Process control strategies are widespread in the industry and provide cost reduction and reliability for different processes. Automation for Well construction technology is still an emerging technology, most probably due to data transmission limitations and to the several uncertainties inherent to the process. The elevated costs, especially in deepwater operations, and the society claims for safety improvement are the major drives for the increasing industrial efforts to overcome the steps for drilling automation. Several process can be controlled during well construction steps, such as: downhole pressure and torque on bit during drilling, bit cost minimization, keeping downhole pressures during influx circulations and tripping. The purpose of this article is to show a comprehensive analysis of the adequacy of different process control strategies to support the automation of the drilling process, with special focus on cost reduction. Initially, a traditional feed back approach was considered to compare different control methodologies, such as Proportional (P), Proportional-Integral (PI) and proportional - Integral- Differential (PID). Comparison in response times, attenuation rates and other control parameters are presented. Control stability performance was evaluated through the analysis of measurement and actuation delays, signal loss, magnitude of disturbs and other classic strategies. A multiple input single output analysis was included, introducing gains to the control process.

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