Logging Formation Evaluation Under Surpressure And High Temperature In Southeast Qiong Area

Along with the development of exploration, more and more overpressured basins are found. The research for reservoir's geophysical response feature has been a important basic task of well log interpretation under surpressure and high temperature. After exact calculation of formation pressure, this paper analyzes the impact of pressure and temperature on the reservoir's geophysical response, and found a method to interpret log data which were derived from the formation under surpressure and high temperature. Subsequently, the method is applied to interpret the log data derived from the studied well, and to calculate the reservoir parameters on which we identified and classified the reservoirs. The economic floors of the studied wells are determined. The paper consist of three parts as follows:1 .The method to calculate formation pressure: The method to calculate formation pressure in this paper is based on the equivalent depth technique, and it extract log characteristic parameters based on log's auto-separating and the lithology recognition. The automatization and precision of formation pressure calculation are upgraded.2. The method to interpret log data under the surpressure and high temperature: This paper analyzed the experiment data that study the rock's compressibilities and that study rock's geophysical response under overpressure & high temperature, and concluded that the effective pressure affect the shaly sand's geophysical response by working on its shale. We found a new method to interpret log data under overpressure & high temperature based on the viewpoint.3. The reservoirs grading and the confirmation of economic floor: The paper classified the reservoirs using dynamic clustering and defined a grading factor to evaluate the reservoirs. On the basis of reservoir grading, the economic floors of the studied wells are determined.