Sampling procedure for polymer-based solutions used in underground formations

Patent metadata

Field	Value
Publication number	US-9714889-B2
Application number	US-201214130015-A
Country	US
Kind code	B2
Filing date	Jul 2, 2012
Priority date	Jul 4, 2011
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

Abstract

This invention concerns a sampling procedure for an aqueous hydrosoluble polymer solution flowing in a main circuit, enabling a sample to be collected to undergo at least one analysis under ambient air giving at least one property of the hydrosoluble polymer characterised in that a stabilizing solution is added to the aqueous hydrosoluble polymer solution, according to a discontinuous addition method, before or after sampling from the main circuit, so as to obtain a sample comprising a mixture of aqueous hydrosoluble polymer solution and stabilizing solution in which the hydrosoluble polymer is protected against attacks it may undergo in an atmosphere containing at least 10% by volume of oxygen.

First claim

The invention claimed is:

1. A sampling procedure for an aqueous hydrosoluble polymer solution flowing in a main circuit, enabling a sample to be collected to undergo at least one characterisation under ambient air comprising:
obtaining the sample by adding to the aqueous hydrosoluble polymer solution a stabilizing solution, according to a discontinuous addition method:
the discontinuous addition method comprising:
adding the stabilizing solution, either after sampling, or, before sampling, to the aqueous hydrosoluble polymer solution circulating in the main circuit, and
obtaining a sample comprising a mixture of aqueous hydrosoluble polymer solution and stabilizing solution, wherein the aqueous hydrosoluble polymer is protected against attacks it may undergo, in the absence of a stabilizing solution, in an atmosphere containing at least 10% by volume of oxygen;
wherein the stabilized solution is added in a predetermined quantity, based on a viscosity of the sample and over a predetermined time based on a flow rate of the aqueous polymer solution circulating in the main circuit, to the collected sample so that the sample contains a mixture of the stabilizing solution and the aqueous hydrosoluble polymer solution.

2. Sampling procedure according to claim 1 characterised in that the at least one characterization under ambient temperature is the measurement of viscosity and the added stabilizing solution enables the measured viscosity of the sample to be maintained approximately constant, when said viscosity is measured in ambient air, for a period of at least 1 hour.

3. Sampling procedure according to claim 1 characterised in that the sampling procedure comprises a prior determining of the volume of stabilizing solution to be added to the aqueous hydrosoluble polymer solution in which the volume of stabilizing solution added is varied and the change in measured viscosity of the mixtures obtained is studied over time.

4. Sampling procedure according to claim 1 characterised in that the sampling procedure comprises an analysis step under ambient air for the sample comprising a mixture of the aqueous hydrosoluble polymer solution and the stabilizing solution.

5. Sampling procedure according to claim 1 characterised in that the volume of stabilizing solution in the sample is less than 25% of the total sample volume.

6. Sampling procedure according to claim 1 characterised in that the stabilizing solution contains at least one stabilizing agent chosen from deoxygenating agents, precipitating agents, free radical scavengers, complexing agents, H 2 S-absorbing agents and sacrificial agents.

7. Sampling procedure according to claim 1 characterised in that the stabilizing solution contains at least three stabilizing agents chosen from deoxygenating agents, precipitating agents, free radical scavengers, complexing agents, H 2 S-absorbing agents and sacrificial agents.

8. Sampling procedure according to claim 1 characterised in that the aqueous hydrosoluble polymer solution circulates in a main circuit (II) used in enhanced oil recovery, the aqueous hydrosoluble polymer solution either on the injection side or on the production side and the sample is collected downstream and/or upstream of the oil reservoir.

9. Sampling procedure according to claim 1 characterised in that the sampling procedure includes a sampling step from a volume of aqueous hydrosoluble polymer solution in a sampling tank ( 1 ) using a sampling pipe ( 3 ) fitted with a non-shearing sampling closure ( 6 ) and a step adding into the sampling tank ( 1 ) a volume of stabilizing solution ( 300 ), sampling steps being carried out under hermetically-sealed conditions.

10. Sampling procedure according to claim 1 characterised in that the sampling procedure includes providing a sampling device connected to the main circuit (II) in which the aqueous hydrosoluble polymer solution ( 200 ) to be sampled in circulating, comprising:
a first vessel ( 1 ), called the sampling tank, capable of containing the sample ( 100 ) collected, including:
an inlet ( 5 ) for aqueous polymer solution to be sampled, and a sampling pipe ( 3 ) connecting the inlet ( 5 ) to the main circuit (II), the said sampling pipe ( 3 ) being fitted with a non-shearing sampling closure ( 6 ) and capable of being connected to the main circuit (II) and
an outlet ( 8 ) and outlet pipe ( 7 ) fitted with an outlet closure ( 9 ) and connected to the outlet ( 8 ),

a second vessel ( 2 ), called the treatment tank, capable of containing a stabilizing solution ( 300 ), comprising an outlet ( 10 ) for the stabilizing solution ( 300 ), a connecting pipe ( 4 ) connected to the outlet ( 10 ) for the stabilizing solution and fitted with a treatment closure ( 11 ) and, the connecting pipe ( 4 ) providing, at least in part, the connection between the treatment tank ( 2 ) and the sampling tank ( 1 ),

and where the sampling tank ( 1 ) is connected hermetically to the main pipe, and is isolated hermetically when the sampling closure ( 6 ), outlet closure ( 9 ) and treatment closure ( 11 ).

Assignees

• Favero Cedrick
• Spcm Sa

Inventors

• Favero Cedrick

Classifications

• C09K8/588 Primary

  characterised by the use of specific polymers {(polymeric surfactants C09K8/584)} · CPC title

• G01N1/34 Primary

  Purifying; Cleaning {(processes or apparatus for extracting or separating nucleic acids from biological samples C12N15/1003)} · CPC title

• Y10T436/2525

  Stabilizing or preserving · CPC title

• C09K8/882

  obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• G01N33/2823

  Raw oil, drilling fluid or polyphasic mixtures · CPC title