Method for determining downhole pressure

Abstract

A pressure in a wellbore and a temperature at least at one point of the wellbore are measured during wellbore testing. Transient profiles of temperature along the wellbore are determined and changes in a density of a downhole fluid and in a length of atubing when the wellbore is shut in are calculated. The pressure measurement results are corrected on the basis of the calculated changes in the density of the downhole fluid and in the length of the tubing.

1 . A method for determining a downhole pressure, comprising:
 measuring the pressure in the wellbore during the wellbore testing;   measuring a temperature at least at one point of the wellbore during the wellbore testing;   determining transient profiles of the temperature along the wellbore during the wellbore testing;   calculating changes in a density of a downhole fluid and in a length of a tubing when the wellbore is shut in; and   correcting the pressure measurement results on the basis of the calculated changes in the density of the downhole fluid and in the length of the tubing.   
     
     
         2 . The method of  claim 1 , wherein the transient profiles of the temperature along the wellbore are determined by measuring the temperature along the wellbore using a system of sensors distributed on the wellbore at different depths. 
     
     
         3 . The method of  claim 2 , wherein the transient profiles of the temperature along the wellbore are obtained by interpolating the measured temperatures. 
     
     
         4 . The method of  claim 1 , wherein the transient profiles of the temperature along the wellbore are determined by numerical or analytical simulating the temperature profile. 
     
     
         5 . The method of  claim 1 , wherein the pressure is measured by at least one sensor disposed at a fixed depth within the wellbore.