Countries that depend heavily on oil for part of their government revenue may see company's investment appetite wane without fiscal reforms, analysis finds.

The International Monetary Fund in April said low oil prices have led to a subdued outlook for the global economy, with importers and exporters alike feeling the impact. Growth would be uneven, it said, as advanced economies expand while developing economies shrink.

Some factors, like the decline in the value of the ruble, the currency in oil-rich Russia, are easily visible, though other factors, like slow capital growth in emerging economies, are less apparent, the IMF said.

Graham Kellas, vice president of fiscal research for Wood Mackenzie, said governments across the globe are examining the terms for investing in the exploration and production sector as the weak market for crude oil endures.

"For some governments, the impact of the lower price has been devastating for public spending plans, especially those forged on oil price expectations of $100 a barrel, forcing them to slash spending with significant economic and political fallout," he said.

Russia's economic stumbles were among the most highly profiled, as its national currency collapsed under the duel strains of sanctions and the low price of crude oil. For the United States, meanwhile, employment in the oil and gas sector continues to lag when compared with other economic sectors.

With companies spending less on exploration and production, governments that depend heavily on tax revenue are facing a decision to either do more with less, or take more in taxes in order to support their budgets.

"This will make new investment in the country appear even less attractive than the lower price has done already," Kellas said in an e-mailed statement.

In its analysis of spending from 2014, Wood Mackenzie, which has headquarters in Scotland, said talk of fiscal change during a slump in oil prices has not been met with action, apart from a few selection circumstances.