In the United States, there's an energy boom ramping up right beneath our feet. The massive amounts of natural gas, that were previously unrecoverable, are now suddenly accessible thanks to new drilling techniques. Advancements in natural gas drilling, such as hydraulic fracturing, have made available the ocean of domestic natural gas in regions like the Marcellus Shale.

As supplies are tapped into and demand for natural gas rises, it goes without saying that infrastructure is key. After all, all that natural gas needs storing, processing, and transporting across the United States. That's why Regency Energy Partners (NYSE: RGP) presents such a strong investment case.

Regency Energy: An aggressive growth strategy
Regency Energy operates solely in the natural gas industry, which is in the midst of a strong growth period. That's due to the natural gas boom taking place in the United States.

In response, Regency Energy is aggressively acquiring various pools of midstream assets. It's clear that management doesn't want to fall behind in the race to profit from the domestic natural gas boom. Late last year, Regency purchased $1.3 billion worth of midstream assets, including pipelines and storage terminals, from Eagle Rock Energy Partners (NASDAQ: EROC).

The acquisition fulfilled several of Regency's strategic growth initiatives. First and foremost, it provides growth on an absolute basis by increasing Regency's footprint in several key targeted areas. Regency will now have an even greater presence in Texas basins. And, the assets will increase Regency's exposure to liquids-rich areas, which management targeted to increase the company's basin diversity. In addition, the acquisition will bring about significant synergies. The deal is expected to close in the latter half of 2014. Upon closing, management expects the acquisition to be immediately accretive to cash flow.

To finance the acquisition, Regency will undergo a round of equity issuances, including $400 million worth of units issued to Energy Transfer Equity (NYSE:ET), the owner of the general partner of Regency Energy.

Very recently, Regency closed on its $300 million purchase of midstream assets from Hoover Energy Partners. These assets are located in Texas, and should fit very well with Regency's current operations. That's because the Hoover assets are already connected to Regency's existing gas gathering systems. At the time the deal was struck, it was expected to integrate fairly quickly. Judging by Regency's full-year earnings report, management was right.

How Regency's strategy is paying off
Regency posted an 18% increase in earnings before interest, taxes, depreciation, and amortization (EBITDA) in 2013 versus the prior year. Management credited strong volume growth as the primary driver of cash flow growth. Regency's distributable cash flow, which measures how much cash the company can afford to pay out to investors, rose by 32% to $411 million.

This allowed management to increase Regency's distribution to $1.90 per unit annualized. At its recent price, Regency yields 7%. Fortunately, this high of a payout is sustainable. Regency generated 1.01 times its distribution in distributable cash flow, meaning it earned enough last year to finance its hefty payout.

Acquisitions and organic growth fuel Regency's future
Clearly, Regency's strategy paid off hugely last year. The company reaped the benefits of its aggressive acquisitions, and increased drilling activity boosted its organic growth projects. Even better, management is forecasting 2014 to be an equally strong year. President and Chief Executive Officer Mike Bradley stated "For 2014, we expect For 2014, we expect strong earnings and volume growth across our base business driven by our substantial organic growth program in 2012 and 2013."

Regency Energy was already successful in its existing natural gas gathering, treating, and processing operations. Adding midstream assets through an aggressive acquisition strategy will ensure future growth as well. That's why management is so confident heading into 2014, after producing such strong results last year.

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