Pressurization problem noticed before Hutchinson blasts, state says

By DIANE CARROLL - The Kansas City Star Date: 02/09/01 22:15

Kansas Gas Service records show there was a problem with the pressurization of a natural-gas cavern sometime before explosions and gas geysers erupted three weeks ago in Hutchinson, Kan., a state official said Friday.

A spokesman for the utility, however, said the records indicated only a slight drop in pressure that utility officials did not think was a matter of concern at the time.

The conflicting statements from the Kansas Department of Health and Environment and Kansas Gas Service came Friday as authorities continued to investigate how two explosions occurred and whether others were possible. The geysers that sprung up have dissipated, but authorities are still not sure how much more gas might be trapped underground.

Investigators think gas leaked from a broken injection pipe at the Yaggy storage field northwest of the city and migrated seven miles underground before building pressure and erupting through uncapped abandoned brine wells. The first blast Jan. 17 leveled two downtown businesses. The next day, an explosion destroyed a mobile home, and two persons suffered fatal injuries.

The Kansas Geological Survey said Friday that a preliminary review of the seismic images it took in recent days showed a possible pathway the gas might have taken from Yaggy to the city. If further studies allow it to pinpoint the route, Kansas Gas Service will have a better idea of where to dig wells to vent gas that might still be trapped underground.

Mike Cochran, chief of the environmental geology unit in the Kansas Department of Health and Environment's Water Bureau, said he looked over Kansas Gas Service records shortly after the first explosion. The records showed an unusual drop in pressure in one of the storage caverns, he said.

Cochran said he could not recall which day the drop was noted. He said he didn't want to be more specific until after he had reviewed the records.

The department has given Kansas Gas Service until Wednesday to turn over those records.

Kansas Gas Service operates the Yaggy fields, which are owned by Oneok Inc. of Tulsa, Okla. The salt caverns contain 160 wells capable of storing 3.2 billion cubic feet of gas.

The problem well, Well S-1, can hold up to 60 million cubic feet. It is part of Pod 1, which has 16 connecting caverns.

Kansas Gas Service spokesman Steve Johnson said Friday that he assumed the drop in pressure Cochran was talking about was one that occurred on Jan. 14, three days before the first explosion.

The pressure in a cavern routinely drops slightly after it is injected with natural gas because it takes a while for the pressure in connecting caverns to equalize, Johnson said. That's what happened Jan. 14, he said.

"After the pressure settled down on Sunday (Jan. 14), we didn't experience any other abnormalities we knew of" until Jan. 17, after the first explosion, he said. A check of the pressure in Well S-1 at that time indicated a problem, he said.

Workers found a fist-size hole in an injection pipe at a depth of 600 feet. They plugged it Jan. 21.

When provided with Johnson's explanation, Cochran replied that the records he saw were "indicating a problem, that's for sure."

Cochran said state regulations did not require Kansas Gas Service to check the mechanical integrity of its injection pipes. Nevertheless, Johnson said, Kansas Gas Service does check the pipes on a rotating basis. The broken pipe was inspected in 1993, he said.

In a related development, Johnson said authorities were able to determine that 70 million cubic feet of gas had escaped from Well S-1.

When asked how more gas could escape than the well holds, he explained that workers resumed the injection of gas on Jan. 15. It's possible Kansas Gas Service was injecting gas at the same time the cavern was leaking, he said.

Kansas Gas Service has dug 16 wells since the explosions to vent any remaining gas. Four wells that have hit gas pockets were flaring Friday, Johnson said. A natural-gas fire also continues to burn downtown at the site of the first explosion. Seventeen more wells are planned, Johnson said.

On Thursday night, about 600 residents braved icy weather to attend a town meeting on the gas situation. Department officials told them that Yaggy would not be allowed to resume operating as usual until Kansas Gas Service demonstrated the integrity of the facility and held another public meeting.

Kansas Gas Service shut down Yaggy for 10 days after the explosions. Since then the state has allowed the utility to take gas out. However, it is not putting any gas in.

More than half the 200 residents who were evacuated from their homes Jan. 18 have been allowed to return. However, no one will be allowed to return to the mobile home park where the second explosion occurred until after the wells under it are capped, a department spokesman said.

Resident Joyce Taylor said at the town meeting that she had one of those flaming vent wells in her backyard. She tearfully told Kansas Gas Service and state officials that she can't sleep.

"I'm having panic attacks," The Associated Press quoted her as saying.

Other residents said they were worried about their property values.

"I get laughed at when I say I have a house for sale in Hutchinson," resident Avona Mitchell said.

http://www.kcstar.com/item/pages/local.pat,local/37751ea0.209,.html

-- Doris (nocents@bellsouth.net), February 10, 2001