Method for Determining A Filtration Velocity of Reservoir Fluids

Abstract

Temperature is measured in a shut-in wellbore and rates of temperature change in depth intervals within productive layers and in depth intervals adjacent to the productive layers are determined. Areas are selected in the depth intervals within the productive layers wherein the rate of temperature change is significantly higher than the rate of change in the depth intervals adjacent to the productive layers. A numerical model of temperature change in the shut-in wellbore is created taking into account a filtration effect of a reservoir fluid on the rate of the temperature change in the shut-in wellbore. The measurement results are compared with the numerical modeling results, and their best match is used for determining a fluid filtration velocity in the selected areas in the depth intervals within the productive layers.

1 . A method for determining a reservoir fluid filtration velocity, comprising:
 measuring temperature in a shut-in wellbore;   determining a rate of temperature change at depth intervals within productive layers and a rate of temperature change at depth intervals adjacent to the productive layers;   selecting areas at the depth intervals within the productive layers wherein the rate of temperature change is significantly higher than the rate of change at depth intervals adjacent to the productive layers;   creating a numerical model of temperature change in the shut-in wellbore taking into account a filtration effect of a reservoir fluid on the rate of the temperature change in the shut-in wellbore;   comparing the measurement results with the numerical modeling results; and   determining the filtration velocity of the reservoir fluids in the selected areas at the depth intervals within the productive layers by matching the measurement results with the numerical simulation results.   
     
     
         2 . The method of  claim 1 , wherein the temperature in the shut-in well is measured with a fiber-optic gauge. 
     
     
         3 . The method of  claim 1 , wherein the temperature in the shut-in well is measured by means of at least three temperature loggings of the well. 
     
     
         4 . The method of  claim 1 , wherein the areas where the rate of temperature change is significantly higher than the rate of change in the depth intervals adjacent to the productive layers are selected after 10 to 30 hours of the wellbore shut-in. 
     
     
         5 . The method of  claim 1 , wherein the temperature measurements in the shut-in wellbore are performed after cementation. 
     
     
         6 . The method of  claim 1 , wherein the temperature measurements in the shut-in wellbore are performed after production. 
     
     
         7 . The method of  claim 1 , wherein the temperature measurements in the shut-in wellbore are performed after fluid injection. 
     
     
         8 . The method of  claim 1 , wherein the temperature measurements in the shut-in wellbore are performed after fluid circulation.