Pressure Volume Temperature System

Abstract

A method and an apparatus for characterizing a fluid including a phase transition cell to receive the fluid, a piston to control fluid pressure, a pressure gauge to measure the fluid pressure and to provide information to control the piston, and connectors to connect the cell, piston, and gauge. The exterior volume of the phase transition cell, piston, gauge, and connectors is less than about 10 liters. A method and an apparatus to characterize a fluid including observing a fluid in an phase transition cell, measuring a pressure of the fluid, and adjusting a pressure control device in response to the measuring.

We claim: 
     
         1 . An apparatus for characterizing a fluid, comprising:
 a phase transition cell to receive the fluid;   a piston to control pressure of the fluid;   a pressure gauge to measure the pressure of the fluid and to provide information to control the piston;   at least one measurement sensor to measure a property of the fluid; and   connectors to fluidly connect the cell, piston, and pressure gauge,   wherein the apparatus utilizes a total fluid volume of about 1.0 mL or less.   
     
     
         2 . The apparatus of  claim 1 , further comprising a membrane. 
     
     
         3 . The apparatus of  claim 2 , wherein the membrane prevents particles with a dimension of 10 microns or greater to flow through the membrane. 
     
     
         4 . The apparatus of  claim 2 , wherein the measurement sensor is selected from the group consisting of a densitometer and a viscometer. 
     
     
         5 . The apparatus of  claim 1 , wherein the at least one measurement sensor comprises a densitometer. 
     
     
         6 . The apparatus of  claim 1 , wherein the at least one measurement sensor comprises a viscometer. 
     
     
         7 . The apparatus of  claim 1 , further comprising a membrane, a densitometer, a viscometer, an inlet valve, and an exit valve. 
     
     
         8 . The apparatus of  claim 7 , wherein the fluid flows through the membrane, then the inlet valve, then the phase transition cell, then the densitometer, then the viscometer, then the pressure gauge, then the piston, then the exit valve. 
     
     
         9 . The apparatus of  claim 1 , wherein the fluid has a total fluid volume of about 0.5 mL or less. 
     
     
         10 . The apparatus of  claim 1 , wherein the connectors electrically isolate when forming a fluidic connection. 
     
     
         11 . The apparatus of  claim 1 , wherein the connectors have a total internal volume of less than 1 mL. 
     
     
         12 . The apparatus of  claim 1 , wherein the connectors comprises tubing. 
     
     
         13 . The apparatus of  claim 12 , wherein the tubing has an internal diameter of about 1.0 mm or less. 
     
     
         14 . The apparatus of  claim 13 , wherein ends of the tubing comprise isolation components. 
     
     
         15 . The apparatus of  claim 1 , wherein the cell, piston, and pressure gauge have a fluid volume less than about 2 ml. 
     
     
         16 . The apparatus of  claim 1 , wherein the pressure gauge has a dead volume of less than 0.5 ml. 
     
     
         17 . The apparatus of  claim 1 , wherein the volume of the apparatus is configured to fit in a wellbore. 
     
     
         18 . The apparatus of  claim 24 , wherein the volume is contained in a cylindrical shaped housing with an inner diameter of 3.875 inches or less. 
     
     
         19 . The apparatus of  claim 1 , further comprising a Peltier cooler. 
     
     
         20 . A method to characterize a fluid, comprising:
 observing a fluid in a phase transition cell;   measuring a pressure of the fluid in the cell; and   adjusting a pressure control device in response to the measuring,   
       wherein the external volume of the phase transition cell, piston, and gauge is less than 10 liters. 
     
     
         21 . The method of  claim 20 , wherein the depressurization or pressurization rate of the fluid is less than 200 psi/second. 
     
     
         22 . The method of  claim 20 , wherein the fluid is circulated through the system at a volumetric rate of no more than 1 ml/sec. 
     
     
         23 . The method of  claim 20 , further comprising measuring a temperature. 
     
     
         24 . The method of  claim 20 , further comprising adjusting the temperature. 
     
     
         25 . The method of  claim 24 , wherein adjusting the temperature comprises increasing the fluid flow through the cell. 
     
     
         26 . The method of  claim 25 , wherein adjusting the temperature comprises a Peltier cooler.