Automated Classification System for Petroleum Well Drilling Using Mud-logging Data

During the petroleum well drilling operation many mechanical and hydraulic parameters are observed by an instrumentation system installed in the rig named mud-logging system. The mud-logging system is composed by several sensors distributed in the rig; these sensors measure different operation parameters like: hook load, column rotation, mud pit level, pumping pressure, etc. The mudlogging system allows to track the evolution of each measured parameter on-line. Nowadays, many parameters are continuously measured in the mud-logging units with a supervising purpose. However, in the most of cases, those data are stored without take advantage of all its potential. In other hand, to make use of the mud-logging data, it is required analyze and interpret it. That is not an easy task because of the large amount of information involved. This work presents a system that can automatically classify the operation stage that is being executed using mud-logging data interpretation. The system allows to classify for instance if the rig is in a rotary drilling process, or if the rig is circulating mud in the well, etc. The here presented system was used to classify two days of an offshore well drilling operation. In order to check the performance of the system, the results obtained were compared with the expert handmade diary drilling report classification. It was observed a high level of conformity between the system classification and the drilling report classification mainly in small time periods where the drilling report classification is more precise. For larger periods of time, the automated system obtained a more precise classification because it make possible to individualize each executed stage. The proposed system allows the online classification of stages or the stages classification from a drilled wells database. The system can also be used to develop a tool able to automatically generate a precise record of the executed stages.