[BiGG]

Oil Reservoirs can be Doubled via Electromagnetic Heating

May 12, 2005 - Heavy Oil Potential Key to Alaskan North Slope Oil Future

Tulsa, Okla. — Alaska’s North Slope boasts a massive heavy oil resource that someday could underpin the survival of one of the Nation’s most critical oil-producing provinces—and research funded by the Department of Energy may provide the key to unlocking this vast but, to date, largely intractable oil resource.

Alaska’s North Slope is home to the largest oilfield ever found in North America, the legendary Prudhoe Bay. Also linked to the Prudhoe Bay infrastructure is Kuparuk River oilfield, the Nation’s second largest oilfield by production. A number of smaller oilfields that still would be considered giants by Lower 48 standards have been developed nearby.

But perhaps the biggest potential source of oil on the North Slope is the less-heralded heavy oil formations overlying the main producing zones at Prudhoe and Kuparuk. As much as 36 billion barrels of original-oil-in-place lie within the Ugnu, West Sak, and Schrader Bluff formations. That surpasses the original-oil-in-place of Prudhoe and Kuparuk combined.

The largest undeveloped accumulations in North America, these reservoirs lie tantalizingly in reach of existing infrastructure. Their recovery, however, has proven a daunting challenge. At a depth of 3,000–3,500 feet, these formations’ proximity to the subsurface permafrost renders the already low-gravity crudes extremely viscous. Viscous crude, which can be as thick as molasses, has trouble flowing to the wellbore for production. Low formation strength presents an additional hurdle to high recovery and productivity rates. North Slope producers have struggled for years to devise an economic plan to recover the heavy oils. This plan has become more important for America’s energy security because of production declines in other North Slope fields.

North Slope operators thus far have focused on the less-viscous crudes in the West Sak and Schrader Bluff heavy-oil formations, where viscosities range from ~30 centipoise to ~3,000 centipoise. Combined original-oil-in-place volumes for these two formations total about 10–20 billion barrels. Even assuming modest recovery rates, producible reserves could total several billion barrels of oil. Because there are even higher viscosities seen in the Ugnu formation, that resource’s exploitation must await future technological advances.

North Slope operators have had some success producing the less-viscous crudes in the West Sak and Schrader Bluff formations by injecting slugs of water alternating with gas (WAG) into the reservoirs; the gas acts as a solvent to reduce oil viscosity, while the water front helps sweep the reservoir, pushing the crude to producing wells.

There are several gas streams available on the North Slope that contain natural gas liquids and carbon dioxide. Natural gas liquids have been used for years as part of a miscible gas enhanced oil recovery effort to bolster recovery at Prudhoe Bay. CO2 flooding is the fastest-growing form of enhanced oil recovery in the United States and creates the opportunity for environmentally safe disposal of the greenhouse gas.

DOE-funded research by the University of Houston has developed tools for modeling the optimum WAG flood design. The goal of the research—managed for DOE’s Office of Fossil Energy by the National Energy Technology Laboratory—was to focus on modeling tools that would determine the best solvent, injection schedule, and well architecture for a WAG process in North Slope shallow-sand viscous oil reservoirs.

In the project, which took place from September 2001 through September 2004, the researchers were tasked with developing a compositional model, devising a new relative permeability model, creating a reservoir simulator, designing the ideal well architecture, and optimizing the WAG flood.

In their final project report, researchers also found a potential for greatly increased production rates for deploying WAG floods in horizontal wells vs. vertical wells, depending on well design and other factors. The research also showed that well productivity for these viscous oil reservoirs can be doubled via electromagnetic heating.

Such models will serve as useful tools in fully commercializing a vast oil resource needed to help stem the decline of production on Alaska’s North Slope. And that could make the difference in keeping America’s most prolific oil province on line.

[Don_Quichote]

Wasn´t the east texas field bigger ?

[Aaron]

There could be trillions of barrels in ANWR.

But the Alaskan pipeline only delivers up to 2 million barrels per day.

[Cyrus]

There could be trillions of barrels in ANWR.

But the Alaskan pipeline only delivers up to 2 million barrels per day.

It could also hold under a billion. We really just don't know. By any rate, the ANWR is not the answer.

[MonteQuest]

There could be trillions of barrels in ANWR.

But the Alaskan pipeline only delivers up to 2 million barrels per day.

And it's half full already with Prudhoe Bay oil.

[RockHind]

Summary:

There is a smidgen of crappy oil that may be recoverable at a high cost if hoped for scientific advancements pan out.


Wo Hooo

[Cash]

"The largest undeveloped accumulations in North America, these reservoirs lie tantalizingly in reach of existing infrastructure. Their recovery, however, has proven a daunting challenge. At a depth of 3,000–3,500 feet, these formations’ proximity to the subsurface permafrost renders the already low-gravity crudes extremely viscous."

This point is pure baloney and mortally damages the credibility of the rest of the article. At that depth, the temperatures are higher due to heat from the Earth's core, not decreasing. There is absolutely no way that surface temperatures can have an effect on temperatures at that depth. Mines from Alaska to Finland to Siberia have all shown this on a practical as well as theoretical basis.

As for the other points in the paper, I'll only point out that they're talking about a model, not real-world experience yet. And the one reference to "elctro-magnetic heating" is never defined or explained.

[Jack]

Marvelous! So this must surely mean that supplies will go up. And that means that the price should go down. Ergo, crude oil and oil company stocks should decline.

So anyone who believes this should short oil or oil stocks.

Go for it! You know you want to!

[rockdoc123]

This point is pure baloney and mortally damages the credibility of the rest of the article. At that depth, the temperatures are higher due to heat from the Earth's core, not decreasing. There is absolutely no way that surface temperatures can have an effect on temperatures at that depth. Mines from Alaska to Finland to Siberia have all shown this on a practical as well as theoretical basis.

I think it is just a matter of poor wording in the article. In actual fact the permafrost and cold surface temperatures create problems since the oil may have lower viscosity at reservoir temperature but much higher viscosity at the well head and in non-heated pipelines.

[TheTurtle]

By any rate, the ANWR is not the answer.

Though it is only 2 letters away from being so.

One of my co-workers told me that he read somewhere that some expert said that ANWR contains enough oil to last us for hundreds of years. So I guess I was needlessly concerned.

[0mar]

Mark this day ten years into the future. Check if said field is developed.

[Cyrus]

Cyrus wrote:
By any rate, the ANWR is not the answer.


Though it is only 2 letters away from being so.

DAMN YOU!! LOL! I logged on just this minute SPECIFICALLY to make that little crack.

[RG73]

Even assuming modest recovery rates, producible reserves could total several billion barrels of oil.

The US uses something on the order of 1 billion barrels every 50 days. So several is what--under 10? Thus we're talking about, best case scenario, 2 years or so of oil.

[gg3]

Permafrost: I think Rockdoc is on-target about this: increasing viscosity as the oil nears the surface.

Two years' worth: Okay, so it buys time. Everything that buys time is a good thing right now, assuming we use the time wisely (nuclear and wind build-outs, solar retrofits, efficiency upgrades, etc.). Or we could squander the next ten years in which case it's for nought.

Right now Bush has an energy policy on the table and the Democrats don't. What we need right now is for the Democrats to come up with something of their own, on the basis that competition between the two sets of policies will produce a stronger outcome that both parties have a stake in.

Re. the pipeline: I'm wondering if the ROI on a replacement (larger) pipeline is sufficient to attract investment. On one hand is the benefit of increased production. On the other hand is the question of whether the expected lifetime of these fields justifies the cost. Anyone...?