Spotlight - hot earth in the world / Eitan Crane

A new method for underground oil production raises great hopes and equally great fears. A visit to the IEI company in Jerusalem.

"Try to imagine a dramatic geopolitical event, or an economic crisis, causing a severe shortage of fuel in Israel," Dr. Yuval Bartov, the chief geologist of Israel Energy Initiatives (IEI), asked me when I visited the company's offices in Jerusalem. "Under the soil of the Judean Lowlands lies a tremendous source of fuel, one of the largest in the world, which can give Israel energy independence for decades and prevent this imaginary, but not improbable, scenario. How would you feel," added Bartov, if you knew that this source was not even investigated?"

The beginning of the story about 70 million years ago in the days when the ancient Tethys sea covered the area. [See "Dinosaur Baron from Transylvania", by Jareth Dyck, page 60 of this issue.] As in many other marine environments, organic matter accumulated on the sea floor - the remains of billions of tons of ancient microorganisms that survived oxidation, eating by living creatures and other decomposition processes - were buried and preserved at the bottom of the sea. Over the years, time, chemistry and temperature did their thing and the organic molecules connected to each other in an insoluble three-dimensional polymeric network called kerogen in the parlance of organic geochemistry. Rock Several technologies that already exist today, the sediment containing kerogen is called bituminous stone or oil shale. The IEI company received a license to explore an oil shale deposit located at a depth of about 300 meters below the surface of the southern Judean lowland in the Adolim region, from the Ella Valley in Vacha Beit Jubrin and south.

When such rocks are buried deeper, and the temperature rises, the kerogen undergoes thermal decomposition and releases new organic molecules, quite different from the biological compounds that created it in the first place: a very complex mixture of hydrocarbons (compounds containing carbon and hydrogen) known as crude oil. This happened, for example, in Saudi Arabia or Libya, but not in the Adulam region. The Israeli deposit is not buried at a great depth and is not exposed to high enough temperatures to create oil. The Adulam shale never entered the "oil window".

"When oil production began in the world, there were 3 trillion barrels of oil," says Dr. Harold Winger, the company's chief scientist. "Since we used a third of them, we know where the second third lies - most of it in the Middle East and North Africa - and the third third needs to be found. The problem is that these reserves are probably located in faraway places that are difficult to reach, such as in the polar regions, so the price of the oil produced from them is expected to be high," concludes Winger and adds, "The world's oil reserves are far from exhausted, but the oil reserves that are easy to extract and are in 'friendly' hands are running out. If we don't find alternatives, OPEC will continue to hold the world by the throat, and even tighten its grip. These countries have no incentive to increase oil production and make it cheaper."

But there is a solution, says Winger, who was formerly the chief scientist of the oil company Shell. There are unconventional sources in the world that until recently there were no methods to tap them, or it was not economically viable: heavy oil, tar sands and oil shale. "The price of 'regular' oil is going up, while the price of 'unconventional' oil is going down. 5 years ago the prices equalized and since then it pays to extract oil in new ways," says Winger. According to calculations made by IEI, it will be possible to produce about 40 billion barrels of oil in its license area, and about 90 billion barrels in the entire central basin of the Judean Lowlands. For comparison, Saudi Arabia's oil field contains about 250 billion barrels of "easy to produce" oil. Israel today uses about 100 million barrels of oil per year. "The utilization of 30 square kilometers underground and only 5 square kilometers on the surface, will be able to satisfy the needs of the State of Israel for about 30 years," says Bartov.

The idea behind IEI's method is quite simple. Every chemist knows that what time does not do, temperature does. If the oil shale of Adulam reached a depth where a temperature of 100 degrees Celsius prevails, it would take a million years to turn into oil. If these shale were mined in an open mine and heated to 800°C we would get oil immediately. The company offers a third alternative: heat the shale in the bowels of the earth to a temperature of only 300°C for three years, and collect the resulting oil.

This method has several advantages, the company says. A temperature of 300°C does not break down the rock itself and does not change its texture. Also, only hydrocarbons in a gaseous accumulation state rise to the surface and condense there. "The system actually works like an underground refinery in the field," says Winger. "And we are able to monitor its pressure and temperature." Laboratory experiments conducted by the company showed that one-third of the organic material produced will be gas and two-thirds will be relatively light liquid oil with a hydrocarbon distribution of up to 12 carbon atoms per compound. The heavier residues, which in other methods need to be specially treated, remain in the soil. Apart from this, hydrogen is expected to be released which will be used to increase the quality of the oil and remove the sulfur found in it.

Furthermore, the production will be carried out through horizontal drilling [see "The truth about underground fracturing", by Chris Mooney, page 32 of this issue] which will avoid the need for open pit mining which is out of the question in a sensitive landscape area such as the Adolum region. The oil produced by this method is of much higher quality than oil produced by rapid heating of the same oil shale. Since most of the production will be done at great depth, the surface production facility will be relatively small. Besides the facilities related to heating the ground and controlling the temperature and pressure, it will also deal with the removal of toxic gases, such as hydrogen sulfide, and the initial treatment of oil. As the underground production progresses, a new facility will be built a few kilometers away from the first one which will be dismantled and its area will be rehabilitated. Progress will be made in leaps and bounds and it is possible to build the facilities along existing roads, the company says.

But is heating large areas of underground rock profitable at all? According to the company's energy balances, the answer is of course positive. In perfect conditions it is possible to produce oil and gas whose energy content is 6 times the energy invested. But if you take into account partial utilization and the use of electricity to heat the ground, a way that is extremely expensive, you get a ratio of 1:3 says Winger. The company plans to use more efficient methods based on natural gas. "In the beginning of the process we will have to purchase gas, but later on the gas produced in the field will be enough to produce the liquid oil," says Winger. "We intend to inject molten salts that will be heated by gas on the surface and penetrated through pipes to the production layer."

Oil production using underground heating is an innovative method that is not used on an industrial scale anywhere in the world. This of course raises many questions and concerns, not all of which can be answered at the moment. One of the most important issues is the question of the possible contamination of the groundwater. A similar attempt to extract the bituminous stone in Colorado in the USA, in which Wenger was a partner, ran into difficulties for this very reason. "The situation in Israel is much better," says Bartov. In Colorado the water aquifer is very close to the shale layer. "In their absence, the shale resides in a geological layer known as the Arab formation, which is isolated from the groundwater in two compressed and impermeable layers, one above it, and one below it." The water aquifer, located in the layer called the "Yehuda Group" is buried in the soil at a depth of 650-700 meters, i.e. a few hundred meters below the planned production area. More than that, says Bartov, the hydrostatic pressure of the groundwater is much higher than the expected pressure in the drilling wells, so the oil will not be able to penetrate this layer even if it gets there.

However, not everyone is convinced. Residents of the area and environmental organizations strongly oppose the initiative. Part of it stems from a principled opposition to the industrialization of this beautiful region of Israel and to the damage to domestic tourism that is developing there. Some are concerned about the effects of this industrialization, such as air pollution, noise and road development typical of any heavy industry whatsoever. But professionals also raise questions. "The underground rocks do not behave like a sealed container in a laboratory," says Professor Zeev Eisenstadt, an expert on Israeli bituminous stone from the Hebrew University of Jerusalem who is not involved in the project. But as with any drilling in the field, "how can it be ensured that all the gases will 'behave well' and actually enter the pipes?" he asks. Eisenstadt is also concerned about what will be left in the soil after the process. It is not oil that was created over millions of years, but a very fast process that leaves behind organic material that has undergone chemical excitation. "The Israeli kerogen is very different from the one in Colorado," he says. This is a high-sulfur material, the residues of which may continue to react in the soil and which must be tested in a field experiment. "I'm uneasy about what they're going to leave there for future generations," he says.

To answer such questions, the company wishes to operate a "pilot", an experimental production facility, which will test the method through a single vertical drilling, at a relatively shallow depth, which will operate for a year. "Currently we are not an oil production company," says Bartov. "We are actually a scientific R&D company that tests the idea, and collects data." Approval for the operation of the experimental facility in Elah Valley has not yet been received and there is also a struggle going on around it that has even reached the High Court of Justice. The company says that they conducted a tour of the field for the members of the green organizations and held many informative meetings for the residents of the area, but are having difficulty convincing them. Eisenstadt certainly supports such a facility provided that its operation is controlled by an external party and its results are available to everyone, both supporters and opponents.

There is no disputing that the oil shale reservoir of the Judean Lowlands is a strategic resource of the State of Israel and that it has tremendous economic potential. However, its judicious use will prevent environmental damage. Only comprehensive scientific research will be able to determine unequivocally what are the ways in which it can be utilized without causing harm, if at all. It seems therefore that a trial facility is a right step and it is not worth waiting for the day when the question with which we opened the article will be topical.

About the author
Eitan Crane is a doctor of organic geochemistry and co-editor-in-chief of Scientific American Israel. Follow him on the editorial committee blog at www.sciam.co.il