Targeted measurements for formation evaluation and reservoir characterization

Abstract

A downhole-reconfigurable tool string is utilized to obtain targeted measurements for formation evaluation and reservoir characterization. Tool string hardware and corresponding analysis software are dynamically adjusted to meet specific reservoir description needs identified during or before the logging run with the downhole-reconfigurable tool string. A technique for utilizing the downhole-reconfigurable tool string includes four different steps. The first step includes detecting first order features and identifying second order features. The second step includes enhancing measurements relative to the second order features by reconfiguring tool hardware to extract at least the desired information of the reservoir in terms of its static and dynamic properties, and software focusing to enhance the sensitivity to a particular reservoir attribute. The third step is performing an inversion to reconstruct the reservoir property as accurately as possible. The fourth step is using these properties and the planned production/injection data to recommend suitable monitoring schema.

1 . A method of obtaining targeted measurements from a logging tool in a borehole environment comprising the steps of:
 identifying at least one second order feature associated with the formation environment;   calculating a sensor configuration for the logging tool which will enhance logging of the identified second order feature;   adjusting the logging tool to achieve the calculated sensor configuration, while the logging tool is in the borehole; and   logging the identified second order feature with the logging tool.   
     
     
         2 . The method of  claim 1  wherein the logging tool includes sensor hardware and wherein calculating the tool sensor configuration includes calculating a weighted combination of different sensor hardware measurements to achieve a predetermined level of sensitivity to the identified second order feature, and employing a cost function to quantify the level of sensitivity to the identified second order feature. 
     
     
         3 . The method of  claim 1  wherein adjusting the logging tool includes adjusting at least one control parameter selected from the group including: number of sources/sinks; number of receivers/observers; source/sink spacing; receiver/observer spacing; frequencies of operation; testing protocol; vector components; polarization; data sampling; and linear combinations thereof. 
     
     
         4 . The method of  claim 1  including the further step of performing a nonlinear inversion to reconstruct properties to achieve a greater degree of accuracy. 
     
     
         5 . The method of  claim 4  including the further step of performing a nonlinear inversion by comparing measured data obtained by the logging tool with data produced by simulation with a model, and adjusting model parameters in order to arrive at an approximate match. 
     
     
         6 . The method of  claim 1  including the further step of detecting first order features associated with the formation. 
     
     
         7 . The method of  claim 1  including the further step of calculating a logging tool sensor configuration for a different second order feature. 
     
     
         8 . The method of  claim 7  including the further step of readjusting the logging tool to achieve the sensor configuration calculated for the different feature while the logging tool is in the borehole. 
     
     
         9 . The method of  claim 1  wherein adjusting the logging tool includes the step of physically moving at least one sensor component. 
     
     
         10 . The method of  claim 1  wherein adjusting the logging tool includes the step of selectively activating at least one sensor component from an array of redundant components disposed at different locations on the logging tool. 
     
     
         11 . Apparatus for obtaining targeted measurements from a borehole environment comprising:
 a logging tool operable within the borehole environment in response to signaling to adopt a specified sensor configuration; and   an analyzer unit operable to identify at least one second order feature associated with the formation, calculate a logging tool sensor configuration to enhance logging of the identified second order feature, and signal to the logging tool, thereby prompting the logging tool to adjust to achieve the calculated sensor configuration, while the logging tool is in the borehole, and log the identified second order feature.   
     
     
         12 . The apparatus of  claim 11  wherein the logging tool includes sensor hardware and wherein the analyzer unit is further operable to calculate a weighted combination of different sensor hardware measurements to achieve a predetermined level of sensitivity to the identified second order feature, and employ a cost function to quantify the level of sensitivity to the identified second order feature. 
     
     
         13 . The apparatus of  claim 11  wherein the logging tool is operable to adjust at least one control parameter selected from the group including: number of sources/sinks; number of receivers/observers; source/sink spacing; receiver/observer spacing; frequencies of operation; testing protocol; vector components; polarization; data sampling; and linear combinations thereof. 
     
     
         14 . The apparatus of  claim 11  wherein the analyzer unit is operable to perform a nonlinear inversion to reconstruct properties to achieve a greater degree of accuracy. 
     
     
         15 . The apparatus of  claim 14  wherein the analyzer unit performs a nonlinear inversion by comparing measured data obtained by the logging tool with data produced by simulation with a model, and adjusting model parameters in order to arrive at an approximate match. 
     
     
         16 . The apparatus of  claim 11  wherein the logging tool is operable to detect first order features associated with the formation. 
     
     
         17 . The apparatus of  claim 11  wherein the analyzer unit is further operable to calculate a logging tool sensor configuration for a different second order feature. 
     
     
         18 . The apparatus of  claim 17  wherein the analyzer unit is operable to prompt the logging tool to readjust to achieve the sensor configuration calculated for the different feature while the logging tool is in the borehole. 
     
     
         19 . The apparatus of  claim 11  wherein the logging tool is operable to physically move at least one sensor component. 
     
     
         20 . The apparatus of  claim 11  wherein the logging tool is operable to selectively activate at least one sensor component from an array of redundant components disposed at different locations on the logging tool.