The second type of structure which interests The Slug is the legal arrangement by which much of the exploration and development occurs in Australia.

In many cases, such as the North-West Shelf joint venture and the Gorgon project, these are shaped into what is called an unincorporated joint venture. In effect this means that each party contributes its own share of the cash needed to explore, and takes its share of any production.

At the centre of these joint ventures is a curious management team which can, at times, seem quite impotent, especially when it comes to making major investment decisions.

The North-West Shelf, with a double-header joint venture arrangement, is a classic in convoluted decision making with different ownership of the export phase of the project and the domestic gas sales phase.

Gorgon is almost as complex with three big oil companies sharing ownership and seemingly never quite able to agree on the timing of development.

None of this should really be a surprise to anyone because every company has its own agenda and finding sufficient common ground for one of these unincorporated joint venture structures is tricky.

Understand this constipated decision-making process and the slow pace of investment decisions (and the near impossibility of sudden variations to accommodate changes in market conditions) and you also understand why some companies are opting to fly solo, or without the encumbrance of a legal structure that has reached its use-by date.

Woodside Petroleum's decision to develop the Pluto liquefied natural gas project is a perfect case study which initially caused a sharp intake of breath around the petroleum world, but which can now be seen as a brilliant move.

In one bold step, Woodside has broken away from the strictures that have hogtied the North-West Shelf and is proceeding with Pluto at a pace which makes all previous decisions in the region look glacial.

It's not alone. A second player on the Shelf is also making brisk progress without the hindrance of co-shareholders peering over the shoulder of management and second-guessing every decision.

Hess Corporation, which raised eyebrows last year with a 16-well drilling commitment on a permit designated WA-390-P, has quietly gone about delivering on its promises. Seismic has been shot, a management team assembled, drill contracts awarded - and all in just 12 months.

Soon, the semisubmersible rig Jack Bates will be busily testing the sub-sea structures at WA-390-P which lies adjacent to the Jansz/Io discovery and due west of the Greater Gorgon gas field where, it might be pointed out, not a lot appears to be happening.

The Slug is not being totally fair to the Gorgon partners because they are hamstrung by certain disadvantages such as high impurity levels in their gas. But Gorgon is also slow-moving because of a bad management decision made years ago to select Barrow Island as a gas-processing centre - a decision which would take heaven and earth to change because of the legal ownership structure which requires all partners to agree on everything from plant site location to the purchase of a new packet of paper clips.

Meanwhile, as debate rages inside Gorgon over whether to buy metal or plastic paper clips, the teams at Woodside and Hess just get on with the business of exploring and developing.

There's a message in what's happening off Australia's northwest coast and when you drill down you can see that it's all about structure - geological and legal.