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:
Mar. 03, 1992
Filed:
Jun. 26, 1991
David M McStravick, Houston, TX (US);
Baker Hughes Incorporated, Houston, TX (US);
Abstract
To significantly reduce voids in cementing fluids and the effects of cement free fall encountered in well cementing operations, a differential pressure control regulator is inserted in series with the bottom of the well casing to be cemented. Fluid passing through the choke portion passes through an annular valve seat to one end of the tool. A valve stem is slidably and sealably mounted in the flow regulator and has a head portion which, in one position, can contact the valve seating surface and prevent any significant flow of fluid through the casing. The valve stem is biased to one position by a trap chamber filled with a fluid at a known pressure, such as atmospheric pressure, or a vacuum, so that the hydrostatic pressure existing at the bottom of the well casing normally urges the valve head into engagement with the valve seat. Increasing the pressure within the casing, as a consequence of pumping cement, forces the valve head away from the valve seat and permits fluid flow only with a positive surface pumping pressure which minimizes the occurrence of voids in the cement.