Ranging While Drilling Using Optical Fiber Sensors

Abstract

A system and methods for drilling a well in a field having an previously drilled well are provided. In accordance with one example, a method includes drilling a new well in a geological formation having an previously drilled well using a bottom hole assembly (BHA) having a transmitter. The method also includes transmitting a signal while drilling using the transmitter of the BHA. Further, the method includes measuring from the previously drilled well the signal from the transmitter received by at least one optical fiber disposed within the previously drilled well.

What is claimed is: 
     
         1 . A method comprising:
 drilling a new well in a geological formation having a previously drilled well using a bottom hole assembly (BHA) having a transmitter;   transmitting a signal while drilling using the transmitter of the BHA; and   measuring from the previously drilled well the signal from the transmitter received by at least one optical fiber disposed within the previously drilled well.   
     
     
         2 . The method of  claim 1 , comprising determining a relative position of the new well to the previously drilled well using measurements of the signal. 
     
     
         3 . The method of  claim 2 , wherein the relative position of the new well to the previously drilled well is determined based on a measurement of a polarization state of light within the at least one optical fiber. 
     
     
         4 . The method of  claim 1 , wherein the transmitter transmits the signal, wherein the signal comprises an electromagnetic field. 
     
     
         5 . The method of  claim 1 , wherein the transmitter transmits the signal, wherein the signal comprises an acoustic signal. 
     
     
         6 . The method of  claim 1 , comprising measuring from the at least one optical fiber disposed within the previously drilled well an acoustic signal originating from acoustic noise associated with drilling the new well. 
     
     
         7 . The method of  claim 6 , comprising monitoring drilling dynamics of the new well based on measurements of the acoustic signal. 
     
     
         8 . The method of  claim 1 , wherein the previously drilled well comprises a production well and the new well comprises an injector well in a steam assisted gravity drainage (SAGD) well system. 
     
     
         9 . The method of  claim 1 , wherein drilling the new well comprises drilling the new well such that the new well maintains an approximately constant distance from the previously drilled well. 
     
     
         10 . A drilling system comprising:
 a bottom hole assembly (BHA) having a transmitting device, the transmitting device configured to transmit a signal from the BHA while drilling a new well;   at least one optical fiber disposed within a previously drilled well and configured to interact with the signal transmitted from the transmitting device; and   a polarization detector coupled to the at least one optical fiber, wherein the polarization detector is configured to measure a polarization state of light within the at least one optical fiber.   
     
     
         11 . The drilling system of  claim 10 , comprising a steerable system configured to adjusting a drilling trajectory of the BHA while drilling the new well based on measurements of the polarization state of the light within the at least one optical fiber. 
     
     
         12 . The drilling system of  claim 11 , wherein the steerable system is configured to maintain a constant distance between the new well and the previously drilled well as the new well is drilled. 
     
     
         13 . The drilling system of  claim 10 , wherein a measurement of the polarization state of the light indicates a distance between the new well and the previously drilled well. 
     
     
         14 . The drilling system of  claim 10 , wherein the transmitting device transmits electromagnetic fields. 
     
     
         15 . The drilling system of  claim 10 , wherein the transmitting device transmits acoustic signals. 
     
     
         16 . The drilling system of  claim 15 , wherein the acoustic signals originate from drilling noise associated with drilling the new well, and wherein measurements of the polarity state of the light represent drilling dynamics in the new well. 
     
     
         17 . A method of drilling a well comprising:
 drilling a second horizontal well above a first horizontal well using a bottom hole assembly (BHA) having a first transmitting device;   transmitting a first signal from the first transmitting device while drilling the second horizontal well; and   measuring from an optical fiber within a first horizontal well the first signal from the first transmitting device.   
     
     
         18 . The method of  claim 17 , comprising adjusting a trajectory of the BHA such that the second horizontal well will be drilled substantially parallel to the first horizontal well based on measurements of the first signal from the first transmitting device. 
     
     
         19 . The method of  claim 18 , wherein the second horizontal well maintains a distance of approximately  5  meters above the first horizontal well. 
     
     
         20 . The method of  claim 17 , comprising estimating a location of the first transmitting device in relation to the first horizontal well based on a change in polarization state of light within the optical fibers of the first horizontal well as the first transmitting device moves toward or away from the first horizontal well. 
     
     
         21 . The method of  claim 17 , wherein the first transmitting device transmits acoustic signals or electromagnetic fields. 
     
     
         22 . The method of  claim 17 , wherein the first horizontal well and the second horizontal well are steam assisted gravity drainage (SAGD) wells. 
     
     
         23 . The method of  claim 17 , comprising transmitting a second signal from a second transmitting device, wherein the second signal is an acoustic signal, and the first signal from the first transmitting device is an electromagnetic field. 
     
     
         24 . The method of  claim 17 , wherein the first transmitting device comprises drilling components for drilling the second horizontal well, and wherein the first signal comprises acoustic signals originating from drilling noise associated with drilling the second horizontal well.