Separator and method for removing free gas from a well fluid

Abstract

A separator for removing free gas from a fluid extracted from a well, comprising a conventional electric submersible pump system, with a centrifugal gas separator, coupled to a static, gas separator of the gas anchor type, via a an ESP capsule, which has a closed upper end that forms a seal against the casing of the centrifugal gas separator and a lower conical end, with an adapter on the lower end of the capsule, which is connected to the upper end of the static separator. Also disclosed is a method for separating free gas from a fluid extracted from a well Among other advantages, aspects disclosed enable gas to be separated more efficiently and a fluid with a larger amount of liquid and low gas concentration to be sent to the production pump, such that the amount of gas enables the pump system to remain as stable as possible.

1 . A separator for removing free gas from a fluid extracted from a well comprising;
 a conventional electric submersible pump system;   a static gas separator, the upper end of which is coupled to the lower end of a capsule, which has a closed upper end and a conical lower end with an adaptor; and   a centrifugal gas separator located inside the capsule, such that the intake holes of the centrifugal gas separator are inside the capsule and the vent holes of said separator are outside the capsule.   
     
     
         2 . The separator for removing free gas from a fluid extracted from a well according to  claim 1 , characterized in that the electric submersible pump system comprises;
 a bottom sensor connected to a motor, which is protected by a lower seal and an upper seal, coupled in the upper part of the latter;   a centrifugal gas separator;   a gas handling pump; and   a production pump;   wherein the bottom sensor, the motor, the lower seal, and the upper seal, the centrifugal gas separator, the gas handling pump, and the produption pump are coupled by flanges.   
     
     
         3 . The separator for removing free gas from a fluid extracted from a well according to  claim 2 , characterized in that the centrifugal gas separator comprises:
 a shaft that rotates at the speed of the electric submersible motor, stabilized on the base thereof by an outer hub and an inner hub and on the head thereof by an outer hub;   a plurality of intake holes, through which the fluid enters, whereby that is the inductor begins centrifugal movement; the fluid rises to the blade guide and the rotor, whereby the centrifugal speed thereof increases and, due to the difference between densities, the liquid remains at the ends inside the compression tube and the gas in the center; wherein the two separated fluids rise through different compartments; wherein the gas is guided towards the vent holes and from there, towards the annular space of the well while the gas-free liquid continues to rise inside a head towards the pump.   
     
     
         4 . The separator for removing free gas from a fluid extracted from a well according to  claim 1 , wherein the lower end of the centrifugal gas separator is not in contact with the adaptor of the capsule. 
     
     
         5 . The separator for removing free gas from a fluid extracted from a well according to  claim 4 , characterized in that the capsule extends up to a length of 30.48 cm (1 foot) under the bottom sensor of the electric submersible equipment. 
     
     
         6 . The separator for removing free gas from a fluid extracted from a well according to  claim 1 , characterized in that the static separator is a gas anchor type separator. 
     
     
         7 . The separator for removing free gas from a fluid extracted from a well according to  claim 6 , characterized in that the static separator comprises a grooved hollow tube, through which the well fluid enters and descends internally until reaching a tube with a larger inner and outer diameter than the grooved hollow tube; wherein a Venturi effect and coalescence effect and subsequently, the separation of free gas, occur inside said tube; wherein the fluid moves through the tube until reaching an immersion tube, having a smaller inner and outer diameter than the tube with a larger inner and outer diameter than the grooved hollow tube, through which the fluid without the gas released in the static gas separator rises to the capsule. 
     
     
         8 . The separator for removing free gas from a fluid extracted from a well according to  claim 7 , characterized in that the static separator further comprises a tube of glue with a bottom plug to store solids for segaration. 
     
     
         9 . The separator for removing free gas from a fluid extracted from a well according to  claim 7 , characterized in that an upper point of the immersion tube of the static separator joins to the adaptor. 
     
     
         10 . The separator for removing free gas from a fluid extracted from a well according to  claim 9 , characterized in that the capsule for the electric submersible pump system (ESP) is a cylindrical tube with a diameter between 6″ (15.24 cm) and 8″ (20.32 cm) and a length between 54 feet (16.46 m) and 60 feet (18.29 m), which hangs via a plurality clamps at the base of the centrifugal gas separator. 
     
     
         11 . The separator for removing free gas from a fluid extracted from a well according to  claim 10 , characterized in that the lower conical end of the capsule has a reduced diameter of between 6″ (15.24 cm) to 8″ (20.32 cm) to one of between 3″ (7.62 cm) to 5″ (12.7 cm) and the height of said end is between 1 foot (30.48 cm) and 2 feet (60.96 cm). 
     
     
         12 . The separator for removing free gas from a fluid extracted from a well according to  claim 10 , characterized in that the lower conical end of the capsule has square threading. 
     
     
         13 . The separator for removing free gas from a fluid extracted from a well according to  claim 10 , characterized in that semi-threaded plugs that seal the annular space between the body of the centrifugal separator and the cylinder itself are installed in the upper stop of the cylinder. 
     
     
         14 . A method for separating gas from a well fluid, the method comprising:
 a. Passing the fluid extracted from a well through a static separator connected to an adaptor, thereby freeing the gas bubbles into the annular space of the well and the descending fluid stream entering through the lower open point of the immersion tube and making it rise until reaching the upper point of said tube, which is connected to the adaptor of tea capsule;   b. Introducing the fluid with a smaller amount of free gas, coming from the static separator into the capsule, through the adaptor;   c. Passing the fluid contained in the capsule through a centrifugal gas separator that is part of a conventional electric submersible pump system;   d. Removing gas from the centrifugal gas separator towards a ring of a well through the a plurality of vent holes of said separator; and   e. Sending the liquid fluid with a smaller amount of gas to a gas handling pump and from the gas handling pump to a production pump.   
     
     
         15 . The method according to  claim 14 , characterized in that stage a) comprises the entry of the fluid with a high amount of gas into upper and lower grooved tubes of the static separator, the descent thereof through the inner space until reaching a pair of tubes, the inner and outer diameter of which are larger than the diameter of the upper and lower grooved tubes; a Venturi effect and a coalescence effect occur inside the pair of tubes, which create larger gas bubbles, which rise through the descending fluid stream due to the difference between densities, and leave through the the upper and lower grooved tubes, through which they entered, to the annular space of a second well. 
     
     
         16 . The method according to  claim 14 , characterized in that in stage c), the fluid contained in the capsule enters the a plurality of intake holes of the centrifugal gas separator, located inside the capsule; a second stage of gas separation occurs in the centrifugal separator, and in stage d), the separated gas leaves through the plurality of vent holes of the centrifugal gas separator, located outside of the capsule, towards the annular space of the well.