PRODUCTION WELLS HAVING PERMANENT DOWNHOLE FORMATION EVALUATION SENSORS

摘要

A downhole control system for a production well is associated with perma- nent downhole formation evaluation sensors which remain downhole throughout production operations. These formation evaluation sensors may include, for e xam-ple, neutron generator, gamma ray detector and resis tivity sensors which can, inreal time, sense and evaluate formation paramete rs including important information regarding formation invading water entering the producing zone. Significantl y, this information can be obtained prior to the water actually entering the produci ng geo- logical formation and therefore corrective action (i.e., closing of a valve or sliding sleeve) can be taken prior to water being produced. This real time acquisiti on of formation data in the production well constitutes an important advance over current wireline techniques in that the present invention is far less costly and can anticipate and react to potential problems before they occur. In addition, the formatio n eval- uation sensors themselves can be placed much closer to the actual formation a.e.adjacent the casting or downhole completion tool) th an wireline devices which are restricted to the interior of the production tubing.