Estudos de controle na perfuração de poços de petróleo em presença de Kick de gás

Abstract

Controling of downhole pressure is essential for a safety process of oil well drilling. In a permeable formation, fluids from reservoir come into the annulus region (wellbore) when the downhole pressure is below pore pressure, featuring a disorder called kick. Literature reports some mathematical models developed to predict the behavior of the wellbore in presence of gas kick, however, there are few works reporting control and experiments. By this reason, it was built an experimental plant in order to study system’s behavior during fluid inlet (gas) from reservoir to annulus, and then, sought to develop a control strategy able to mitigate this disorder, without shut-in the well. A strategy with reconfiguration of the control law feedback↔feedforward was designed to reject disturbance (gas inlet in the annular), to ensure the drilling within the operating window. Parallelly,simulation studies were developed which are: the construction of mathematical model, validated by the employment of the experimental unit, and the implementation of control based on reconfiguration of control law.