System and method for communicating complex downhole information

Abstract

A system and method for communicating downhole information through a wellbore to a surface location includes a drill string with a downhole tool, a pump for flowing drilling mud through the drill string and wellbore, a valve for flow restriction of the drilling mud, a sensing module for measuring downhole conditions in first and second orientations of the downhole tool, an actuator between two static positions, and a detector for measurement values at the surface location correlative to time between changes of pressure of the drilling mud. The time between pressure changes, as the actuator moves between static positions, conveys encoded data to the detector. The encoded data is compiled from downhole conditions measured by the sensing module, in addition to orientation of the downhole tool. Complex downhole conditions dependent on knowing the multiple orientations of the sensing module can now be communicated by a pressure releasing encoding system.

We claim: 
     
         1 . A system for communicating downhole information through a wellbore to a surface location comprising:
 a drill string with a downhole tool at an end thereof, said downhole tool having a first orientation and a second orientation;   a pumping means for pumping drilling mud into the wellbore, said pumping means being positioned at the surface location and being in fluid connection with said drill string; and   a valve means for providing a flow restriction to said drilling mud passing through said downhole tool, said valve means being suitable for controlling a flow of said drilling mud in said downhole tool;   a sensing module being positioned in said downhole tool and being comprised of a first sensor means for measuring a first downhole condition in said first orientation, and a second sensor means for measuring a second downhole condition in said second orientation, said first orientation being different from said second orientation;   an actuator means cooperative with the valve means for fixing said valve means in at least two static positions in timed relation to any downhole information from said sensing module; and   a detector means positioned at the surface location and cooperative with said drilling mud passing through said downhole tool for providing a measurement value at the surface location correlative to time between changes of pressure of said drilling mud.   
     
     
         2 . The system for communicating downhole information, according to  claim 1 , wherein said first orientation is generally vertical, wherein said second orientation is generally lateral,
 wherein said first sensor means is comprised of an inclination sensor, said first downhole condition being angle of inclination, and   wherein said second sensor means is comprised of an inclination sensor, said second downhole condition being toolface inclination.   
     
     
         3 . The system for communicating downhole information, according to  claim 1 , wherein said first orientation is generally vertical, wherein said second orientation is more than 20 degrees from vertical,
 wherein said first sensor means is comprised of an inclination sensor calibrated for a vertical direction, said first downhole condition being angle of inclination, and wherein said second sensor means is comprised of an inclination sensor calibrated for a toolface direction, said second downhole condition being toolface inclination.   
     
     
         4 . The system for communicating downhole information, according to  claim 1 , wherein said sensing module further comprises:
 a third sensor means for measuring a third downhole condition in said first orientation and in said second orientation.   
     
     
         5 . The system for communicating downhole information, according to  claim 4 , wherein said third sensor means is comprised of an azimuth sensor, said third downhole condition being direction of slant in said first orientation, said third downhole condition being direction of toolface inclination in said second orientation. 
     
     
         6 . The system for communicating downhole information, according to  claim 1 , further comprising:
 a means for switching between measuring said first downhole condition by said first sensor means and measuring said second downhole condition by said second sensor means, in coordination with said downhole tool switching between said first orientation and said second orientation respectively.   
     
     
         7 . The system for communicating downhole information, according to  claim 1 , said detector means comprising:
 means for detecting orientation of said downhole tool;   a logic means for correlating a sensed time between controlled static pressure drops across the valve means to the first downhole condition, the second downhole condition, and orientation of said downhole tool; and   a display means for providing a generally real-time humanly perceivable indication of downhole conditions, according to said orientation of said downhole tool.   
     
     
         8 . A system for communicating downhole information through a wellbore to a surface location comprising:
 a drill string with a downhole tool at an end thereof, said downhole tool having a first orientation and a second orientation;   a pumping means for pumping drilling mud into the wellbore, said pumping means being positioned at the surface location and being in fluid connection with said drill string; and   a valve means for providing a flow restriction to said drilling mud passing through said downhole tool, said valve means being suitable for controlling a flow of said drilling mud in said downhole tool;   a sensing module being positioned in said downhole tool and being comprised of a sensor means for measuring a first downhole condition in said first orientation and measuring a second downhole condition in said second orientation, said first orientation being different from said second orientation;   an actuator means cooperative with the valve means for fixing said valve means in at least two static positions in timed relation to any downhole information from said sensing module; and   a detector means positioned at the surface location and cooperative with said drilling mud passing through said downhole tool for providing a measurement value at the surface location correlative to time between changes of pressure of said drilling mud.   
     
     
         9 . The system for communicating downhole information, according to  claim 8 , wherein said sensor means is comprised of an azimuth sensor, said first downhole condition being direction of slant in said first orientation, said second downhole condition being direction of toolface in said second orientation. 
     
     
         10 . The system for communicating downhole information, according to  claim 8 , further comprising:
 means for detecting orientation of said downhole tool; and   a logic means for correlating a sensed time between controlled static pressure drops across the valve means to downhole conditions, according to orientation of said downhole tool.   
     
     
         11 . The system for communicating downhole information, according to  claim 8 , wherein said sensor means is selected from a group consisting of an azimuth sensor, a magnetometer, a transducer, a gamma scintillator, nuclear detectors, an accelerometer, and a magnetic resonance imaging device. 
     
     
         12 . The system for communicating downhole information, according to  claim 11 , further comprising:
 means for detecting orientation of said downhole tool; and   a logic means for correlating a sensed time between controlled static pressure drops across the valve means to downhole conditions, according to orientation of said downhole tool.   
     
     
         13 . A method for communicating downhole information through a wellbore to a surface location, said wellbore having a drilling mud circulation system therein, the circulation system being through a drill string, a downhole tool, and an interior of said wellbore, the method comprising the steps of:
 positioning a valve means in a fluid passageway of said downhole tool;   positioning an actuator means cooperative with said valve means for fixing said valve means in at least two static positions;   forming a flow restriction within the circulation system at said downhole tool, said flow restriction being comprised of said valve means and said actuator means;   sensing said first downhole condition in said first orientation;   applying a quantified pressure of drilling mud in the circulation system against said flow restriction;   releasing a first percentage of pressure within said flow restriction at a first time;   releasing a second percentage of pressure within said flow restriction at a second time, a time between said first time and said second time being correlative to said first downhole condition;   determining said first downhole condition at a surface location by sensing the time between said first time and said second time and according to orientation of said downhole tool;   sensing said second downhole condition in said second orientation, said first orientation being different from said second orientation;   repeating releases of percentages of pressure within said flow restriction at additional times, at least one of said additional times being correlative to said second downhole condition; and   determining said second downhole condition at a surface location by sensing the time between said additional times and according to orientation of said downhole tool.   
     
     
         14 . The method for communicating downhole information, according to  claim 13 , further comprising the steps of:
 switching between determining said first downhole condition by said first sensor means and determining said second downhole condition by said second sensor means, in coordination with said downhole tool switching between said first orientation and said second orientation respectively.   
     
     
         15 . The method for communicating downhole information, according to  claim 13 , wherein the step of sensing said first downhole condition in said first orientation comprises taking a measurement with a first sensor, and wherein the step of sensing said second downhole condition in said second orientation comprises taking a measurement with a second sensor. 
     
     
         16 . The method for communicating downhole information, according to  claim 15 , wherein said first sensor is comprised of an inclination sensor, said first downhole condition being angle of inclination, and
 wherein said second sensor is comprised of an inclination sensor, said second downhole condition being toolface inclination.   
     
     
         17 . The method for communicating downhole information, according to  claim 13 , further comprising the steps of:
 sensing a third downhole condition in said first orientation and in said second orientation;   repeating releases of percentages of pressure within said flow restriction at additional times, said additional times being correlative to said third downhole condition; and   determining said third downhole condition at a surface location by sensing the time between said additional times and according to orientation of said downhole tool.   
     
     
         18 . The method for communicating downhole information, according to  claim 13 , wherein the step of sensing said first downhole condition in said first orientation comprises taking a measurement with a sensor,
 wherein the step of sensing said second downhole condition in said second orientation comprised taking a measurement with said sensor.   
     
     
         19 . The method for communicating downhole information, according to  claim 18 , wherein said sensor means is comprised of an azimuth sensor, said first downhole condition being direction of slant in said first orientation, said second downhole condition being direction of toolface in said second orientation. 
     
     
         20 . The system for communicating downhole information, according to  claim 18 , further comprising the steps of:
 detecting orientation of said downhole tool; and   correlating a sensed time between controlled static pressure drops across the valve means to first and second downhole conditions, according to orientation of said downhole tool.