Application Of Real-Time Solids Monitoring in Well Design, Annulus Pressure Control And Managed Pressure Drilling

The key to successful drilling through a narrow operating window zone and using MPD operations is to apply proper annular backpressure to get the desired bottom hole pressure. This requires accurate knowledge of the pressure loss in the wellbore. Solids have important effects on annular pressure profile, which must be considered when drilling through a narrow mud window zone and using MPD operations. This paper focuses on the effects of real-time solids monitoring on the wellbore pressure profile. A practical approach is proposed to determine the solids concentration and solids behavior in different positions of the wellbore at any time during drilling, which can give an accurate real-time annular pressure profile in the well. To study the solids behavior in the wellbore, a series of experiments were conducted on a 90-ft-long, 4.5”×8” full-scale flow loop to simulate field conditions. Solids concentration, bed development and pressure gradient as a function of time were recorded. A solid-liquid moving pattern map including fluid velocity, ROP, inclination angle and fluid properties has been developed for practical applications. Engineering formulas have been proposed to account for the complex solids behaviors in calculating a real-time annular pressure profile in the wellbore. Results of this work can be used to precisely control the annular pressure profile, guide the setting of annular backpressure in MPD, operation parameter optimization and well path design. Examples of applications of this method are shown in the paper.