They have also called for new gas sources to be developed within three years.

Sims this week warned that east coast gas market has experienced a triple-whammy of local and international events and changes: the rise of CSG-LNG on the east coast, the collapse in oil prices and gas exploration, and the rise of regulatory uncertainty and exploration moratoriums across Australia.

“In this environment commercial and industrial gas users particularly have had a difficult time,” Sims said.

The ACCC is about to deliver a key report to the Commonwealth on the state of the Australian gas markets which will recognise that more sources of gas supply for south-eastern Australia are needed to constrain gas prices.

“The key point is that the effect of the level of LNG netback prices on domestic gas prices depends more than is realised on the level of competition in the market,” Sims said.

“With many gas suppliers competing for business their (seller) alternative is to send gas to Queensland for export. With few gas suppliers competing for business you need to ask why would they sell their gas for less than the buyers alternative of buying gas from Queensland?

“The difference in the domestic price of gas, therefore, depends on the level of competition to supply gas, and can be double the transport cost to Queensland, which is a large amount,” Sims said.

To Australian Petroleum Production and Exploration Association CEO Dr Malcolm Roberts, Sims is just stating the obvious.

“While attention is often focused on market conduct and structure, the ACCC is right to indicate that a more competitive market requires removing barriers to developing gas,” Dr Roberts said.

“As Mr Sims said, moratoriums are ‘blanket bans’ on supplying gas.

“Analysts are becoming increasingly concerned by the widening gap between local demand and local supply in states such as NSW and Victoria. NSW already imports 95% of its gas.

“There is a risk we will see an artificial shortage of supply in those states if development of new local reserves is blocked.”

Roberts said that the exploration climate for his members is difficult, and the number of onshore exploration wells drilled in 2015 was at its lowest level for 20 years.

That will eventually bite in the form of a lack of future gas supply, and higher prices.

“There is an urgent need for policies that provide greater certainty, support exploration and reduce exploration and development costs,” he said.

AEMO’s Gas Statement of Opportunities, published today, shows that Australia probably has enough gas for the next two decades, with no significant shortfalls until the late 2020s when existing infrastructure will reach its limits.

However, that requires investment decisions on existing undeveloped gas reserves by 2019.

Without that investment, there is a real risk to maintain adequate gas supply in eastern and south-eastern states.

“Currently undeveloped gas reserves, including those reported as contingent resources and possible reserves, will be required to ‘come online’ to meet forecast demand as early as 2019 when developed reserves are forecast to start to deplete,” AEMO managing director Matt Zema said.

“It’s important we highlight this now, as there are technical and commercial uncertainties associated with developing contingent resources and possible gas reserves.”

AEMO says export and domestic demand will be about 2000 petajoules a year.

Without sufficient development, shortfalls will occur from 2018 and reach nearly 300PJ by 2030.

“Reducing this uncertainty requires the timely development of these resources at a time when low oil prices have led to a significant fall in revenue streams and reductions in capital budgets for gas developers and producers, heightening the risk that some resource development may not be commercially viable,” Zema said.

AEMO says by 2029 it expects a 50PJpa shortfall, even if known gas resources are developed and if there are no big pipeline additions.

AEMO's report assumes the development of Santos' Narrabri CSG project.

Last year AEMO warned that could be a 164PJ shortfall by 2030, but said recent investments in processing capacity would help.

Queensland will feel the most pain, while the by 2035 pipelines from Moomba and the South East will be maxed out without further investment in the 2020s.

Sims also warned of ineffective regulation of gas transmission pipelines, and the risk of monopoly pricing and inefficient downstream investment decisions, which in turn will lead to less incentive for upstream regulation.

The ACCC will hand its East Coast Gas Inquiry to the Commonwealth on April 13.