Optimization of Deviated and Horizontal Wells Trajectories and Profiles in Rumaila Oilfield

Abstract

Directional and horizontal wellbore profiles and optimization of trajectory to minimize
borehole problems are considered the most important part in well planning and design. This
study introduces four types of directional and horizontal wells trajectory plans for Rumaila
oilfield by selecting the suitable kick off point (KOP), build section, drop section and
horizontal profile. In addition to the optimized inclination and orientation which was
selected based on Rumaila oilfield geomechanics and wellbore stability analysis so that the
optimum trajectory could be drilled with minimum wellbore instability problems. The four
recommended types of deviated wellbore trajectories include: Type I (also called Build and
Hold Trajectory or L shape) which target shallow to medium reservoirs with low
inclination (20o) and less than 500m step out, Type II (S shape) that can be used to
penetrate far off reservoir vertically, Type III (also called Deep Kick off wells or J shape)
these wells are similar to the L shape profile except the kickoff point is at a deeper depth,
and design to reach far-off targets (>500m step out) with more than 30o inclination, and
finally Type IV (horizontal) that penetrates the reservoir horizontally at 90o. The study also
recommended the suitable drilling mud density that can control wellbore failure for the four
types of wellbore trajectory.