Multi-column gas chromatography for analysis of a formation sample

Patent metadata

Field	Value
Publication number	US-12480930-B2
Application number	US-202218070046-A
Country	US
Kind code	B2
Filing date	Nov 28, 2022
Priority date	Nov 28, 2022
Publication date	Nov 25, 2025
Grant date	Nov 25, 2025

Abstract

Embodiments of multi-column gas chromatography for analysis of a formation sample are disclosed. In one embodiment, an apparatus comprises a gas chromatography instrument and a controller. The gas chromatography instrument comprises a sample injector; a primary column to separate out a hydrocarbon subset; a secondary column valve coupled to the primary column; a primary detector configured to analyze the hydrocarbons of the subset; a heart cutting unit coupled to the secondary column valve and configured to cut, from the subset, at least one isomer having a weight greater than a threshold; a secondary column coupled to an output of the heart cutting unit configured to separate out the at least one isomer; and a secondary detector configured to analyze the at least one isomer. The controller controls the secondary column valve to output the hydrocarbons to the heart cutting unit in response to at least one trigger event.

First claim

The invention claimed is:

1 . An apparatus comprising:
a gas chromatography instrument comprising:
a sample injector configured to inject a gas sample that includes a number of chemical compounds;
a primary column to separate out a hydrocarbon subset that includes hydrocarbons from the number of chemical compounds;
a secondary column valve coupled to an output of the primary column;
a primary detector coupled to a first output of the secondary column valve and configured to analyze the hydrocarbons of the hydrocarbon subset;
a heart cutting unit coupled to a second output of the secondary column valve, the heart cutting unit configured to cut, from the hydrocarbon subset, isomers having a weight greater than a threshold;
a secondary column coupled to an output of the heart cutting unit, the secondary column configured to separate out at least one isomer from the cut isomers; and
a secondary detector configured to analyze the at least one isomer separated out; and
a controller to control the secondary column valve such that the controller is to open the secondary column valve to output the hydrocarbons to the heart cutting unit in response to at least one trigger event having occurred.

2 . The apparatus of claim 1 , wherein the at least one trigger event comprises that the number of chemical compounds includes at least one isomer having a weight greater than a heavy weight threshold.

3 . The apparatus of claim 1 , wherein the at least one trigger event comprises the gas sample being injected being a formation sample that originates from a subsurface formation at a depth in a wellbore within a trigger depth range.

4 . The apparatus of claim 3 , wherein the trigger depth range comprises a depth range having a probability of recoverable hydrocarbon that is greater than a threshold.

5 . The apparatus of claim 1 , wherein the controller is configured to transmit a communication to a device to cause the device to perform or adjust a downhole operation in a wellbore formed in a subsurface formation from which the gas sample originated, based on analysis of at least one of the hydrocarbon subset and the at least one isomer separated out.

6 . The apparatus of claim 1 ,
wherein the gas chromatography instrument comprises a back flush valve having an input coupled to an output of the sample injector and an output coupled to an input of the secondary column, and wherein the controller is to control the back flush valve such that the controller is to open the back flush valve to flow the hydrocarbons to the heart cutting unit in response to a weight of at least one of the hydrocarbons being greater than a threshold.

7 . The apparatus of claim 1 ,
wherein the gas chromatography instrument comprises a carrier gas valve having multiple inputs, wherein each of the multiple inputs is coupled to input a different carrier gas to mix with the gas sample, and wherein the controller is to control the carrier gas valve such that the controller is to selectively open at least one of the multiple inputs based on types of the hydrocarbons.

8 . A method comprising:
injecting, into a gas chromatography instrument, a gas sample having a number of chemical compounds; separating out, by a primary column, a hydrocarbon subset that includes hydrocarbons from the number of chemical compounds; analyzing, by a primary detector, the hydrocarbon subset for hydrocarbons having a weight that is less than a lower weight threshold; determining whether at least one trigger event that is associated with gas sample has occurred; and in response to determining that the at least one trigger event occurred,
separating out, by a secondary column, at least one isomer from the hydrocarbon subset; and
analyzing, by a secondary detector, the at least one isomer separated out by the secondary column.

9 . The method of claim 8 , wherein determining whether the at least one trigger event occurred comprises determining whether the number of chemical compounds includes at least one isomer having a weight greater than an isomer threshold.

10 . The method of claim 8 , wherein the gas sample is from a formation sample, wherein determining whether the at least one trigger event occurred comprises determining that the formation sample originates from a subsurface formation at a depth in a wellbore within a trigger depth range.

11 . The method of claim 10 , wherein the trigger depth range comprises a depth range having a probability of recoverable hydrocarbon that is greater than a threshold.

12 . The method of claim 8 , wherein determining whether the at least one trigger event occurred comprises determining whether an amount of gas in the gas sample exceeds a minimum gas level threshold.

13 . The method of claim 8 , further comprising:
in response to determining that the at least one trigger event occurred and prior to separating out the at least one isomer,
cutting, from the hydrocarbon subset, at least one isomer having a weight greater than a threshold.

14 . The method of claim 8 , further comprising:
performing a downhole operation in a wellbore based on at least one of analyzing the hydrocarbon subset and analyzing the at least one isomer separated out.

15 . The method of claim 14 , further comprising:
receiving a formation sample from a subsurface formation into which the wellbore is formed, the formation sample including the gas sample; and separating the gas sample from the formation sample.

16 . A system comprising:
a gas separator, during drilling of a wellbore into a subsurface formation by a drill string, to receive a formation sample from the subsurface formation, wherein the gas separator is to separate out a gas sample from the formation sample; a gas chromatography instrument comprising:
a sample injector configured to inject the gas sample that includes a number of chemical compounds;
a primary column to separate out a hydrocarbon subset that includes hydrocarbons from the number of chemical compounds;
a secondary column valve coupled to an output of the primary column;
a primary detector coupled to a first output of the secondary column valve and configured to analyze the hydrocarbons of the hydrocarbon subset;
a heart cutting unit coupled to a second output of the secondary column valve, the heart cutting unit configured to cut, from the hydrocarbon subset, isomers having a weight greater than a threshold;
a secondary column coupled to an output of the heart cutting unit, the secondary column configured to separate out at least one isomer from the cut isomers; and
a secondary detector configured to analyze the at least one isomer separated out; and
a controller to control the secondary column valve such that the controller is to open the secondary column valve to output the hydrocarbons to the heart cutting unit in response to at least one trigger event having occurred, wherein the controller is configured to transmit a communication to a device to cause the device to perform or adjust the drilling, based on analysis of at least one of the hydrocarbon subset and the isomers separated out.

17 . The system of claim 16 , wherein the at least one trigger event comprises that the number of chemical compounds includes at least one isomer having a weight greater than a heavy weight threshold.

18 . The system of claim 16 , wherein the at least one trigger event comprises the formation sample originating from the subsurface formation at a depth in the wellbore within a trigger depth range.

19 . The sys

Assignees

• Halliburton Energy Services Inc

Inventors

• Rowe Mathew Dennis
• Kevadiya Jhanvi Manishkumar

Classifications

• G01N30/6043

  in parallel · CPC title

• G01N2030/025

  Gas chromatography · CPC title

• G01N30/8679

  Target compound analysis, i.e. whereby a limited number of peaks is analysed · CPC title

• G01N2030/8804

  automated systems · CPC title

• G01N30/20 Primary

  using a sampling valve · CPC title