- 行业: Oil & gas
- Number of terms: 8814
- Number of blossaries: 0
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A type of corrosion produced when a metal absorbs hydrogen atoms. This phenomenon can cause undesirable effects such as blistering, cracking, methane formation above 400<sup>o</sup>F (204<sup>o</sup>C) and hydrogen embrittlement.
Industry:Oil & gas
A type of corrosion in which two different metals are placed in contact in a corrosive environment. A small electric current flows from one piece of metal to the other, accelerating the corrosion rate of the more reactive of the two metals. <br><br>Bimetallic corrosion is sometimes found when new pipe is added to old pipelines. The old pipeline covered by oxide and rust is cathodic to the new pipe, thus accelerating the corrosion rate in the new pipe. Another type of bimetallic corrosion is ringworm corrosion.
Industry:Oil & gas
A type of corrosion in which there is loss of metal in localized areas. The corrosion rate in the pits is many times greater than the corrosion rate on the entire surface. <br><br>The resultant pits can be large and shallow or narrow and deep. Pitting is a more dangerous problem than general corrosion because the pitted areas can be easily penetrated.
Industry:Oil & gas
A type of corrosion in which the metal components of a structure fail due to cyclic stresses applied in a corrosive environment, such as salt water. Consequently, a break in the metal will occur at stresses considerably lower than the tensile strength of the material. <br><br>Corrosion fatigue is the main cause of sucker-rod and drillstring failures.
Industry:Oil & gas
A type of check valve often used in the lines or manifolds associated with kill and choke lines or pressure-control equipment.
Industry:Oil & gas
A type of check valve, typically installed in the tubing hanger, to isolate the production tubing. The back-pressure valve is designed to hold pressure from below yet enable fluids to be pumped from above, as may be required for well-control purposes.
Industry:Oil & gas
A type of circular seal commonly found in downhole tools and a wide range of surface equipment applications. The specification of O-ring material depends on the conditions for which the seal is intended, such as system operating temperature and pressure. Various backup systems are used to support the O-ring seal in either dynamic or static sealing applications.
Industry:Oil & gas
A type of blowout preventer (BOP) in which each ram set combines two conventional ram functions, such as blind/shear and pipe/slip. The principal advantage of the combi-BOP is the reduced height required for rig up of the required ram functions.
Industry:Oil & gas
A type of bimetallic corrosion. Ringworm corrosion has the shape of a ring and is located a few inches from the pipe upset. The 鈥渞ing鈥?can either be very smooth or have severe pitting. <br><br>Ringworm corrosion is caused by the upsetting process, in which the heat required for upsetting creates two different grain structures, one in the upset and another in the rest of the pipe. This condition can be avoided by fully normalizing the pipe after upsetting. To normalize the pipe, heat is applied to change the grains to a uniform structure.
Industry:Oil & gas
A type of batch-treating technique used in corrosion control. The batch of corrosion inhibitor is displaced through the annulus to the bottom of the well. Once the inhibitor is at the bottom, it is circulated up the tubing and returned back into the annulus, leaving a considerable amount of inhibitor in the annulus for further circulation. <br><br>A standard batch treatment is used mainly in pumping wells and could last from a day to several months depending on the specific corrosion inhibitor used.
Industry:Oil & gas
