Suction stabilizer for pump assembly

Abstract

A fluid flow stabilizing method and a pump having a stabilized fluid flow passage where a process fluid contains suspended solid particles and is subject to pressure oscillations. The method comprises positioning an expandable membrane along the lower transverse surface, inflating the membrane with a compressible fluid, and alternatingly expanding and contracting the membrane to dampen the pressure oscillations and inhibit settling of the solid particles at the lower transverse surface. The pump comprises a stabilizer comprising a compressible fluid in an expandable membrane elongated along the lower transverse surface of a manifold in fluid communication with the fluid end. Another method comprises reciprocating a plunger in the pump to pass a slurry through the manifold, and alternatingly expanding and contracting a stabilizer in the manifold.

We claim: 
     
         1 . A stabilized pump manifold, comprising:
 a manifold in fluid communication with a fluid end of a pump for passage of a process fluid therethrough over a lower surface transverse to vertical, wherein the lower surface is elongated in a direction of fluid flow through the manifold; and   a stabilizer comprising an expandable membrane elongated along the lower transverse surface and defining a compliant chamber comprising a compressible fluid in the direction of fluid flow to dampen pressure oscillations within the manifold;   wherein the expandable membrane is capable of expansion and contraction pulsations; and   wherein the compliant chamber spans the length of the expandable membrane.   
     
     
         2 . The stabilized pump manifold of  claim 1  wherein the manifold comprises an inlet to the pump and the stabilizer is a suction stabilizer. 
     
     
         3 . The stabilized pump manifold of  claim 1  wherein the process fluid comprises a slurry, the pump comprises a plurality of chambers with reciprocating plungers to alternatingly suction and discharge the slurry, and the manifold comprises a plurality of branches transverse to the elongated lower surface to supply the slurry to the chambers. 
     
     
         4 . The stabilized pump manifold of  claim 3  wherein the manifold dissipates an acceleration head during normal operation of the plungers. 
     
     
         5 . The stabilized pump manifold of  claim 1  wherein the expandable membrane is formed from a compliant material. 
     
     
         6 . The stabilized pump manifold of  claim 1  wherein the expandable membrane comprises a hose in fluid communication with a source of the compressible fluid at a pressure exceeding a pressure of the process fluid in the manifold corresponding to a low pressure cycle. 
     
     
         7 . The stabilized pump manifold of  claim 1  wherein the compressible fluid is compressed air. 
     
     
         8 . The stabilized pump manifold of  claim 1  wherein variation of the compressible fluid pressure is adapted to displace solids from the lower transverse surface. 
     
     
         9 . The stabilized pump manifold of  claim 1  comprising a retainer to secure the expandable membrane adjacent the lower transverse surface. 
     
     
         10 . The stabilized pump manifold of  claim 1  wherein the process fluid comprises a proppant- or sand-laden oilfield treatment fluid. 
     
     
         11 . The stabilized pump manifold of  claim 1  further comprising a tapered insert in the expandable membrane adjacent an attachment fitting. 
     
     
         12 . A method, comprising:
 reciprocating a plunger in a fluid end of a pump to alternatingly suction and discharge a slurry;   passing the slurry through a manifold in fluid communication with the fluid end, wherein the manifold comprises a lower surface transverse to vertical; and   alternatingly expanding and contracting a stabilizer comprising a compressible fluid in a compliant chamber defined by an expandable membrane, the expandable membrane elongated along the lower transverse surface to dampen pressure oscillations within the manifold and inhibit solids settling in the manifold;   wherein the compliant chamber spans the length of the expandable membrane.   
     
     
         13 . The method of  claim 12  wherein the manifold comprises an inlet to the pump and further comprising expanding the stabilizer during a low pressure cycle and contracting the stabilizer during a high pressure cycle. 
     
     
         14 . The method of  claim 13  wherein a pressure variation between the low and high pressure cycles is effective to displace solids from the lower transverse surface. 
     
     
         15 . The method of  claim 12  comprising securing the expandable membrane adjacent the lower transverse surface. 
     
     
         16 . The method of  claim 12  wherein the slurry comprises an oilfield fluid and the solids comprise proppant, sand or a mixture thereof. 
     
     
         17 . A method for stabilizing fluid flow in a flow conduit having a lower surface transverse to vertical in contact with the fluid, wherein the fluid contains suspended solid particles and is subject to pressure oscillations, comprising:
 positioning an expandable membrane defining a compliant chamber along the lower transverse surface;   inflating the compliant chamber of the membrane with a gas isolated from the fluid flow;   alternatingly expanding and contracting the compliant chamber of the membrane to dampen the pressure oscillations and inhibit settling of the solid particles at the lower transverse surface; wherein the compliant chamber spans the length of the expandable membrane.   
     
     
         18 . The method of  claim 17  wherein the flow conduit comprises an inlet manifold to a positive displacement pump, the fluid comprises a proppant- or sand-laden oilfield treatment fluid, and the expandable membrane comprises a hose. 
     
     
         19 . A reciprocating pump comprising the stabilized pump manifold of  claim 1 . 
     
     
         20 . A method comprising operating the reciprocating pump of  claim 19  to pump a slurry.