John Wright, who is in charge of the operation aboard the Development Driller III vessel, said in an e-mail Monday to The Associated Press that drilling has resumed.
BP and the government have said it would take about four days from the time crews started drilling again to intersect the blown-out well.
Once the relief well intersects the blown-out well, crews will pump in mud and cement to permanently seal the well.
The flow of crude was first stopped with a cap in mid-July.
The April 20 rig explosion killed 11 workers and led to 206 million gallons of oil spewing from BP's undersea well.