Method and apparatus for wireless communication in wells using fluid flow perturbations

Abstract

Disclosed are perturbation signaling systems and methods for use in a downhole well. Such systems can include a downhole tool configured to hang from a wellbore anchoring mechanism. The tool can have or associate with an energy harvesting system, a power management system, a sensing system, and a wireless communication system. A turbine generator can encode signals into flowing fluid through electric load and related changes in hydraulic energy, transmitting information through the fluid. A receiver station positioned at another well location can decode and or relay the signals. Signals can bypass impediments such as noise zones by inducing signals in adjacent parallel well environments such as an annulus. The receiver station can accumulate energy from repeated redundant signaling over time to enhance communication and signal resolution. An additional wireless communication system can receive and/or relay data to a remote location.

What is claimed is: 
     
         1 . A method of measuring reservoir and fluid conditions related to a well bore, the method comprising:
 installing a downhole tool at a downhole location in the well bore;   using the tool to measure reservoir and fluid conditions and create measurements;   processing the measurements and storing them at the downhole location in a local memory;   encoding the measurements into a data record using a wireless communication protocol;   establishing a data record from the downhole measurements by assembling a synchronizing head, payload, and tail bit patterns, the tail bit pattern comprising a checksum validation bit pattern;   transmitting the data record by using a downhole tool to induce perturbations in a fluid environment within at least one tube or borehole;   at a surface receiver station, using a pressure sensor in fluid communication with an annulus pressure port to acquire pressure signals comprising the data record;   decoding the pressure signals using selected baseband characteristics from a transmitter to reveal the transmitted data record; and   storing the transmitted data record in a memory of the surface receiver, thereby facilitating further analysis and display to a user at the surface receiver.   
     
     
         2 . The method of  claim 1 , further comprising relaying data from the transmitted data record to a remote server. 
     
     
         3 . The method of  claim 1 , wherein the at least one tube comprises a flowline of production tubing. 
     
     
         4 . The method of  claim 3 , further comprising inducing corresponding perturbations in the fluid of an annulus such that signal transfer occurs through an outer wall of production tubing and an inner wall of a surrounding casing string. 
     
     
         5 . The method of  claim 3 , wherein the downhole tool is a turbine generator. 
     
     
         6 . The method of  claim 5 , further comprising determining an effective transmission zone where the production tubing and annulus overlap below a bubble point and using the length of that zone to select an optimal baseband frequency signal for the perturbations such that a multiple of the half wavelength of each perturbation corresponds to the length of that zone to enhance signal energy transfer. 
     
     
         7 . The method of  claim 6 , wherein the optimal baseband frequency signal is configured such that the half wavelength of each perturbation corresponds to the length of a noise zone. 
     
     
         8 . The method of  claim 7 , wherein the optimal baseband frequency signal is configured such that the half wavelength of each perturbation covers the distance from a depth of a lower annulus volume constraint to a depth of the noise zone. 
     
     
         9 . The method of  claim 1 , further comprising relaying the data record to a remote location using a wireless system selected from the group comprising: WIFI, GSM, Iridium satellite, and radio communication. 
     
     
         10 . The method of  claim 1 , further comprising a using a downhole energy recovery device configured to use flowing fluid to power at least one of a sensory system, an electronics assembly, and a rechargeable battery bank. 
     
     
         11 . The method of  claim 1 , wherein processing the measurements, storing them, and encoding them into data is performed by a sensory system, an electronics assembly, and an energy storage system, each located in a downhole location. 
     
     
         12 . The method of  claim 11 , further comprising using a downhole energy recovery device configured to use flowing fluid to power at least one of the sensory system, the electronics assembly, and the energy storage system. 
     
     
         13 . The method of  claim 1 , wherein the at least one tube or borehole comprises at least one of a production line and an annulus. 
     
     
         14 . The method of  claim 13 , wherein at least one tube is filled with at least one of diesel and brine fluid. 
     
     
         15 . A method of controlling a downhole tool with wireless command signals, the method comprising:
 using a turbine generator to establish perturbation signals in flowing fluid of a flowline that extends to the surface of a wellbore, the perturbation signals comprising command information;   using a pressure sensor or energy recovery device in fluid communication with the flowline to receive the perturbation signals at a downhole tool located at first downhole location in the flowline of the wellbore;   using a predetermined protocol and baseband characteristics to decode the perturbation signals and reveal the transmitted command information; and   after decoding, providing the command information to the downhole tool for execution, thereby establishing wireless control of the downhole tool at the first downhole location.   
     
     
         16 . The method of  claim 15 , wherein the first downhole tool is an energy recovery device configured to harness energy from flowing fluid. 
     
     
         17 . The method of  claim 16 , further comprising wirelessly receiving and relaying signals from one downhole location to another by, after receiving the perturbation signals using the pressure sensor at the first downhole location, using the energy recovery device to relay said received perturbation signals toward a second downhole location by establishing relay perturbation signals. 
     
     
         18 . The method of  claim 15 , further comprising receiving and relaying signals between two downhole tools at first and second downhole locations by receiving and transmitting perturbation signals at two separate baseband frequencies, enabling duplex communication. 
     
     
         19 . A method of communication from a down-hole well location to a remote receiver, the method comprising:
 after an estimated or measured noise zone in a flow line has been determined, establishing an annulus surrounding the flow line such that a portion of the annulus extends below the noise zone to create a signal inducement transfer zone, the signal transfer zone having a length;   propagating primary perturbation signals in the flow line from below the annulus, the primary perturbation signals having at least two distinct wavelengths, including a baseband wavelength that is compatible with a length of the signal transfer zone;   propagating the primary perturbation signals using a transmission protocol that repeats perturbation signals over several periods;   measuring induced perturbation signals in the annulus according to a complimentary protocol that accumulates the repeated signal energy in the channel for each bit and allows the underlying data to achieve higher resolution and transmission success over time.   
     
     
         20 . The method of  claim 19 , wherein the baseband wavelength is configured to be compatible with a length of the signal transfer zone by causing the baseband wavelength to be no more than ten times the length of the signal transfer zone. 
     
     
         21 . A method of improving wireless gauge communication from a down-hole well position, the method comprising:
 determining an induced signal transfer zone length by determining a vertical distance between a lower end of a well's annulus and a noise zone of a well's flow line;   controlling a signal source to propagate baseband and frequency signals that have wavelengths compatible with the transfer zone length, thereby enhancing induced signal transfer and improving communication results; and   repeating portions of the signals from the signal source to allow a receiver to repeatedly receive a version of the same transmission and using the repetition to correct, confirm, or accumulate information regarding the received signal, thereby improving accuracy, confidence in, and resolution of the received signal.   
     
     
         22 . The method of  claim 21 , wherein the noise zone comprises a length of well starting at the bubble point and extending from there to the surface.