Pulsation Dampening System for High-Pressure Fluid Lines

Abstract

Disclosed is an in-flow pulsation dampening system for high-pressure (e.g., 10K psi and higher) fluid lines. At high fluid flow pressures, the dampening system is a dual stage dampening system, responsive to low (e.g., when first charging the fluid line) and to very high-pressure pulsations. An external containment shell handles the full fluid flow pressures. One or more internal shells contain and handle the internal gas dampening system. The in-flow relationship of the gas dampening component assures that pressure differences between the internal gas handling system and the high-pressure fluid flow is always relatively small. This enables the gas handling components to be constructed of less robust material than the external shell (even though the gas system's internal pressure can equal that of the fluid flow), and be less susceptible to pressure failure.

What is claimed is: 
     
         1 . A pulsation dampener apparatus ( 10 ) for dampening pressure pulses in a high-pressure fluid flow line ( 16 ), the pulsation dampener apparatus ( 10 ) comprising:
 a dampener housing ( 12 ), the dampener housing ( 12 ) substantially being an elongated pipe having two ends ( 14 ) a first-end ( 14   a ) and a second-end ( 14   b ), and internally having a fluid flow thru-path ( 22 ) and a non-flow fluid chamber ( 24  ) both along a length (L) of the dampener housing ( 12 ), the dampener housing ( 12 ) in liquid communication with the fluid flow thru-path ( 22 );   a housing-to-flow line adapter ( 20 ) adapted to connect the ends ( 14 ) of the dampener housing ( 12 ) to said high-pressure fluid flow line ( 16 );   a series of high-pressure damper canisters (50) internally disposed in the non-flow fluid chamber ( 24 ) of the dampener housing ( 12 ), the damper canisters ( 50 ) each having a damper piston assembly ( 70 ) received in the damper canister ( 50 ) with the piston assembly ( 70 ) having a damper piston ( 72 ) disposed to move vertically to compress the gas above and within the damper canister ( 50 ) in the non-flow fluid chamber ( 24 ) and each damper canister ( 50 ) in pressure communication with the fluid flow thru-path ( 22 ) and adapted to dampen a portion of a pressure change of the fluid in the fluid flow thru-path ( 22 ); and   a union interface ( 30 ) adapted to join one end ( 14 ) of the dampener housing ( 12 ) to a housing-to-flow line adapter ( 20 ), the union interface ( 30 ) having a flange member ( 33 ) connectable to another flange member ( 33 ) on the housing-to-flow line adapter ( 20 ) using flange fasteners ( 36 ), the combination when installed in the high-pressure fluid flow line ( 16 ), providing dampening of pressure pulsations of the fluid in the high-pressure fluid flow line ( 16 ).   
     
     
         2 . The pulsation dampener apparatus ( 10 ) for dampening pressure pulses in a high-pressure fluid flow line ( 16 ) of  claim 1 , wherein the fluid is a fracing fluid. 
     
     
         3 . A damper canister ( 50 ) for use in a pulsation dampener apparatus ( 10 ) for dampening fluid pressure pulses in a fluid in a high-pressure fluid flow line ( 16 ), the damper canister ( 50 ) comprising:
 a canister housing ( 52 ) in the form of a high-pressure gas cylinder, the canister housing ( 52 ) having a housing interior space ( 54 ) and a cross-sectional housing opening ( 56 ) at one end, and an interior wall ( 58 ) adapted to slideably receive a piston assembly ( 70 ) along a depth (D) of the interior wall ( 58 );   a damper piston assembly ( 70 ) is closely received in the cross-sectional opening ( 56 ) of the canister housing ( 52 ), the piston assembly ( 70 ) is freely slideable vertically along the depth (D) of the interior wall ( 58 ) to compress the gas above and within the interior space ( 54 ) of the canister housing ( 52 ) and to avoid accumulating suspension materials;   a stop ring ( 60 ) is fixable to a housing rim ( 57 ) at the housing opening ( 56 ) with a stop ring fastening means ( 62 ) and adapted to retain the damper piston assembly ( 70 ) slideably within the canister housing ( 50 ); and the canister housing ( 52 ), damper piston assembly ( 70 ) and stop ring ( 60 ) in combination adapted to contain a gas in the housing interior space ( 54 ) at continuously varying pressures up to 12,000 psi to provide said damper canister ( 50 ).   
     
     
         4 . The damper canister ( 50 ) of  claim 3 , wherein the piston assembly ( 70 ) comprises:
 a damper piston ( 72 ) having a damper piston head ( 74 ) portion and a damper piston skirt ( 76 ) portion;
 the piston head ( 74 ) portion having gas pressure surface ( 75   a ) and a fluid pressure surface ( 75   b ); 
 the piston skirt ( 76 ) portion, having a piston ring channel ( 79 ) within which a wiper ring ( 82 ) is received; 
   the wiper ring ( 82 ) being biased by the ring channel ( 79 ) to form a slideable gas/fluid pressure seal between the piston skirt ( 76 ) and the interior wall ( 58 ) of the canister housing ( 52 ); and   the piston assembly ( 70 ) being slideable within the canister housing ( 52 ) in response to a sufficient positive pressure difference between a gas pressure within the canister interior space ( 54 ) and a fluid pressure of a fluid flow thru-path ( 22 ) of said pulsation dampener apparatus ( 10 ).   
     
     
         5 . The damper canister ( 50 ) of  claim 3 , wherein the piston assembly ( 70 ) further comprises the damper piston head ( 74 ) portion of the damper piston ( 72 ) having a gas port fitting ( 90 ) adapted to provide a sealable through-port between the gas pressure surface ( 75   a ) and the fluid pressure surface ( 75   b ) of the piston head ( 74 ) to enable the housing interior space ( 54 ) to receive and contain a gas charge to bias the housing interior space ( 54 ) at an initial gas pressure. 
     
     
         6 . The piston assembly ( 70 ) of  claim 5  wherein gas port fitting ( 90 ) of the damper piston ( 72 ) comprises:
 a gas through-port ( 92 ) between the gas pressure surface ( 75   a ) and the fluid pressure surface ( 75   b ) of the piston head ( 74 ); 
 a normally closed gas valve ( 94 ) providing a means to charge the housing interior space ( 54 ) with a gas; and 
 a gas port cover protecting the gas valve ( 94 ) from a fluid at the fluid pressure surface ( 75   b ) of the piston head ( 74 ). 
 
     
     
         7 . The piston assembly ( 70 ) of  claim 5  wherein a structure of the damper piston ( 72 ) provides a pressure differential energized seal system designed to maintain a constant clearance between the piston assembly ( 70 ) and the canister wall, with the deformation of the piston from the internal gas pressure causes the piston assembly ( 70 ) to flatten, thus further biasing the seal portion of the piston assembly radially and toward the canister wall, effecting an improved seal.