By Susan Daker Of DOW JONES NEWSWIRES HOUSTON(Dow Jones)--BP PLC's (BP, BP.LN) well integrity test survived the night as pressures steadily rose showing that a newly placed cap might have the ability to complete shut-in an overflowing well in the Gulf of Mexico, a company vice president said Friday morning. For now, the flow of oil out of the Macondo well remains temporarily halted as the well continues to undergo the test, which could last until Saturday. "Pressure continues to rise," BP Vice President Kent Wells said during a teleconference. "The current monitoring shows no negative evidence, if you remember the big concern was whether we could have a breach to surface." Prior to the test's start, officials raised concerns that there could be a problem in the formation of the well which could lead to another oil leak. The pressure on the cap is over 6,700 pounds per square inch, Wells said. If the well had not reached a pressure reading of at least 6,000 PSI, the test could have been halted and the cap deemed unable to seal off the well. The U.S. federal response commander, Retired Coast Guard Adm. Thad Allen still holds the power to stop the test at anytime and order that BP use the recently placed device to produce oil and natural gas from the well, Kent Wells said. In that case, the cap would funnel up oil and gas to four ships on the surface and could be collecting up to 60,000 barrels to 80,000 barrels a day by the end of the month, BP has said. The well is estimated to be spewing between 35,000 to 60,000 barrels of oil a day. Work on drilling of the first relief well is ongoing but drilling it not underway, Wells said. The completion of the well could be done by the end of July even though it has been delayed by "a couple of days," because of the pressure tests, Wells has said. However, Allen puts the first relief well's finish date at mid-August. Another relief well is also being drilled as a back-up plan. The relief wells are seen as the ultimate way to kill the runaway well, which has caused economic and environmental devastation across the U.S. Gulf Coast. -By Susan Daker, Dow Jones Newswires; 713-547-9208; susan.daker@dowjones.com (END) Dow Jones Newswires July 16, 2010 09:21 ET (13:21 GMT)