Improving Cement Placement in Horizontal Wells of Unconventional Reservoirs Using Magneto-Rheological Fluids

Abstract

Summary URTeC 1619212 Development of unconventional hydrocarbon resources as a result of horizontal drilling and multistage fracturing has raised several environmental concerns. Long-term zonal isolation provided by cement is one of the major challenges in the completion of horizontal wells since the implementation of casing centralization in the wellbore is a difficult task. This situation can create eccentricity in the wellbore, thus affecting the mud displacement process in the narrow region of the casing. During the mud displacement process, cement has the tendency to flow in the upper wide part of the annulus, thus bypassing mud in the narrow part of the annulus. This causes channeling of the cement in the wide side, leaving slow moving or immobile mud in the narrow region behind. In such cases, the poor cementing can have consequences such as gas migration to surface or water zone and stimulation failure. Current best cementing practices have deficiencies in providing excellent cementing efficiency especially in long horizontal section of the wellbore. Therefore, a novel technique, using Magneto-Rheological fluid, is proposed to improve the mud displacement efficiency in the narrow side. Magneto-Rheological fluid can act as a smart spacer by a moving magnetic field to balance the fluid flow in the annulus. Consequently, more flow will be directed to the narrower annular region that could not be cemented or swept otherwise. The simulation results on the impact of magneto-rheological fluids as a smart spacer on velocity distribution and volumetric movement of fluids are presented.