Fiber optic sensing systems and methods

Abstract

Fiber optic sensing systems and methods. In a described embodiment, a fiber optic sensing system includes an optical fiber transmitting energy to a chemical vapor deposited diamond material proximate a substance in a well. The diamond material is deposited as a coating on a substrate. The substrate and coating are heated when the energy is transmitted by the optical fiber. This heats the substance in the well, which is detected to determine a property of the substance. In another embodiment, light energy is transmitted through the diamond material.

What is claimed is:  
     
         1 . A fiber optic sensing system for sensing at least one property of a substance, the system comprising: 
 a sensor surface proximate the substance;    an optical fiber transmitting energy to the sensor surface; and    the energy being transmitted to the substance via the sensor surface.    
     
     
         2 . The sensing system according to  claim 1 , wherein the sensor surface is formed on a relatively erosion resistant material.  
     
     
         3 . The sensing system according to  claim 1 , wherein the sensor surface is formed on a highly thermally conductive material.  
     
     
         4 . The sensing system according to  claim 1 , wherein the sensor surface is formed on a light transmitting material.  
     
     
         5 . The sensing system according to  claim 1 , wherein the sensor surface is formed on a diamond material.  
     
     
         6 . The sensing system according to  claim 5 , wherein the diamond material is a chemical vapor deposition coating on a substrate of the sensor.  
     
     
         7 . The sensing system according to  claim 1 , wherein the sensor detects a response of the substance to the energy transmitted to the substance from the sensor surface.  
     
     
         8 . The sensing system according to  claim 7 , wherein temperature transmitted to the substance causes a change in phase of the substance.  
     
     
         9 . The sensing system according to  claim 7 , wherein the response is a change in temperature of the substance.  
     
     
         10 . The sensing system according to  claim 9 , wherein the temperature of the substance is detected remote from the sensor surface.  
     
     
         11 . The sensing system according to  claim 7 , wherein the response is a change in phase of the substance.  
     
     
         12 . The sensing system according to  claim 1 , wherein the energy transmitted by the optical fiber is light energy, the light energy being transmitted to the substance through the sensor surface.  
     
     
         13 . The sensing system according to  claim 1 , wherein an intensity of the energy transmitted by the optical fiber is varied, and wherein a transient response of the substance to the varied energy is detected to thereby sense a property of the substance.  
     
     
         14 . A fiber optic sensing system for use in detecting at least one property of a substance or heat transfer characteristic of a location proximate to the substance in a subterranean well, the sensing system comprising: 
 an optical fiber for transmitting energy to a sensor surface, the sensor surface being heated when energy is transmitted by the optical fiber; and    a first temperature sensor for detecting a temperature of the substance.    
     
     
         15 . The sensing system according to  claim 14 , wherein the substance is a fluid, and wherein the first temperature sensor detects a temperature of the fluid proximate the sensor surface.  
     
     
         16 . The sensing system according to  claim 15 , wherein the substance is a fluid, and wherein the first temperature sensor detects a temperature of the fluid remote from the sensor surface.  
     
     
         17 . The sensing system according to  claim 16 , wherein the first temperature sensor detects a temperature of the fluid upstream from the sensor surface.  
     
     
         18 . The sensing system according to  claim 16 , wherein the first temperature sensor detects a temperature of the fluid downstream from the sensor surface.  
     
     
         19 . The sensing system according to  claim 14 , further comprising a second temperature sensor positioned remote from the first temperature sensor.  
     
     
         20 . The sensing system according to  claim 19 , wherein the first temperature sensor detects the temperature of the substance proximate the sensor surface, and the second sensor detects the temperature of the substance remote from the sensor surface.  
     
     
         21 . The sensing system according to  claim 20 , wherein the second temperature sensor is downstream from the first temperature sensor.  
     
     
         22 . The sensing system according to  claim 20 , wherein the second temperature sensor is upstream from the first temperature sensor.  
     
     
         23 . The sensing system according to  claim 14 , further comprising an energy converter between the optical fiber and the sensor surface, the converter converting light energy transmitted by the optical fiber into heat energy in the sensor surface.  
     
     
         24 . The sensing system according to  claim 23 , wherein the energy converter is a black body interface.  
     
     
         25 . The sensing system according to  claim 14 , wherein the sensor surface is on a diamond material.  
     
     
         26 . The sensing system according to  claim 25  wherein the diamond material is a chemical vapor deposition coating.  
     
     
         27 . The sensing system according to  claim 14 , wherein energy transmitted by the optical fiber heats a substrate on which the sensor surface is disposed.  
     
     
         28 . The sensing system according to  claim 27 , further comprising an energy converter between the optical fiber and the substrate, the converter converting light energy transmitted by the optical fiber into heat energy in the substrate.  
     
     
         29 . The sensing system according to  claim 28 , wherein the energy converter is a black body interface.  
     
     
         30 . The sensing system according to  claim 27 , wherein the sensor surface is on a diamond material attached to the substrate, the diamond material having greater thermal conductivity than the substrate.  
     
     
         31 . The sensing system according to  claim 14 , further comprising a laser transmitting the energy through the optical fiber.  
     
     
         32 . The sensing system according to  claim 31 , wherein the laser is positioned in the well.  
     
     
         33 . The sensing system according to  claim 31 , wherein the laser is positioned at the earth's surface.  
     
     
         34 . The sensing system according to  claim 14 , wherein the substance is a fluid within a tubular string in the well.  
     
     
         35 . The sensing system according to  claim 14 , wherein the substance is a fluid external to a tubular string in the well.  
     
     
         36 . The sensing system according to  claim 35 , wherein the fluid is disposed in an annulus between the tubular string and casing in the well.  
     
     
         37 . The sensing system according to  claim 35 , wherein the tubular string is casing, and wherein the fluid is formation fluid.  
     
     
         38 . The sensing system according to  claim 14 , wherein the substance is a hardenable material positioned in an annulus between a wellbore and casing in the well.  
     
     
         39 . The sensing system according to  claim 14 , wherein the substance is a formation intersected by a wellbore of the well.  
     
     
         40 . The sensing system according to  claim 14 , wherein the substance is a solid structure in the well.  
     
     
         41 . The sensing system according to  claim 40 , wherein the structure is a tubular string.  
     
     
         42 . The sensing system according to  claim 14 , wherein the sensing system includes multiple sensors distributed circumferentially about a tubular string in the well.  
     
     
         43 . The sensing system according to  claim 14 , wherein the sensing system detects a level of an interface between different fluids flowing through a tubular string in the well.  
     
     
         44 . The sensing system according to  claim 14 , wherein the sensing system includes multiple sensors distributed longitudinally along a tubular string in the well.  
     
     
         45 . The sensing system according to  claim 14 , wherein the sensing system detects a level of an interface between different fluids in a formation intersected by the well.  
     
     
         46 . The sensing system according to  claim 14 , wherein the substance is a hardenable material installed external to a tubular string in the well, and wherein the sensing system detects a quality of installation of the hardenable material.  
     
     
         47 . The sensing system according to  claim 46 , wherein the sensing system detects a presence of a fluid in the hardenable material.  
     
     
         48 . The sensing system according to  claim 46 , wherein the sensing system detects a presence of a void in the hardenable material.  
     
     
         49 . The sensing system according to  claim 46 , wherein the sensing system detects a presence of a crack in the hardenable material.  
     
     
         50 . The sensing system according to  claim 14 , wherein the sensing system detects a direction of flow of the substance through a tubular string in the well.  
     
     
         51 . The sensing system according to  claim 14 , wherein the sensing system detects a rate of flow of the substance through a tubular string in the well.  
     
     
         52 . The sensing system according to  claim 14 , wherein the sensing system detects a property indicative of an identity of the substance in the well.  
     
     
         53 . The sensing system according to  claim 14 , wherein the sensing system detects a phase change in the substance in the well.  
     
     
         54 . The sensing system according to  claim 14 , wherein the sensing system detects a ratio between different fluids included in the substance in the well.  
     
     
         55 . The sensing system according to  claim 14 , wherein the substance is a tubular string material, and wherein the sensing system detects a thermal property of the tubular string material.  
     
     
         56 . The sensing system according to  claim 14 , wherein the substance is a formation, and wherein the sensing system detects a thermal property of the formation.  
     
     
         57 . The sensing system according to  claim 56 , wherein the sensing system detects a thermal property of a fluid in the formation.  
     
     
         58 . The sensing system according to  claim 56 , wherein the sensing system detects a location of a fluid in the formation.  
     
     
         59 . The sensing system according to  claim 56 , wherein the sensing system detects a presence of a fracture in the formation.  
     
     
         60 . The sensing system according to  claim 56 , wherein the sensing system detects a location of a fracture in the formation.  
     
     
         61 . The sensing system according to  claim 14 , wherein the detection of the substance temperature by the sensing system is indicative of a heat transfer characteristic of a local well environment.  
     
     
         62 . The sensing system according to  claim 61 , wherein the heat transfer characteristic is a heat capacity of the local well environment.  
     
     
         63 . The sensing system according to  claim 14 , wherein the substance is a hardenable material positioned external to a tubular string, and wherein the sensing system detects a thermal property of the hardenable material.  
     
     
         64 . The sensing system according to  claim 14 , wherein the substance is a tubular string material, and wherein the sensing system detects a thermal property of the tubular string material.  
     
     
         65 . The sensing system according to  claim 14 , wherein the substance is a fluid in the well, and wherein the sensing system detects a thermal property of the fluid.  
     
     
         66 . A fiber optic sensing system for use in detecting at least one property of a substance in a subterranean well, the sensing system comprising: 
 a sensor surface configured for transmitting energy to the substance in the well;    an optical fiber for transmitting light energy to the sensor surface, the light energy being transmitted from the optical fiber through the sensor surface and to the substance; and    the light energy causing a response in the substance.    
     
     
         67 . The sensing system according to  claim 66 , further comprising a sensor for detecting the substance response.  
     
     
         68 . The sensing system according to  claim 67 , wherein the sensor is a spectrometer.  
     
     
         69 . The sensing system according to  claim 67 , wherein the sensor is a fluoroscope.  
     
     
         70 . The sensing system according to  claim 67 , wherein the substance response is transmitted through the optical fiber to the sensor.  
     
     
         71 . The sensing system according to  claim 66 , wherein the light energy excites the substance to give off a spectrum indicative of an elemental composition of the substance.  
     
     
         72 . The sensing system according to  claim 66 , wherein the light energy causes at least a portion of the substance to fluoresce.  
     
     
         73 . The sensing system according to  claim 66 , wherein the light energy heats the substance.  
     
     
         74 . The sensing system according to  claim 73 , wherein the substance undergoes a phase change when the light energy heats the substance.  
     
     
         75 . The sensing system according to  claim 66 , wherein the sensor surface is formed on a diamond material.  
     
     
         76 . The sensing system according to  claim 66 , wherein the sensor surface is formed on a chemical vapor deposited coating.  
     
     
         77 . The sensing system according to  claim 66 , further comprising a laser positioned in the well transmitting the light energy through the optical fiber.  
     
     
         78 . The sensing system according to  claim 66 , further comprising a laser positioned at the earth's surface transmitting the light energy through the optical fiber.  
     
     
         79 . The sensing system according to  claim 66 , wherein the substance is a fluid within a tubular string in the well.  
     
     
         80 . The sensing system according to  claim 66 , wherein the substance is a fluid external to a tubular string in the well.  
     
     
         81 . The sensing system according to  claim 80 , wherein the fluid is disposed in an annulus between the tubular string and casing in the well.  
     
     
         82 . The sensing system according to  claim 80 , wherein the tubular string is casing, and wherein the fluid is formation fluid.  
     
     
         83 . The sensing system according to  claim 66 , wherein the substance is a hardenable material positioned in an annulus between a wellbore and casing in the well.  
     
     
         84 . The sensing system according to  claim 66 , wherein the substance is a formation intersected by a wellbore of the well.  
     
     
         85 . The sensing system according to  claim 66 , wherein the substance is a solid structure in the well.  
     
     
         86 . The sensing system according to  claim 85 , wherein the structure is a tubular string.  
     
     
         87 . The sensing system according to  claim 66 , wherein the sensing system includes multiple sensing devices distributed circumferentially about a tubular string in the well.  
     
     
         88 . The sensing system according to  claim 66 , wherein the sensing system detects a level of an interface between different fluids flowing through a tubular string in the well.  
     
     
         89 . The sensing system according to  claim 66 , wherein the sensing system includes multiple sensing devices distributed longitudinally along a tubular string in the well.  
     
     
         90 . The sensing system according to  claim 66 , wherein the sensing system detects a level of an interface between different fluids in a formation intersected by the well.  
     
     
         91 . The sensing system according to  claim 66 , wherein the substance is a hardenable material installed external to a tubular string in the well, and wherein the sensing system detects a quality of installation of the hardenable material.  
     
     
         92 . The sensing system according to  claim 91 , wherein the sensing system detects a presence of a fluid in the hardenable material.  
     
     
         93 . The sensing system according to  claim 91 , wherein the sensing system detects a presence of a void in the hardenable material.  
     
     
         94 . The sensing system according to  claim 91 , wherein the sensing system detects a presence of a crack in the hardenable material.  
     
     
         95 . The sensing system according to  claim 66 , wherein the sensing system detects a direction of flow of the substance through a tubular string in the well.  
     
     
         96 . The sensing system according to  claim 66 , wherein the sensing system detects a rate of flow of the substance through a tubular string in the well.  
     
     
         97 . The sensing system according to  claim 66 , wherein the sensing system detects an identity of the substance in the well.  
     
     
         98 . The sensing system according to  claim 66 , wherein the sensing system detects a chemical composition of the substance in the well.  
     
     
         99 . The sensing system according to  claim 66 , wherein the sensing system detects a phase change in the substance in the well.  
     
     
         100 . The sensing system according to  claim 66 , wherein the sensing system detects fluorescence of the substance in the well.  
     
     
         101 . The sensing system according to  claim 66 , wherein the sensing system detects a ratio between different fluids included in the substance in the well.  
     
     
         102 . The sensing system according to  claim 66 , wherein the substance is a tubular string material, and wherein the sensing system detects a thermal property of the tubular string material.  
     
     
         103 . The sensing system according to  claim 66 , wherein the substance is a formation, and wherein the sensing system detects a thermal property of the formation.  
     
     
         104 . The sensing system according to  claim 103 , wherein the sensing system detects a thermal property of a fluid in the formation.  
     
     
         105 . The sensing system according to  claim 103 , wherein the sensing system detects a location of a fluid in the formation.  
     
     
         106 . The sensing system according to  claim 103 , wherein the sensing system detects a presence of a fracture in the formation.  
     
     
         107 . The sensing system according to  claim 103 , wherein the sensing system detects a location of a fracture in the formation.  
     
     
         108 . The sensing system according to  claim 66 , wherein the substance is a hardenable material positioned external to a tubular string, and wherein the sensing system detects a thermal property of the hardenable material.  
     
     
         109 . The sensing system according to  claim 66 , wherein the substance is a tubular string material, and wherein the sensing system detects a thermal property of the tubular string material.  
     
     
         110 . The sensing system according to  claim 66 , wherein the substance is a fluid in the well, and wherein the sensing system detects a thermal property of the fluid.  
     
     
         111 . A method of detecting at least one property of a substance in a subterranean well, the method comprising the steps of: 
 positioning a sensor surface in the well proximate the substance;    transmitting energy through an optical fiber to the sensor surface, thereby heating the sensor surface and the substance proximate the sensor surface; and    detecting a temperature of at least one of the heated substance and the sensor surface.    
     
     
         112 . The method according to  claim 111 , wherein the substance is a fluid flowing in the well, and wherein the detecting step is performed using a first temperature sensor positioned downstream relative to the sensor surface.  
     
     
         113 . The method according to  claim 112 , further comprising the step of detecting a temperature of the heated substance using a second temperature sensor proximate the sensor surface.  
     
     
         114 . The method according to  claim 112 , further comprising the step of detecting a temperature of the heated substance using a second temperature sensor upstream relative to the sensor surface.  
     
     
         115 . The method according to  claim 111 , further comprising the step of forming the sensor surface on a chemical vapor deposited diamond material.  
     
     
         116 . The method according to  claim 115 , further comprising the step of chemical vapor depositing the diamond material on a substrate.  
     
     
         117 . The method according to  claim 116 , wherein the transmitting step further comprises heating the substrate positioned between the optical fiber and the diamond material.  
     
     
         118 . The method according to  claim 111 , wherein the transmitting step further comprises varying the transmission of energy through the optical fiber, thereby producing a transient heating of the substance.  
     
     
         119 . The method according to  claim 118 , wherein the energy transmission varying step further comprises varying an intensity of the energy transmitted through the optical fiber.  
     
     
         120 . The method according to  claim 118 , wherein the energy transmission varying step further comprises alternately transmitting and not transmitting the energy through the optical fiber.  
     
     
         121 . The method according to claim ill, wherein the transmitting step further comprises heating the substance, thereby causing a phase change in the substance.  
     
     
         122 . The method according to  claim 121 , further comprising the step of detecting a pressure of the substance proximate the sensor.  
     
     
         123 . A method of detecting at least one property of a substance in a subterranean well, the method comprising the steps of: 
 positioning a sensor surface in the well proximate the substance;    transmitting light energy through an optical fiber to the sensor surface;    transmitting the light energy through the sensor surface to the substance; and    detecting a response of the substance to the transmitted light energy.    
     
     
         124 . The method according to  claim 123 , wherein the detecting step further comprises detecting the response as a temperature change in at least one of the substance and the sensor surface.  
     
     
         125 . The method according to  claim 123 , wherein the detecting step further comprises detecting the response as a spectral emission from the substance.  
     
     
         126 . The method according to  claim 123 , wherein the detecting step further comprises detecting the response as a fluorescence of at least a portion of the substance.  
     
     
         127 . The method according to  claim 123 , further comprising the step of forming the sensor surface on a diamond material.  
     
     
         128 . The method according to  claim 127 , wherein the forming step further comprises chemical vapor depositing the diamond material.  
     
     
         129 . A method of detecting at least one property of a substance, the method comprising the steps of: 
 positioning a sensor surface proximate the substance;    transmitting energy through an optical fiber to the sensor surface, thereby heating the sensor surface and the substance proximate the sensor surface; and    detecting a temperature of at least one of the heated substance and the sensor surface.    
     
     
         130 . The method according to  claim 129 , wherein the substance is a flowing fluid, and wherein the detecting step is performed using a first temperature sensor positioned downstream relative to the sensor surface.  
     
     
         131 . The method according to  claim 130 , further comprising the step of detecting a temperature of the heated substance using a second temperature sensor proximate the sensor surface.  
     
     
         132 . The method according to  claim 130 , further comprising the step of detecting a temperature of the heated substance using a second temperature sensor upstream relative to the sensor surface.  
     
     
         133 . The method according to  claim 129 , further comprising the step of forming the sensor surface on a chemical vapor deposited diamond material.  
     
     
         134 . The method according to  claim 133 , further comprising the step of chemical vapor depositing the diamond material on a substrate.  
     
     
         135 . The method according to  claim 134 , wherein the transmitting step further comprises heating the substrate positioned between the optical fiber and the diamond material.  
     
     
         136 . The method according to  claim 129 , wherein the transmitting step further comprises varying the transmission of energy through the optical fiber, thereby producing a transient heating of the substance.  
     
     
         137 . The method according to  claim 136 , wherein the energy transmission varying step further comprises varying an intensity of the energy transmitted through the optical fiber.  
     
     
         138 . The method according to  claim 136 , wherein the energy transmission varying step further comprises alternately transmitting and not transmitting the energy through the optical fiber.  
     
     
         139 . The method according to  claim 129 , wherein the transmitting step further comprises heating the substance, thereby causing a phase change in the substance.  
     
     
         140 . The method according to  claim 139 , further comprising the step of detecting a pressure of the substance proximate the sensor.