Pump jacks and wells on the Monterey Shale formation in California David McNew / Stringer | Getty Images News

The $6 billion deal announced last week between Whiting Petroleum and Kodiak Oil and Gas has fanned expectations that more U.S. energy producers will actively seek deals—the better to capitalize on a surge of shale that is expected to push U.S. production close to 10 million barrels of oil per day. Yet echoes of bygone mergers, which created the modern day cohort of energy behemoths, linger in the background. More than a decade ago, a flurry of deals gave birth to the "Big Three" oil companies of ExxonMobil, Chevron and ConocoPhillips. Fast forward several years, and all three have been relegated to the sidelines of the U.S. shale boom, where independent firms are rolling in oil, gas and profits. Read MoreSaudi America? Close...but no cigar: Analysts In fact, a defining characteristic of the domestic energy resurgence is the lack of Big Oil's influence. Years of gorging themselves on pricey mergers have left them unable to challenge smaller players in hot spots like North Dakota, Texas and Pennsylvania, analysts say. Even as U.S. shale companies pursue mergers, energy watches don't expect them to become imitations of Big Oil deals that eventually fell flat. "Mega-mergers were about rising costs and declining oil prices. It was survival mode," said Fadel Gheit, Oppenheimer's managing director and senior energy analyst, in an interview. "This time around, it's growth focused." Rather than "a wave" of deals like Exxon's wallet-busting $82 billion deal to purchase Mobil, or Chevron's nearly $40 billion marriage to Texaco, shale deals going forward will be "very company-specific," Gheit said.

Not like buying cheap shirts

In fact, oil and gas mergers plummeted by nearly 50 percent in 2013 from a record high $250 billion the year before, according to data from research firm IHS. That suggests energy players are becoming circumspect about where and how to create shareholder value. Because big oil companies have found merger-driven growth elusive at best, mega deals are unlikely to become a hallmark of the shale renaissance, experts say. "It's not like going to a store to buy shirts that are not your size but are cheap," Gheit added. "They have to find the fit first, and this has to enhance existing assets. Synergy is critical to future mergers." When ExxonMobil purchased XTO for $31 billion in 2009, analysts at the time perceived it as the company placing a big bet on its future in natural gas production. Thus far, it hasn't worked out as planned. Although on paper Exxon is the largest nat gas producer in the country, its profit is overwhelmingly derived from crude produced abroad, and nat gas production hasn't staved off falling profits. Read MoreChevron suffers Big Oil blues as US gushes fossil fuels