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:
Apr. 10, 1990
Filed:
Mar. 04, 1988
Schlumberger Technology Corporation, New York, NY (US);
Abstract
The present invention relates to a device for placing a radioactive source into a formation through which a borehole passes. The device includes a gun barrel, a bullet containing a radioactive source and engaged in the barrel, and an explosive device for propelling the bullet towards the formation. The device further includes two items which reduce the speed at which the bullet, when fired, penetrates into the formation. These items are a spacer, placed in the barrel between the bullet and the explosive device, and a braking shield placed at the port end of the barrel. The spacer reduces the effect of the gases produced by the explosive device upon detonation. The braking shield is entrained with the fired bullet, the front end of the shield producing drag which also acts to retard the forward propulsion of the bullet. The shield is designed to break away from the bullet upon formation impact, further reducing the kinetic energy of the bullet. The invention is applicable to soft formations.