"Can Trinidad and Tobago finally crack the deepwater code?" asks Energy and Energy Affairs Minister Kevin Ramnarine, and though he does not answer his own question, he plainly hopes that, in due course, it will certainly do so.

The Minister is, of course, referring to the exploration that is due to commence in the two blocks qualifying as lying in water depths that range from 1,000 to 3,500 metres, which is the Ministry of Energy and Energy Affairs (MEEA) definition of deep water.

These blocks, 23a and TTDAA 14 were both awarded to the BP Exploration Operating Co in the 2010 auction round.

A third block, 25b, was bid for by BHPBilliton and Repsol and negotiations for an improvement in the work programme originally offered have been taking place for a year and presumably stand a good chance of being favourably concluded in the near future.

If that happens, there will be three attempts being made, virtually simultaneously, to "crack the deepwater code" in the Minister's colourful phraseology.

It is clearly imperative that this code be cracked, because deep water is one of the last three remaining "frontier provinces" for the Trinidad and Tobago hydrocarbon industry.

The other two are the deep horizons on land and the deeper reaches of the shallow water continental shelf area off the east coast.

As far as the latter is concerned, the most notable attempt to explore deeper than the existing operators have gone was by bpTT in 2006, when it sank the Ibis Deep well to 19,068 feet in a specially carved-out area of the South East Coast Consortium (SECC) block, held by EOG Resources and state companies Petrotrin and NGC.

This ranked as the deepest vertical well in the country's hydrocarbon history and cost about US$83 million in 2006 dollars but disappointingly turned out to be a dry hole.

No company has deliberately gone after the continental shelf deep horizon area since.

Deep horizons on land have also largely remained a "no go" region but the ministry has for some years been nudging companies in that direction and specifically designated two land blocks as "deep" in the 2006 bid round – Central Range Deep and Guayaguayare Deep.

The former is operated by Parex Resources, which is obliged to sink one well there but is likely to drill two to around 12,000 feet, and the latter by Niko Resources, whose one deep well (actually in the nearshore part of the acreage) is expected to go to 10,500 feet. We shall see what the outcome of the latter efforts turns out to be but MEEA, under its current Minister, seems primarily to be focussing on the deep water frontier.

Not only has it signed production sharing contracts (PSCs) for 23a and TTDAA 14 and may do so for 23b, it has moved smartly to offer yet more deep water blocks in an effort to keep the momentum going.

As is well known to my readers, it put out blocks TTDAA 1, TTDAA 5, TTDAA 6, TTDAA 28, TTDAA 29 and 25a in April this year and recently extended the closing date to September 4. This could be a good sign because it means companies are interested and want more time to pour over the available data on the blocks.

We shall see the extent of the interest displayed when the bid boxes are opened. Minister Ramnarine is clearly hoping that all, or certainly the majority, of the six attract offers for exploration. In 2010, when the bid round that led to the PSCs for 23a and TTDAA 14 took place, only three out of the 13 blocks offered evoked any interest.

Ramnarine believes MEEA has played its hand more astutely on this occasion (he was not in charge in 2010).

"The feedback coming out of the 2010 bid round," he has pointed out, "indicated that the companies thought the technical risk too high in the southern part of the basin (where six of the 13 blocks were located) because of their inability to map the Cretaceous source rock on the available seismic. They felt that the most likely product would have been natural gas, that the Cretaceous was too deeply buried and had already passed out of the oil window. However, this Cretaceous reflector was clearly visible in the northern part of the acreage and correlative with that mapped in the block 2c area."

So MEEA arranged for the reprocessing of previous seismic, specifically the 2002 industry-funded 2D data, the GT Technology regional study and a 1996 2D data set acquired by the then Amoco Trinidad Oil Co (ATOC), now bpTT.

This has engendered "heightened interest" in the six blocks, three of which are in the southern half of the deep water region, itself located to the east of Trinidad and north of Tobago.

The Minister also believes that the Zaedyus discovery of around 700 million barrels of oil made by UK explorationist Tullow off French Guiana in September, 2011, has also served to "increase the prospectivity of the entire region and, no doubt, increased the interest in our own deep water round." It is also worth observing that over the past ten years, 35 per cent of discovered reserves in the world were located in waters deeper than 1,000 metres and, since 2008, more than 50 per cent.

In addition to improved seismic imagery and the Zaedyus-effect, MEEA is offering more attractive fiscal terms than attended the 2010 auction, including 80 per cent cost recovery if reserves are discovered.

It should be noted that one of the six blocks on offer, 25a, was part of the first deep water auction in 1998 and was awarded then to Royal Dutch Shell.

Of the four blocks given and (25a, 25b, 26 and 27) only Shell made a discovery of any kind, with its Haydn 1 well, though it only identified an uncommercial 0.3 trillion cubic feet (tcf) of gas. Ramnarine takes heart from the fact that this, at least, "established the existence of a working hydrocarbon system".

The Energy Minister in the United National Congress (UNC) government at the time, Finbar Gangar, also put a very brave face on it, telling me that "to find hydrocarbons of any kind in the first well you drill in the deepwater is incredible."

The six now on offer were selected from the list of "nominated blocks" put forward by exploration companies themselves and, says Richard Jeremie, MEEA's senior energy analyst, "represent the highest percentage of the blocks so nominated".

The US$64,000 question, of course, is whether the six are likely to be oil or gas prone (or, of course, neither). If, as the Minister implies, companies were put off by the possibility of gas in 2010, it must be assumed that the same would apply in 2012, when the returns from gas, at least in the United States market, have nosedived.

Ramnarine has not said whether the reprocessing of the seismic data has suggested that oil might be a greater possibility this time around.

He has quoted estimates for 23a and TTDAA 14 which suggest that as much as 8.8 tcf of unrisked natural gas reserves might lie between the two.

That will be fine for bpTT, which is essentially now a gas company in Trinidad and Tobago.

But it may be less appealing, should the likelihood of gas also apply to the six blocks in the current deepwater round, to companies that may wish to enter Trinidad and Tobago but have much more interest in identifying oil.

David Renwick was awarded the Hummingbird Medal (Gold) in 2008 for the development of energy journalism in Trinidad and Tobago.