Tangent Section
During the eighties, a number of extended reach projects were successfully
completed. If wells are drilled at inclinations (up to 80°), the area which
can be covered from a single platform is approximately 8 times that
covered when maximum inclination of the wells is limited to 60°.
However, high inclination angles can result in excessive torque and drag on
the drill string and present hole cleaning, logging, casing, cementing and
production problems. These can generally be avoided with current
technology.
Experience over the years has shown that directional control problems are
aggravated when tangent inclinations are less than 15°. This is because
there is more tendency for the bit to walk (i.e. change in azimuth) so more
time is spent keeping the well on course. As such, most run-of-the-mill
directional wells are still planned with inclinations in the range 15° - 60°.
During the eighties, a number of extended reach projects were successfully
completed. If wells are drilled at inclinations (up to 80°), the area which
can be covered from a single platform is approximately 8 times that
covered when maximum inclination of the wells is limited to 60°.
However, high inclination angles can result in excessive torque and drag on
the drill string and present hole cleaning, logging, casing, cementing and
production problems. These can generally be avoided with current
technology.
Experience over the years has shown that directional control problems are
aggravated when tangent inclinations are less than 15°. This is because
there is more tendency for the bit to walk (i.e. change in azimuth) so more
time is spent keeping the well on course. As such, most run-of-the-mill
directional wells are still planned with inclinations in the range 15° - 60°.
