Gulf gusher to keep flowing as cap test delayed, Associated Press, July 14, 2010:
BP and federal officials did not say what prompted the decision or when the testing would begin on a new, tighter-fitting cap it had just installed on the blown-out well. The oil giant had been scheduled to start slowly shutting off valves on the 75-ton cap, aiming to stop the flow of oil for the first time in three months.
It seemed BP was on track to start the test Tuesday afternoon... Engineers spent hours on a seismic survey, creating a map of the rock under the sea floor to spot potential dangers, like gas pockets. It also provides a baseline to compare with later surveys during and after the test to see if the pressure on the well is causing underground problems.
An unstable area around the wellbore could create bigger problems if the leak continued elsewhere in the well after the cap valves were shut, experts said.
"It's an incredibly big concern," said Don Van Nieuwenhuise, director of Professional Geoscience Programs at the University of Houston. "They need to get a scan of where things are, that way when they do pressure testing, they know to look out for ruptures or changes."