초록 ▼

Disclosed is a surface controlled subsurface safety valve wherein the greater of well pressure and balance pressure assists in closing the safety valve. Well pressure assist for valve closure is obtained without creating additional depth sensitive limitations as the balance pressure approaches zero.

Disclosed is a surface controlled subsurface safety valve wherein the greater of well pressure and balance pressure assists in closing the safety valve. Well pressure assist for valve closure is obtained without creating additional depth sensitive limitations as the balance pressure approaches zero. Balance pressure assist for valve closure is obtained without well pressure tending to maintain the valve open. This abstract is neither intended to define the scope of the invention, which, of course, is measured by the claims, nor is it intending to be limiting in any way.

대표청구항 ▼

A surface controlled subsurface safety valve comprising: a housing having a bore extending therethrough; closure means disposed in said bore and adapted for movement between position opening and closing said bore; operator means for moving said closure means and axially movable within said bore betw

A surface controlled subsurface safety valve comprising: a housing having a bore extending therethrough; closure means disposed in said bore and adapted for movement between position opening and closing said bore; operator means for moving said closure means and axially movable within said bore between a first and second position; means for resiliently urging said operator means to its first position wherein said closure means closes said bore; control pressure responsive means for moving said operator means to its second position, said control pressure responsive means including control pressure chamber means formed between said housing and said operator means and said control presure responsive means moving said operator means to its second position, wherein said closure means opens said bore, when said control pressure chamber means is pressurized a sufficient amount; and means for moving said operator means to said first position, said moving means including: floating piston means disposed between said operator means and said housing, balance pressure chamber means formed between said operator means and said housing, and defined in part by said floating piston means; means for exposing one portion of said floating piston to well fluid pressure within said bore; and wherein said floating piston has two positions: a first position which allows said floating piston to assist said resilient urging means when the pressure of fluid in said bore is greater than the pressure of fluid in said balance chamber means; and a second position which allows the operator means to be responsive only to the pressure of fluid in the balance chamber means and control chamber means when the pressure of fluid in the balance chamber means exceeds the pressure of fluid in said bore.