Slip spool assembly and method of using same

A slip spool that selectively supports or snubs a tubing string in a wellbore under pressure, the slip spool comprising:

• a slip spool body that is mounted to a wellhead, the slip spool body having an axial passage with a slip bowl formed in the axial passage, and at least two radial passages communicating with the axial passage;
• a slip block assembly displaceably supported within each radial passage and displaceable from a cached position in which the slip block assembly clears the axial passage and an engaged position in which slip blocks of the slip block assembly are seated in the slip bowl and cooperate with slip blocks of at least one other slip block assembly to grip the tubing string;
• and
• actuators that are operated to displace each slip block assembly from the cached position to the engaged position, and from the engaged position to the cached position.