Downhole tubing assembly for downhole sensing

Abstract

A method of cementing a bore-lining tubing in a drilled bore includes providing an inner tubing for location within the bore-lining tubing. The inner tubing has distal and proximal ends, and a sensor unit at the distal end of the inner tubing. The inner tubing is translated into the bore with the sensor unit being operated to determine a parameter of the bore. Fluid is then circulated through the inner tubing, the flow port, and an annulus between the bore-lining tubing and the drilled bore with the sensor unit being operated to determine a parameter of the fluid. The fluid comprises a settable material, such as cement slurry, which at least partially fills the annulus between the bore-lining tubing and the drilled bore. The inner tubing is then translated out the bore-lining tubing with the sensor unit being operated to determine a parameter of the settable material in the annulus.

1 . A downhole tubing assembly comprising:
 an inner tubing having distal and proximal ends located within a bore-lining tubing and forming an inner annulus, and   a sensor unit at the distal end of the inner tubing, whereby the sensor unit is operable to determine at least one of:
 a parameter of a bore; 
 a parameter of fluid circulating through the inner tubing, the flow port, and an outer annulus between the bore-lining tubing and a surrounding bore wall, and 
 a parameter of fluid in the outer annulus between the bore-lining tubing and the surrounding bore wall. 
   
     
     
         2 . The downhole tubing assembly of  claim 1 , wherein the sensor unit is operable to determine a parameter of a sealing fluid that has been circulated into the outer annulus between the bore-lining tubing and the surrounding bore wall. 
     
     
         3 . The downhole tubing assembly of  claim 2 , wherein the sensor unit is operable to determine a parameter of cement slurry that has been circulated into the outer annulus between the bore-lining tubing and the surrounding bore wall. 
     
     
         4 . The downhole tubing assembly of  claim 3 , wherein the sensor unit is operable to determine at least one of the presence of contamination in the sealing fluid, and the degree of contamination in the sealing fluid. 
     
     
         5 . The downhole tubing assembly of  claim 1 , wherein the sensor unit comprises at least one of: a sensor operable to detect tracers in fluid that has been circulated into the outer annulus between the bore-lining tubing and the surrounding bore wall; an azimuthal acoustic transponder/receiver, and a temperature sensor. 
     
     
         6 . The downhole tubing assembly of  claim 1 , wherein the sensor unit is operable to measure the diameter of the bore as the sensor unit is translated into the bore. 
     
     
         7 . The downhole tubing assembly of  claim 1 , wherein the sensor unit is operable to determine at least one of temperature, pressure, density, flowrate, pH, and acoustic impedance of fluid circulating through the inner string. 
     
     
         8 . The downhole tubing assembly of  claim 1 , further comprising a bore-lining tubing having distal and proximal ends and a flow port at the distal end of the bore-lining tubing. 
     
     
         9 . The downhole tubing assembly of  claim 8 , wherein the distal end of the inner tubing is coupled to the distal end of the bore-lining tubing. 
     
     
         10 . A method of cementing a bore-lining tubing in a drilled bore, the bore-lining tubing having distal and proximal ends and a flow port at the distal end, the method comprising:
 providing an inner tubing having distal and proximal ends, and a sensor unit at the distal end of the inner tubing;   translating the inner tubing into the bore-lining tubing and into the bore;   circulating fluid through the inner tubing, the flow port, and an annulus between the bore-lining tubing and the bore, the fluid comprising a settable material;   at least partially filling the annulus between the bore-lining tubing and the drilled bore with the settable material;   translating the inner tubing out of the bore-lining tubing, and   operating the sensor unit to determine at least one of: a parameter of the bore, and a parameter of the fluid.   
     
     
         11 . The method of  claim 10 , further comprising operating the sensor unit as the inner tubing is translated out of the bore-lining tubing and determining at least one parameter of the settable material in the annulus. 
     
     
         12 . The method of  claim 11 , wherein the at least one parameter of the settable material in the annulus comprises a degree of contamination of the settable material. 
     
     
         13 . The method of  claim 11 , further comprising at least one of: circulating an initial fluid in advance of the settable material and determining the degree of contamination relating to mixing of the initial fluid and material entrained in the initial fluid with the settable material, and determining properties of a test sample of a contaminated settable material to determine the properties of the contaminated settable material in the annulus. 
     
     
         14 . The method of  claim 10 , further comprising at least one of: determining a parameter of fluid circulating through the distal end of the inner tubing, and wherein the parameter includes at least one of temperature, pressure, density, flowrate, pH, and acoustic impedance, and determining a degree of contamination of the settable material circulating through the distal end of the inner tubing. 
     
     
         15 . The method of  claim 14 , further comprising determining the rheology of the fluid circulating through the distal end of the inner tubing and thereby determining bore-cleaning properties of the circulating fluid. 
     
     
         16 . The method of  claim 14 , further comprising comparing the determined parameter of the fluid circulating through the distal end of the inner tubing with a corresponding parameter of the circulating fluid as the fluid is being pumped into the inner tubing. 
     
     
         17 . The method of  claim 10 , further comprising at least one of operating the sensor unit as the inner tubing is translated into the bore-lining tubing and determining at least one parameter of the bore, and operating the sensor unit as the inner tubing is translated into the bore-lining tubing and determining a diameter profile of the bore. 
     
     
         18 . The method of  claim 10 , further comprising:
 operating the sensor unit as the inner tubing is translated into the bore to determine a parameter of the bore;   operating the sensor unit as the fluid is circulated to determine at least one of the temperature, pressure, density, flowrate, pH, and acoustic impedance of the fluid passing through the distal end of the inner tubing, and   operating the sensor unit as the inner tubing is translated out of the bore-lining tubing to determine a parameter of the settable material in the annulus.   
     
     
         19 . The method of  claim 10 , further comprising: coupling the distal ends of the inner tubing and the bore-lining tubing and, after circulating the fluid, uncoupling the distal ends of the inner tubing and the bore-lining tubing. 
     
     
         20 . A method of cementing a bore-lining tubing in a drilled bore, the bore-lining tubing having distal and proximal ends and a flow port at the distal end, the method comprising:
 providing an inner tubing having distal and proximal ends, and a sensor unit at the distal end of the inner tubing;   translating the inner tubing into the bore-lining tubing and into the bore;   circulating fluid through the inner tubing, the flow port, and an annulus between the bore-lining tubing and the drilled bore, the fluid comprising a settable material;   at least partially filling the annulus between the bore-lining material and the drilled bore with the settable material, and   translating the inner tubing out of the bore-lining tubing while operating the sensor unit to determine a parameter of the settable material in the annulus