TUBING WITH AN INNER COATING PROTECTING IT AGAINST DEPOSITS AND A METHOD FOR APPLYING SAID COATING

摘要

The invention relates to the oil industry, in particular to protecting against deposits (asphaltic-resin-paraffin, saline, hydrate and other deposits) on the inner surface of tubings, can be used for coating the inner surface of tubings and for any production of crude hydrocarbons (oil and gas) regardless of well operational conditions and the quality of the crude hydrocarbons to be extracted. The technical result is achieved by a method involving pumping polyurethane into an annular cavity which is formed by the internal surface of the tubing and an punch which is inserted by means of mandrels and has a highly finished surface, holding the polyurethane to the full cure thereof and subsequently extracting the punch from the tubing, thereby enabling the polyurethane to be fully adhered to the tubing metal wall and to obtain the coating having a brightly finished surface and a uniform thickness. According to the polyurethane shrinkage ratio, the tubing can be provided with a tube made from a perforated metal mesh the outer diameter of which is equal to the inner diameter of the tubing. Also, when required by the processing of some polyurethanes, prior to the polyurethane pumping, the tubing is heated to a required temperature by means of any of known methods. The use of the inventive structural design and the application method in combination with the above-mentioned material makes it possible to produce a quality homogenised coating layer having a uniform thickness, a bright finished surface, highly resistant to aggressive media, highly adhesive to the inner surface of a tubing, highly wear-resistant and highly heat-resistant, that excludes the formation of deposits and the consequents associated to said phenomena, to extend the time between maintenance works and overhauls repairs of production wells and, finally to extend the service live of tubings