Method and system for monitoring smart structures utilizing distributed optical sensors

• US 20030094281A1
• Filed: 12/23/2002
• Published: 05/22/2003
• Est. Priority Date: 06/29/2000
• Status: Active Grant

• Current Assignee: Ziebel (Us), Inc.
• Original Assignee: Tube Technology, Inc.
• Inventors: Tubel, Paulo S.
• Granted Patent: US 6,913,079 B2
• Time in Patent Office: Days
• US Class Current: 166/250.03
• CPC Class Codes: E21B 41/0099 specially adapted for drilling for or production of natural hydrate or clathrate gas reservoirs; Drilling through or monitoring of formations containing gas hydrates or clathrates
• CPC Class Codes: E21B 47/114 using light radiation
• CPC Class Codes: E21B 47/135 using light waves, e.g. infrared or ultraviolet waves
• CPC Class Codes: G01N 21/774 the reagent being on a grating or periodic structure
• CPC Class Codes: G01V 2210/647 Gas hydrates
• CPC Class Codes: G01V 8/16 using optical fibres

Abstract

A monitoring system and method for monitoring a predetermined set of physical characteristics associated with a structure using the monitoring system. The system is distributed in the structure and comprises a distributed optical sensing device (30), further comprising a fiber optic cable (20, 22); a light source (18a) operatively in communication with the fiber optic cable (20, 22); a light detection device (18b), operatively in communication with the fiber optic cable (20, 22), for measuring the light received at the light detection device (18b) from the fiber optic cable (20, 22); and a data processor (18) capable of using the light measured to calculate a predetermined set of physical parameters describing the predetermined set of physical characteristics.

Claims

1. An system for monitoring physical parameters distributed in a structure, comprising:

a. a distributed optical sensing device (30), comprising a fiber optic cable (20,22), deployed proximate a predetermined structure;

b. a light source (18a) operatively in communication with the fiber optic cable (20,22);

c. a light detection device (18b), operatively in communication with the fiber optic cable (20,22), for measuring the light received at the light detection device (18b) from the fiber optic cable (20,22); and

d. a data processor (18) operatively connected to the light detection device (18b);

e. wherein the data processor (18) uses light measured at the light detection device (18b) to calculate at least one of the physical parameters.

2. The system of claim 1 wherein a predetermined portion of a length of the fiber optic cable (20,22) is the distributed sensing device (30).

3. The system of claim 2 wherein the distributed optical sensing device (30) further comprises a discrete fiber optic sensor (32) operatively connected to the fiber optic cable (20,22).

4. The method of claim 2 wherein the distributed optical sensing device (30) further comprises Bragg Grating sensors (32) sensitive to temperature, transverse strain, and longitudinal strain effects, the sensors (32) operatively connected to the fiber optic cable (20,22).

5. The system of claim 1 wherein the physical parameters comprise temperature, vibration, pressure, stress, strain, magnetic phenomena, electric phenomena, and fluid levels.

6. The system of claim 1 further comprising:

f. a time domain reflectometer operatively connected to the light detection device (18b) and the data processor (18) wherein a location of the physical parameter being monitored is measured using the time domain reflectometer.

7. The system of claim 1 wherein the light source (15a) of element (b) comprises a lasers, laser LEDs, non-laser light sources (18a), non-laser LEDs, spread spectrum light sources, single spectrum light sources, and multiple spectrum light sources.

8. The system of claim 1, wherein light detection device (18b) of element (e) further comprises a light detection device (18b) capable of detecting modulation of a spontaneous antiStokes Raman photon backscattering wave, modulation of a spontaneous Rayleigh backscattering photon wave, and scattered photons using Brillouin scattered techniques.

10. The system of claim 1 wherein at least one fiber optic cable (20,22) comprises fiber optic cable (20,22) optimized for use undersea and capable of measuring physical parameters over a predetermined portion of a length of the fiber optic cable (20,22), the fiber optic cable (20,22) being deployed undersea, the physical parameters comprising predetermined physical characteristics of methane hydrate.

9. The system of claim 9 wherein the distributed optical sensing device (30) is integrated within a downhole component deployed permanently or temporarily in a wellbore (10) to measure physical parameters of a well, drilling of and production from the well, and geological formation parameters.

11. A method for monitoring a predetermined set of physical characteristics associated with a structure or a process involving the structure, for a monitoring system, distributed in the structure, comprising a distributed optical sensing device (30) further comprising a fiber optic cable (20,22);

a light source (18a) operatively in communication with the fiber optic cable (20,22);

a light detection device (18b), operatively in communication with the fiber optic cable (20,22), for measuring light received at the light detection device (18b) from the fiber optic cable (20,22); and

a data processor (18) capable of using the light measured to calculate a predetermined set of physical parameters describing the predetermined set of physical characteristics, the method comprising;

a. deploying the distributed optical sensing device (30) in the structure;

b. providing light to the distributed optical sensing device (30) from the light source (18a);

c. measuring light from the distributed optical sensing device (30) incident at the light detection device (18b) with the light detection device (18b);

d. using the data processor (18) to substantially simultaneously obtain and continuously monitor a plurality of measurements from the distributed optical sensing device (30) at a plurality of locations along the distributed optical sensing device (30) using the measured light incident at the light detection device (18b); and

e. calculating the predetermined set of physical characteristics for the one or more desired physical parameters using the plurality of measurements.

12. The method of claim 11 further comprising:

a. providing continuous light from a source of continuous light;

b. providing pulsed light from a pulsed light probe beam;

c. determining Brillouin loss; and

d. using the Brillouin loss to obtain the desired physical parameter measurements.

13. The method of claim 12 further comprising:

i. stepping the continuous light source (18a) and the pulsed light source (18a) through a range of frequencies around an anticipated Brillouin frequency and measuring power loss at each frequency;

ii. determining a Brillouin shift at a frequency where a highest power loss is encountered; and

iii. determining a desired physical parameter measurement by using a predetermined relationship between power loss and desired signal amplitude.

14. The method of claim 11 further comprising using interferometric methods for strain, acoustic, and pressure measurements wherein scattering photons created by light traveling through the fiber optic cable (20,22) provide information related to a status of the structure.

15. The method of claim 11, further comprising monitoring construction processes of the structure wherein step (e) further comprises calculating a progression of the construction of the structure using the one or more desired physical parameters.

16. The method of claim 11, wherein the structure is a downhole structure, further comprising:

a. deploying the distributed optical sensing device (30) in the downhole structure in conjunction with a drilling, production, or fishing apparatus; and

b. obtaining measurements using the distributed optical sensing device (30), the measurements comprising measurements of;

i. parameters comprising borehole and geological parameters as a drilling or hydrocarbon production apparatus traverses formations during construction of a wellbore (10) wherein the borehole and geological parameters comprise pressures of formations through which the borehole proceeds and temperature of the formations;

ii. production of fluids from formations in the wellbore (10) wherein the parameters comprise pressures of the formations and temperature of the formations;

iii. strain on drilling pipe deployed in the structure;

iv. parameters calculated from data obtained while drilling wherein noise created by a drilling process or external acoustic source located at a remote location generates an acoustic signal capable of traveling through geological formations proximate the structure, the noise being detected by the fiber optic cable (20,22) as the light from the light source (18a) travels through the fiber optic cable (20,22) by using reflected photons to determine information related to temperature, strain, pressure, and acoustic disturbances;

v. corrosion of casing (12) or tubing deployed within the structure;

vi. parameters comprising production parameters required to optimize production in intelligent wells;

vii. parameters comprising production and physical parameters in laterals to determine optimum parameters, the optimum parameters further comprising pressure and flow, useful for production of hydrocarbons;

viii. parameters comprising production and physical parameters in laterals to monitor production in the laterals where at least one lateral is divided in multiple zones isolated by downhole hardware including Intelligent Completion Systems;

ix. parameters obtained from data measurements in abandoned wells useful to determine presence of leaks within formations in the well;

x. parameters obtained from data measurements in abandoned wells useful to monitor compaction and subsidence of formations through which the structure passes;

xi. parameters obtained from data measurements during artificial lift applications, the parameters comprising pressure, strain, flow, fluid identification, and temperature, the parameters useful to optimize production in gas lift, rod pump, progressive cavity pump, and electrical submersible pump applications;

xii. parameters obtained from data measurements in injector wells to monitor movement of injected fluid or steam into the structure to assure that injected fluid reaches its proper destination in the structure;

xiii. parameters obtained from data measurements in geothermal wells, the parameters comprising pressure, strain, and temperature; and

xiv. parameters obtained from data measurements in multilateral wells comprising laterals wherein each lateral is monitored.

17. The method of claim 11 wherein the distributed optical sensing device (30) is deployed on a seabed to monitor a desired set of physical characteristics of the seabed, the set of physical characteristics comprising movement of the seabed, temperature of the seabed, and predetermined characteristics of methane hydrate present proximate the seabed useful in evaluating methane hydrate stability undersea.