US 6,467,544 B1 · Sample chamber with dead volume flushing

Abstract

A sample module for use in a downhole tool includes a sample chamber for receiving and storing pressurized fluid. A piston is slidably disposed in the chamber to define a sample cavity and a buffer cavity, and the cavities have variable volumes determined by movement of the piston. A first flowline is provided for communicating fluid obtained from a subsurface formation through the sample module. A second flowline connects the first flowline to the sample cavity, and a third flowline connects the sample cavity to one of the first flowline and an outlet port. A first valve is disposed in the second flowline for controlling the flow of fluid from the first flowline to the sample cavity, and a second valve is disposed in the third flowline for controlling the flow of fluid out of the sample cavity, whereby any fluid preloaded in the sample cavity may be flushed therefrom using the formation fluid in the first flowline and the first and second valves.

Claims37

Dependent claims

A sample module for use in a tool adapted for insertion into a subsurface wellbore for obtaining fluid samples therefrom, said sample module comprising:

a sample chamber for receiving and storing pressurized fluid;
a piston slidably disposed in said chamber to define a sample cavity and a buffer cavity, the cavities having variable volumes determined by movement of said piston;
a first flowline for communicating fluid obtained from a subsurface formation through the sample module;
a second flowline connecting said first flowline to the sample cavity;
a third flowline connecting the sample cavity to one of said first flowline and an outlet port;
a first valve disposed in said second flowline for controlling the flow of fluid from said first flowline to the sample cavity;
and
a second valve disposed in said third flowline for controlling the flow of fluid out of the sample cavity, whereby any fluid preloaded in the sample cavity may be flushed therefrom using the formation fluid in said first flowline and said first and second valves.

5 more elements

An apparatus for obtaining fluid samples from a subsurface formation penetrated by a wellbore, comprising:

a probe assembly for establishing fluid communication between the apparatus and the formation when the apparatus is positioned in the wellbore;
a pump assembly for drawing fluid from the formation into the apparatus via said probe assembly;
a sample module for collecting a sample of the formation fluid drawn from the formation by said pumping assembly, said sample module comprising:
a chamber for receiving and storing the formation fluid;
a piston slidably disposed in said chamber to define a sample cavity and a pressurization cavity, the cavities having variable volumes determined by movement of said piston;
a first flowline in fluid communication with said pump assembly for communicating fluid obtained from the formation through the sample module;
a second flowline connecting said first flowline to the sample cavity;
a third flowline connecting the sample cavity to one of said first flowline fluid and an outlet port;
a first valve disposed in said second flowline for controlling the flow of fluid from said first flowline to the sample cavity;
and
a second valve disposed in said third flowline for controlling the flow of fluid out of the sample cavity, whereby any fluid preloaded in the sample cavity may be flushed therefrom using formation fluid and said first and second valves.

8 more elements

Dependencies are inferred from the claim text.

Sample chamber with dead volume flushing

Life of this patent

Sample chamber with dead volume flushing

Life of this patent

Abstract

Claims37