Oil prices have increased by 14% over the last month. Despite the rally, many oil companies still have dividend yields far greater than the S&P 500's dividend yield of 2.1%. 

Let's look at three oil corporations with rising dividends and dividend yields of at least 3.0% or more. The first is a well-known oil refiner that ranks in the top 20 high-quality dividend stocks using The 8 Rules of Dividend Investing. The second is a rapidly growing midstream oil business. It will very likely continue to reward investors with higher dividends. The third is the undisputed king of the oil industry based on its $375 billion market cap. It is also one of only 50 Dividend Aristocrats thanks to its 34 consecutive dividend increases.

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1. Phillips 66 (PSX) - Get Report

Phillips 66 is an oil refiner. This puts it in an advantageous position, since refining companies typically perform better when oil prices decline.

This might sound crazy. How could an oil company do better with low oil prices? The answer is because the refining business isn't like other areas of the oil and gas industry. Refining activities benefit from low oil prices, because low prices reduce the feedstock costs refiners must pay. When that happens, refining margins widen and profitability expands. This explains why refining stocks performed well, even from 2014-2016 when oil prices collapsed.

For example, Phillips 66 grew its adjusted profit by 11% in 2015. This was due to the refining unit. Adjusted profits in the core refining business, which make up the majority of Phillips 66's total annual earnings, soared 60% for the year. As a result, Phillips 66 could be a great stock to buy for investors who believe oil prices are set to fall back toward the February lows.

Phillips 66 stock is up 4.4% in the past 12 months and has outperformed the S&P 500 index over that period. The S&P 500 is up only 1.2%. Plus, Phillips 66 offers investors a solid 3.1% dividend yield, and has aggressively raised its dividend in recent years.

Phillips 66 increased its dividend by 13% earlier this year. It has given investors six dividend increases since its IPO in 2012. According to the company, it has raised its dividend by 33% per year on average since the IPO.

Its strong business and excellent returns have gotten the attention of some high-profile investors, including none other than Warren Buffett. Buffett's investment firm Berkshire Hathaway owns more than 75 million shares of Phillips 66. Click here to see Buffett's top 20 high dividend stocks. Berkshire Hathaway owns a 14% stake in the company and is its largest institutional shareholder. As arguably the world's most famous value investor, Buffett knows a good deal when he sees one.

With a highly profitable business model, a proven track record of growth and a price-to-earnings ratio of just 12, Phillips 66 is a good stock choice for a high dividend yield and dividend growth.

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2. Enterprise Products Partners (EPD) - Get Report

Enterprise Products Partners is probably not a household name, but it's a very appealing stock for income investors. 

Enterprise Products is a midstream energy company. It is involved in the storage and transportation of crude oil, natural gas, liquefied natural gas and other refined products.

It has a massive network of high-quality assets, which include 49,000 miles of pipelines, 24 natural gas processing plants, and storage facilities with 225 million barrels of crude oil, refined products and natural gas liquids storage capacity.

Enterprise Products has exhibited massive growth since its 1998 initial public offering, growing its asset base from $715 million to $48 billion as of June 2015. The company has achieved this growth both organically and through acquisitions, and has benefited from the expansion of energy infrastructure in the U.S.

Enterprise Products is classified as a Master Limited Partnership, or MLP. This means it has to pass along most of its cash flow through to investors as distributions, which results in very high yields.

Enterprise Products yields 5.5%, which is very attractive for income investors.

The company has hiked its distribution for the past 47 quarters in a row, and has raised distributions a total of 56 times since its IPO. Its most recent increase came in April, when Enterprise hiked its distribution by 5.3%.

The reason why it can continue to raise dividends is because midstream companies aren't as highly reliant on commodity prices as other energy firms. Midstream businesses operate similarly to toll roads: They collect fees based on volumes of liquids transported and stored.

Enterprise Products' distributable cash flow grew 37% last year, to $5.61 billion. Its excellent results were driven by its fee-based assets, organic growth from new assets and growth through acquisitions.

Continued growth in cash flow and distributions are very likely. Enterprise Products retained $2.6 billion of distributable cash flow last year to reinvest in future growth opportunities. In addition, the company completed $2.7 billion of organic growth projects last year that will add to growth going forward.

With such strong growth and a 5.5% yield -- highly attractive in a low-rate environment, considering the S&P 500 yields only 2.1% on average -- Enterprise Products is a high-quality holding for income investors.

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3. Exxon Mobil (XOM) - Get Report

Exxon Mobil is the premier integrated energy company in the entire world, with a $380.44 billion market cap. It has achieved decades of steady growth and has paid dividends to shareholders all along the way.

Its massive size provides the company with a great deal of economic scale, which allows it to survive downturns in commodity prices much better than many smaller competitors in the oil and gas industry.

Exxon Mobil has paid dividends for more than a century and has increased its dividend for 34 years in a row. That makes it a member of the exclusive Dividend Aristocrats list, a select group of firms that have raised shareholder dividends for at least 25 years in a row.

Even in a brutal environment, in which oil prices fell from over $100 per barrel two years ago to less than $30 at the 2016 low, Exxon Mobil continues to increase its dividend. The company hiked its dividend by 2.7% this year, despite its profits falling by approximately 50% last year.

This is a testament to Exxon Mobil's financial strength. The company still earns industry-leading returns on capital, thanks to its focus on efficiency. Last year, Exxon Mobil lowered its share repurchase activity by $9 billion, and it reduced capital spending by 19% as well.

Going forward, while 2016 is likely to be another difficult year -- Exxon Mobil's first-quarter profit was its lowest in more than a decade -- next year should be better, because the company has a number of major upstream projects set to come online.

Exxon Mobil's impressive project line-up includes its major Kearl facility in the Canadian Oil Sands. Completion of these projects will help improve the company's cash flow because the projects will turn from a use of cash to a source of cash. That will be greatly helpful, even with low commodity prices.

On average, analysts expect Exxon Mobil's adjusted earnings per share to decline to $2.69 this year, but they expect them to rise again to $4.37 per share in 2017. 

If these projections prove accurate, Exxon Mobil should have plenty of financial flexibility to once again raise its dividend next year, even if commodity prices stay at current low levels.

This article is commentary by an independent contributor. At the time of publication, the author held shares of XOM.