The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 07, 2019
Filed:
Mar. 04, 2015
Kureha Corporation, Tokyo, JP;
KUREHA CORPORATION, Tokyo, JP;
Abstract
A degradable rubber member for a downhole tool formed from a rubber material containing from 0.1 to 20 parts by mass of a degradation accelerator relative to 100 parts by mass of a degradable rubber (optionally containing other rubber materials and/or reinforcing materials), of which, preferably, the decrease rate of the mass or the 50% strain compressive stress after immersion for 24 hours in 150° C. water is not less than 5%, and/or the mass loss rate after immersion for 72 hours in 150° C. water is from 5 to 100%, and further, as desired, the tensile fracture strain at 66° C. is not less than 50%, the 70% strain compressive stress is not less than 10 MPa, and the compressive fracture strain is not less than 50%; a degradable seal member or a protecting member for downhole tools comprising such a rubber member; and a downhole tool such as a plug for well drilling, and a method for well drilling.