NEW ORLEANS â BP said its capped-off well appeared to be holding steady Friday morning, almost midway into a white-knuckle waiting period in which engineers watched the pressure gauges for signs of a leak. Results monitored from control rooms on ships at sea and hundreds of miles away at the company's U.S. headquarters in Houston showed the oil staying inside the cap, rather than escaping through any undiscovered breaches, BP PLC vice president Kent Wells said on a conference call. Four underwater robots scoured the sea floor but had also found no signs of new leaks. President Barack Obama said Friday the progress was good news, but cautioned an anxious public not to "get too far ahead of ourselves." Obama said the cap was still being tested and there was still an "enormous clean up job" and ensuring quick compensation for Gulf residents and business in the offing. There was no evidence of a leak in the pipe under the sea floor, Wells said, one of the main concerns. Wells said the results were encouraging 17 hours after valves were shut to trap oil inside the cap, a test that could last up to 48 hours. He said pressure continued to rise inside the tight-fighting cap, a good sign that oil was not getting out somewhere else. The pressure was more than 6,700 pounds per square inch, above the minimum they were hoping to see, but not yet in the high range of 8,000 to 9,000 psi they were hoping for. "The pressures we've seen so far are consistent with the engineering analysis work that BP has done," Wells said. "It's been a very steady build." Wells also said work would resume on a relief well, the oil giant's more permanent solution meant to plug the leak for good underground to end one of the nation's worst environmental catastrophes. That's also a sign that things were going well. Engineers had stopped drilling one of the wells Thursday in case that bore hole deep underground could be affected by the oil cap effort. Engineers and scientists continue to monitor the cap's pressure. When the test is complete, more sea floor mapping will be done to detect any damage or deep-water leaks. BP finally stopped oil from spewing into the sea Thursday for the first time since an April 20 explosion on the BP-leased Deepwater Horizon oil rig killed 11 workers and unleashed the spill 5,000 feet beneath the water's surface. The accomplishment was greeted with hope, high expectations â and, in many cases along the beleaguered coastline, disbelief. BP Chief Operating Officer Doug Suttles urged caution and warned the flow could resume, saying it wasn't a time for celebration. There was no end in sight to cleaning the oil already in the water and on shore. Somewhere between 94 million and 184 million gallons spilled into the Gulf, according to government estimates. Long strands of white absorbent boom strung along the beach were stained chocolate brown at Orange Beach, Ala., early Friday after a fresh wave of pea-sized tar balls washed ashore. Charter boat captains who can't fish because of the oil spill patrolled the shore looking for more oil slicks. A few miles away, an oily sheen swirled around a $4.6 million steel oil barrier erected at the pass into Perdido Bay, located near the Alabama-Florida border.