* Top Permian drillers: tmsnrt.rs/2laHhq1
* Top Permian land holders: tmsnrt.rs/2laok6R
* Chevron turns to Permian partners to ramp up output
By Jennifer Hiller
MIDLAND, Texas, Oct 3 (Reuters) - U.S. oil company Chevron Corp is turning to joint ventures and drilling alliances in its bid to dominate the Permian Basin after abandoning a takeover that would have made it the leading producer in the world's biggest shale field.
It is now in a race with Exxon Mobil to be the first to pump a million barrels of shale oil a day from the field in the U.S. southwest, using a strategy that depends on a host of partners sharing their expertise and their output.
Chevron's joint venture with Cimarex Energy, one of the few Permian operators that has been consistently profitable since late 2016, is well known.
But it also has dozens of other agreements with companies including Concho Resources, Devon Energy, EOG Resources, and even arch-rivals Exxon and Occidental Petroleum, people familiar with the matter told Reuters.
"We're partners with all of the great operators," said Scott Neal, a Chevron exploration executive. He declined to name any partners, besides Cimarex. Concho, Devon, EOG, Occidental and Exxon declined to comment.
Chevron's deals, ranging from large-scale joint ventures to small deals where it has leased land to other operators, give it a share of the oil its partners produce.
They also provide data from thousands of wells stretching back years, allowing Chevron to hone drilling strategies. In return, partners get access to areas adjacent to their wells and pipelines, reducing their costs.
Shale drilling has helped the United States reverse decades of declines in output to become the world's largest oil producer and all the major U.S. oil companies have jumped on the shale bandwagon to boost their own production.
Unlike conventional oil fields, however, shale wells decline quickly, producing most of their oil in the first few years, so fields such as the Permian Basin require constant, and costly, drilling just to keep production steady.
"If there's a downside, that's the downside," said Jeff Gustavson, who oversees Chevron's Permian operations. "You're always having to put more in."
At a site near Midland, Texas, know-how gleaned from Cimarex and other partners is helping Chevron drill a series of ultra-deep wells - named after the mythical three-headed hound Cerberus - to reach an oil-rich layer more than a mile underground.
The alliances and vast land holdings Chevron can tap allow it to drill longer wells than some rivals, giving it an edge as long wells generally pump more oil and save money.
Chevron said its Permian wells average nearly 9,000 feet (2,743 meters) this year, while consultancy Wood Mackenzie said the industry average is 8,500 feet. Next year, its wells will stretch almost 10,000 feet on average.
In one formation near Midland, Chevron's peak average production rate runs at 760 barrels per day (bpd) for each well while rivals are producing at 705 bpd, according to IHS Markit.
Shale drilling combines horizontal wells with hydraulic fracturing, the process of pumping water, sand and chemicals at high pressure to crack rocks that hold oil and gas.
Those wells and partnerships in the Permian, the fastest growing shale field, are critical to Chevron's future.
It missed the first phase of the shale boom early this decade but reversed course in 2014 when it drilled its first horizontal well in Permian and embarked on an investment spree to try to become the world's largest shale oil producer.
It has been shedding assets in the North Sea, Africa and Asia and expects to sell up to another $10 billion worth of properties to focus on projects including the Permian, where it has controlled some of the best and cheapest acreage since the 1920s.
Those holdings helped lift Chevron's oil and gas output to a record high in the second quarter. In the Permian, output leapt 56% from a year earlier to 421,000 bpd and Chevron's goal is to pump 900,000 bpd from the oilfield by 2023.
Chevron's Gustavson said its long-standing relationships provide it with "all of the data, all of the cost information" from wells across the basin. "It's a huge advantage. Huge."
For a chart of the top Permian drillers: tmsnrt.rs/2laHhq1
Chevron is not the only energy company claiming a unique position in the Permian Basin.
Occidental outbid Chevron for Anadarko Petroleum in a takeover battle this year, spending $38 billion and vowing to use its technology to squeeze more oil from the deal which gave it a combined 3 million Permian acres.
Exxon, meanwhile, spent $6.6 billion two years ago to buy more Permian land and is now running nearly three times more rigs than Chevron in a race to reach its target of producing 1 million bpd of shale by 2024.
But Chevron has two key advantages: it holds 2.2 million Permian acres, second only to the Occidental-Anadarko trove, and it owns mineral rights on much of its land so it doesn't pay the 20%-25% production royalties most rivals face.
Chevron's Permian oil and gas output last quarter was second to Occidental's 533,000 bpd, but rising faster. Exxon is in the top 10 with production of 274,000 bpd.
For a chart of the top Permian land holders: tmsnrt.rs/2laok6R
Chevron's mineral rights reduce its breakeven, or the oil price it needs to make a profit, while other savings come from drilling ventures. Chevron operates 20 rigs, far fewer than the 56 Exxon operated in June and Occidental-Anadarko's 27.
But Chevron estimates its partners contributed the equivalent of another seven to 10 rigs.
Cimarex struck a small deal with Chevron in 2009 to drill on its land and share data, and then broadened the agreement in 2013, said Michael DeShazer, Permian manager at Cimarex.
He said the two companies were able to learn faster, deploy faster and, by sharing resources, they could more easily invest in infrastructure such as pipelines, roads and electricity.
Shale output drops sharply the first year and declines 80% to 90% over two to three years, but Chevron has been able to slow the decrease.
In the formation near Midland, Chevron's wells lost 52% of their output after the first 12 months compared with an average decline of 70% for rivals, according to IHS Markit. Output from Chevron's wells in the first two years was also 40% higher.
While most shale firms have spent heavily but failed to deliver the returns demanded by investors, Chevron's "slow and steady" approach to the Permian is welcomed by investor Matrix Asset Advisors, which holds 55,000 Chevron shares.
"They've got a game plan. They're executing on the plan," said Matrix President David Katz.
Reporting by Jennifer Hiller; editing by Gary McWilliams and David Clarke