Coaxial pumping apparatus with internal power fluid column

Abstract

A pump having an increased energy efficiency is provided. The pump has an internal power fluid column and a transfer piston which is reciprocatingly mounted about the power fluid column. The transfer piston defines a product fluid chamber, located above the transfer piston valve, and a transfer chamber, located below the transfer piston valve. The power fluid column has at least one passageway, which allows the fluid inside the power fluid column to be in communication with a power fluid chamber. The power fluid chamber, the transfer chamber, and the product chamber are situated coaxially about the power fluid column.

What is claimed is: 
     
         1 . A method for pumping a fluid, the method comprising:
 introducing a power fluid into a power fluid chamber of a pumping apparatus via an internal power fluid column, whereby a transfer piston is lifted so as to close a transfer piston valve, whereby fluid to be pumped is drawn into a transfer chamber via an inlet valve;   decreasing a pressure of the power fluid in the power fluid column and the power fluid chamber, whereby the transfer piston falls, the transfer piston valve is opened, and the inlet valve is closed, whereby the fluid to be pumped passes from the transfer chamber via the transfer piston valve into a product chamber; and   increasing the pressure of the power fluid in the power fluid column and the power fluid chamber, whereby the transfer piston is raised, the transfer piston valve closes, and the transfer piston valve closes, such that fluid to be pumped in the product chamber is forced out of the product chamber, such that the fluid is pumped.   
     
     
         2 . The method of  claim 1 , wherein the pumping apparatus comprises a housing; a first inlet disposed within the housing, the first inlet having an inlet valve; an outlet disposed within the housing; an internal power fluid column disposed within the housing, the internal power fluid column having a second inlet; a transfer piston reciprocatingly mounted about the power fluid column, the transfer piston slidably and sealingly extending between the power fluid column and an interior wall of the housing; a product fluid chamber positioned above the transfer piston and at least partially defined by the interior wall of the housing; a transfer chamber positioned below the transfer piston and at least partially defined by the interior wall of the housing; a sealable channel in the transfer piston fluidly connecting the product fluid chamber and the transfer chamber, the sealable channel having a transfer piston valve; and at least one passageway fluidly connecting the power fluid column with a power fluid chamber. 
     
     
         3 . The method of  claim 1 , wherein the pressure of the power fluid is increased and decreased through application of an oscillating pressure to the power fluid. 
     
     
         4 . The method of  claim 3 , wherein the oscillating pressure is provided by moving a piston back and forth in a cylinder containing the power fluid. 
     
     
         5 . The method of  claim 4 , wherein motion of the piston is induced by operation of at least one device selected from the group consisting of a motor, an engine with a crank mechanism, a pneumatic device, and a hydraulic device. 
     
     
         6 . The method of  claim 3 , wherein providing oscillating pressure to the power fluid comprises providing a column of power fluid extending to an elevation higher than an elevation at which product fluid is recovered. 
     
     
         7 . The method of  claim 6 , wherein introducing a power fluid into a power fluid chamber of a pumping apparatus via an internal power fluid column comprises:
 closing a valve to a power fluid source; and   opening a power fluid release valve at an elevation lower than an elevation at which the pumped fluid is recovered, whereby the power fluid is introduced into the power fluid chamber.   
     
     
         8 . The method of  claim 1 , wherein at least one of the inlet valve and the transfer piston valve is a one-way valve. 
     
     
         9 . The method of  claim 8 , wherein the one-way valve is a self-actuating one-way valve. 
     
     
         10 . The method of  claim 1 , wherein the fluid to be pumped contains particles, the method further comprising filtering particles from the fluid to be pumped, such that the fluid entering the transfer chamber contains a reduced amount of particles. 
     
     
         11 . The method of  claim 1 , wherein the particles are filtered from the fluid to be pumped by the fluid to be pumped passing through a fluid inlet screen of the pumping apparatus. 
     
     
         12 . The method of  claim 1 , wherein the pumping apparatus in situated in a well, such that the inlet valve is submerged in the fluid to be pumped from the well. 
     
     
         13 . The method of  claim 1 , wherein the pumping device is situated in a well, the method further comprising:
 introducing a coaxial tube with a coaxial disconnecting device attached thereto into the well;   separately sealing the coaxial disconnecting device to the power fluid column and the product fluid chamber, whereby fluid communication between the power fluid column and the coaxial disconnecting device is provided, and whereby fluid communication between the product fluid chamber and the coaxial disconnecting device is provided;   pumping up through the coaxial tube the fluid to be pumped; and   pumping down through the coaxial tube the power fluid.   
     
     
         14 . The method of  claim 1 , wherein the transfer piston is configured such that the fluid acts against a first area comprising at least a portion of the transfer piston in a direction of transfer piston movement. 
     
     
         15 . The method of  claim 14 , wherein the first area is greater than a second area comprising at least a portion of the transfer piston in the power fluid chamber, and wherein the transfer piston is configured such that the fluid in the power fluid chamber acts against the second area in a direction of movement of the transfer piston. 
     
     
         16 . The method of  claim 1 , wherein the pumping apparatus further comprises a first valve stop configured to prevent closing of the inlet valve and a second valve stop configured to prevent closing of the transfer piston valve. 
     
     
         17 . The method of  claim 16 , wherein at least one of the first valve stop and the second valve stop comprises an extended portion on the rod portion of the transfer piston. 
     
     
         18 . The method of  claim 16 , wherein at least one of the first valve stop and the second valve stop comprises a v-shaped member configured to prevent the transfer piston valve from closing. 
     
     
         19 . The method of  claim 18 , wherein the v-shaped member is configured to prevent the transfer piston valve from closing when the v-shaped member contacts an activator. 
     
     
         20 . The method of  claim 1 , wherein the power fluid column is internal to the power fluid column; and the power fluid chamber, the transfer chamber and the product chamber are situated coaxially about the power fluid column.