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. 04, 2000
Filed:
Mar. 09, 1998
Robert W Dinning, Houston, TX (US);
Other;
Abstract
A differential pressure operated free piston for lifting well fluids from a subterranean reservoir to the surface through a well conduit. The free piston includes a piston body adapted for up and down sliding disposition within the conduit and a sealing assembly carried in a cylindrical space surrounding the piston body. The sealing assembly includes upper and lower juxtaposed sets of longitudinally separated cylindrical segments providing relatively smooth cylindrical surfaces on the exterior thereof for sliding and sealing contact with inner walls of the conduit, the upper and lower set of segments being radially oriented so that separations between the segments of the upper set and separations between the segments of the lower set are not aligned, providing a seal which, when pressure in the well conduit near the surface is subsequently reduced, sufficiently elevates the piston and well fluids thereabove to the surface.