smooth, and no burrs, tears or other defects sufficient to interrupt the thread and affect the strength and tight connection are allowed.     http://www.xysteelpipe.com/info/The-Appearance-Quality-Requirements-of-Oil-Casing-Pipe-1658-1.htm

    Common defects of spiral steel pipe welding zone     1. Bubbles     Most of the bubbles appear in the center of the weld, and the hydrogen is still hidden in the weld metal in the form of bubbles. The main reason is that there is moisture and flux on the surface of the welding wire, which can be used directly without drying. There is also a relatively large current during the welding process. It is small, the welding speed is too fast, and accelerated solidification of the metal may also occur.     2. Undercut     Undercut occurs along the center-line of the weld. V-grooves appear at the edge of the weld. The main reason is that the welding speed, current and voltage are not suitable. The welding speed is too high to be more suitable than the current welding speed. It is easy to cause undercut defects.     3. Hot crack     The cause of thermal cracking is when the welding stress is high or when the Si...

    Marine natural gas must be transported by offshore pipelines, and crude oil produced in shallow water can be directly loaded into tankers by production platforms. However, the crude oil produced in the deep sea, the large oil tanker docking on the production platform will threaten the platform safety, so there is a single point mooring in the sea dedicated to docking large oil tankers. In this way, there must be an oil pipeline connecting the production platforms to a single point mooring.     The marine pipeline laying operation is developed by the construction method of land pipelines crossing rivers and lakes. There are three main methods of pipe laying: pipe laying, towing, and drum boat laying. Which operation method is selected depends on the diameter of the pipe, the depth of the seawater, the sea conditions, and the distance from the shore.     ① Pipelaying vessel laying     This is the most commonly used method. The operation p...

    First of all, the place or warehouse where ERW steel pipes are stored should be selected in a clean and well-drained place, away from factories and mines that produce harmful gases or dust. On the site, weeds and all debris should be removed to keep ERW straight seam steel pipe equipment accessories clean.     Secondly, in the warehouse, it should not be stacked with materials that are corrosive to ERW straight seam steel pipes such as acids, alkalis, salts, cement, etc. Different types of ERW straight seam steel pipes should be stacked separately to prevent confusion and prevent contact corrosion.     In addition, the warehouse should be selected according to geographical conditions.Generally, the general closed warehouse is used, that is, the warehouse has a roof with walls, tight doors and windows, and a ventilation device.     The ERW straight seam steel warehouse requires attention to ventilation in sunny days, and shutting off mois...

    Oil casing pipe is a steel pipe used to support the wall of oil and gas wells to ensure the normal operation of the entire oil well during the drilling process and after completion.     According to the American Petroleum Institute standard APISPEC5CT first edition in 1988, casing steel grades H-40, J-55, K-55, N-80, C-75, L-80, C-90, C-95, P- There are 10 types of 110 and Q-125. The casing should be supplied with threads and couplings, or in the form of any of the following pipe ends: flat ends, round threads without couplings or couplings, partial trapezoidal threads with couplings or couplings, straight Thread, special end processing, seal ring structure.     (1) The main importing countries of petroleum casing are: Germany, Japan, Romania, Czech Republic, Italy, Britain, Austria, Switzerland, United States, Argentina, and Singapore. Import standards refer to API5A, 5AX, 5AC standards of the American Petroleum Institute. The steel grades are H-40...

    1. Reduce the time of starting and drilling. It is about 5-10 times faster to replace the drill bit with a wire rope than with a conventional drill pipe .     2. Save on the purchase, transportation, inspection, maintenance and replacement costs related to drill pipes and drill collars;     3, because there is always a casing in the well-bore, there is no longer the pumping effect on the well-bore when the drill pipe is lowered, which improves the well control situation;     4. Eliminate the pumping effect and pressure pulsation caused by the lower drill pipe;     5. When the drill bit is lifted with a wire rope, the mud can be continuously circulated, which can prevent the accumulation of cuttings and reduce the occurrence of well surge;     6. Improved annulus return speed and well-bore cleaning. When the mud is pumped into the casing, its inner diameter is larger than that of the drill pipe, which reduces hydra...

    In recent years, in order to reduce the billet's cost, vigorously developing oxygen converter steel and continuous casting billet to produce billet can reduce the cost of about 15%. The quality of the billet is influenced by the quality of seamless pipe for structure: Is the primary factor in determining the quality of seamless pipes. Cold drawn seamless pipe believes that in order to ensure the reasonable progress of the perforation process and obtain high-quality seamless pipes, strict requirements must be imposed on the geometric dimensions, low magnification structure and surface state of the tube blank     If the diameter of the tube blank is too large or the ellipse is too large, the bite conditions during perforation will be deteriorated, and the inward folding will be caused due to the excessive compression of the tube blank diameter.     Internal organization refers to shrinkage and central porosity, accumulation of non-metallic inclusions...

    Different types of casing pipe used in oil extraction: Surface oil casing protects the well from being contaminated by shallow water and shallow gas layers, supports wellhead equipment and maintains the weight of other layers of casing. The technical oil casing separates the pressure at different levels so that the drilling fluid can flow properly and protect the production casing. In order to install anti-burst devices, leak-proof devices and tail pipes in the drilling. Reservoir oil casings direct oil and gas from reservoirs below the surface. It is used to protect drilling and to layer drilling mud. When producing oil casing, the outer diameter is usually 114.3 mm to 508 mm.     Protect wells from contamination from shallow water and shallow gas layers, support wellhead equipment and maintain the weight of other layers of casing.     The technical oil casing separates the pressure at different levels so that the drilling fluid can flow properly a...

　　Frequently Asked Questions on Welding of Long Distance Pipeline Construction 　　1. Slag inclusion 　　Reason: Because long-distance pipelines are mostly filled and covered with the semi-automatic downward welding process using flux-cored wire, the top wire phenomenon often occurs when the semi-automatic equipment has gap failures. At this time, the welding wire penetrates into the molten pool, When the pool is rapidly cooled and ignited again, the weld is often wrapped with metal debris or slag, which causes slag inclusion. 　　Measures: Bevel should be carefully cleaned before root welding, and slag should be carefully cleaned during filling and cover welding. 　　2. Stomata 　　Cause: The pores in the filling layer are mainly caused by the high arc voltage during the semi-automatic welding of the self-protecting flux core. 　　Measures: In the welding process, select the appropriate arc voltage and wire feed speed, maintain a certain wire extension length, and control the appr...