钻井工程英文课件11.1 Cementing.pptVIP

Cementing 11.1 Cementing Variables that affect liner cementing performance in deviated and horizontal wells Cementing Displacement flow rate Cement slurry rheology Turbulators placement Centralization Displacement flow rate Prudhoe Bay wells 8-1/2” x 7” liner Circulate at a velocity of 420-540 ft/min 6-3/4” x 5-1/2” liner Circulate at 600 ft/min Cement slurry was displaced at 12 BPM Cement slurry rheology Field results show more success with thinner cement slurries. This allow turbulent flow PV of 30-40 YP of 3-5 Results in a maximum swirl and turbulence Turbulators placement Short 5 inch cylinders with spiral rigid vanes welded and positioned at approximately 30-45 deg. Forces the fluid to flow in a spiral pattern around the casing and wellbore. Two per joint is usually good Point in same direction Centralization Must have enough centralizers to support the casing to centralize properly * * In many cases these are the most important variables in successful cementing operations. Example in Prudhoe Bay, success in horizontal liner jobs was achieved through this process. Turbulent flow while cement is much more effective in complete displacement of mud from the annulus. Turbulators in addition to centralization has been effective. Turbulators cause the fluid flow to spiral around the casing. Two per joint with the vanes in the same direction is sufficient to keep the cement swirling around the casing. * * * In many cases these are the most important variables in successful cementing operations. Example in Prudhoe Bay, success in horizontal liner jobs was achieved through this process. Turbulent flow while cement is much more effective in complete displacement of mud from the annulus. Turbulators in addition to centralization has been effective. Turbulators cause the fluid flow to spiral around the casing. Two per joint with the vanes in the same direction is sufficient to keep the cement swirling around the casing. Calculation of the load on centralizers in critic