Detecting Anomalies in Annular Materials of Single and Dual Casing String Environments

Abstract

An x-ray based cement evaluation tool for measurement of the density of material volumes within single, dual and multiple-casing wellbore environments is provided, the tool including at least an internal length -comprising a sonde section, wherein said sonde section further comprises an x-ray source; a radiation shield for radiation measuring detectors; sonde-dependent electronics; and a plurality of tool logic electronics and PSUs, wherein the tool uses x-rays to illuminate the formation surrounding a borehole and a plurality of detectors are used to directly measure the density of the cement annuli and any variations in density within. Detectors used to measure casing standoff such that other detector responses are compensated for tool stand-off and centralization; a plurality of reference detectors is used to monitor the output of the x-ray source, and a shortest-axial offset detector is configured to distribute incoming photons into energy classifications such that photoelectric measurements may be made.

1 . An x-ray based cement evaluation tool for measurement of the density of material volumes within single, dual and multiple-casing wellbore environments wherein said tool comprises:
 an internal length comprising a sonde section, wherein said sonde section further comprises an x-ray source; a radiation shield for radiation measuring detectors; sonde-dependent electronics; and a plurality of tool logic electronics and PSUs,   wherein the tool uses x-rays to illuminate the formation surrounding a borehole and a plurality of detectors are used to directly measure the density of the cement annuli and any variations in density within.   
     
     
         2 . The tool of  claim 1 , further comprising a detector that is used to measure casing standoff such that other detector responses may be compensated for tool stand-off and centralization. 
     
     
         3 . The tool of  claim 1 , wherein said shield further comprises tungsten. 
     
     
         4 . The tool of  claim 1 , wherein the tool is configured so as to permit through-wiring. 
     
     
         5 . The tool of  claim 1 , wherein a plurality of reference detectors is used to monitor the output of the x-ray source. 
     
     
         6 . The tool of  claim 1 , wherein the shortest-axial offset detector is configured to distribute incoming photons into energy classifications such that photoelectric measurements may be made. 
     
     
         7 . The tool in  claim 1 , wherein the x-ray source energy can be modulated to modify the optimum-detector axial offset to aid the creation of response sensitivity functions. 
     
     
         8 . The tool in  claim 1 , wherein the tool would be combinable would other measurement tools comprising one or more of neutron-porosity, natural gamma and array induct-ion tools. 
     
     
         9 . The tool in  claim 1 , wherein an azimuthally segmented acoustic measurement is integrated into the tool. 
     
     
         10 . The tool in  claim 1 , wherein the tool would be used to determine the position, distribution and volume of fractures, either natural or artificial, within the formation surrounding the cased wellbore. 
     
     
         11 . The tool in  claim 1 , wherein the tool is integrated into a logging-while-drilling assembly. 
     
     
         12 . The tool in  claim 1 , wherein the tool is powered by mud-turbine generators. 
     
     
         13 . The tool in  claim 1 , wherein the tool is powered by batteries. 
     
     
         14 . The tool of  claim 1 , wherein the tool is configured so as to permit through-wiring. 
     
     
         15 . The tool of  claim 1 , wherein a plurality of reference detectors is used to monitor the output of the x-ray source. 
     
     
         16 . The tool of  claim 1 , wherein the shortest-axial offset detector is configured to distribute incoming photons into energy classifications such that photoelectric measurements may be made. 
     
     
         17 . The tool in  claim 1 , wherein the x-ray source energy are modulated to modify the optimum-detector axial offset in order to aid the creation of response sensitivity functions. 
     
     
         18 . The tool in  claim 1 , wherein the tool would be combinable would other measurement tools comprising one or more of neutron-porosity, natural gamma and array induction tools. 
     
     
         19 . The tool in  claim 1 , wherein an azimuthally segmented acoustic measurement are integrated into the tool. 
     
     
         20 . The tool in  claim 1 , wherein the tool would be used to determine the position, distribution and volume of fractures, either natural or artificial, within the formation surrounding the cased wellbore.