Self-inflatable packer

Abstract

The invention discloses a self-inflatable packer, comprising an oil tube body, a self-inflatable rubber tube, and two limiting rings, wherein the oil tube body penetrates through the self-inflatable rubber tube in an axial-movement manner; and the two limiting rings sleeved outside the oil tube body and fixedly connected with two ends of the self-inflatable rubber tube, wherein an opening stop ring for enabling the limiting rings to be relatively fixed with an oil tube body at normal temperature and enabling the limiting rings and the oil tube body to float relatively when the temperature rises to the high temperature is installed in each limiting ring; and a dynamic sealing device is installed between the oil tube body and the limiting rings. Because the opening stop ring for enabling the limiting rings to be relatively fixed with the oil tube body at normal temperature and enabling the limiting ring and the oil tube body to float relatively when the temperature rises to the high temperature is installed in each limiting ring, the expansion and deformation generated by heating the oil tube body do not influence the self-inflatable rubber tube, the damage of the setting seal is avoided and the setting seal effect of the packer is good.

Description

technical field [0001] The invention relates to a downhole tool for oil and gas wells for oil development, in particular to a self-expanding packer. Background technique [0002] As the national economy's demand for oil and natural gas energy continues to increase, the development of oil and gas resources has gradually shifted from focusing on conventional resources to focusing on both conventional and unconventional resources. Among unconventional resources, heavy oil resources have a large proportion and have become one of the main battlefields for development. Among the various processes for developing heavy oil, steam injection thermal recovery technology is the mainstream technology, and downhole insulation is the key technology to ensure thermal recovery effect and improve thermal recovery rate. The high temperature resistant packer is a key downhole supporting tool. It seals the annular space of the tubing and casing during steam injection in heavy oil wells, reducin...

AI Technical Summary

Problems solved by technology

[0004] The existing packers for thermal recovery mainly include four types: mechanical type, hydraulic type, thermal expansion type and heat-sensitive metal type. The first two types have the following disadvantages: (1) Complex structure, unstable thermal sealing performance, and poor heat insulation effect (2) The damage to the casing is serious, the economic loss is huge, it is inconvenient for multi-stage use, and it is difficult to realize layered or multi-layer steam injection; (3) It must be connected with a thermal expansion tube, which cannot be self-compensated and adjust

The thermal expansion packer has made great progress compared with the previous two packers, but the existing thermal expansion packer has the following disadvantages: (1) The expansion agent is a kind of alkane with a relatively large molecular weight and is flammable 1. Volatile solution, poor stability, easy to decompose, once decomposed, it is difficult to unseal; (2) The carbon content of the expansion cylinder material is too low, the yield strength is low, and the plastic deformation is large, so the pressure resistance is poor and it is difficult to unseal; (3) The overall deformation increases the difficulty of the packer going into the well, and the length of the sealing jacket of the material is small and the outer diameter is equal, which affects the sealing pressure resistance performance

The heat-sensitive metal packer overcomes the shortcomings of the previous packers to a certain extent, but there are problems of limited use conditions, such as the applied oil well inclination angle cannot exceed 30°, the well depth should be less than 1800m, and the To be fitted with extension tube

[0005] In addition, there are also self-expanding packers. The existing self-expanding packers include a self-expanding rubber tube and a tubing, and the tubing is relatively fixed to the self-expanding rubber tube. Since the expansion rates of the two are not the same, the expansion and contraction deformation of the tubing caused by heating will have an impact on the sealed rubber tube, making the sealing effect of the packer poor

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