Multisection Downhole Separator and Method

Abstract

A downhole separator has first and second separation sections each with a housing defining an interior cavity divided into a first chamber and a second chamber by a flow restricting bearing housing. Each separation section has an internal pump that pumps production fluid into the first chamber and to the bearing housing. The bearing housing limits flow into the second chamber and releases pressure on gas in the production fluid entering the second chamber, separating gas from liquid. A vortex generator in the second chamber segregates the liquid to the outside and the gas to the inside of the second chamber. The bearing housing of the upstream separation section has a greater capacity than the bearing housing of the downstream separation section.

1 . A downhole gas and liquid separator for a well comprising:
 an upstream, first separation section and a downstream, second separation section in flow communication with said first separation section, said first and second separation sections each including:
 first and second chambers, 
 an internal pump, for pumping production fluid through said first chamber, and into said second chamber, and 
 means, positioned a between said first and second chambers, for restricting fluid flow to release pressure on gas in said production fluid and to separate gas and liquid as said production fluid enters said second chamber, and 
 a vortex generator in said second chamber to centrifugally separate said fluid into gas and liquid, 
   wherein said means for restricting fluid flow of said first separation section has a selected capacity and said means for restricting fluid flow of said second separation section has a selected capacity that is smaller than said capacity of said means for restricting fluid flow of said first separation section,   whereby said first separation section separates a first portion of gas from said production fluid and said second separation section separates a remaining portion of gas from said production fluid.   
     
     
         2 . The separator as set forth in  claim 1  wherein said internal pump in at least one of said first and second separation sections includes an inducer. 
     
     
         3 . The separator as set forth in  claim 1  wherein said internal pump of in least one of said first and second separation sections includes an impeller. 
     
     
         4 . The separator as set forth in  claim 1  wherein said first and second separation sections each include a driven rotary shaft extending through said first and second chambers. 
     
     
         5 . The separator as set forth in  claim 4  wherein said vortex generator includes a pair of spaced paddle assemblies on said shaft. 
     
     
         6 . The separator as set forth in  claim 4  wherein said means for restricting fluid flow is a bearing housing that has a bearing that stabilizes said shaft. 
     
     
         7 . The separator as set forth in  claim 6  wherein said bearing housing has a plurality diagonally extending passages between said first and second chambers that restrict fluid flow and propel said production fluid into said second chamber in a diagonal direction, and thereby initiate vortex generation. 
     
     
         8 . The separator as set forth in  claim 6  wherein said second chamber is elongated and said vortex generator is positioned near said bearing housing,
 whereby said production fluid has increased time to separate before exiting said second chamber. 
 
     
     
         9 . The separator as set forth in  claim 1  wherein:
 said first and second separation sections each include an elongated housing having a first and second end, a base and a head, said base attaching to said first end and including inlet ports, and said head attaching to said second end and including gas and liquid outlet ports, and 
 said inlet ports in said base of said second separation section connect to said liquid outlet ports in said head of said first separation section. 
 
     
     
         10 . A downhole gas and liquid separator for a well comprising:
 a first separation section having a housing with a first end and a spaced second end, a base at said first end with inlet ports and a head at said second end with gas and liquid outlet ports, said first separation section having a first chamber and a downstream second chamber, an inducer for pumping production fluid through said first chamber and into said second chamber, a bearing housing positioned between said first and second chambers that restricts fluid flow to release pressure on gas in said production fluid and to separate gas and liquid as said production fluid enters said second chamber, and a vortex generator in said second chamber to centrifugally separate said fluid into gas and liquid, said first separation section having a driven rotary shaft connecting to and rotating said inducer and said vortex generator, said bearing housing having a selected capacity, and   a second separation section having a housing with a first end and a spaced second end, a base at said first end connected to said liquid outlet ports of said first separation section and a head at said second end with gas and liquid outlet ports, said second separation section having a first chamber and a downstream second chamber, an inducer for pumping production fluid through said first chamber, and into said second chamber, a bearing housing positioned between said first and second chambers that restricts fluid flow to release pressure on gas in said production fluid and to separate gas and liquid as said production fluid enters said second chamber, and a vortex generator in said second chamber to centrifugally separate said fluid into gas and liquid, said second separation section having a driven rotary shaft connecting to and rotating said inducer and said vortex generator, said bearing housing having a selected capacity that is less than said capacity of said bearing housing in said first separation section,   whereby said first separation section separates a first portion of gas from said production fluid and said second separation section separates a remaining portion of gas from said production fluid.   
     
     
         11 . A method of separating gas and liquid from production fluid in a well comprising the steps of:
 providing a first separation section with connected first and second chambers,   pumping said production fluid into said first chamber of said first separation section,   restricting flow of said production fluid from said first chamber into said second chamber of said first separation section to a selected first flow rate,   generating a vortex in said second chamber of said first separation section, to further separate said gas and said liquid,   providing a second separation section connected to said first separation section and having connected first and second chambers,   pumping said production fluid from said second chamber of said first separation section into said first chamber of said second separation section,   restricting flow of said production fluid from said first chamber into said second chamber of said second separation section to a selected second flow rate that is less than said first flow rate, and   generating a vortex in said second chamber of said second separation section, to further separate said gas and said liquid.   
     
     
         12 . The method as set forth in  claim 11  wherein:
 said step of restricting flow of said production fluid into said second chamber of said first separation section includes the steps of:
 providing a bearing housing between said first and second chambers with said bearing housing having a plurality of restrictive passages extending between said first and second chambers, and 
 passing said production fluid through said passages, and 
 said step of restricting flow of said production fluid into said second chamber of said second separation section includes the steps of: 
 providing a bearing housing between said first and second chambers with said bearing housing having a plurality of restrictive passages extending between said first and second chambers, and 
 passing said production fluid through said passages. 
 
 
     
     
         13 . The method as set forth in  claim 12  wherein said bearing housing in said first separation section has a selected capacity and said bearing housing in said second separation section has a selected capacity that is less than said capacity of said bearing housing in said first separation section. 
     
     
         14 . The method as set forth in  claim 11  wherein:
 said step of generating a vortex in said second chamber of said first separation section includes the steps of: 
 providing a pair of spaced paddle assemblies and 
 rotating said paddle assemblies, and 
 said step of generating a vortex in said second chamber of said second separation section includes the steps of: 
 providing a pair of spaced paddle assemblies and 
 rotating said paddle assemblies.