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:
Jul. 25, 2017
Filed:
May. 29, 2014
Kureha Corporation, Tokyo, JP;
Masayuki Okura, Tokyo, JP;
Takeo Takahashi, Tokyo, JP;
KUREHA CORPORATION, Tokyo, JP;
Abstract
A plug for well drilling process comprising: (a) a mandrel formed from a degradable material; (b) a pair of rings placed on an outer peripheral surface existing in the orthogonal to an axial direction of the mandrel, at least one of the rings being formed from a degradable material; and (c) at least one diameter-expandable circular rubber member placed at a position between the pair of rings on the outer peripheral surface existing in the orthogonal to the axial direction of the mandrel; the percentage of mass loss in the degradable material after immersion for 72 hours in water at a temperature of 150° C. preferably being from 5 to 100%; and a well drilling method comprising the step of plugging well hole using the plug for well drilling process, wherein part or all of the plug for well drilling process degrades after the plugging.