Shrouded band-pass filter for oil well

Abstract

Generally, embodiments described herein take the form of a shrouded band-pass filter that ensures liquid flow past the filter while reducing or minimizing gas contact with the filter. A shroud encircles the band-pass filter and is affixed to a dip tube (to which the band-pass filter is also affixed). The shroud and band-pass filter are contained within tubing within the oil well. As the pump operates, a fluid and gas mixture is drawn into the tube by operation of the pump. Gas may exit the tubing through vents while the fluid flows downward within the tubing. Fluid flows around the shroud and thus past the band-pass filter, before entering a dip tube via a strainer positioned within the shroud and above the filter. The dip tube permits the fluid to flow upward and, ultimately, out of the oil well as the pump operates.

What is claimed is: 
     
         1 . A gas separator for use with a reciprocating pump in a well, comprising:
 a tube;   a plug capping a lower end of the tube;   a dip tube in fluid communication with the reciprocating pump, at least a portion of the dip tube positioned within the tube;   a strainer at an opposing end of the dip tube from the reciprocating pump;   a band-pass filter attached to an end of the strainer opposite the dip tube; and   a shroud affixed to the dip tube above the strainer and the band-pass filter.   
     
     
         2 . The gas separator of  claim 1 , wherein the shroud extends downward within the tube toward the plug and past an end of the band-pass filter. 
     
     
         3 . The gas separator of  claim 2 , wherein the shroud defines a fluid flow path past the band-pass filter. 
     
     
         4 . The gas separator of  claim 3 , wherein:
 the fluid flow path is a first fluid flow path; and   the shroud further defines a second fluid flow path into the strainer.   
     
     
         5 . The gas separator of  claim 3 , wherein an upper portion of the tube defines a gas vent. 
     
     
         6 . The gas separator of  claim 3 , wherein a lower portion of the shroud defines at least one through-hole. 
     
     
         7 . The gas separator of  claim 1 , wherein the dip tube is attached to an inlet of the reciprocating pump. 
     
     
         8 . A gas separator for use with a reciprocating pump in a well, comprising:
 a tube;   a plug capping a lower end of the tube;   a sealing coupling attached to an upper end of the tube;   a dip tube attached to the sealing coupling, at least a portion of the dip tube positioned within the tube;   a strainer at an opposing end of the dip tube from the reciprocating pump;   a band-pass filter attached to an end of the strainer opposite the dip tube; and   a shroud affixed to the dip tube above the strainer and the band-pass filter and encircling the band-pass filter.   
     
     
         9 . The gas separator of  claim 8 , wherein the sealing coupling allows gas to flow from a lower face of the sealing coupling to a side surface of the sealing coupling. 
     
     
         10 . The gas separator of  claim 9 , wherein the sealing coupling restricts flow of a hydrocarbon fluid from the lower face to an upper face of the sealing coupling. 
     
     
         11 . The gas separator of  claim 8 , wherein a lower portion of the shroud defines an annular space between an interior surface of the shroud and an exterior surface of the band-pass filter. 
     
     
         12 . The gas separator of  claim 11 , wherein an upper portion of the shroud extends outward from the dip tube to the lower portion of the shroud. 
     
     
         13 . The gas separator of  claim 8 , wherein the dip tube is in fluid communication with an inlet to the reciprocating pump. 
     
     
         14 . The gas separator of  claim 8 , wherein the gas separator further includes a mud joint. 
     
     
         15 . A method of treating a fluid, the method comprising:
 receiving a fluid from an oil well in a gas separator, the fluid from the oil well comprising a mixture of a hydrocarbon fluid and a gas;   producing an at least partially degasified fluid by directing the fluid from the oil well toward a lower end of the gas separator; and   producing a treated fluid by directing the at least partially degasified fluid along a flow path between an exterior surface of a band-pass filter of the gas separator and an interior surface of a shroud of the gas separator.   
     
     
         16 . The method of  claim 15 , wherein the shroud limits contact between the band-pass filter and gas separated from the fluid during the operation of producing the at least partially degasified fluid. 
     
     
         17 . The method of  claim 15 , wherein:
 the method further comprises directing the treated fluid through a strainer of the gas separator and into a dip tube of the gas separator.   
     
     
         18 . The method of  claim 17 , wherein:
 gas exits the gas separator through a vent in a tube of the gas separator during the operation of producing the at least partially degasified fluid, the tube at least partially surrounding the dip tube, the band-pass filter, and the shroud.   
     
     
         19 . The method of  claim 17 , wherein:
 the operation of receiving the fluid from the oil well into the gas separator comprises receiving the fluid from the oil well through an opening in a tube of the gas separator, the tube at least partially surrounding the dip tube, the band-pass filter, and the shroud and the opening located above a fluid entry zone of the oil well.   
     
     
         20 . The method of  claim 15 , further comprising an operation of directing the treated fluid through a dip tube of the gas separator and into an inlet of a reciprocating pump.