System, Apparatus and Method For Producing A Well

Abstract

A system is provided that is capable of providing heat across a produced interval during oil and gas production to minimize or reduce undesirable formation of gas hydrates in the wellbore. In one embodiment, the configuration provides a means to recycle heat generated by an electrical submersible pump. Heat from the pump may be applied downhole. One configuration is capable of providing for downhole separation of gas from produced fluids to reduce or eliminate gas transit through the pump. A heating element also may apply heat to produced fluids. In one embodiment, a system may provide for the safe containment and control of gas within the wellbore by the utilization of a safety valve.

1 . A system for producing oil and gas from a wellbore penetrating a subterranean formation, the system comprising:
 (a) a wellbore lined with a casing, the wellbore having an upper end and a lower end, the lower end of the wellbore being adjacent the subterranean formation, further wherein the casing is tubular in shape with an interior cavity;   (b) production tubing positioned within the interior cavity of the casing;   (c) a pump connected to the production tubing, the pump being adapted for lifting hydrocarbons within the production tubing;   (d) an isolation sleeve positioned circumferentially outside of the production tubing and within the interior cavity of the casing,   (e) an inner space between the isolation sleeve and the production tubing;   (f) an outer space between the isolation sleeve and the casing;   (g) the isolation sleeve being configured to facilitate the upward movement, within the outer space, of production fluids and gas towards the upper end of the wellbore;   (h) the isolation sleeve being configured to facilitate the downward movement, within the inner space, of production fluids toward the lower end of the wellbore;   (i) the pump being adapted for transmission of heat to the production fluids in the inner space, thereby elevating the temperature of the production fluids;   (j) the system being configured for transferring heat carried by the production fluids to the lower end of the wellbore to reduce the formation of gas hydrates in the wellbore.   
     
     
         2 . The system of  claim 1 , the system further comprising a heating element positioned to contact production fluids in the inner space. 
     
     
         3 . The system of  claim 1  further comprising a ported bushing sub, wherein the ported sub is configured to receive production fluids and gas from the outer space and facilitate the movement of the production fluids to the inner space. 
     
     
         4 . The system of  claim 3  wherein the ported bushing sub is positioned adjacent a gas collection space, wherein production fluids and gas from the inner space may proceed through the ported bushing sub for separation such that gas is accumulated in the gas collection space while production fluids are provided to the inner space for transport downhole. 
     
     
         5 . The system of  claim 4  wherein an annular seal locator sub is positioned above the gas collection space, the annular seal locator sub being configured for releasing gas from the gas collection space towards the upper end of the wellbore. 
     
     
         6 . The system of  claim 5  wherein a safety valve is positioned upon the annular seal locator sub for controlling gas release from the gas collection space. 
     
     
         7 . The system of  claim 3  wherein the ported bushing sub is adapted for sealed engagement with a polished bore receptacle. 
     
     
         8 . A method of producing oil and gas from a wellbore, the wellbore having a casing penetrating a subterranean formation, the wellbore having an upper end and a lower end, the method comprising:
 (a) providing production tubing within an interior cavity of a casing, the production tubing being connected to a pump, the pump being adapted for lifting hydrocarbons within the production tubing;   (b) providing an isolation sleeve positioned circumferentially outside of the production tubing and within the interior cavity the casing, there being an inner space between the isolation sleeve and the production tubing, further providing an outer space between the isolation sleeve and the casing;   (c) moving production fluids and gas within the outer space towards the upper end of the wellbore;   (d) separating the production fluids from the gas;   (e) moving production fluids downward within the inner space adjacent the pump;   (f) transferring heat from the pump to the production fluids;   (g) elevating the temperature of the production fluids;   (h) transferring heat carried by the production fluids towards the lower end of the wellbore; and   (i) reducing the formation of gas hydrates in the wellbore.   
     
     
         9 . The method of  claim 8  wherein at least one heating element is provided upon or adjacent the production tubing, the method comprising the additional step of transferring heat from the heating element to the production fluids and transferring such heat towards the lower end of the wellbore. 
     
     
         10 . The method of  claim 8  further comprising the step of:
 (j) transporting the production fluids through the production tubing towards the upper end of the wellbore. 
 
     
     
         11 . A system for isolating gas in a wellbore, the wellbore having a casing with an interior cavity formed by an interior surface, the wellbore having an upper end and a lower end, the system comprising:
 (a) a polished bore receptacle forming a seal with the interior surface of the casing; and   (b) an annular seal locator sub mated with the polished bore receptacle, the annular seal locator sub being configured to form a gas-tight collection space below the annular seal locator sub to collect gas within the casing of the wellbore, the annular seal locator sub further comprising at least one gas-tight penetration adapted for a safety valve, further wherein the system is configured to control the release of gas from the wellbore.   
     
     
         12 . The system of  claim 11  further comprising production tubing positioned within the casing and extend through the annular seal locator sub. 
     
     
         13 . The system of  claim 12  further comprising a pump connected to the production tubing, the pump being positioned downhole from the annular seal locator sub, the pump further being adapted for lifting hydrocarbons within the production tubing. 
     
     
         14 . The system of  claim 13  further comprising an isolation sleeve positioned circumferentially outside of the production tubing and within the casing. 
     
     
         15 . The system of  claim 14  further comprising: (a) an inner space between the isolation sleeve and the production tubing and (b) an outer space between the isolation sleeve and the casing. 
     
     
         16 . The system of  claim 15  wherein the isolation sleeve is configured to facilitate the upward movement, within the outer space, of production fluids and gas towards the upper end of the wellbore. 
     
     
         17 . The system of  claim 16  wherein the isolation sleeve is configured to facilitate the downward movement, within the inner space, of production fluids toward the lower end of the wellbore. 
     
     
         18 . The system of  claim 17  wherein the pump is adapted for transmission of heat to the production fluids in the inner space, thereby elevating the temperature of the production fluids. 
     
     
         19 . The system of  claim 18  wherein heat is carried by the production fluids to the lower end of the wellbore to minimize the formation of gas hydrates in the wellbore. 
     
     
         20 . The system of  claim 19  further comprising a heating element positioned as to contact production fluids in the inner space.