01 April, 2011

A Gas Find of Leviathan Proportions

Israel joins ME producers

 

The Biblical land of milk and honey, aka Israel, has long been considered a kind of enigma in the oil-rich Middle East.

Atwood Hunter rig drilling for Noble Energy at Tamar discovery. Photo provided courtesy of Noble Energy
Atwood Hunter rig drilling for Noble Energy at Tamar discovery. Photo provided courtesy of Noble Energy

The Biblical land of milk and honey, aka Israel, has long been considered a kind of enigma in the oil-rich Middle East.

With the exception of a few small oil and gas finds made by Israeli explorers over the years, the country appeared to be lacking the bountiful hydrocarbon deposits common to this part of the world.

No more.

Today, headlines abound in both the mainstream media and the trade press touting the humongous supplies of natural gas recently discovered by Noble Energy just offshore Israel in the Levant Basin in the eastern Mediterranean Sea.

We’re talking supplies that could turn Israel into a natural gas exporter after historically depending on fuel imports to meet its needs.

The lid has been popped right off the richly endowed hydrocarbon deposits long lying in wait for the drill bit in the Levant.

Noble’s recently announced giant find, christened Leviathan, is said to harbor 16 Tcf of natural gas, which positions it as the world’s largest deepwater gas find in a decade.

Noble operates Leviathan with a 39.66 percent working interest. Other interest owners are Delek Drilling (22.67 percent), Avner Oil Exploration (22.67 percent) and Ratio Oil Exploration (15 percent).

Leviathan comes on the heels of other Levant Basin discoveries by Noble, including the nearby giant Tamar field, where gross mean resources of 8.4 Tcf have been determined.

A Geologic Perspective
Susan Cunningham
Susan Cunningham

Noble, which first became interested in the region in 1998 when the company then was known as Noble Affiliates, joined a consortium of Israeli companies called the Yam Tethis Joint Venture group to act as operator to explore the waters offshore Israel, according to AAPG member Susan Cunningham, senior vice president of exploration at Noble Energy.

“Within the first two years, Noble via subsidiary Samedan had made two discoveries, Noa and Mari-B,” she noted. “Then in July 2006, Noble farmed into what would become the Tamar and Dalit discoveries and picked up the Leviathan acreage in a licensing round in 2008.

“The Tamar natural gas discovery was the largest conventional gas discovery in the world in 2009,” Cunningham emphasized.

These discoveries are notable in many ways, including the drilling environment. Water depths are in the 5,500-foot range, with target reservoirs a few miles subsea.

Cunningham provided a brief look at the geology.

“The Levant Basin is a deep, long-standing basin initiated at the time of Mesozoic rifting and infilled by post-rift Tertiary sedimentation,” she said. “The Oligo-Miocene reservoir rocks at Tamar/Dalit/Leviathan are deep basin floor turbidite fan sandstones sealed by shales of mid- to late Miocene age and Messinian age salt.

“The traps are structurally closed,” Cunningham added.

The Oligo-Miocene clastics at Tamar occur at depths of almost 15,000 feet sebsea. Until the Tamar discovery, these reservoirs had never been tapped into by the drill bit.

Cunningham noted the Tamar well encountered more than 600 feet of net pay in three high quality reservoirs; the gas reportedly is essentially pure methane. An appraisal well has been drilled on the flank of the structure.

First production at the Tamar field is expected to occur by the end of 2012.

Now What?

Meanwhile, the drill bit continues to turn in the almost-17,000-foot Leviathan-1 well, which kicked off in October 2010 and is slated to go down to 23,000 feet. This is not necessarily with the intent to find additional reservoirs but to learn more about this large basin.

Noble and its partners at Leviathan intend to drill two field appraisal wells with the first one planned to spud eight miles northeast of the discovery well early in 2011. The Leviathan Field is estimated to cover 125 square miles.

Even before the hubbub over the recent eye-popping discoveries, the U.S. Geological Survey had taken the hydrocarbon potential of the Levant Basin seriously enough to conduct a resource assessment. The study was released in March 2010, reportedly estimating that the zone harbors 1.7 Bbo and 122 Tcf of natural gas.

The huge discoveries in the basin thus far inarguably are plenty impressive. However, there’s the thorny issue of how to make use of this bountiful supply of natural gas.

Noble has had a team evaluating market possibilities for more than a year, which includes various pipeline and LNG options, according to company president and COO David Stover. He noted they believe the natural gas resources at Leviathan are sufficient to support one or more of the options being studied.

Additional discoveries are a distinct possibility.

Cunningham noted that Noble holds other licenses in the Levant Basin.