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:
Sep. 29, 1981
Filed:
Nov. 05, 1979
Ronald K Churchman, Carrollton, TX (US);
Otis Engineering Corporation, Dallas, TX (US);
Abstract
A drill string safety and kill valve for a string of drill pipe used for drilling wells including a tubular valve body connectible in the drill pipe, a ball valve in the body mounted to rotate between open and closed positions for controlling flow through the body, a longitudinally movable tubular ball valve operator in the body connected with the ball valve, a spring biased flapper valve in the ball valve operator mounted to permit downward flow and to close responsive to upward flow for raising the ball valve operator to close the ball valve, a side port provided in the side of the ball valve positioned upwardly when the ball valve is closed for pumping drilling fluids downwardly into the bore of the closed ball valve, and a spring biased lower ball valve seat moved downwardly by downward flow of drilling fluid when the ball valve is closed to allow pumping into a well for killing the well after valve closure. During normal drilling operations drilling fluids are pumped downwardly through the open flapper and ball valves. A sudden upward pressure surge closes the flapper valve which in turn closes the ball valve. Heavier drilling fluid for killing the well may then be pumped downwardly through the flapper valve into and around the closed ball valve pushing the lower ball valve seat downwardly away from the ball valve and downwardly between the ball valve and lower seat to enter the formation being drilled.