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:
Jun. 23, 1987
Filed:
Oct. 16, 1985
Wayne V Vogen, Oakland, CA (US);
URS Corporation, San Mateo, CA (US);
Abstract
Method and apparatus for improving oil production in oil wells. The lower end of an elastic steel column is attached to the upper end of a liner. The upper end of the column extends above the top of the well and is attached to a reaction mass lying vertically thereabove through (1) an accelerometer and (2) vertically mounted compression springs in parallel with a vertically mounted servo-controlled hydraulic cylinder-piston assembly. A substantially constant upward load is applied to the reaction mass, and the piston of the hydraulic assembly is reciprocated under servo control to apply vertical vibration to the upper end of the column. This vertical vibration is adjusted through the servo control to an appropriate resonant frequency for the column in the range of 5 Hz to 25 Hz, and the frequency is maintained at resonance by a feedback system relying on maintaining a phase difference of 90.degree. between a displacement signal developed from the accelerometer and a pressure-differential signal related to the pressure difference between the opposite sides of the piston.