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

Patent metadata

Field	Value
Publication number	US-10060215-B2
Application number	US-201715791988-A
Country	US
Kind code	B2
Filing date	Oct 24, 2017
Priority date	Sep 30, 2015
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

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 core samples collected from a reservoir, comprising:
providing a pressurized vessel comprising one or more core samples immersed in a hydrogen-free fluid, the pressurized vessel sealed downhole in a wellbore extending into a reservoir after collecting the one or more core samples from the reservoir, the pressurized vessel comprising a gas;
heating the pressurized vessel to a temperature value;
reducing, in one or more steps, a pressure of the pressurized vessel to atmospheric pressure, each step comprising:
releasing an amount of the gas, an amount of the hydrogen-free fluid, an amount of hydrocarbons, 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 hydrogen-free fluid, the released amount of the hydrocarbons, or any combination thereof;

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

2. The method of claim 1 , wherein the temperature value is substantially equal to a temperature of the reservoir.

3. 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.

4. The method of claim 3 , wherein the second pressure value is substantially equal to a pressure of the reservoir.

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

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

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

Assignees

• Aramco Services 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