Oil recovery sensor

Patent metadata

Field	Value
Publication number	US-2021080418-A1
Application number	US-202017106967-A
Country	US
Kind code	A1
Filing date	Nov 30, 2020
Priority date	May 31, 2018
Publication date	Mar 18, 2021
Grant date	—

Abstract

The present disclosure relates to systems and methods for measuring oil/water content in oil-water mixtures, regardless of the salinity of the mixture and regardless of air in the sensor pipe. In some embodiments, the oil content is measured using a dielectric sensor. It is determined whether the oil content is above or below a threshold. If the oil content is above the threshold, the oil content is reported using the measurement from the dielectric sensor. If the oil content is below the threshold, the oil content is reported using the measurement from the eddy current sensor. In some embodiments, which improve performance when there is air in the sensor pipe, two dielectric sensors with different geometries are used instead of the one dielectric sensor.

First claim

1 . A system for measuring oil content of a fluid, the system comprising:
an electrically insulating channel; a first electrode disposed on an outside of the electrically insulating channel; a second electrode disposed on the outside of the electrically insulating channel, wherein the first electrode and the second electrode are spaced apart along the electrically insulating channel by a distance L; a capacitance meter connected to measure capacitance between the first electrode and the second electrode; and one or more processors configured to determine an oil content of a fluid contained in the electrically insulating channel based on the measured capacitance between the first electrode and the second electrode.

2 . The system of claim 1 wherein:
the electrically insulating channel comprises an electrically insulating pipe;
the first electrode at least partially encircles the outside of the electrically insulating pipe; and
the second electrode at least partially encircles the outside of the electrically insulating pipe.

3 . The system of claim 2 wherein the electrically insulating pipe is straight at least over the distance L between the first electrode and the second electrode.

4 . The system of claim 2 wherein the electrically insulating pipe includes:
a straight pipe portion having a length greater than or equal to the distance L wherein the first electrode is disposed on the outside of the straight pipe portion and the second electrode is disposed on the outside of the straight pipe portion; and
bent pipe portions at the ends of the straight pipe portion whereby the electrically insulating pipe defines a U-trap.

5 . The system of claim 2 wherein the capacitance meter comprises a capacitance-to-digital converter implemented as an integrated circuit (IC).

6 . The system of claim 2 further comprising:
at least one dielectric sensor, wherein each dielectric sensor includes:
a first dielectric sensor electrode disposed on the outside of the electrically insulating pipe;
a second dielectric sensor electrode disposed on the outside of the electrically insulating pipe, wherein the first dielectric sensor electrode and the second dielectric sensor electrode are disposed on radially opposite sides of the electrically insulating pipe; and
a dielectric sensor capacitance meter connected to measure a capacitance between the first dielectric sensor electrode and the second dielectric sensor electrode;
wherein the one or more processors are configured to determine the oil content of the fluid contained in the electrically insulating channel further based on the measured capacitance between the first dielectric sensor electrode and the second dielectric sensor electrode.

7 . The system of claim 6 wherein at least one dielectric sensor includes:
a vertically oriented dielectric sensor in which the first and second dielectric sensor electrodes are spaced apart vertically; and
a horizontally oriented dielectric sensor in which the first and second dielectric sensor electrodes are spaced apart horizontally.

8 . The system of claim 6 comprising a multi-channel capacitance-to-digital converter implemented as an integrated circuit (IC), wherein the capacitance meter and the dielectric sensor capacitance meter of each dielectric sensor are implemented using respective channels of the multi-channel capacitance-to-digital converter.

9 . The system of claim 2 wherein:
the first electrode comprises a first electrically conductive ring completely encircling the outside of the electrically insulating pipe; and
the second electrode comprises a second electrically conductive ring completely encircling the outside of the electrically insulating pipe.

10 . The system of claim 1 wherein one or more processors are configured to determine the oil content of the fluid contained in the electrically insulating channel based on the measured capacitance between the first electrode and the second electrode and further based on a salinity of a water component of the fluid contained in the electrically insulating channel.

11 . The system of claim 1 wherein the one or more processors are configured to determine the oil content of the fluid contained in the electrically insulating channel based on the measured capacitance between the first electrode and the second electrode and further based on the distance L.

12 . The system of claim 1 wherein the one or more processors are configured to determine the oil content of the fluid contained in the electrically insulating channel by operations including:
converting the measured capacitance between the first and second electrodes to an electrical conductivity of the fluid contained in the electrically insulating channel based on the measured capacitance and the distance L; and
determining the oil content of the fluid contained in the electrically insulating channel based on the electrical conductivity of the fluid contained in the electrically insulating channel.

13 . The system of claim 1 wherein the capacitance meter is configured to measure the capacitance between the first electrode and the second electrode at a frequency in a range of 10 kHz to 10 MHz.

14 . A method for measuring oil content of a fluid, the method comprising:
disposing a mixture of oil and water in an electrically insulating channel; and determining an oil content of the mixture of oil and water in the electrically insulating channel by operations including:
using a capacitance meter, measuring a capacitance between a first electrode and a second electrode wherein the first electrode is disposed on an outside of the electrically insulating channel, the second electrode is disposed on the outside of the electrically insulating channel, and the first electrode and the second electrode are spaced apart along the electrically insulating channel by a distance L; and
using one or more processors, determining an oil content of the mixture of oil and water in the electrically insulating channel based on the measured capacitance between the first electrode and the second electrode.

15 . The method of claim 14 wherein the electrically insulating channel comprises an electrically insulating pipe.

16 . The method of claim 14 wherein the capacitance meter comprises a capacitance-to-digital converter implemented as an integrated circuit (IC).

17 . The method of claim 14 wherein the oil content of the fluid contained in the electrically insulating channel is determined based on the measured capacitance between the first electrode and the second electrode and further based on a salinity of a water component of the mixture of oil and water in the electrically insulating channel.

18 . The method of claim 14 wherein the oil content of the fluid contained in the electrically insulating channel is determined based on the measured capacitance between the first electrode and the second electrode and further based on the distance L.

19 . The method of claim 14 wherein the disposing of the oil and water in the electrically insulating channel comprises obtaining the mixture of oil and water by performing oil recovery comprising mechanical surface skimming.

20 . The method of claim 19 wherein the electrically insulating channel comprises an electrically insulating pipe and the disposing comprises flowing the mixture of oil and water through the electrically insulating pipe while determining the oil content of the mixture of oil and water.

Assignees

• Battelle Memorial Institute

Inventors

• Winecki Slawomir

Classifications

• G01N27/90

  using eddy currents · CPC title

• G01D5/24

  by varying capacitance · CPC title

• G01N33/241 Primary

  for hydrocarbon content · CPC title

• G01F1/86

  Indirect mass flowmeters, e.g. measuring volume flow and density, temperature or pressure · CPC title

• G01R27/2605

  Measuring capacitance (capacitive sensors G01D5/24) · CPC title