There is little doubt that private equity has grown considerably to help the independent oil and gas deal machine go ‘round. A 2013 study by PricewaterhouseCoopers found that the number of private-equity investments in oil and gas in 2012 was twice that of 2002.

But private equity, while a popular choice for financing, might not always be the best, depending on the type and scope of the project being funded.

“One of the questions I’ve heard come up again and again and again is, ‘What if I don’t need $100 million or $200 or $300? What if I only need $25 million or $50 million or $100 million?’” Jay Snodgrass , founder and managing partner of Energy Access Capital , said during a family wealth panel at Hart’s Energy Capital Conference in June. Energy Access Capital provides a platform for family offices to invest in North American oil and gas. “The private-equity funds have grown to be so big that they just can’t do deals less than that size. So with the smaller deals, I think you’ll find that family office route could be a good way to go.”

“Family office” has a nice, homey ring to it, but make no mistake: There is real opportunity to be found from high-net-worth individuals seeking to make long-term investments to enrich the next generation.

Snodgrass classified high-net-worth investors as anyone with $2 million to $10 million in liquid assets. “There’s an estimated 5 to 7 million people in the U.S. who have that much capital available to invest,” he said. There are also multifamily offices that pool their money between $10 million and $100 million in liquid assets that will traditionally invest with private wealth management groups such as Goldman Sachs (NYSE: GS) and UBS AG (NYSE: UBS). Beyond that are family offices with at least $100 million, in which case the family hires its own in-house staff to manage its money.

“Globally, there are 37,000 people with at least $100 million in liquid assets,” Snodgrass said.

That is a lot of capital. But accessing family office money isn’t as comfortable as the name suggests.

“It’s not as easy as going down the sponsorship list at this conference and deciding who to call,” Martin Fleming , co-founder and managing director of GMF Energy LLC , said. GMF partners with families to strategically acquire nonoperated working interest in currently producing reservoirs