Pemex is trying again with a bid process to hire a rig to drill the key Asab-1 prospect off Mexico after its first selection attempt ended in all the companies being disqualified.

The target will be an appraisal well on what could be the state-led company’s side of the blockbuster Zama discovery made by a consortium led by US independent Talos Energy.

Pemex had published its new call to bid on 17 July with offers presented on 6 August. The opening of the commercial aspects of the bid will be announced on 13 August and awards are to be made on 20 August.

It is unclear if delays announced to early-stage meetings might result in delays to the presentation of offers.

An initial clarification meeting attracted questions from 12 players, much of the same list of contractors that had initially expressed interest in the work.

Those players are Ardica Construciones, COSL Mexico, Ensco, Goimar, Marinsa, Mexdrill, Noble Drilling, Pemex Drilling & Services, Seadrill affiliate Sea Dragon, Mexiship, Grinnav and Grupo Rosales.

The tender is unusual because it requires a rig to operate in depths that are deeper than a traditional shallow-water well but nowhere near the depths of what is usually considered a deep-water well.

Market watchers said that there are only a handful of the desired type of unit — essentially a moored semi-submersible — on the market.

The rig will have to operate in a minimum water depth of 328 feet and be able to drill to a depth of at least 26,500 feet.

In the previous version of the tender, Pemex had shortlisted COSL, Ensco, Marinsa in collaboration with Pemex Drilling & Services, and Seadrill.

Talos Energy used the semisub rig Ensco 8503 to drill the original Zama probe, and will also use that same unit for its appraisal programme of the discovery set to start closer to the end of this year.

Pemex chief executive Carlos Trevino told Upstream earlier this year that the company is planning to drill the well as soon as possible once the rig tender is finalised.

The work will be a crucial step for Pemex in defining the field that is believed to extend into its acreage.

Pemex and the Talos-led consortium have already signed a pre-unitisation agreement that acknowledges the possibility of a shared reservoir.

Once appraisal work is carried out on both sides, Talos and Pemex will together study the discovery to confirm or deny the existence of shared volumes and, if it is confirmed, work towards a joint development plan to maximise productive recovery for the Mexican state.