Production wells having permanent downhole formation evaluation sensors

摘要

A downhole control system for a production well is associated with permanent downhole formation evaluation sensors which remain downhole throughout production operations. These formation evaluation sensors may include, for example, neutron generator, gamma ray detector and resistivity sensors which can, in real time, sense and evaluate formation parameters including important information regarding formation invading water entering the producing zone. Significantly, this information can be obtained prior to the water actually entering the producing geological 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 acquisition 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 formation evaluation sensors themselves can be placed much closer to the actual formation (i.e., adjacent the casing or downhole completion tool) then wireline devices which are restricted to the interior of the production tubing.