Apparatus and method for transmitting information to and communicating with a downhole device

Abstract

An apparatus for use in drilling or producing from a well bore, the apparatus comprising a downhole member such as a drilling device or a production device which is capable of being attached to a tubular such as a drill string, production string or the like, means for rotating a tubular, control means for controlling the rotation of said tubular in order to transmit information along said tubular and means for monitoring the rotation of said tubular and for decoding said information transmitted along said tubular such that a magnitude of a parameter can be determined by the drilling member from the rotation or said tubular. The invention also relates to a method for communicating with a downhole tool using the apparatus.

1. An apparatus for the use of drilling or producing from a well bore, the apparatus comprising:
 a downhole member having a non-rotating part and having a rotating part freely rotating within said non-rotating part and capable of being attached to a tubular, 
 means for rotating the tubular, 
 control means for controlling the rotation of said tubular in order to transmit information along said tubular, 
 means for monitoring the rotation of said tubular with respect to said non-rotating part, and 
 means for decoding said information transmitted along said tubular said means configured to determine a magnitude of a parameter from the rotation of said tubular, such that each complete revolution of the tubular is equal to an analogue or binary data point. 
 
     
     
       2. The apparatus of  claim 1 , wherein the control means is configured to control the rotational velocity or frequency of the tubular. 
     
     
       3. The apparatus of  claim 1 , wherein the control means is configured to stop the rotation of the tubular for a predetermined time. 
     
     
       4. The apparatus of  claim 3 , wherein the monitoring means is configured to measure the time of non-rotation of the tubular. 
     
     
       5. The apparatus of  claim 3 , wherein the monitoring means is configured to measure the time over which the tubular is continuously rotating. 
     
     
       6. The apparatus of  claim 5 , wherein the monitoring means is configured to measure the time over which the tubular is continuously rotating at a particular rotational speed. 
     
     
       7. The apparatus of  claim 1 , wherein the monitoring means is configured to count the number of rotations of the tubular. 
     
     
       8. The apparatus of  claim 1 , wherein the monitoring means comprises a magnet. 
     
     
       9. The apparatus of  claim 1 , wherein the monitoring means comprises at least one of a radioactive or sonic source. 
     
     
       10. The apparatus of  claim 1 , wherein the monitoring means comprises a magnet and said decoding means is configured to detect a maxima in the magnetic field of the magnet so that said analogue or binary data point corresponds to a detected maxima. 
     
     
       11. The apparatus of  claim 1 , wherein said rotating part comprises:
 a hollow rotatable mandrel having a concentric longitudinal bore; 
 an inner sleeve rotatably coupled about said mandrel, said inner sleeve having an eccentric longitudinal bore of sufficient diameter to allow free relative motion between said mandrel and said inner sleeve; 
 
       and wherein said non-rotating part comprises:
 an outer housing having an outer surface, said outer housing is rotatably coupled around said inner eccentric sleeve, said outer housing having an eccentric longitudinal bore forming a weighted side adapted to automatically seek the low side of the wellbore and having sufficient diameter to allow free relative motion between said inner sleeve; 
 a plurality of stabilizer shoes longitudinally attached to or formed integrally with said outer surface of said outer housing; 
 drive means for selectively rotating said inner eccentric sleeve with respect to said outer housing and 
 logic means for controlling said drive means based on the information transmitted along said drill string. 
 
     
     
       12. An apparatus for transmitting information in a timely manner from the face of the Earth to a downhole assembly, whereby the rotation of the drill string is used as an output device, conveying information to components which are located in the wellbore, the apparatus comprising:
 a downhole member having a non-rotating sub-assembly and having a rotating sub-assembly freely rotating within said non-rotating sub-assembly and capable of being attached to the drill string, 
 a device which is closely coupled to either said rotating sub-assembly, or a said non-rotating sub assembly, which emits a signal or influences its environment such that the rotation of the drill string is used to activate a sensor means which may be integrated into either the drill string, or a non-rotating sub-assembly with a timing device such that the sensor outputs derived from the rotation of the drill string system may be measured against a time-based system such that meaningful encoding may be accomplished, which may be coupled to an actuation or switching mechanism or mechanisms. 
 
     
     
       13. The apparatus of  claim 12 , wherein the emitter or device influencing the environment comprises a magnet or a magnetic device. 
     
     
       14. The apparatus of  claim 12 , wherein the emitter or device influencing the environment comprises a mechanical switch which is activated by the rotation of the drill string. 
     
     
       15. The apparatus of  claim 12 , wherein the emitter or device influencing the environment comprises at least one of a sonic or radioactive source. 
     
     
       16. A method of transmitting information along a tubular to a downhole member located within a well bore, the method comprising the steps of:
 rotatably driving said tubular attached to a downhole member having a rotating sub-assembly rotating within a non-rotating sub-assembly, wherein the rotation of said tubular is controlled accordance with information which is to be transmitted along said tubular; 
 monitoring the rotation of said tubular; 
 detecting complete revolutions of said tubular; and 
 analysing the monitored rotation of said tubular such that a magnitude of a parameter can be determined from the rotation of said tubular. 
 
     
     
       17. The method of  claim 16 , wherein the step of monitoring of the rotation of said tubular comprises the step of monitoring the rotational velocity of the tubular. 
     
     
       18. The method of  claim 16 , wherein the step of monitoring of the rotation of the tubular comprises the step of timing a period of non-rotation of the tubular. 
     
     
       19. The method of  claim 16 , wherein the step of driving of the tubular comprises the step stopping the rotation of the tubular for a pre-determined time determined by the information which is to be transmitted along the tubular. 
     
     
       20. The method of  claim 16 , wherein the step of monitoring of the rotation of the tubular comprises the step of measuring the time over which the tubular is continuously rotating at a particular frequency. 
     
     
       21. An apparatus comprising:
 a downhole tool that includes,
 a non-rotating part; 
 a rotating part coupled to a tubular, wherein a control means at a surface of the Earth is coupled to the tubular to transmit information from the surface to downhole based on variation of a speed of rotation of the tubular from a first speed to a second speed, wherein the first speed and the second speed are non-zero; and 
 a sensor positioned on at least one of the non-rotating part and the rotating part, the sensor to monitor the speed of rotation. 
   
     
     
       22. The apparatus of claim 21, wherein the downhole tool further comprises an analysis means coupled to the sensor, the analysis means to decode the information from the surface that is received by the sensor based on the first speed and the second speed. 
     
     
       23. The apparatus of claim 22, wherein the control means is to rotate the tubular at the first speed of rotation for a first rotation cycle, the control means to rotate the tubular at the second speed of rotation for a second rotation cycle. 
     
     
       24. The apparatus of claim 22, wherein the analysis means is to decode the information based on a time period of the first rotation cycle relative to a time period of the second rotation cycle. 
     
     
       25. The apparatus of claim 23, wherein the sensor is to monitor at least one of a length of a time period at a frequency of the speed of rotation and the frequency of the speed of rotation. 
     
     
       26. The apparatus of claim 22, wherein the control means is to rotate the tubular at a third speed of rotation for a third rotation cycle, wherein the third rotation cycle is between the first rotation cycle and the second rotation cycle. 
     
     
       27. The apparatus of claim 26, wherein the analysis means is to decode the information based on a time period of the first rotation cycle, a time period of the second rotation cycle and a time period of the third rotation cycle. 
     
     
       28. The apparatus of claim 21, wherein the control means is to rotate the tubular at different speeds across a number of rotation cycles, wherein one or more of the first of the number of rotation cycles is a preparatory data sequence, wherein one or more of the number of rotation cycles after the preparatory data sequence is representative of a magnitude value of a parameter to be altered downhole. 
     
     
       29. The apparatus of claim 21, wherein an emitter is positioned on the rotating part and is to emit a field, and wherein the sensor is to monitor the speed of rotation based on the field from the emitter. 
     
     
       30. The apparatus of claim 29, wherein the emitter comprises a magnet and the field comprises a magnetic field. 
     
     
       31. The apparatus of claim 21, wherein the information represents a parameter that is to be adjusted downhole. 
     
     
       32. An apparatus comprising:
 a directional steering tool to control drilling direction downhole, the directional steering tool comprising,
 a non-rotating part; 
 a rotating part coupled, by a tubular, to a control means at a surface of the Earth and to a drill bit downhole, wherein the control means communicates information downhole based on rotation of the rotating part at a first speed and at a second speed, wherein the first speed and the second speed are non-zero; 
 a sensor located on at least one of the non-rotating part and the rotating part to monitor rotation of the rotating part relative to the non-rotating part; and 
 an analysis means to decode the information based on the first speed and the second speed of rotation of the rotating part relative to the non-rotating part to control a steering parameter of the drill bit. 
   
     
     
       33. The apparatus of claim 32, wherein the directional steering tool further comprises a drive means to alter a parameter downhole based on the decoded information. 
     
     
       34. The apparatus of claim 32, wherein the steering parameter comprises a drilling direction of the drill bit. 
     
     
       35. The apparatus of claim 32, wherein the control means is to rotate the directional steering tool at the first speed of rotation for at least a first rotation cycle, the control means to rotate the directional steering tool at the second speed of rotation for at least a second rotation cycle, wherein the first speed of rotation and the second speed of rotation are above a threshold value. 
     
     
       36. The apparatus of claim 35, wherein the analysis means is to decode the information based on a time period of the first rotation cycle relative to a time period of the second rotation cycle. 
     
     
       37. A method comprising:
 communicating information, from a surface of the Earth to downhole, along a tubular that is coupled to a rotating part that is part of a downhole tool, based on rotation of the tubular at a first speed and a second speed, wherein the first speed and the second speed are non-zero;   sensing the first speed and the second speed of rotation downhole through reference to a generally non-rotating part of the downhole tool; and   decoding the sensed first speed and the second speed into the information.   
     
     
       38. The method of claim 37, wherein the communicating of the information comprises:
 rotating the tubular at the first speed of rotation for a first rotation cycle, wherein the first speed of rotation is above a threshold value; and   rotating the tubular at a second speed of rotation for a second rotation cycle, wherein the second speed of rotation is above a threshold value.   
     
     
       39. The method of claim 38, wherein the decoding comprises decoding the information based on a time period of the first rotation cycle relative to a time period of the second rotation cycle. 
     
     
       40. The method of claim 37, wherein decoding information comprises decoding the information using code correction. 
     
     
       41. A method comprising:
 receiving control information for transmitting information downhole based on rotation of a first portion of a downhole tool relative to a generally non-rotating portion of the downhole tool; and   transmitting the information downhole based on the control information by rotating the tubular at a first speed for a first time period and a second speed for a second time period, wherein the first speed and the second speed are non-zero.   
     
     
       42. The method of claim 41, wherein transmitting the information comprises transmitting the information for altering a drilling direction of a drill bit coupled to the downhole tool. 
     
     
       43. The method of claim 37, wherein the sensing is performed through use of a sensor and an emitter, and wherein one of the sensor and emitter is coupled to the rotating part of the downhole tool, and wherein the other of the sensor and emitter is coupled to the non-rotating part of the downhole tool. 
     
     
       44. The method of claim 41, wherein the receiving of control information is performed through use of a sensor and an emitter, and wherein one of the sensor and emitter is coupled to the first part of the downhole tool, and wherein the other of the sensor and emitter is coupled to the non-rotating portion of the downhole tool.