Methods for quantifying and tracking amine-based shale inhibitors in drilling fluids

Patent metadata

Field	Value
Publication number	US-12473828-B2
Application number	US-202318170752-A
Country	US
Kind code	B2
Filing date	Feb 17, 2023
Priority date	Feb 17, 2023
Publication date	Nov 18, 2025
Grant date	Nov 18, 2025

Abstract

Described is a method for quantifying and tracking an amine-based shale inhibitor in a drilling fluid through UV-visible spectroscopy. A correlation is determined between varying concentrations of an amine-based shale inhibitor in a water-based drilling fluid sample and an ultraviolet (UV)-visible absorption intensity. A calibration plot is generated based on the correlations. Samples of a circulating drilling fluid having an unknown concentration of amine-based shale inhibitor are obtained. Using the calibration plot, the concentration of amine-based shale inhibitor in the samples of the circulating drilling fluid is estimated.

First claim

What is claimed:

1 . A method for quantifying and tracking an amine-based shale inhibitor in a drilling fluid through UV-visible spectroscopy, comprising:
for a plurality of varying concentrations of the amine-based shale inhibitor, determining a correlation between a concentration of the amine-based shale inhibitor in a water-based drilling fluid sample and an ultraviolet (UV)-visible absorption intensity; generating a calibration plot of the correlations; obtaining one or more samples of a circulating drilling fluid having an unknown concentration of the amine-based shale inhibitor; using the calibration plot, estimating the concentration of the amine-based shale inhibitor in the one or more samples of the circulating drilling fluid; formulating a plurality of water-based drilling fluid samples having a plurality of varying concentrations of the amine-based shale inhibitor; collecting a mud filtrate from each water-based drilling fluid sample; mixing an amount of each mud filtrate with an amount of an amine precipitating reagent and allowing each mixture to precipitate; collecting a colored solution from each precipitated mixture; and performing UV-visible spectroscopy on each colored solution to measure the UV-visible absorption intensity of each colored solution, wherein the UV-visible absorption intensity of each colored solution decreases with an increase in the concentration of the amine-based shale inhibitor.

2 . The method of claim 1 , wherein each colored solution is characterized by at least one absorption peak wavelength in a range of about 400 nanometers (nm) to about 800 nm.

3 . The method of claim 1 , wherein the amine precipitating reagent is Reinecke's salt.

4 . The method of claim 1 , wherein the plurality of varying concentrations of the amine-based shale inhibitor comprises 0 pounds per barrel (ppb), 2 ppb, 4 ppb, 6 ppb, 8 ppb, and 10 ppb.

5 . The method of claim 1 , further comprising maintaining the concentration of the amine-based shale inhibitor in the one or more samples of the circulating drilling fluid from about 2% v/v to 3% v/v of the circulating drilling fluid.

6 . A method for quantifying and tracking an amine-based shale inhibitor in a drilling fluid through visualization, comprising:
formulating a plurality of water-based drilling fluid samples having a plurality of varying concentrations of the amine-based shale inhibitor; collecting a mud filtrate from each water-based drilling fluid sample; mixing an amount of each mud filtrate with an amount of an amine precipitating reagent and allowing each mixture to precipitate; collecting a colored solution from each precipitated mixture; preparing a chart of colored solutions and corresponding amine-based shale inhibitor concentrations, obtaining one or more samples of a circulating drilling fluid having an unknown concentration of the amine-based shale inhibitor; and using the chart, estimating the concentration of the amine-based shale inhibitor in the one or more samples of the circulating drilling fluid, wherein a color intensity of the colored solution decreases with an increase in the concentration of the amine-based shale inhibitor.

7 . The method of claim 6 , wherein the plurality of varying concentrations of the amine-based shale inhibitor range from 0 pounds per barrel (ppb) to 20 ppb.

8 . The method of claim 6 , wherein the plurality of varying concentrations of the amine-based shale inhibitor range from 0 ppb to 2 ppb.

9 . The method of claim 6 , wherein the plurality of varying concentrations of the amine-based shale inhibitor range from 2 ppb to 4 ppb.

10 . The method of claim 6 , wherein the plurality of varying concentrations of the amine-based shale inhibitor range from 4 ppb to 8 ppb.

11 . The method of claim 6 , wherein the plurality of varying concentrations of the amine-based shale inhibitor range from 6 ppb to 10 ppb.

12 . The method of claim 6 , wherein the plurality of varying concentrations of the amine-based shale inhibitor range from 10 ppb to 16 ppb.

13 . The method of claim 6 , wherein the plurality of varying concentrations of the amine-based shale inhibitor range from 16 ppb to 20 ppb.

14 . The method of claim 6 , wherein the amine precipitating reagent is Reinecke's salt.

15 . The method of claim 6 , further comprising maintaining the concentration of the amine-based shale inhibitor in the one or more samples of the circulating drilling fluid from about 2% v/v to 3% v/v of the circulating drilling fluid.

Assignees

• Saudi Arabian Oil Co

Inventors

• Wagle Vikrant
• Pal Omprakash
• Al-Yami Abdullah S
• Alanqari Khawlah A

Classifications

• G01N15/06

  Investigating concentration of particle suspensions (by weighing G01N5/00; investigating sedimentation of particle suspensions G01N15/04; investigating individual particles G01N15/10) · CPC title

• C09K8/54

  Compositions for in situ inhibition of corrosion in boreholes or wells · CPC title

• G01N21/29

  using visual detection (G01N21/31 takes precedence) · CPC title

• G01N21/78

  producing a change of colour · CPC title

• G01N21/31

  Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry {(G01N21/72 takes precedence)} · CPC title