Sometimes the hottest new play in oil and gas is the old one that someone just purchased.

That appeared to be the case as 2012 spiraled to a close. A flurry of deals in the second half of the year promised to manifest as E&P momentum in 2013—and beyond.

But the deals were also a signal that the industry appears to be restructuring in subtle ways. If tight-formation oil and gas is the future of the American oil patch, the economic tailwinds favor operators with deeper pockets.

This trend is evident in the Permian Basin, where vertical Wolfberry drilling activity is gradually shedding rigs as well costs rise toward $3 million, yield stays flat, and commodity prices—oil in this instance—remain stubbornly in the mid-$80 range, eroding the cost-benefit ratio. For smaller independents, making the switch to horizontal drilling in the Permian Basin is challenging, because well costs can triple even as capital demand expands exponentially from the multiwell effort required to make a resource play profitable.

Couple that with potential changes to the capital gains tax structure, and the waning days of 2012 were the best time the private independents will have in several years to execute an exit strategy.

Consequently, there is discussion that the move to tight-formation oil and gas is creating a structural change in the industry that benefits the largest companies with the best balance sheets, including the majors, that are better equipped to endure years of outspending cash flow before realizing a return on investment from resource plays.

Benefiting also is conventional legacy production at the other end of the spectrum, in the form of aggregating acreage into yield vehicles like those characteristic of upstream master limited partnerships (MLPs). The latter are able to maintain production with a small percentage of capital flow reinvested into the properties. The difference between the large volume of free cash and the smaller reinvestment threshold creates a dividend for unit holders.

Lost in the shuffle, according to this theory, is the independent who will see the best opportunities gravitate to larger firms at the top while MLPs aggregate the vast majority of legacy properties at the bottom, or at least the portion that is 85% proved developed.

This is reflected in recent transactions. In the U.S., investment dollars for acquisitions have flowed toward the Permian Basin and the Bakken shale—more than $6 billion each. In both regions, major oil companies, including Chevron Corp., Royal Dutch Shell Plc, and ExxonMobil spent more than $4 billion acquiring parcels from Chesapeake Energy Corp. in the Permian and Denbury Resources Inc. in the Bakken.

For Shell, it means a return to the Permian Basin after an absence of nearly two decades.

Previously, investment dollars flowed into the U.S. market via joint ventures, often with international oil companies. For now, the JV movement appears to have slowed. That’s not to say JVs are finished: there is still substantial capital in foreign hands looking to exchange greenbacks earned through trade for U.S. oil and gas assets. But with $43 billion in joint ventures extant, the game is closer to the seventh inning stretch than it is to the early innings.

Meanwhile, MLPs have been active as well, steadily enlarging their position in the oil patch with more than $6 billion in 2012 acquisitions.

Is the outcome of this industry restructuring pre-destined? Maybe not. One theory is that the oil and gas pie is going to grow over time so there will be room for the majors, the upstream MLPs and the independents. Another argument is that independents, at least their management teams, aren’t going anywhere, since they are the creative energy in the industry, exploring new concepts, blocking up acreage packages, and demonstrating how to exploit the properties before flipping them to bigger entities to develop.

The management team takes its pay out and starts anew. There is ample energy-focused private-equity capital to keep this cycle running indefinitely.

Meanwhile, the regional roll-up of tight-formation oil and gas has shifted from the Marcellus and Eagle Ford shales to the oilier Bakken and Permian Basin. The influx of acquisition or JV capital into the Marcellus and Eagle Ford in the 2008-2010 era expanded activity and attracted oil service providers. As those acquisition dollars switch to the Permian and the Bakken, it is reasonable to expect the same will transpire in 2013, and for years to come.