The broker was previously anticipating Chevron to commit to the second phase of the project, especially due to Chevron's active exploration program in South Australia's offshore Bight Basin.

It consequently cut its rating of Beach to neutral.

"Following Chevron's withdrawal Beach appears catalyst-light over coming months," Macquarie said in a research note.

"Furthermore, with the new managing director only recently commencing, communication of the new strategy is likely to be also a number of months away.

"That said, Beach could now prove a more likely takeover target (although we continue to believe that Beach is likely to be the consolidator, not necessarily the target)."

On Chevron's decision, Macquarie took in the oil major's comments on significantly reducing its exploration spend, made during the December quarter results period, plus the recent divestment of its Caltex Australia stake (50%).

"This appears a portfolio decision rather than purely a reflection of the geological results to date," the broker said of Chevron's Cooper exit.

The next price catalyst for Beach shares was flagged to be a possible reserves upgrade at the Bauer field in the coming months.

Chevron's exit has left Beach with 100% stakes of the project's PRLs33-49 and a 64% stake of ATP855P over the border in Queensland.