They are raising equity to pay for the BP assets and pay down a chunk of debt.
Looks like they can't make repayments due in June 2021 so they are going for an equity raise which, if works, will finally sort their balance sheet out.
Some people here are very concerned about the obvious dilution in shares, which the market is aware of, others are optimistic and think that at healthier balance sheet will bring in more investors which will add value to the sp in the long run.
The Mexican government have told the parties to come together to determine how much of the reservoir is in Pemexs block and then Pemex will join the consortium, pay there share of exploration costs to date and have whatever share they are entitled to.
My guess is it's not a substantial share that will have to be given to Pemex