The utility's announcement marks the first time the leak at the Aliso Canyon storage facility has been under control since it was first reported on Oct. 23.
The well still needs to be permanently sealed with cement and inspected by state regulators, a process that could take several days.
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If the plug holds and all goes according to plan, the Porter Ranch community could soon begin to return to normalcy. Schools were closed and about 6,000 families were uprooted as they complained of headaches, nausea, nosebleeds and other symptoms as an intermittent stench wafted through the area.
Public health officials blamed their woes on an odorant added to gas so it can be detected and have said they don't expect long-term health impacts.
The leak at the largest underground gas storage reservoir in the west was declared an emergency by Gov. Jerry Brown.
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The blowout happened in a 60-year-old well that was built to pump oil from porous rock a mile-and-a-half below the Santa Susana Mountains. After the oil ran dry in the 1970s, the field of 115 wells was reused to store natural gas.
Regulators will use high-tech equipment to survey the ruptured pipe for clues about what went wrong before cement is poured into the well to permanently cap it.
Residents who moved out and signed short-term leases can stay through the end of their lease but residents who relocated to hotels will have up to eight days to return to their homes after inspectors deem it safe.
U.S. Sen. Barbara Boxer will meet with affected residents from Porter Ranch and surrounding communities at Shepherd Church Friday afternoon.
The Associated Press contributed to this report.