Experimental study on physical and chemical properties in mining areas in Northeast China and Bayangala in Mongolia

Oil shale Oil shale

Usually refers to sedimentary rocks containing solid oil matrix that are heated for a chemical reaction, and the oil matrix will crack and be released in a form similar to hydrocarbon oil gas.

Oil shale is formed by the sedimentation of lake beds and seafloor silt and organic detritus millions of years ago, and transformed into oil shale after a long period of heat and pressure.

Oil shale is rich in organic matter and burns under normal conditions to be used as fuel or burned to generate electricity. At present, there are two main methods of oil shale extraction.

One is to produce shale oil and gas, a hydrocarbon oil gas similar to conventional petroleum, through dry distillation, which is first extracted to the surface and then heated to a higher temperature.

Finally, the oil and gas are separated and collected; The other, called in-situ conversion, is where organic matter in oil shale is solid and cannot be extracted directly from the ground.

Instead, the oil shale is heated directly underground and the resulting oil and gas are extracted to the surface.

Oil shale extracting shale oil and gas is more complex and more expensive to extract than traditional oil extraction.

Distribution of oil shale resources

Due to the long-term uncertainty of crude oil supply and the world energy crisis, oil shale, which can replace conventional fossil fuels, has attracted new attention.

Oil shale reserves refer to oil shale resources that are economically recoverable under existing economic and technical conditions.

The range of oil shale deposits is as small as the current economically recoverable reserves and as large as the current economically unrecoverable resources.

Due to the chemical composition of different oil shales and their kerogen content, extraction techniques vary greatly, so it is difficult to determine oil shale reserves.

The economic viability of oil shale extraction depends largely on the price of conventional oil, if the price per barrel of crude oil is lower than the price per barrel of shale oil produced.

Oil shale extraction is uneconomical. As source rocks in most conventional oil and gas reservoirs, oil shale deposits are found in oil reservoirs around the world.

But most of them are too deep to be economically mined. There are about 600 known oil shale deposits in the world.

Many deposits require more exploration to determine their potential as reserves.

Well-explored deposits include the Green River deposit in the western United States, Queensland, Tertiary deposits in Australia, and deposits in Sweden and Estonia.

ElLajjun deposits in Jordan and deposits in France, Germany, Brazil, China and Russia.

Using Fisher analysis, these oil shales are expected to produce at least 40 liters (0.25 bbl.) of shale oil per metric ton of oil shale.

Although the information on many of the world's oil shale deposits is basic, the resource potential of oil shale is enormous.

At present, the total amount of oil shale oil resources in the world is conservatively estimated at 4.8 trillion barrels. This is almost four times the current 1.3 trillion barrels of crude oil resources.

However, the economically recoverable reserves of oil shale are much lower. Because there are many ways to assess oil shale resources in the world, the assessment of oil shale resources is particularly difficult.

The current evaluation focuses only on large oil shale deposits that are being exploited or that have the best potential for development due to their size and grade.

Major countries with significant known oil shale resources include the United States, Australia, Morocco, Jordan, Brazil, China, Russia and Estonia. Currently, oil shale deposits are in the world.

There are ongoing projects in China, Estonia, Morocco and Australia, and project evaluations are also under way in Israel, China and Jordan.

It has a core strategy to build a large, diversified surface-exploited shale project with three to five world-class deposits.

Global oil shale is planned to be developed in stages, from the initial test production of 1000~5000 barrels of shale oil per day to commercial production of 50000 barrels per day, as well as energy equivalent power generation.

In addition, the Global Oil Shale Development Sector works closely with local natural resource authorities and local environmental organizations.

to develop environmentally sustainable, long-term shale oil and other value-added products. Oil shale resources are distributed all over the world.

The world's largest deposit to date was discovered in the Green River Formation in the United States. The Green River Oil Shale deposits cover portions of Colorado, Utah and Wyoming.

The Green River Shale oil resource is estimated at 1.2 trillion barrels to 1.8 trillion barrels, although not all resources are recoverable.

But even the extraction of 800 billion barrels of shale oil from the oil shale of the Green River Formation is three times higher than Saudi Arabia's proven oil reserves.

U.S. demand for petroleum products is currently about 20 million barrels per day, if oil shale could meet a quarter of the demand.

Then the 800 billion barrels of recoverable shale oil extracted from the Green River Formation can be used continuously for more than 400 years.

More than 70% of the total area of the Green River Formation oil shale distribution, including the richest and thickest oil shale deposits, is federally owned and managed.

As a result, the federal government directly controls the most commercially attractive portion of the Green River Oil Shale resource.

Oil shale surface dry distillation technology

Surface distillation of oil shale refers to the extraction of oil shale to the surface and then heating it to a higher temperature.

Finally, a technology for separating and collecting oil and gas has a long development history and is basically mature, and many countries in the world have achieved technological breakthroughs.

Generally speaking, the surface dry distillation of oil shale mainly includes three stages: First, the beneficiation and mining of oil shale.

the second is to crack oil shale to produce oil and gas; The third is shale oil treatment to produce industrial raw materials and high-quality oil.

There are usually two methods of surface dry distillation: one is surface distillation of oil shale ore extracted through underground mining.

In this process, the oil shale ore is mined and sent to the ground for crushing, where it is put into a dry distillation furnace.

It is heated to produce combustible gases and liquid fuels, after which the oil shale semi-coke can be burned to generate electricity or transported to other treatment areas.

Second, the oil shale extracted by open-pit mining is used for surface distillation: in this process, the oil shale mine is mined, washed by open-pit miners, and then dry distilled.

At present, the main surface dry distillation technologies in the world include the following:

1. Petrobras' PetroSix gas burner (GCR) technology (PetroSix) used by Petrobras began in the 60s of the 20th century.

Oil extraction from shale. Some of the advantages of the PetroSix process are: simple design and high operating coefficient (approx. 94%).

High thermal efficiency and recovery efficiency with minimal environmental impact.

1. China's Fushun dry distillation furnace In China, Fushun dry distillation furnace is used in large quantities to achieve high production of shale oil.

The advantage of Fushun dry distillation furnace is that 20 dry distillation furnaces can be combined together and share a condenser system.

1. Estonia's Kivet and Galoter dry distillation furnaces are horizontal fluidized bed dry distillation furnaces with a processing capacity of 3,000 tons of oil shale per day.

Kiviter's dry distillation furnace treats massive shale with a gas-fired processor and vertical design.

The medium-sized plant has a production capacity of 1,000 tonnes of oil shale per day, one-third the size of a Galoter dry distillation furnace.

Compared to Kiviter dry distillation furnaces, the main features of Galoter dry distillation furnaces are higher thermal efficiency, higher yield, better shale gas quality and lower energy input.

1. Australia's ATP dry distillation technology has the advantages of large processing capacity, high daily output, high utilization rate of oil shale, high oil yield, thermal self-sufficiency and environmental protection. But the device is complicated and difficult to repair.

In situ conversion technology for oil shale

In recent years, there have been tremendous advances in in-situ extraction of economically viable, environmentally friendly oil shale.

1. Conduction heating technology diagram 1.10 Shell ICP process: Install a heating rod in a heating well to heat the kerogen.

High-quality oil and gas are obtained, which are then transported to the surface through production wells. Figure 1.11 ExxonMobilTM process.

First, the shale formation was fractured horizontally with horizontal wells. Then the conductive medium is heated in the crack to obtain oil gas

1. Figure 1.12 of the convection heating technology shows IEP's GPC process: a group of wells are separated, fractured and connected, and then the injection and production wells are constructed.

Hydrocarbon gas at 400-700°C is injected into the shale layer through a heat injection well, which heats kerogen, produces oil gas, and extracts it to the surface by water or cryogenic gas.

For the Chevron CRUSH process: fracturing shale formations, increasing the contact area between hot steam and kerogen, and then injecting hot steam into the cracks to obtain oil and gas.

Heating process for air probes: Compressed air and dry distillate gas are first passed into the burner and heated to a certain temperature.

After consuming part of the oxygen, the mixture is sent to the drying and heating oil shale to convert part of the organic matter into hydrocarbon gas.

+ Then the hydrocarbon gas is exported to the ground, and the extracted hydrocarbon gas is condensed to obtain light oil.

IGE process for MME: High-temperature steam is injected into shale formations for heating to obtain oil and gas that needs to be extracted, concentrated and recovered.

The non-condensable gas separated after heating to a certain temperature is injected into the formation and exchanged with the oil shale to achieve circulation.

For the TS process: hot air is injected around the well to form a local columnar microreaction unit, and the scope of the unit gradually expands as the kerogen continues to decompose.

1. Radiant heating technology figure 1.17 shows Raytheon's RF/CF process, a patented technology that combines RF heating and critical fluid displacement.
2. Oil shale is heated using radio frequency energy to oil shale using oil drilling methods.

Critical carbon dioxide drives oil to the well, where it is then pumped to the surface for condensation and storage.

The carbon dioxide is separated and pumped into wells for recycling. It is a radio frequency heating technology that uses vertical combination electrodes to slowly heat shale.

This technology takes a lot of time to heat the oil shale layer through heat conduction. To avoid this defect.

LLNL uses radio frequency to heat shale, which is highly penetrating and easier to control.

Current situation of oil shale development and utilization in China and Mongolia

China's oil shale has a long history of development, and many technologies have matured and accumulated a lot of experience, while Mongolia's oil shale started late.

There are few studies, so this paper hopes to study the experience of oil shale development and utilization in China, learn from it, and provide ideas for the development of oil shale in Mongolia.

1.2.1 Current status of oil shale resources and development in China

China's oil shale resources total 719.9 billion tons, distributed in 80 deposits in 47 oil shale basins.

That's equivalent to 47.6 billion tons of shale oil, the second largest in the world after the United States. As early as the 2020s, the oil shale industry was established in China.

Increased oil demand in China, while chronic production shortages prompted the oil shale industry to begin to grow, as of 2008.

There are several companies engaged in shale oil production or oil shale power generation, and after 2005, China became the world's largest oil shale oil producer.

At the end of 2006, the Fushun Oil Shale Oil Plant was the largest oil shale refinery in the world, consisting of 7 dry distillation units and a total of 140 Fushun dry distillation furnaces.

The annual production of shale oil is 180,000 tons, reaching 362,400 tons in 2020. In 2005, the China Oil Shale Association was established in Fushun.

China's major oil shale research institutions are Jilin University and Taiyuan University of Technology.

1.2.2.1 Oil shale resource reserves and distribution

China's commercially valuable oil shale reserves are mainly located in Fushun, Maoming, Huadian, Nong'an and Longkou.

The Fushun oil shale deposit, associated with coal mines, is located in northeastern China, south of Fushun, Liaoning, and the coal and oil shale is located in a small periphery of Mesozoic and Tertiary sedimentary and volcanic rocks.

It underlies Precambrian granitic gneiss. The thickness of oil shale formations varies from 48 meters to 190 meters, with an average of 80 meters.

The lacustrine oil shale is produced in the Jijuntun Formation, overlying the Gucheng Sub-Formation, containing coal, and the green argillaceous mudstone of the Xilutian Formation in the lower Fuxirutian Formation.

The Tertiary Maoming oil shale deposits are 50 km long, 10 km wide and 20 m to 25 m thick. The ore is yellow-brown in color and has a bulk weight of about 1.85g/cm3.

Oil shale contains 72.1% ash, 10.8% moisture, 1.2% sulfur, and calorific value 1745kcal/kg (dry basis). Not suitable for aboveground dry distillation.

However, it can be used for fluidized bed combustion to generate electricity. Professor Alan R. Carroll of the University of Wisconsin-Madison estimates.

The presence of lacustrine oil shale deposits in the Upper Permian in the Junger Basin of northwest China, not in previous global oil shale assessments, can be compared to the Green River Formation.