Sleeve suitable for evaporite bed of oil well

Abstract

The present invention provides a sleeve which is suitable for an evaporate bed of an oil well, which is composed of the following components by weight: 0.26%-0.31% of C; 0.25-0.35% of Si; 0.80-1.00% of Mn; less than or equal with 0.015% of P; less than or equal with 0.010% of S; 0.90-1.00% of Cr; 0.40-0.50% of Mo; 0.07-0.10% of V; and the balance of Fe and inevitable trace elements. The mechanical property is characterized in that: the yield strength is between 896MPa and 1034MPa; the tensile strength is larger than or equal with 1000MPa; an impact toughness index is characterized in that a Charpy impact energy is larger than or equal with 42J (0 DEG C+ / -3, 10*10*55mm, transverse sample); the elongation percentage is larger than or equal with 16%; the wall thickness precision reaches + / -10%; a ratio between an external diameter and the wall thickness reaches 9-14; the collapse resistance strength index exceeds an API 5C3 theoretical value for more than 40%; and the steel pipe is a seamless polished pipe structurally. The sleeve which is suitable for the evaporate bed of the oil well is advantageous in that: the ratio between the external diameter and the wall thickness is 9-14 under a non-uniform load environment when the non-uniform load Pu is larger than PO, an obvious advantage is obtained; and the sleeve can bear larger non-uniform load.

Description

technical field [0001] The invention relates to the production of a casing, in particular to a casing suitable for oil well salt-gypsum layers. Background technique [0002] At present, in the oil drilling industry, salt-gypsum formations and rock-salt formations are often encountered. After ordinary casings are run in, due to their thin wall thickness, the ratio of outer diameter / wall thickness is very large, and the general ratio may exceed 16, or the application In the perforated section of ordinary casing, the anti-collapse ability of the original casing decreases due to perforation. Although the anti-collapse strength index of the casing often meets the requirements of the industry standard (API theoretical value), the actual resistance If the formation pressure is not enough, the running casing body will be collapsed, or the service life will not be long after running, resulting in the scrapping of the whole well or failing to meet investment expectations, resulting in...

AI Technical Summary

Problems solved by technology

However, the alloy cost and raw material cost of the steel pipe are relatively high. This method is not scientific, and the smelting and rolling process is more difficult when the alloy content is high.

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