Method for estimating the quantity of free hydrocarbons in a sample of sedimentary rock

Patent metadata

Field	Value
Publication number	US-2019107522-A1
Application number	US-201816154218-A
Country	US
Kind code	A1
Filing date	Oct 8, 2018
Priority date	Oct 9, 2017
Publication date	Apr 11, 2019
Grant date	—

Abstract

A sample of sedimentary rock and a sample of total organic matter isolated from the rock are heated in a sequence under an inert atmosphere and quantities of hydrocarbon-containing compounds, CO and CO2 released by each sample are measured. The residue from each sample originating from heating under an inert atmosphere is subjected to a heating sequence under an oxidizing atmosphere, and quantities of CO and CO2 released by each residue are measured. A quantity of hydrocarbon-containing compounds in free form in the rock is determined from measurements is carried out, from a quantity of hydrocarbon-containing compounds in free and retained form of the rock sample and a quantity of hydrocarbon-containing compounds in retained form in a sample of organic matter. The invention is used for oil exploration and exploitation.

First claim

1 .- 12 . (canceled)

13 . A method for determining a parameter representative of a quantity of hydrocarbon-containing compounds present in free form within a sedimentary rock, wherein from a first representative sample of the rock and from a second representative sample of the isolated total organic matter from the rock in which at least the following steps are applied for each of the samples comprising:
A. heating the sample according to a first heating sequence under an inert atmosphere, and continuously measuring a representative quantity of the hydrocarbon-containing compounds released during at least a part of the first heating sequence with a representative quantity of CO and a representative quantity of CO 2 being released during the first heating sequence; and B. heating a residue of the sample originating from the first heating sequence according to a second heating sequence under an oxidizing atmosphere, and measuring a representative quantity of CO and a representative quantity of CO 2 released during said second heating sequence; and determining the parameter representative of the quantity of hydrocarbon-containing compounds present in free form within the rock from at least measurements from the first and second samples.

14 . The method according to claim 13 , comprising determining at an end of steps A and B applied at least to the first and to the second samples:
i. for each of the samples, a level of total organic carbon from the measurements of the quantity of CO 2 and CO obtained during the first and second heating sequences; ii. a parameter representative of a quantity of hydrocarbon-containing compounds present in the first sample in both a free and retained form, from at least the measurement of the representative quantity of the hydrocarbon-containing compounds released during the part of the first heating sequence applied to the first sample, and of the level of total organic carbon determined for the first sample; iii. a parameter representative of a quantity of hydrocarbon-containing compounds present in the second sample in retained form, from at least the measurement of the representative quantity of the hydrocarbon-containing compounds released during the part of the first heating sequence applied to the second sample, the level of total organic carbon determined for the second sample; and and determining the parameter representative of the quantity of hydrocarbon-containing compounds present in free form in the rock from a difference between the parameter representative of the quantity of hydrocarbon-containing compounds present in the first sample in both a free and a retained form and at least the parameter representative of the quantity of hydrocarbon-containing compounds present in the second sample in retained form.

15 . The method according to claim 13 , wherein the second heating sequence under an oxidizing atmosphere applied to one of the residues of one of the first and second samples comprises starting from a temperature between 200° C. and 400° C., and the temperature of the residue is raised according to a temperature gradient comprised between 20 and 40° C./minute, up to a temperature between 750 and 950° C.

16 . The method according to claim 14 , wherein the second heating sequence under an oxidizing atmosphere applied to one of the residues of one of the first and second samples comprises starting from a temperature between 200° C. and 400° C., and the temperature of the residue is raised according to a temperature gradient comprised between 20 and 40° C./minute, up to a temperature between 750 and 950° C.

17 . The method according to claim 14 , wherein the parameter representative of the quantity of hydrocarbon-containing compounds present in the first sample in both a free and a retained form is determined according to a formula:

HC

Total
,
rock

=

SurfQ
rock

m
rock

*

TOC
rock

wherein SurfQ rock corresponds to at least a part of the area under the measurement curve of the quantity of hydrocarbon-containing compounds released by the first sample, m rock corresponds to an initial mass of the first sample, and TOC rock is the level of total organic carbon determined for the first sample.

18 . The method according to claim 15 , wherein the parameter representative of the quantity of hydrocarbon-containing compounds present in the first sample in both a free and a retained form is determined according to a formula:

HC

Total
,
rock

=

SurfQ
rock

m
rock

*

TOC
rock

wherein SurfQ rock corresponds to at least a part of the area under the measurement curve of the quantity of hydrocarbon-containing compounds released by the first sample, m rock corresponds to an initial mass of the first sample, and TOC rock is the level of total organic carbon determined for the first sample.

19 . The method according to claim 16 , wherein the parameter representative of the quantity of hydrocarbon-containing compounds present in the first sample in both a free and a retained form is determined according to a formula:

HC

Total
,
rock

=

SurfQ
rock

m
rock

*

TOC
rock

wherein SurfQ rock corresponds to at least a part of the area under the measurement curve of the quantity of hydrocarbon-containing compounds released by the first sample, m rock corresponds to an initial mass of the first sample, and TOC rock is the level of total organic carbon determined for the first sample.

20 . The method according to claim 14 , wherein the parameter representative of the quantity of hydrocarbon-containing compounds present in the second sample in retained form is determined according to a formula:

HC

Sorbed
,
TOM

=

SurfQ
TOM

m
TOM

Assignees

• Ifp Energies Now

Inventors

• Romero-Sarmiento Maria-Fernanda
• Youssouf Said
• Letort Geremie

Classifications

• G01N33/241 Primary

  for hydrocarbon content · CPC title

• G01N31/12 Primary

  using combustion (G01N25/20 takes precedence) · CPC title