A principle source of methane leakage is from gas wells themselves, as well as the extensive infrastructure involved in processing and transporting gas from its point of extraction to usage.
In situ / on-prem methane production, storage, and usage would tend to minimise much of that.
Further, I don't see methane synthesis as a likely option for synfuel storage applications as described here, as heavier fuels (~C-12 -- C-15 chain-length kerosene) is liquid (far easier to handle than a gas), nonvolatile (as contrasted with petroleum or lighter hydrocarbon distillates), and can be stored in simple, unpressurised, unrefrigerated tanks virtually indefinitely. You're creating a problem which needn't exist.
<https://www.epa.gov/natural-gas-star-program/primary-sources...>
In situ / on-prem methane production, storage, and usage would tend to minimise much of that.
Further, I don't see methane synthesis as a likely option for synfuel storage applications as described here, as heavier fuels (~C-12 -- C-15 chain-length kerosene) is liquid (far easier to handle than a gas), nonvolatile (as contrasted with petroleum or lighter hydrocarbon distillates), and can be stored in simple, unpressurised, unrefrigerated tanks virtually indefinitely. You're creating a problem which needn't exist.