Italy’s Eni and Spain’s Repsol, two of the largest European energy companies, are struggling to recover about $6 billion from Venezuela for the gas and naphtha they have supplied to the South American country, the Financial Times reported on Tuesday, citing sources with knowledge of the matter. Eni and Repsol jointly own the Perla gas field offshore Venezuela. For years, the two European oil and gas majors had supplied gas and naphtha to Venezuela’s state oil firm PDVSA, to use as diluents to make the extra heavy…