North Sea oil available before the Second World War

What would be the benefits and drawbacks if North Sea oil came online before World War II?

Britain gains domestic fuel and reduces imports, but must defend the oil infrastructure; earlier improvements to Scapa Flow depend on timing and funding.

North Sea production before World War II would give Britain more domestic fuel and reduce dependence on energy imports. The oil infrastructure would also attract German attack and require protection. A follow-up asks whether that pressure would secure improvements to Scapa Flow before the war. Those upgrades remain conditional on production beginning early enough for the Treasury to fund the work.