it is physically impossible to protect oil and gas infrastructure, even if Egyptians wanted to. Israel needs to either pay market rate plus a premium or but elsewhere. Israelis able to get oil so it should be able to get gas too, they will just have to pay a much higher price. Note that the gas that Egypt can't sell to Israel because the pie is blown, gets sold at much higher profit to Europe. In fact now that winter is coming, the Europeans would be glad to buy all the gas that would have gone to Israel.
UN: At least 1,332 Iraqis killed by violence in July (AP)
from the article: Blast destroys Egypt gas pipeline to Israel for sixth time