Expansion casing for plugging medium-high-pressure stratum and manufacturing method of expansion casing

Abstract

The invention discloses an expansion casing for plugging a medium-high-pressure stratum. The expansion casing comprises, by mass percentage, 0.08-0.18% of C, 0.18-0.38% of Si, 0.5-1.2% of Mn, 0.35-0.85% of Mo, 0.25-0.55% of Ni, 0.04-0.15% of Nb, 0.05-0.12% of RE, not larger than 0.005% of S, not larger than 0.010% of P, 0.0005-0.001% pf B and the balance Fe and inevitable impurities. The expansioncasing comprises the following preparation steps of coiled plate manufacturing, ERW pipe making, weld heat treatment, whole pipe heat treatment and stress relief treatment, nondestructive flaw detection and thread processing. After the expansion casing undergoes radial expansion deformation of not larger than 15%, the longitudinal ReL of the casing is in the range of 655-758 MPa, Rm is larger than 724 MPa, A is larger than 13%, and the external collapsing strength is larger than or equal to 32 MPa.

Description

technical field [0001] The invention relates to the technical field of metal materials, in particular to an expansion casing for medium and high pressure formation sealing and a manufacturing method thereof. Background technique [0002] The expansion pipe technology is to lower the pipe string into the well, and make the pipe string undergo permanent plastic deformation by mechanical or hydraulic methods, so as to enlarge the inner diameter of the wellbore or the production pipe string. This technology can increase the casing layer, simplify the wellbore structure, and save drilling costs. It is a more flexible completion method and a brand-new workover method, and it is also one of the most revolutionary technologies in oil field drilling and completion (Li Yiliang , Chen Qiang, Li Tao, Han Weiye, Bi Xiuling, Sun Qiang. New progress in the application of foreign expansion tube technology. Petroleum Machinery, 2013, 42(1): 24-27). Since 2001, domestic research on solid exp...

AI Technical Summary

Problems solved by technology

Chinese patent CN104087834B adds Ca, Cu, Ce / La mixed rare earths to medium and low carbon steel, and adds one or more of Ni, Mo, Nb, V, Ti, and adopts HFW welding-weld seam online normalizing treatment-whole The method of quenching and tempering in the two-phase zone of the pipe, invented J55, N80 steel grade groove corrosion-resistant expansion pipe steel and welded expansion sleeve, but its strength and expandability cannot meet the plugging requirements of high-pressure formations

At the same time, on the one hand, the above three patents do not mention the external pressure collapse resistance of the expansion tube before and after expansion; secondly, the radial expansion rate is ≤10%; thirdly, the minimum yield strength of the P110 steel grade expansion tube in the API 5CT standard is 758MPa, This puts forward higher requirements for the operating pressure and operating equipment of oil field expansion construction

Pipe expansion and deformation is a kind of cold processing. The higher the yield strength, the greater the expansion pressure required for on-site expansion operations, and the higher the requirements for operating equipment. The purpose of this patent is to develop 95ksi steel grade expansion pipes, taking into account the on-site operation, to overcome the problem of insufficient anti-extrusion performance