This article details the field implementation experience of an in house developed system for drilling problems detection and identification. Starting from real time drilling data (including MWD, PWD and mud logging sources), the system was designed to investigate reasons for deviations in important measured variables (such as downhole and pumping pressures, temperatures, torque and drag, etc.) during drilling operations. Based on a hybrid approach, including multi phase hydraulics and torque & drag modeling, case history matching and specialists knowledge, the system should identify undesirable events, such as influxes, poor solids transport, bit balling, bit wear, drillpipe washouts, hole instabilities among several others.
Field implementation issues includes offshore installations and remote operations from onshore decision support rooms, necessity of team working, requirements for conventional and MPD operations, software calibration and validation challenges and continuous knowledge updating. Examples highlight the benefits on investing in data interpretation and drilling automation technologies for deepwater exploratory scenarios.
Deep and ultra deepwater exploratory drilling are very risky and costly operations, in which every effort to guarantee performance and operational safety is welcome. Low frac gradients, abnormal pressures, losses, unstable formations are among the topics which make well design complex and well construction a continuous challenge.
Several exploratory prospects currently ongoing in PETROBRAS faces very narrow or even zero operational windows and well construction will demand non conventional techniques such as MPD or UBD. Figures 1 and 2 show examples about narrow operational windows.