EOG Resources (NYSE:EOG) continues to deliver for investors. The company followed up its stellar fourth-quarter results with an equally impressive first quarter. The oil and gas producer reported net income of $660.9 million, or $1.21 per share. But on an adjusted basis, first-quarter income was $767.7 million, or $1.40 per share. That beat analysts' estimates by a whopping $0.21 per share. Let's drill down and take a closer look at the company's outstanding results.

It's all about the oil
EOG Resources' production surged 18% year over year, with domestic oil production leading the way growing 45% over the past year. As the following slide notes, EOG Resources' production surge is being fueled by its strong position in the Eagle Ford Shale and complemented by solid positions in the Bakken and Permian Basin.

Eog Resoruces Horizontal

Source: EOG Resources Investor Presentation (Link opens a PDF

The company drilled a number of exceptional Eagle Ford Shale wells last quarter. Three of the company's wells on its Korth Unit delivered average initial production rates that averaged 3,185 barrels of oil per day along with substantial NGL and natural gas production. On top of that a well on its Lynch Unit and one on the Presley Unit delivered initial oil rates of 4,260 and 4,970 barrels of oil per day, respectively. With initial production rates north of 1,000 barrels of oil per day considered pretty good, these wells were true Texas oil gushers, which helped to fuel EOG Resources' production surge in the quarter.

EOG Resources is really seeing the benefit of its strong position in the Eagle Ford Shale. It's a play that's really changing the game for companies focused on drilling its oil-rich rocks. Penn Virginia (NYSE:PVA), for example, expects the Eagle Ford Shale to fuel 66%-78% oil production growth this year as the company drills its position in the play. As the following slide shows, Penn Virginia has become an oil growth story thanks to the Eagle ford Shale. 

Penn Virginia Oil Growth

Source: Penn Virginia Investor Presentation (Link opens a PDF)

What's really interesting is that while Penn Virginia is growing faster than EOG Resources, it's doing so off of a much smaller base of production. That really makes EOG Resources' oil production growth rate truly remarkable considering the sheer size of the company.

In addition to the Eagle Ford Shale, EOG Resources also enjoyed solid well results in the Bakken Shale. Its wells there delivered initial production rates ranging from 1,000 to 2,220 barrels of oil per day. Meanwhile, the company continues to see solid results in the Delaware Basin Leonard Shale. The company's wells in the New Mexico portion of the play are delivering initial production rates north of 1,000 barrels of oil per day. Finally, the company's results farther south in that play are lower, however, these wells tend to maintain steady production, which is still delivering strong returns.

Looking ahead
These strong well results are now pushing EOG Resources to raise its full-year oil-production growth goal from 27% to 29%. That will push the company's overall production 12% higher, which is about half a percent more than its previous estimate.

The guidance raise is mostly attributable to the expectation of continued strong well results in the company's three core plays. But EOG Resources also announced that it's now adding four new horizontal plays to its drilling inventory. The company has been evaluating a number of plays in the Rocky Mountains and is now ready to move the Codell, Niobrara, Parkman, and Turner plays into development phase.

Of the four plays the Niobrara is likely the one most well known to investors. Bakken focused drillers like Whiting Petroleum (NYSE:WLL) have turned to that play to fuel the next phase of production growth. Whiting Petroleum recently experienced tremendous production growth out of its Redtail Niobrara asset as production surged 41% over the prior quarter. That growth should continues well into the future as company sees the potential for up to 6,600 future wells on its 174,892 gross acreage position as the following slide details.

Whiting Redtail

Source: Whiting Petroleum Investor Presentation (Link opens a PDF)

EOG Resources' position in this Colorado oil play isn't quite as large as the company currently has 50,000 net acres. Given current well spacing the company sees 235 future drilling locations, but as Whiting Petroleum is discovering there is the potential to add wells to the drilling inventory by spacing wells closer together.

In addition to the Niobrara, EOG Resources is adding 72,000 net acres with 225 future drilling locations in the Codell play in Colorado to its inventory. On top of that the company is adding the Parkman and Turner plays in Wyoming to its inventory. Parkman adds 30,000 net acres and 115 drilling locations while Turner adds 63,000 net acres and 160 drilling locations. Together these plays should add 400 million barrels of oil equivalent to the company's recoverable resources base.

Investor takeaway
EOG Resources continues to defy the odds and deliver impressive results. The company really is firing on all cylinders as its developmental wells continue to exceed expectations while it's adding new areas through its exploration program. It remains one of the best oil-growth stocks in America these days. 

Matt DiLallo has no position in any stocks mentioned. The Motley Fool owns shares of EOG Resources. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.