US 9,810,039 B2
Variable diameter piston assembly for safety valve
James Dan Vick, Jr., Dallas, TX (US); and Bruce Edward Scott, McKinney, TX (US)
Assigned to Halliburton Energy Services, Inc., Houston, TX (US)
Appl. No. 14/396,546
Filed by Halliburton Energy Services, Inc., Houston, TX (US)
PCT Filed Dec. 31, 2013, PCT No. PCT/US2013/078432
§ 371(c)(1), (2) Date Oct. 23, 2014,
PCT Pub. No. WO2015/102603, PCT Pub. Date Jul. 9, 2015.
Prior Publication US 2016/0273304 A1, Sep. 22, 2016
Int. Cl. F16K 31/00 (2006.01); E21B 34/10 (2006.01); F16K 1/20 (2006.01); F16K 31/122 (2006.01); E21B 34/00 (2006.01)
CPC E21B 34/10 (2013.01) [F16K 1/2007 (2013.01); F16K 31/1221 (2013.01); E21B 2034/005 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A safety valve, comprising:
a housing having a piston bore defined therein and configured to receive hydraulic fluid pressure, the piston bore providing an upper bore having a first diameter, a lower bore having a second diameter, and an intermediate bore interposing the upper and lower bores and having a third diameter, wherein the third diameter is greater than the second diameter and the second diameter is greater than the first diameter; and
a piston assembly movably arranged within the piston bore and comprising an upper piston operatively coupled to and axially offset from a lower piston, wherein the upper piston is configured to sealingly engage the upper bore and the lower piston is configured to sealingly engage the lower bore, wherein, when the upper piston is arranged in the intermediate bore, the hydraulic fluid pressure acts on the lower piston.