# US 9,435,190 B2 · Wireless communication system for monitoring of subsea well casing annuli > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,435,190 B2 - Document ID: US9435190B2 - Status: Granted - Kind: B2 - Application number: 13/812,130 - Filed: 2010-08-05 - Published: 2013-10-17 - Granted: 2016-09-06 - Earliest claimed: 2010-08-05 - Assignees: FMC Technologies, Inc. - Applicants: John J. Mulholland; Corey Jaskolski; Gabriel Silva - Inventors: John J. Mulholland; Corey Jaskolski; Gabriel Silva - Web page: https://patentgrep.com/patent/US9435190B2 ## CPC - E21B 47/001: for underwater installation - E21B 17/0283: {characterised by the coupling being contactless, e.g. inductive} - E21B 47/13: by electromagnetic energy, e.g. radio frequency - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract A non-invasive wireless communication system for monitoring parameters existing within the casing annuli of a subsea hydrocarbon production system. The subsea hydrocarbon production system includes a wellhead housing mounted at the upper end of a well bore and a number of concentric well casings extending from the wellhead housing through the well bore, and the casing annuli are formed between successive ones of the wellhead housing and the well casings The monitoring system comprises an interrogation package which is adapted to wirelessly transmit and receive NFM and/or inductive signals and at least one sensing package which is located in one of the casing annuli and is adapted to wirelessly receive the signals from and transmit response signals to the interrogation package. ## Claims ### Claim 1 In a subsea hydrocarbon production system which comprises a wellhead housing mounted at the upper end of a well bore, a number of concentric well casings extending from the wellhead housing through the well bore, including an innermost casing through which a hydrocarbon fluid is produced, and a plurality of casing annuli formed between successive ones of the wellhead housing and the well casings, an improvement comprising a monitoring system for monitoring a parameter existing in at least one of the casing annuli which comprises: an interrogation package which is operable to wirelessly transmit an interrogation signal; and at least one sensing package which is located in a corresponding casing annulus and which includes at least one sensor for sensing the parameter, the sensing package being operable to wirelessly receive the interrogation signal and in response thereto wirelessly transmit a response signal to the interrogation package which is indicative of the parameter sensed by the sensor; wherein the interrogation package communicates with the at least one sensing package using near-field magnetic induction (NFM) signals. ### Claim 2 (depends on 1) The subsea hydrocarbon production system of claim 1, wherein the interrogation package is located externally of the wellhead housing. ### Claim 3 (depends on 2) The subsea hydrocarbon production system of claim 2, wherein the sensing package is located in one of the casing annuli. ### Claim 4 (depends on 3) The subsea hydrocarbon production system of claim 3, wherein the interrogation signals are transmitted directly between the interrogation package and the sensing package. ### Claim 5 (depends on 2) The subsea hydrocarbon production system of claim 2, wherein the at least one sensing package comprises a plurality of sensing packages, each of which is located in a corresponding casing annulus. ### Claim 6 (depends on 1) The subsea hydrocarbon production system of claim 1, wherein each sensing package comprises a plurality of sensors for monitoring corresponding parameters in the casing annuli. ### Claim 7 (depends on 1) The subsea hydrocarbon production system of claim 1, further comprising means for powering the interrogation package. ### Claim 8 (depends on 1) The subsea hydrocarbon production system of claim 1, further comprising means for powering the sensing package. ### Claim 9 (depends on 8) The subsea hydrocarbon production system of claim 8, wherein the means for powering the sensing package comprises a transmitter for generating an AC magnetic field, a receiver which is exposed to the magnetic field and which in response thereto generates an AC current, and an energy storage device which is charged by the current, wherein the energy storage device powers the sensing package. ### Claim 10 (depends on 9) The subsea hydrocarbon production system of claim 9, wherein the transmitter is located in the interrogation package. ### Claim 11 (depends on 9) The subsea hydrocarbon production system of claim 9, wherein the energy storage device is continuously charged by the current and the power stored in the energy storage device is expended by the sensing device in a single burst. ### Claim 12 (depends on 1) The subsea hydrocarbon production system of claim 1, wherein the plurality of casing annuli comprises at least an A annulus and a B annulus, and wherein the interrogation package is located in the A annulus and the sensing package is located in the B annulus. ### Claim 13 (depends on 1) The subsea hydrocarbon production system of claim 1, wherein the plurality of casing annuli comprises at least an A annulus, a B annulus and a C annulus, and wherein the interrogation package is located in the A annulus and the sensing package is located in the C annulus. ### Claim 14 In a subsea hydrocarbon production system which comprises a wellhead housing mounted at the upper end of a well bore, a number of concentric well casings extending from the wellhead housing through the well bore, including an innermost casing through which a hydrocarbon fluid is produced, and a plurality of casing annuli formed between successive ones of the wellhead housing and the well casings, an improvement comprising a monitoring system for monitoring a parameter existing in at least one of the casing annuli which comprises: an interrogation package which is operable to wirelessly transmit an interrogation signal; and at least one sensing package which is located in a corresponding casing annulus and which includes at least one sensor for sensing the parameter, the sensing package being operable to wirelessly receive the interrogation signal and in response thereto wirelessly transmit a response signal to the interrogation package which is indicative of the parameter sensed by the sensor; wherein the interrogation package is located externally of the wellhead housing, the at least one sensing package comprises a plurality of sensing packages, each of which is located in a corresponding casing annulus, and the interrogation signals are transmitted between the interrogation package and the sensing packages using a multi-hop signal transmission technique; and wherein the interrogation package communicates with a radially adjacent sensing package and the sensing packages communicate with each other using near-field magnetic induction (NFM) signals. ### Claim 15 In a subsea hydrocarbon production system which comprises a wellhead housing mounted at the upper end of a well bore, a number of concentric well casings extending from the wellhead housing through the well bore, including an innermost casing through which a hydrocarbon fluid is produced, and a plurality of casing annuli formed between successive ones of the wellhead housing and the well casings, an improvement comprising a monitoring system for monitoring a parameter existing in at least one of the casing annuli which comprises: an interrogation package which is operable to wirelessly transmit an interrogation signal; and at least one sensing package which is located in a corresponding casing annulus and which includes at least one sensor for sensing the parameter, the sensing package being operable to wirelessly receive the interrogation signal and in response thereto wirelessly transmit a response signal to the interrogation package which is indicative of the parameter sensed by the sensor; wherein the interrogation package is located within the innermost casing; and wherein the interrogation package communicates with the at least one sensing package using near-field magnetic induction (NFM) signals. ### Claim 16 (depends on 15) The subsea hydrocarbon production system of claim 15, wherein the sensing package is located in one of the casing annuli. ### Claim 17 (depends on 16) The subsea hydrocarbon production system of claim 16, wherein the interrogation signals are transmitted directly between the interrogation package and the sensing package. ### Claim 18 (depends on 15) The subsea hydrocarbon production system of claim 15, wherein the at least one sensing package comprises a plurality of sensing packages, each of which is located in a corresponding casing annulus. ### Claim 19 In a subsea hydrocarbon production system which comprises a wellhead housing mounted at the upper end of a well bore, a number of concentric well casings extending from the wellhead housing through the well bore, including an innermost casing through which a hydrocarbon fluid is produced, and a plurality of casing annuli formed between successive ones of the wellhead housing and the well casings, an improvement comprising a monitoring system for monitoring a parameter existing in at least one of the casing annuli which comprises: an interrogation package which is operable to wirelessly transmit an interrogation signal; and at least one sensing package which is located in a corresponding casing annulus and which includes at least one sensor for sensing the parameter, the sensing package being operable to wirelessly receive the interrogation signal and in response thereto wirelessly transmit a response signal to the interrogation package which is indicative of the parameter sensed by the sensor; wherein the interrogation package is located within the innermost casing, the at least one sensing package comprises a plurality of sensing packages, each of which is located in a corresponding casing annulus, and the interrogation signals are transmitted between the interrogation package and the sensing packages using a multi-hop signal transmission technique; and wherein the interrogation package communicates with a radially adjacent sensing package and the sensing packages communicate with each other using near-field magnetic induction (NFM) signals. ### Claim 20 In a subsea hydrocarbon production system which comprises a wellhead housing mounted at the upper end of a well bore, a number of concentric well casings extending from the wellhead housing through the well bore, including an innermost casing through which a hydrocarbon fluid is produced, and a plurality of casing annuli formed between successive ones of the wellhead housing and the well casings, an improvement comprising a monitoring system for monitoring a parameter existing in at least one of the casing annuli which comprises: an interrogation package which is operable to wirelessly transmit an interrogation signal; and at least one sensing package which is located in a corresponding casing annulus and which includes at least one sensor for sensing the parameter, the sensing package being operable to wirelessly receive the interrogation signal and in response thereto wirelessly transmit a response signal to the interrogation package which is indicative of the parameter sensed by the sensor; and means for powering the sensing package, said means comprising a transmitter for generating an AC magnetic field, a receiver which is exposed to the magnetic field and which in response thereto generates an AC current, and an energy storage device which is charged by the current, wherein the energy storage device powers the sensing package; wherein the monitoring system comprises a plurality of sensing packages, each of which is positioned in a corresponding casing annulus, and wherein the means for powering the sensing packages comprises a plurality of transmitters and receivers arranged in transmitter/receiver pairs, each transmitter/receiver pair being positioned in a corresponding casing annulus and being connected to a corresponding energy storage device which in turn is connected to a corresponding sensing package, wherein power for at least one sensing package is transmitted to its corresponding transmitter/receiver pair by the transmitter/receiver pair of a radially adjacent sensing package.