Measuring the in situ static formation temperature

Abstract

Measuring the in situ temperature of a formation traversed by a borehole comprising lowering to a predetermined position in the borehole a tool that comprises a central conduit having an inlet an dbeing provided with a temperature sensor in contact with the fluid, means for analysing the fluid, and means for discharging fluid; allowing only formation fluid to pass through the central conduit; analysing the formation fluid; and measuring the temperature when the formation fluid is substantially uncontaminated.

1 . A method of measuring the in situ static temperature of a formation traversed by a borehole, which method comprises the steps of 
 a) lowering to a predetermined position in the borehole a tool that comprises a central conduit having an inlet and being provided with a temperature sensor in contact with the fluid, means for analysing the fluid, and means for discharging fluid;    b) making an exclusive fluid communication between the formation and the inlet of the central conduit;    c) allowing formation fluid to pass through the central conduit;    d) analysing the formation fluid; and    e) measuring the temperature when the formation fluid is substantially uncontaminated.    
     
     
         2 . The method according to  claim 1 , wherein making an exclusive fluid communication between the formation and the inlet of the central conduit comprises extending into the formation a probe having an outlet that is in direct fluid communication with the inlet of the central conduit of the tool.  
     
     
         3 . The method according to  claim 2 , wherein making an exclusive fluid communication further includes activating a heating device arranged near the probe to heat the formation fluid.  
     
     
         4 . The method according to  claim 1 , wherein the formation is traversed by a cased borehole, wherein step 
 a) comprises 
 a1) making a perforation set through the casing wall into the formation at a location where the temperature needs to be established;  
 a2) lowering the tool into the borehole to the perforation set, which tool is further provided with an upper and a lower packer arranged at either side of the inlet of the central conduit, wherein the central conduit opens below the lower packer or above the upper packer, and wherein the distance between the upper and the lower packer is larger than the height of a perforation set, and wherein step b) comprises setting the packers so that the perforation set is straddled between the packers.