Workers had difficulty monitoring key data during a critical time in the final hour before the Gulf of Mexico oil rig explosion because so many activities were happening at once, a contractor said Friday.

Data presented by John Gisclair, a support services coordinator for a unit of Halliburton, to a federal panel investigating the April 20 disaster shows there was a sharp rise in pressure that was later followed by a sharp drop in pressure.

Gisclair said that could have been an indicator that something was wrong.

But Gisclair said one of his workers who was on the rig later told him that there were so many simultaneous activities — starting with the displacing of mud to the pumping of fluids overboard — it was difficult to see what was going on.

"We're pretty close to blind," at one point, Gisclair testified.

The company Gisclair works for had sensors on the Deepwater Horizon that were helping collect real-time data from the rig, which could be viewed by workers on the rig and managers on shore. In particular, there were technicians known as mud loggers who use an assortment of electronic instruments to monitor the mud system for possible indications of hydrocarbons.

The explosion killed 11 workers and led to more than 200 million gallons of oil spewing from BP PLC's undersea well. BP owned the well and was leasing the rig from owner Transocean Ltd.

The testimony was part of the joint U.S. Coast Guard-Bureau of Ocean Energy Management, Regulation and Enforcement investigative panel's fifth session of hearings aimed at determining the cause of the explosion and how regulation, safety and oversight can be improved.

At least one more series of hearings was planned after the series that wrapped up Friday.

Under the April 27 order that convened the investigative panel, the team was given nine months to submit its final report, which means a deadline of Jan. 27. That deadline may be hard to meet because of delays in analyzing the blowout preventer that failed to stop the oil spill, a key piece of evidence.

A federal judge overseeing hundreds of lawsuits sparked by the spill wrote in a court filing Wednesday that he has been told that the forensic analysis and testing of the device would likely not be completed until February. Interior Department spokeswoman Kendra Barkoff provided a timeline late Friday that suggested the testing could be done by mid-December.

The testing had not even begun as of Friday, a month after the device was raised from the sea floor and taken to a NASA facility in New Orleans. Steps have been taken, however, to prepare for the analysis. Panel members have indicated they want the results of the analysis before issuing their report.

Barkoff said in a statement e-mailed to The Associated Press that the start of the testing has taken longer than originally anticipated because of the time it is taking to reach agreement among the various parties on the procedures to be used in the testing. She indicated testing could begin after a final plan is received from an examiner late next week. She said the testing was only expected to take two months from the time it starts.


Deepwater Horizon Joint Investigation: http://www.deepwaterinvestigation.com

BP PLC: http://www.bp.com/