Four years after BP’s Deepwater Horizon offshore drilling rig exploded, killing 11 workers and spewing millions of barrels of oil into the Gulf of Mexico, experts are warning that similar disasters could happen again.

They say government regulations and companies’ safety cultures have not kept pace with increases in global offshore oil production and rapid changes in the technology used to capture that oil. Without more regulations and changes at the top of multinational corporations, experts believe that another disaster like the Deepwater Horizon explosion is imminent.

“What we are talking about here is not an isolated event that happened four years ago on April 20 in the Gulf of Mexico,” said Najmedin Meshkati, a professor of civil and environmental engineering at the University of Southern California. “There is ultradeepwater drilling in the Black Sea in Turkey, deepwater drilling off the coast of Cuba, off the coast of Florida, in Alaska ... BP was a wake-up call, but we put the wake-up call on snooze.”

Meshkati and others say that while there were a slew of recommendations, reports and regulatory action in the months following the Deepwater Horizon disaster, fervor surrounding deepwater drilling safety has since faded.

Some changes have been made: In 2011 Barack Obama’s administration, responding to a perceived conflict of interest for the Bureau of Ocean Energy Management, Regulation and Enforcement to be responsible for leasing land for drilling and protecting the environment, split the agency in two. The new Bureau of Safety and Environmental Enforcement (BSEE) operates independently of the arm of the government responsible for developing offshore oil and gas fields.

The industry has changed as well. BP created a 24-hour offshore monitoring station in Houston, where engineers watch computer monitors in an attempt to spot problems on their drilling rigs before they turn into full-fledged disasters.

The oil and gas industry created the Center for Offshore Safety, which is meant to share ideas and strategies for increasing drilling safety.

But beyond the bifurcation of one agency and the creation of several industry-backed groups as well as the proliferation of dozens of consortiums, panels and white papers on offshore drilling safety, some say that tangible regulations are still sorely lacking and that the culture of oil companies is focused more on profit than safety.

Since the 2010 BP spill, there have been several smaller offshore oil rig accidents, most notably the Black Elk Energy rig that ignited in 2012, killing four. And in July a natural gas well blew, leaking gas into the Gulf of Mexico for two days.

The BSEE’s director, Brian Salerno, said at a conference on offshore safety earlier this month that there was still a long way to go in achieving safety but shied away from calling for more regulation.

“Regulations — while important — will only get you so far,” he said. “If we really want safety, we have to do more. We have to foster a culture of safety among all involved in offshore operations so that it becomes part of the way business is conducted … Now, even as we talk about … advancing the safety culture, the sad fact remains there are some who still don’t get it.”

Some have criticized the Obama administration for not implementing and enforcing safety and environmental regulations more forcefully. In a recent New York Times op-ed, S. Elizabeth Birnbaum, director of the federal Minerals Management Service at the time of the BP disaster, blasted Obama for not acting faster to issue new rules for deepwater drilling.

Robert Bea, a professor of engineering at the University of California at Berkeley who is a veteran offshore drilling safety expert, pointed out that most of the recommendations made by a presidential commission appointed to study drilling safety after the spill have not been implemented. He said the United States has yet to set safety standards for much of the new technology used on deepwater rigs — which he says increases the risk that they’ll operate unsafely.

“If you drive an automobile, you have a speedometer,” Bea said. “In terms of safety and risk today, we don’t have a speedometer. There’s no valid way to quantify what’s safe.”

As offshore production increases around the world — accounting for about 35 percent of total production in 2013 and expected to rise to 50 percent in the next two years, according to the International Energy Agency — experts say it’s more important than ever to take deepwater drilling safety seriously.

Otherwise, they say, another BP-style disaster is virtually guaranteed to happen again.

“I’m nervous and depressed,” said Bea. “I’m nervous that we have not taken aggressive action and learned the lessons that [Deepwater Horizon] had to teach. And I’m depressed because I know it can happen again. It’s just a matter of when and where.”