🔍 Key Concepts

• Station keeping and offset limits for dynamically positioned (DP) and moored drilling units • Relationship between water depth and allowable horizontal offset at the wellhead • Industry practice/USCG/IMO guidance on maximum offset percentages for safe wellbore integrity

💭 Think About

• If the rig moves sideways, how does that motion translate into stress at the wellhead and along the riser in deeper water? • As water depth increases, would you expect the permissible percentage offset to be relatively large or relatively small to keep the well safe? • Which of these percentages seems most consistent with a conservative safety margin commonly used in drilling operations?

✅ Before You Answer

• Compare how each option would change the absolute horizontal distance at 1,000 m (or ft) water depth – which seems operationally realistic? • Think about whether deepwater drilling operations typically tolerate large or small lateral movement of the rig from the well location. • Ask: which percentage aligns better with maintaining riser angle limits and avoiding excessive bending at the BOP (blowout preventer)?