# US 2021/0080418 A1 · Oil recovery sensor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0080418 A1 - Document ID: US20210080418A1 - Status: Published application - Kind: A1 - Application number: 17/106,967 - Filed: 2020-11-30 - Published: 2021-03-18 - Earliest claimed: 2018-05-31 - Assignees: Battelle Memorial Institute - Applicants: Battelle Memorial Institute - Inventors: Slawomir Winecki - Web page: https://patentgrep.com/patent/US20210080418A1 ## CPC - G01N 33/241: {for hydrocarbon content} - G01D 5/24: by varying capacitance - G01F 1/74: Devices for measuring flow of a fluid or flow of a fluent solid material in suspension in another fluid - G01F 1/86: Indirect mass flowmeters, e.g. measuring volume flow and density, temperature or pressure - G01F 23/263: by measuring variations in capacitance of capacitors - G01N 27/023: {where the material is placed in the field of a coil} - G01N 27/221: {by investigating the dielectric properties (using microwaves G01N22/00; measuring loss factors or dielectric constants per se G01R27/26)} - G01N 27/227: {Sensors changing capacitance upon adsorption or absorption of fluid components, e.g. electrolyte-insulator-semiconductor sensors, MOS capacitors (G01N27/225 takes precedence)} - G01N 27/90: using eddy currents - G01N 33/1833: {Oil in water} - G01N 33/2823: {Raw oil, drilling fluid or polyphasic mixtures} - G01N 33/2847: {Water in oils} - G01R 27/06: Measuring reflection coefficients; Measuring standing-wave ratio - G01R 27/2605: {Measuring capacitance (capacitive sensors G01D5/24)} - G01N 27/025: {a current being generated within the material by induction} - G01N 27/74: of fluids (G01N24/00 takes precedence) - G01R 27/2617: {Measuring dielectric properties, e.g. constants (testing dielectric strength G01R31/12; detecting insulation faults G01R31/52; G01R27/2688 takes precedence)} - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR - G01F: MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## 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. ## Claims ### 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. ### Claim 2 (depends on 1) 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. ### Claim 3 (depends on 2) 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. ### Claim 4 (depends on 2) 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. ### Claim 5 (depends on 2) The system of claim 2 wherein the capacitance meter comprises a capacitance-to-digital converter implemented as an integrated circuit (IC). ### Claim 6 (depends on 2) 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. ### Claim 7 (depends on 6) 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. ### Claim 8 (depends on 6) 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. ### Claim 9 (depends on 2) 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. ### Claim 10 (depends on 1) 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. ### Claim 11 (depends on 1) 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. ### Claim 12 (depends on 1) 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. ### Claim 13 (depends on 1) 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. ### Claim 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. ### Claim 15 (depends on 14) The method of claim 14 wherein the electrically insulating channel comprises an electrically insulating pipe. ### Claim 16 (depends on 14) The method of claim 14 wherein the capacitance meter comprises a capacitance-to-digital converter implemented as an integrated circuit (IC). ### Claim 17 (depends on 14) 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. ### Claim 18 (depends on 14) 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. ### Claim 19 (depends on 14) 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. ### Claim 20 (depends on 19) 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.