The Texas oil company fined $25,000 for violating its state permit while drilling a well amid a wildlife sanctuary was not doing any hydraulic fracturing, also known as "fracking," according to Dan A. Hughes Co. spokesman David Blackmon.

Instead of using water mixed with chemicals to create fractures, as is common in fracking, it was using acid, Blackmon said, adding that company officials don't see anything wrong with what they did.

"We were never sure," he said. "We have never really been told what the objection was."

Department of Environmental Protection spokeswoman Dee Ann Miller said the company got in trouble because it had done one acid treatment that was allowed by its permit — but then proceeded to do a second that had not yet been approved.

And the permit application for that second acid treatment wasn't just routine, either. Miller said injecting a proppant after an acid treatment "has never been done before in Florida."

The company was injecting the acid deep underground to fracture the limestone, then injecting a mix of sand and chemical gel under pressure, to prop open the new fractures and let the oil flow out, he said. That's called using a "proppant."

Although the whole process is similar to fracking, Blackmon called it an "acid stimulation treatment," which he said "is used very commonly in Florida."

In addition to the $25,000 fine, the DEP worked out a deal with the company requiring it to put in monitoring wells on the four property corners around the well site to check on whether any pollution flows outward toward drinking supplies, and to hire independent experts to determine whether any water pollution problems will result from what Hughes did.

But Blackmon contended the monitoring is unnecessary. "There is absolutely no geological chance of any fluids getting into that groundwater," he said.

Hughes' permit violation has prompted the Collier County Commission to urge the DEP to cancel the company's drilling permit, and a local environmental group called Preserve Our Paradise plans to use it as an argument for denying Hughes any new drilling permits.

The Hughes company, whose president was recently named chairman of the Texas Parks and Wildlife Commission, has been the focus of controversy in Collier County since last year, when it revealed plans to drill next door to the Florida Panther National Wildlife Refuge and less than 1,000 feet from homes in Naples' Golden Gate Estates community.

The company is already drilling in several other South Florida locations associated with the Sunniland formation, a geological feature that has been producing oil since 1943. The well site that drew the DEP fine is on an island surrounded by the National Audubon Society's Corkscrew Swamp Sanctuary, a major nesting site for wood storks. Hughes has had a permit to drill there since 2012.

In December, Hughes applied for and received a DEP permit to inject acid into the 11,500-foot-deep well, Blackmon said. "You're just trying to loosen the rock in the limestone formation," he said. However, "it didn't produce the desired result."

So Hughes asked the DEP to allow it to do a second acid treatment — and this time to use the proppant to hold the fractures open. But DEP officials asked for more information. Instead, Hughes plunged ahead with the second acid injection, Miller said. The well is now producing oil, according to Blackmon, who would not say how much.

Craig Pittman can be reached at craig@tampabay.com. Follow him on Twitter at @craigtimes.