Apparatus, System and Method for Lifting Fluids in a Wellbore

Abstract

Disclosed are numerous downhole valves, systems, and a method that increases wellbore production and liquid lift efficiency and provides other benefits. The disclosed valves are designed to replace surface intermitted valves that waste reservoir energy and reduce liquid lift inefficiency in stop cocking and plunger lift systems. Additionally, the disclosure may be used to improve production and lift efficiency for surfactant lift systems and to raise liquids from below to above conventional liquid lift equipment. The disclosed valves open with energy supplied from the reservoir and utilize reservoir gas to lift liquids; therefore, no external gas injection or other energy is required. The design of the disclosed valves reduce or eliminate valve chatter, erosion and plugging issues that affect other downhole valves. Included in the disclosure are numerous valve embodiments comprising a tubular housing, an inlet and an outlet, a closing member, and a seat.

What is claimed is: 
     
         1 . A valve with high spread pressure means positioned in the subsurface for the intermittent lift of fluids in a subterranean wellbore comprising a reservoir and said reservoir comprising fluids and said valve comprising:
 a tubular housing;   a bore with an inlet and an outlet;   a closing member;   a seat; and   said valve has means for unidirectional flow and said reservoir fluids intermittently flow from said inlet to said outlet; and   the valve spread pressure of said valve is attained by a variable force applied to said closing member and said variable force is greater when said closing member is in contact with said seat and said variable force is lower when said closing member is not in contact with said seat; and   said valve opens with wellbore pressure supplied from said reservoir on said inlet side of said valve; and   upon the opening of said valve energy from the pressured gas supplied by said reservoir on the inlet side of said valve lifts said fluids on said outlet side of said valve; and   said valve closes by the reduction of said fluid flow through said valve.   
     
     
         2 . The valve of  claim 1 , wherein said variable force is provided by at least one:
 a pivot arm assembly;   a flat spring;   a magnet;   an imbalance between the combined fluid force vectors acting on the surface area of said closing member on said outlet side and the combined fluid force vectors acting on the surface area of said closing member on said inlet side while said closing member is in a closed position.   
     
     
         3 . The valve of  claim 2 , wherein said pivot arm assembly comprises at least one of: a pivot arm, a compression spring, a rotating wheel. 
     
     
         4 . The valve of  claim 2 , wherein said flat spring comprises at least one rotating wheel. 
     
     
         5 . The valve of  claim 1 , wherein the ratio of said imbalance of combined fluid force vectors is at least one and fifteen hundredths (1.15). 
     
     
         6 . The valve of  claim 1 , wherein said closing member has centralization means to enable an effective seal between said closing member and said seat. 
     
     
         7 . The valve of  claim 1 , wherein said closing member comprises the shape of at least one of a: sphere, ball, cone, a disk, conical frustum, cylinder, cube, cuboid, prism, stem, dart, flapper, an amorphous shaped object. 
     
     
         8 . The valve of  claim 1 , further including a spring in said bore. 
     
     
         9 . A liquid lift system in a wellbore comprising a reservoir comprising fluids and at least one tubular string comprising at least one downhole valve that intermittently opens and closes to control fluid flow in said wellbore and said valve comprising an inlet and an outlet with means for unidirectional flow; and
 when said valve is in a closed position, fluid communication between said outlet side and said reservoir ceases and the liquids in said tubular string above said outlet descend and accumulate on said outlet side of said valve while said inlet side of said valve remains in fluid communication with said reservoir and a downhole chamber is created in said wellbore on said inlet side of said valve and said reservoir increases the gas and liquid pressure in said downhole chamber; and   when said valve is in an open position, said pressured gas in said downhole chamber lifts said accumulated liquids in said tubular string.   
     
     
         10 . The liquid lift system of  claim 9 , wherein said valve further comprises:
 a tubular housing;   a bore;   a seat;   a closing member; and   wherein said closing member creates a seal when in contact with said seat.   
     
     
         11 . The liquid lift system of  claim 9 , wherein said wellbore includes additional liquid lift equipment comprising at least one of: a downhole pump, a gas injection valve, a plunger lift system, a surfactant injection system. 
     
     
         12 . The liquid lift system of  claim 11 , wherein said liquids are lifted to at least one of: the surface, above said additional lift equipment. 
     
     
         13 . The liquid lift system of  claim 11 , wherein supplemental gas is injected into said wellbore to reduce the time interval between the opening and closing of said valve. 
     
     
         14 . A method for the intermittent lift of liquids in a wellbore that extends from a surface to a subterranean reservoir containing reservoir fluids comprising gas and liquids and said wellbore comprising at least one tubular string and said tubular string comprising at least one valve with an inlet and an outlet and said method comprising the steps of:
 flowing said fluids out of said wellbore;   closing said valve by the reduction of said fluid flow through said valve;   accumulating said liquids in said tubular string above said outlet;   increasing the pressure of said reservoir gas in said wellbore on said inlet side of said valve by the inflow of said fluids from said reservoir into said wellbore;   opening said valve with said increased pressure in said inlet side of said valve;   flowing said pressured reservoir gas from said inlet to said outlet;   lifting at least a portion of the volume of said accumulated liquids in said tubular string with said pressured reservoir gas in the direction of said surface;   repeating said steps.   
     
     
         15 . The method of  claim 14 , further including the step of decreasing the time interval between the opening and closing of said valve by supplemental gas injection into the wellbore after the step of increasing the pressure of said reservoir gas in said wellbore on said inlet side of said valve by the inflow of said reservoir fluids into said wellbore. 
     
     
         16 . The method of  claim 14 , wherein said wellbore further includes additional downhole liquid lift equipment.