Rumour has it,
that deep drilling in Russia, below all chance of biologic influence, encountered pockets of methane in basement granites. I recall articles about mantle methane, but I've no quick footnotes to provide in support of this idea. I give the idea a "plausable" rating and defer to Nick's greater knowledge.
That terrestrial abiotic hydrocarbons will be economic sources of energy I give a "highly dubious" rating.
That oil fields are fed by abiotic sources, and are thus en-riched and renewed, is wishful thinking. Even if it occured, it would occur at such a slow rate that it wouldn't recharge fast enough to keep up with h. sapiens' enormous thirst for da crude.