Characterizing lubricant oil degradation using fluorescence signals

Patent metadata

Field	Value
Publication number	US-10060899-B2
Application number	US-201715496953-A
Country	US
Kind code	B2
Filing date	Apr 25, 2017
Priority date	Apr 26, 2016
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

Methods, systems, and apparatus to diagnose lubrication oil deterioration. In one aspect, a method includes irradiating a lubrication oil sample with a light beam to emit a light-induced fluorescence, detecting and processing the light-induced fluorescence signal to determine a temporal variation of a fluorescence intensity, identifying a steady state of the light-induced fluorescence signal, processing the temporal variation of the fluorescence intensity to determine a lubrication oil parameter, and correlating the oil parameter to a calibration curve to diagnose the lubrication oil deterioration.

First claim

What is claimed is:

1. A system to diagnose lubrication oil deterioration, the system comprising:
a memory;
a hardware processor interoperably coupled with the memory and configured to:
guide a first light beam to a fresh lubrication oil sample obtained from a hydrocarbon well equipment;
guide a second light beam to a deteriorated lubrication oil sample obtained from the hydrocarbon well equipment;
detect a first light-induced fluorescence signal from the fresh lubrication oil sample;
detect a second light-induced fluorescence signal from the deteriorated lubrication oil sample;
process the first light-induced fluorescence signal and the second light-induced fluorescence signal to determine a respective damping effect or natural frequency of each of the first light-induced fluorescence signal and the second light-induced fluorescence signal;
based on results of processing the first light-induced fluorescence signal and the second light-induced fluorescence signal, determine a lubrication oil parameter for the fresh lubrication oil sample and a lubrication oil parameter for the deteriorated lubrication oil sample; and
determine an amount of lubrication oil deterioration of the lubrication oil sample by correlating the lubrication oil parameter for the fresh lubrication oil sample and the deteriorated lubrication oil sample to a calibration curve.

2. The system of claim 1 , wherein the hardware processor is configured to:
determine a temporal variation of a first fluorescence intensity from the first light-induced fluorescence signal; and
determine a temporal variation of a second fluorescence intensity from the second light-induced fluorescence signal.

3. The system of claim 2 , wherein the hardware processor is configured to:
determine a steady-state of the first light-induced fluorescence signal from the temporal variation of the first fluorescence intensity; and
determine a steady-state of the second light-induced fluorescence signal from the temporal variation of the second fluorescence intensity.

4. The system of claim 3 , wherein the hardware processor is configured to:
determine the lubrication oil parameter for the fresh lubrication oil sample from the steady-state of the first light-induced fluorescence signal; and
determine the lubrication oil parameter for the deteriorated lubrication oil sample from the steady-state of the second light-induced fluorescence signal.

5. The system of claim 2 , wherein the hardware processor is configured to represent each of the first fluorescence intensity and the second fluorescence intensity as a second order dynamic system corresponding to one of an over-damped oscillator with a damping ratio larger than 1 or an under-damped oscillator with a damping ratio smaller than 1.

6. The system of claim 1 , wherein the hardware processor is configured to:
guide the first light beam at an acute angle on a front surface of a container holding the fresh lubrication oil sample; and
guide the second light beam at an acute angle on a front surface of a container holding the deteriorated lubrication oil sample.

7. The system of claim 1 , wherein the hardware processor is configured to:
filter each of the first light-induced fluorescence signal and the second light-induced fluorescence signal.

8. The system of claim 1 , wherein the hardware processor is configured to capture each of the first light-induced fluorescence signal and the second light-induced fluorescence signal by a fast photodiode.

Assignees

• Saudi Arabian Oil Co

Inventors

• Hegazi Ezzat
• Cunningham Vincent
• Nour Maha

Classifications

• G01N21/6402

  Atomic fluorescence; Laser induced fluorescence · CPC title

• G01N21/6408

  with measurement of decay time, time resolved fluorescence · CPC title

• G01N21/643

  non-biological material · CPC title

• G01N33/2888 Primary

  Lubricating oil characteristics, e.g. deterioration (lubricating properties G01N33/30) · CPC title

• G01J3/4406

  Fluorescence spectrometry · CPC title