Use of deuterium oxide-depleted water as a tracer in downhole and core analysis applications

Abstract

A method of ascertaining or measuring subterranean events includes use of deuterium oxide-depleted water as a tracer. The presence of deuterium oxide-depleted water may be measured at a subterranean location by means such as core sampling, for any purpose for which tracers are known to be useful. For example, the presence or absence, and level, of deuterium oxide-depleted water in a core sample may be used to determine fluids saturation levels, porosity and permeability, as well as other subterranean formation and/or reservoir characteristics important to the oil and gas production industry.

1 . A method of ascertaining or measuring an event comprising using deuterium oxide-depleted water as a tracer.  
   
   
       2 . The method of  claim 1  wherein the event being ascertained or measured occurs in a subterranean formation.  
   
   
       3 . The method of  claim 2  wherein the event is fluid migration.  
   
   
       4 . The method of  claim 3  wherein the fluid migration indicates a property of a subterranean formation.  
   
   
       5 . The method of  claim 4  wherein the property is the porosity, permeability or fluids saturation of the subterranean formation.  
   
   
       6 . The method of  claim 5  wherein the subterranean formation is being drilled for recovery of oil or gas.  
   
   
       7 . A method of ascertaining or measuring a subterranean event comprising 
 transporting deuterium oxide-depleted water, as a tracer, to a first subterranean location;    allowing a time period sufficient for the tracer to migrate to a second subterranean location, assuming such migration is possible; and    using a tracer detection means or method to measure such tracer in the second subterranean location.    
   
   
       8 . The method of  claim 7  wherein the first subterranean location is a well-bore, the second subterranean location is a subterranean formation, and the tracer detection means or method includes obtaining a core sample from the subterranean formation.  
   
   
       9 . The method of  claim 8  wherein the tracer detection means or method is selected from the group consisting of mass spectrophotometry, gas chromatography-mass spectrophotometry, HPLC mass spectrophotometry, and nuclear magnetic resonance (NMR) imaging.  
   
   
       10 . The method of  claim 8  wherein the core sample is a sponge core.  
   
   
       11 . The method of  claim 7  wherein the second subterranean location is a subterranean formation and the measurement of tracer in the subterranean formation is used to determine a property of the subterranean formation.  
   
   
       12 . The method of  claim 11  wherein the property is porosity, permeability or fluids saturation.  
   
   
       13 . A method of ascertaining or measuring filtrate contamination of a subterranean formation comprising 
 transporting deuterium oxide-depleted water, as a tracer, to a downhole location having adjacent thereto a subterranean formation wherein fluid is located;    allowing a time sufficient for the tracer to infiltrate the adjacent subterranean formation, assuming such infiltration is possible;    obtaining a sample of the subterranean formation such that the fluid therein is preserved; and    measuring the amount of tracer in the fluid.    
   
   
       14 . The method of  claim 13  wherein the sample of the subterranean formation is a sponge core sample.  
   
   
       15 . The method of  claim 14  further comprising extracting the fluid from the sponge core sample by means of retort distillation or use of a Dean and Stark apparatus.  
   
   
       16 . The method of  claim 13  wherein a tracer detection means or method, selected from the group consisting of mass spectrophotometry, gas chromatograph-mass spectrophotometry, HPLC mass spectrophotometry, and nuclear magnetic resonance (NMR) imaging, is used to measure the amount of tracer in the fluid.  
   
   
       17 . The method of  claim 13  wherein the amount of the tracer in the fluid is used to determine a property of the subterranean formation.  
   
   
       18 . The method of  claim 17  wherein the property is porosity, permeability or fluids saturation.  
   
   
       19 . The method of  claim 13  further comprising transporting a second tracer.  
   
   
       20 . The method of  claim 18  wherein the second tracer is tritium.