According to Bloomberg, Blackstone is scrambling to invest more than $US10 billion ($A12.8 billion) in energy companies with its head of energy deals, David Foley, looking for US shale operators and international opportunities that exclude deepwater drilling and heavy oil.

Shale production in the US is largely resilient to lower oil prices, Foley told the newswire.

Blackstone, Carlyle, KKR and Apollo have reportedly raised more than $15 billion recently for energy investing.

"Apollo last week registered a fund that will invest in less liquid or illiquid energy assets," the newswire reported.

"The filing didn't disclose how much the New York-based firm plans to raise.

"Carlyle, based in Washington, has about $7 billion dedicated to investing in energy companies and assets, co- founder David Rubenstein said last month. That includes a first- time international energy fund and North American energy and power funds.

"KKR, run by Henry Kravis and George Roberts, is seeking as much as $3 billion for its second special situations fund to provide financing to troubled companies, including those hurt by plunging oil prices, two people with knowledge of the plans said last week. The New York-based firm also invests in oil and gas assets through a $2 billion energy income and growth fund."

KKR sold off its remaining 12% stake of Seven West Media in 2013, while the Seven Group started eyeing oil and gas assets from 2014, most notably including its takeover attempts for Nexus Energy.