Methods and apparatus for collecting and preserving core samples from a reservoir

Patent metadata

Field	Value
Publication number	US-10246962-B2
Application number	US-201816012190-A
Country	US
Kind code	B2
Filing date	Jun 19, 2018
Priority date	Sep 30, 2015
Publication date	Apr 2, 2019
Grant date	Apr 2, 2019

Abstract

Provided herein are methods and apparatus for collecting and preserving core samples from a reservoir. In some embodiments, a method includes obtaining core samples from a reservoir using a rock and fluid sampling tool and depositing the core samples in a vessel filled with a hydrogen-free fluid such that a portion of the hydrogen-free fluid is displaced by the core samples and the core samples are immersed in the hydrogen-free fluid. The method also includes transferring a gas into the vessel to occupy a space in the vessel and sealing the vessel via a cap on an end of the vessel. Methods of analyzing the core samples core samples collected from a reservoir and a rock and fluid sampling tool are also provided.

First claim

What is claimed is:

1. A method of analyzing a core sample collected from a reservoir, comprising:
providing a pressurized vessel comprising the core sample, the pressurized vessel sealed downhole in a wellbore extending into a reservoir after collecting the core sample from the reservoir
reducing, in one or more steps, a pressure of the pressurized vessel to atmospheric pressure, each step comprising:
releasing an amount of a gas, an amount of a fluid or any combination thereof, to reduce the pressure of the pressurized vessel by a pressure value; and
determining the released amount of the gas, the released amount of the fluid, or any combination thereof;

determining, after reducing the pressure of the pressurized vessel to atmospheric pressure, a total amount of the gas released and a total amount of the fluid released; and
calculating a hydrocarbons-in-place value based on the total amount of the gas released and the total amount of the fluid released.

2. The method of claim 1 , comprising heating the pressurized vessel to a temperature value.

3. The method of claim 2 , wherein the temperature value is substantially equal to a temperature of the reservoir.

4. The method of claim 1 , wherein the pressure value is a first pressure value, the method comprising pressuring the pressurized vessel to a second pressure value before reducing, in one or more steps, the pressure of the pressurized vessel to atmospheric pressure.

5. The method of claim 4 , wherein the second pressure value is substantially equal to a pressure of the reservoir.

6. The method of claim 1 , wherein the core sample is immersed in a hydrogen-free fluid in the pressurized vessel.

7. The method of claim 1 , wherein the hydrogen-free fluid comprises a fluorocarbon-based fluid.

8. The method of claim 1 , wherein the gas comprises nitrogen.

9. The method of claim 1 , wherein the vessel comprises a eutectic metal component.

Assignees

• Saudi Arabian Oil Co

Inventors

• Gupta Anuj
• Georgi Daniel T
• Hull Katherine L

Classifications

• G01N33/24

  Earth materials (G01N33/42 takes precedence) · CPC title

• E21B49/06

  using side-wall drilling tools {pressing} or scrapers · CPC title

• E21B25/08 Primary

  Coating, freezing, consolidating cores (E21B25/06 takes precedence); Recovering uncontaminated cores or cores at formation pressure · CPC title

• E21B25/005 Primary

  Above ground means for handling the core, e.g. for extracting the core from the core barrel · CPC title

• G01N23/046

  using tomography, e.g. computed tomography [CT] · CPC title