Apache’s (NYSE:APA) shares dipped about 2% Thursday afternoon in the wake of a rig explosion at Mariner Energy (NYSE:ME), which Apache agreed to acquire in April for $2.7 billion.

The deal to take over Houston-based Mariner had been expected to close some time during the third quarter. An Apache spokesman told Dow Jones Newswires the transaction is still expected to close in late September or in the first two weeks of October despite the rig incident. Apache said the timing depends more on the deal receiving a green light from regulators. 

Shares of Apache were down 1.69% to $90.89 in recent trading. After tumbling about 8%, Mariner’s stock was recently off just 2.18% to $22.84.

According to the U.S. Coast Guard, there were seven helicopters on the scene in the Gulf of Mexico “pulling people out of the water.” FOX News Radio reported all 13 workers onboard the rig have been accounted for.

In April, Apache inked a $2.7 billion deal to acquire Mariner for a mix of cash and stock that translated to $26.22 a share. Mariner has nearly 100 blocks in its deepwater portfolio, including seven discoveries in development and more than 50 prospects.

The Mariner incident comes just months after the explosion of Deepwater Horizon, an oil rig in the Gulf of Mexico owned by BP (NYSE:BP) that caused the worst oil spill in U.S. history. That April 20 explosion killed 11 workers.