Nowadays, with the increasing depletion of onshore oil, deep-sea oil drilling has become the main target of countries looking for oil resources. Deep-sea oil drilling conditions are different from land operations. There are two main differences between them. First, deep-sea oil drilling is deeper than land, and the length of casing is lengthened. Secondly, due to the impact of the waves, the stability of the oil casing in the ocean is worse than on land, which isOil casingThe connection strength and anti-rotation ability of the joint put forward higher requirements. The oil casing is about 1m long and is usually connected by threaded joints, that is, one end of the oil casing has a threaded female joint, the other end has a threaded male joint, and the upper and lower joints are connected. Due to the strong waves, the stability of the joint oil casing in seawater is poor, and frequent shaking is easy to cause the two threaded joints to loosen. Therefore, it is urgent to put forward a kind of oil casing sealing connection structure which can be processed in China's machinery factory and meet the requirements of oil field.

In order to achieve the above purpose, the sealing connection structure adopts the following scheme: the oil casing or oil pipe with external cone barb thread and the casing or oil pipe with internal cone barb thread are matched with each other, and a sealing ring is arranged between the external thread end of the oil casing or oil pipe and the casing or oil pipe, which is characterized in that: the step surface contacting the end surface of the casing or oil pipe is an inclined surface, A groove is machined in the face and a sealing ring is placed in the groove. On the oil casing or tubing, a cylindrical surface is machined before the tapered thread (to match the surface, the two surfaces should be closely fitted together. The utility model has the advantages that: because the step surface of the oil casing or oil pipe in contact with the end surface of the sealing ring is an inclined surface, the radial contact stress of the sealing ring is greater than the radial contact stress of the flat step surface, which can ensure the sealing under high pressure, thereby Greatly improve its sealing effect. The threaded joint is the weak part of the casing or tubing, and the corrosive medium penetrates into the thread, which will accelerate the failure of the connection thread. A sealing ring is provided to prevent the corrosive medium in the outer ring space of the casing or tubing from penetrating into the thread, thereby extending the service life of the connecting thread. The cylindrical surface is closely matched, which can ensure that the radial contact stress of the sealing ring will not be reduced under the bending moment of the connecting joint in the horizontal or inclined well, so as to ensure the reliable sealing.

a kindOil casingThe sealing connection structure with the oil pipe includes a casing or oil pipe with an outer tapered barb thread and a casing or oil pipe with an inner tapered barb thread that are matched with each other. A sealing ring is provided between the outer thread end of the oil casing or oil pipe and the casing or oil pipe. Make the groove on the surface and place the sealing ring in the groove. The cylindrical surface is machined in front of the tapered thread of the casing or tubing to match the surface, and the two surfaces should fit closely together. A sealed connection structure of an oil casing and an oil pipe includes a casing or an oil pipe with internal and external tapered barb threads that cooperate with each other. Both ends of the connecting surface are respectively provided with sealing rings, so that the internal and external corrosive media are not easy to immerse in the threads. The contact surface between the end surface of the sealing ring and the oil pipe is an inclined surface, so that it has a higher radial contact stress. The joint surface of the two casings or tubing at the sealing ring is a smooth cylindrical surface, which is closely combined to ensure that the sealing ring will not fail when the joint is subjected to bending moment. The utility model can effectively prevent the corrosive medium from being immersed in the thread, prolong the service life of the connecting thread, and is suitable for oil and gas vertical wells, horizontal wells and inclined wells without corrosive medium or containing corrosive medium.