When drilling in congested fields, there is significant danger of catastrophic
collisions with an existing (offset) wellbore. Apart from the economic damage of
destroying two valuable wellbores, a collision may also result in a health, safety
and environmental event. That is why many operators maintain anti-collision
policies aimed at reducing the risk of such events.
These policies define the safe distance that must be maintained between two
wellbores to increase the separation factor (SF). To increase the SF between a
planned wellbore and its offset wells, the planned wellbore can sometimes be
moved or shortened. However, these modifications to the well plan can result in
suboptimal drainage and field development, stranded reserves, added drilling
complexity or additional directional work.
Instead of moving or shortening the planned wellbore, a more economical
approach is to increase the positional accuracy by correcting survey
measurements. The higher the confidence in their position, the more it increases
the SF between the old and new wellbores - reducing the collision risk.
Therefore, before modifying the well plan to move the new wellbore to a
suboptimal position, it is advised and has become widespread practice in the
United States, to first increase the wellbore surveying accuracy as much as
possible by employing enhanced survey management techniques.
Well-established techniques of IFR, and advanced MWD analytics corrections
reduce the wellbore placement uncertainty by up to 60%*. Applying these
techniques will significantly increase the SFs between new
wells drilled in congested fields.
With increased SFs, fewer wells will be considered to be a collision risk.
Additionally, increased SFs further improve the safety of in-fill drilling campaigns
in congested environments.
collisions with an existing (offset) wellbore. Apart from the economic damage of
destroying two valuable wellbores, a collision may also result in a health, safety
and environmental event. That is why many operators maintain anti-collision
policies aimed at reducing the risk of such events.
These policies define the safe distance that must be maintained between two
wellbores to increase the separation factor (SF). To increase the SF between a
planned wellbore and its offset wells, the planned wellbore can sometimes be
moved or shortened. However, these modifications to the well plan can result in
suboptimal drainage and field development, stranded reserves, added drilling
complexity or additional directional work.
Instead of moving or shortening the planned wellbore, a more economical
approach is to increase the positional accuracy by correcting survey
measurements. The higher the confidence in their position, the more it increases
the SF between the old and new wellbores - reducing the collision risk.
Therefore, before modifying the well plan to move the new wellbore to a
suboptimal position, it is advised and has become widespread practice in the
United States, to first increase the wellbore surveying accuracy as much as
possible by employing enhanced survey management techniques.
Well-established techniques of IFR, and advanced MWD analytics corrections
reduce the wellbore placement uncertainty by up to 60%*. Applying these
techniques will significantly increase the SFs between new
wells drilled in congested fields.
With increased SFs, fewer wells will be considered to be a collision risk.
Additionally, increased SFs further improve the safety of in-fill drilling campaigns
in congested environments.