This article is behind a paywall, but it looks interesting, if someone has a subscription:

Pemex Defends Deepwater Potential

With allegations surfacing in the Mexican press this week that state-owned oil and gas monopoly Pemex overestimated its much-touted deepwater and ultra-deepwater reserves, analysts and oil professionals are once again casting heavy scrutiny on the validity of the company's assertions.

Well, Dante had some light to shed on this story:

Estimates of offshore reserves were reduced by 60%, per El Universal on March 3.

I gather that even the reduced estimate would not meet US standards for proven reserves.

they want someone else to spend the cash so they don't have to? No cuts to the government income? hmmmm....