Drilling control

A system comprising:

• a processor;
• memory accessible by the processor;
• processor-executable instructions stored in the memory and executable to instruct the system to:
• receive block position data of a rig prior to addition of a length of pipe to a drillstring, wherein the drillstring is disposed at least in part in a borehole and supported by the rig;
• receive block position data of the rig after addition of the length of pipe to the drillstring;
• and
• control position of the drillstring with respect to time using the rig and at least a portion of the block position data for landing a drill bit of the drillstring on a bottom of the borehole,
• wherein the block position data of the rig, prior to addition of the length of pipe to the drillstring, comprises block position data for an on-bottom state of the drillstring that is prior to an in-slips state of the drillstring.

A non-transitory computer readable storage medium storing instructions that when executed by a computer, which includes a processor performs a method, the method comprising:

• receiving block position data of a rig prior to addition of a length of pipe to a drillstring, wherein the drillstring is disposed at least in part in a borehole and supported by the rig;
• receiving block position data of the rig after addition of the length of pipe to the drillstring;
• and
• controlling position of the drillstring with respect to time using the rig and at least a portion of the block position data for landing a drill bit of the drillstring on a bottom of the borehole,
• wherein controlling position of the drillstring with respect to time comprises controlling velocity of the drillstring in an in-hole direction based at least in part on a computed distance between the drill bit and the bottom of the borehole, wherein the computed distance is based at least in part on at least a portion of the block position data.