Production fluid control device and method for oil and/or gas wells

Abstract

A device and method for selectively controlling the flow of production fluid through a tubing string in an oil and gas well according to which a housing is connected to a tubing string for insertion into the well, and well fluid is passed from the ground surface into the housing. The housing is provided with a plug to establish well fluid pressure in the housing to actuate a packer and/or other ancillary devices. The plug can be removed from the hosing by increasing the pressure of the well fluid in the housing above a predetermined value, thus permitting the flow of production fluid from the formation zone, through the housing and the tubing string, and to the ground surface.

1. A method for controlling the flow of production fluid from a formation zone in an oil and/or gas well to the ground surface, the method comprising the steps of introducing a fluid into the well for normally preventing the flow of production fluid from the formation zone, inserting a tubing string including a packet and a housing into the well, passing well fluid from the ground surface into one end of the housing, closing the other end of the housing for creating a well fluid pressure in the housing to set the packer in the annulus between the tubing string and the wall of the well, increasing the pressure of the well fluid in the housing sufficient to open the other end of the housing and thus permit the flow of production fluid from the formation zone through the housing and the tubing string and to the ground surface. 
     
     
       2. The method of  claim 1  comprising the steps of retaining a piston in the housing, the increased-pressure well fluid in the housing releasing the piston and sliding the piston in the housing against the plug for opening the housing. 
     
     
       3. The method of  claim 2  wherein a plug closes the other end of the housing and the piston fractures the plug. 
     
     
       4. The method of  claim 2  wherein the well fluid in the housing acts on the respective ends of the piston with a force corresponding to the respective areas of the surfaces of the latter ends, wherein the area of the surface of one of the ends of the piston is greater than the area of the surface of the other end of the piston to create a differential force, and wherein the piston slides in response to the differential force exceeding a predetermined value. 
     
     
       5. The method of  claim 4  wherein the housing and the piston extend substantially vertically, with the surface of the upper end of the piston having a greater area that the surface of the lower end of the piston so that the piston slides substantially downwardly in the housing. 
     
     
       6. A device for controlling the flow of production fluid from a formation zone in an oil and/or gas well to the ground surface, the device comprising:
 a housing adapted to be connected at one end to a tubing string for insertion into the well and forming an annulus between the outer surface of the housing and the inner surface of the well, the one end of the housing being open for receiving well fluid from the ground surface;  
 a plug disposed in the other end of the housing for permitting the increase in pressure of the well fluid in the housing;  
 a piston disposed in the housing;  
 a plurality of shear pins connected to the piston for normally retaining the piston in the housing, the shear pins responding to the pressure of the well fluid in the housing exceeding a predetermined value for shearing to permit slidable movement of the piston in the housing against the plug to remove the plug from the housing and open the other end of the housing to permit the flow of production fluid from the formation zone, through the housing and the tubing string and to the ground surface;  
 a packer extending in the annulus, that portion of the annulus extending between the packer and the formation zone containing well fluid under pressure to normally maintain the production fluid in the formation zone; and  
 a port defined in the wall of the housing to permit the latter well fluid to enter the housing and act against the piston.  
 
     
     
       7. A method for controlling the flow of production fluid from a formation zone in an oil and/or gas well to the ground surface, the method comprising the steps of:
 connecting one end of a housing to a tubing string for insertion in a vertical orientation into the well;  
 passing well fluid from the ground surface into the one end of the housing;  
 normally closing the other end of the housing for creating a well fluid pressure in the housing;  
 retaining a piston in the housing so that the well fluid in the housing acts on the respective ends of the piston, the area of the surface of the upper end of the piston being greater than the area of the surface of the lower end of the piston so that the fluid acts on the respective ends of the piston to create a differential force;  
 the piston sliding downwardly in the housing in response to the differential force exceeding a predetermined value to open the other end of the housing and thus permit the flow of production fluid from the formation zone through the housing and the tubing string and to the ground surface;  
 forming an annulus between the outer surface of the housing and the inner surface of the well;  
 setting a packer in the annulus;  
 maintaining pressurized well fluid in that portion of the annulus extending between the packer and the formation zone to normally maintain the production fluid in the formation zone; and  
 permitting the latter well fluid to enter the housing and act against the piston to change the differential force.  
 
     
     
       8. A device for controlling the flow of production fluid from a formation zone in an oil and/or gas well to the ground surface, the device comprising:
 a housing adapted to be connected at one end to a tubing string for insertion into the well, the one end of the housing being open for receiving well fluid from the ground surface;  
 a frangible plug extending in the housing and closing the other end of the housing being closed to permit the pressure of the well fluid in the housing to build up; and  
 a piston normally retained in the housing and having a pointed end, the piston being responsive to the pressure of the well fluid in the housing exceeding a predetermined value for sliding in the housing towards the plug so that the pointed piston end fractures the frangible material of the plug to open the other end of the housing and permit the flow of production fluid from the formation zone, through the housing and the tubing string and to the ground surface.  
 
     
     
       9. The device of  claim 8  further comprising a plurality of shear pins connected to the piston for normally retaining the piston in the housing, the shear pins responding to the pressure of the well fluid in the housing exceeding the predetermined value for shearing to permit the slidable movement of the piston. 
     
     
       10. A method for controlling the flow of production fluid from a formation zone in an oil and/or gas well to the ground surface, the method comprising the steps of:
 connecting one end of a housing to a tubing string for insertion into the well; passing well fluid from the ground surface into the one end of the housing; closing the other end of the housing with a frangible plug for creating a well fluid pressure in the housing; and  
 providing a piston having a sharp end in the housing and adapted to respond to the pressure of the well fluid in the housing exceeding a predetermined value and to slide in the housing until its sharp end fractures the plug to open the other end of the housing to permit the flow of production fluid from the formation zone through the housing and the tubing string and to the ground surface.  
 
     
     
       11. The method of  claim 10  further comprising the step of retaining the piston in the housing by a plurality of shear pins, the shear pins responding to the pressure of the well fluid in the housing exceeding the predetermined value for shearing to permit the slidable movement of the piston. 
     
     
       12. A device for controlling the flow of fluid in a well, the device comprising:
   a housing having a bore therethrough;        a frangible plug blocking flow through the bore; and        a piercing structure which pierces the plug in response to a pressure differential between an interior of the housing and an atmospheric chamber, thereby opening the bore to flow therethrough.     
     
     
       13. A device for controlling the flow of fluid through a tubular string in a wellbore, the device comprising:
   a housing interconnectable in the tubular string for insertion into the wellbore to thereby form an annulus between an outer surface of the housing and the wellbore;        a plug disposed in the housing and blocking fluid flow therethrough, thereby permitting an increase in pressure in the tubular string to set a packer interconnected in the tubular string;        a gas chamber;        a piston exposed to fluid pressure in the tubular string and to pressure in the gas chamber;        at least one retainer member connected to the piston for retaining the piston against displacement in the housing, the retainer member permitting displacement of the piston when fluid pressure in the tubular string exceeds pressure in the gas chamber by a predetermined amount, the piston thereby piercing the plug and opening the plug to fluid flow therethrough.     
     
     
       14. A method for controlling the flow of fluid in a tubular string positioned in a wellbore, the method comprising the steps of:
   interconnecting a housing in the tubular string, a plug in the housing preventing fluid flow through the housing and thereby permitting pressure in the tubular string to be increased;        retaining a piston in the housing, the piston being exposed to pressure in the tubular string and pressure in a gas chamber;        setting a packer interconnected in the tubular string by increasing pressure in the tubular string;        then further increasing pressure in the tubular string, thereby achieving a predetermined differential between pressure in the tubular string and pressure in the gas chamber;        displacing the piston in response to the predetermined pressure differential; and        piercing the plug in response to the piston displacing, thereby permitting fluid flow through the housing.     
     
     
       15. A device for controlling the flow of fluid in a tubular string in a well, the device comprising:
   a housing adapted to be interconnected in the tubular string for insertion into the well;        a frangible plug disposed in the housing and preventing fluid flow through the housing; and        a piston normally retained against displacement in the housing, the piston being responsive to pressure in the housing exceeding pressure in a gas chamber by a predetermined amount to displace toward the plug and cause at least a portion of the plug to be broken, thereby permitting fluid flow through the housing.     
     
     
       16. A method for controlling the flow of fluid through a tubular string in a wellbore, the method comprising the steps of:
   interconnecting a housing in the tubular string, a frangible plug in the housing preventing fluid flow through the housing;        providing a chamber in the housing, the chamber being isolated from fluid communication with an interior of the tubular string, and the chamber being isolated from fluid communication with an annulus formed between the tubular string and the wellbore;        providing a piston in the housing, the piston being nonresponsive to pressure in the annulus and nonresponsive to a difference in pressure between the annulus and the interior of the tubular string;        increasing pressure in the tubular string, thereby achieving a predetermined differential between pressure in the interior of the tubular string and pressure in the chamber; and        displacing the piston in response to the pressure increasing step, thereby breaking at least a portion of the plug and permitting fluid flow through the housing.