Scientists believe that the formation of natural gas is mostly related to organisms, such as reef-type natural gas resources. In geological history, there are a large number of creatures living in the ocean, and they have the ability to secrete calcareous bones during their growth. Under the suitable conditions of water depth, temperature, light and seawater salinity, these creatures multiply from generation to generation and form solid reefs. Studies show that calcareous algae, sponges, corals, bryozoa, foraminifera, corals and so on. They are reef-building organisms in geological history, and reefs in modern oceans are formed by corals and algae. The reefs formed in the long geological history are huge in thickness. After their death, they were covered with sediments and buried deep in the stratum. Under the long-term geological action, they have gradually become the material basis for the formation of oil and natural gas. Through the study of geological history and reefs, scientists found that there are thousands of holes and voids in the skeleton remains of reefs, which contain ideal porosity and permeability, providing convenient conditions for the formation and storage of oil and natural gas. As early as 1980s, China discovered a batch of abundant bioherm natural gas fields in Hubei and Sichuan.
How is oil formed?
The raw material of petroleum is the corpse of living things, and the cells of living things contain fat and grease, which are composed of three elements: carbon, hydrogen and oxygen. When biological debris settles on the seabed or lake bottom and is covered with mud, oxygen is separated and carbon and hydrogen form hydrocarbons.
We have found more than 3000 kinds of hydrocarbons on the earth. Oil consists of about 350 kinds of hydrocarbons, and hydrocarbons lighter than oil become natural gas. The origin of coal mine is very similar to that of oil, but coal is a fossil of plants and solids.
Rocks that produce a lot of hydrocarbons are called "petroleum hydrocarbon source rocks". Buried oil source rocks are influenced by geothermal energy and pressure, and together with other chemical reactions, oil is produced, and oil accumulates among rocks to form oil fields.
The earth's crust changed and oil was produced.
Recently, we have come to understand that the changes in the earth's interior are closely related to the production of oil. Before describing this relationship, let's learn something about the situation on earth.
Radius of the earth is about 6,400 kilometers. Below the crust covering the earth's surface is a "slow earth" with a thickness of 2900 kilometers, and below it is a "core" with a depth of about 5 100 kilometers, which is divided into "outer core" and "inner core". The outer core is mainly composed of liquid metallic iron, while the inner core is mainly solid iron. The earth's surface is covered with hard "plates" with a thickness of about 100 km. These plates are produced by the "ocean ridges" that are sprayed upward, and then slowly move to the "trench" and then settle under another plate. At the end of 1980s, people learned to capture the three-dimensional map of seismic waves entering the earth's interior, so they found surprising slow ground movement. After rising from the ground, the huge upwelling "super plume" with high temperature exists directly under Hawaii and Africa in the form of mushrooms. In addition, the huge downward flow "cold plume" occupied the Asian continent and South America continent in the form of water droplets at low temperature, and the cold plume seemed to settle to the bottom of the mantle.
What we know now is that the tribal thermal convection in the mantle is formed in the form of cold plumes moving to super plumes. This movement not only affects the plate movement, but also seems to have a great influence on the geological and environmental changes of the whole earth.
Supercyclone produces oil?
At present, 60% of the rocks produced in the world are oil source rocks formed during the reign of dinosaurs, and the "black shale" formed is all over the world. Black shale is mainly composed of the remains of phytoplankton such as non-oxidized algae. It can be seen that at that time, there must be anoxic environmental conditions for phytoplankton to reproduce without oxidation, and a large number of black shale will be formed.
Recently, it seems that the formation of petroleum source rocks and the activation of super cyclone movement in this era can increase the volume of ocean ridges formed by mantle materials spewing out of the ground, and the sea surface will rise accordingly, so that the lower land will become shallow sea, and the shallow sea has an environment where phytoplankton, such as algae, which can be used as petroleum raw materials, can easily reproduce.
As a result, phytoplankton, such as algae, increased and died in a large number in the shallow sea area, and the surrounding bacteria consumed oxygen to decompose their fragments, so there was an anoxic environment.
Global warming will also change the flow of deep water. Because the temperature of high-latitude seawater is different from that of low-latitude seawater, deep seawater with low temperature but rich oxygen will flow to low-latitude seawater. But the phenomenon of global warming has decreased. As a result, the sea area with less oxygen content expands, and phytoplankton that cannot be oxidized gradually accumulates, leaving a lot of organic matter to form oil source rocks.
Biological evolution has changed the nature of oil.
Because the raw material of oil is biological remains, we can understand the biological evolution process and the history of the earth's environment in ancient times by investigating the nature of oil.
The evolution of life probably has the following process. Life was born 3.8 billion years ago and gradually evolved. In the Paleozoic Cambrian 550 million years ago, explosive evolution began, and about 445 million years ago, life also landed on land.
During the period from 440 million years ago to 400 million years ago, the main component of oil source rocks was hydrocarbon-tolerant hydrocarbons formed by lush phytoplankton at that time. On the other hand, during this period, pteridophytes flourished near the coast, so oil source rocks with terrestrial plants as raw materials also appeared.
290 million years ago, forests composed of gymnosperms appeared on the vast land, lakes surrounded by swamps were formed everywhere, and algae began to multiply in the lakes. This has also produced a new oil source rock with algae as raw material, which is also an example of the birth of new oil source rock caused by the prosperity of terrestrial plants.
90 million years ago, angiosperms and coniferous forests began to spread to high latitudes and highlands, so oil source rocks with terrestrial wood as raw materials appeared. On the other hand, the resin of trees becomes the raw material of light crude oil, forming new oil source rocks. With the increase of coniferous forests, wood has replaced algae and become the main raw material of petroleum source rocks.
Recently, the analysis technology of petroleum properties has made great progress, and we can gradually get information about Shituo? Idle disaster left? What about the dam fan? What's the plan? Phlegm magpie Nanhan cylinder persimmon thin S yarn crisp swollen persimmon Xia Zifu? Are you fooling around? Fairy? Hey, hey? Is it pure?
The global "Alpine orogeny" from about 654.38+0.7 billion years ago to 2 million years ago also produced huge oil fields. During this period, all the oil source rocks formed about 654.38 billion years ago were buried underground. About two-thirds of the existing oil and gas were formed during this period.
How is oil formed 2
Oil is an extremely important industrial energy source in the world today, which is called "the blood of industry" and is known as black gold. Oil, a dark brown viscous liquid, has penetrated into many fields of human life. So, how is oil formed?
After long-term research, it is proved that oil comes from ancient organic matter. In ancient geological times, after a large number of creatures, animals and plants died in ancient oceans or large lakes, their remains were buried under sediments and gradually decomposed and changed under anoxic conditions. With the rise and fall of the earth's crust, they are sent to the bottom of the sea, buried in sedimentary rocks, baked by high pressure and geothermal energy, and finally transformed into oil, a liquid hydrocarbon.
It is estimated that the world's total submarine oil reserves are 325 billion tons, accounting for one-third of the whole earth's oil reserves. Moreover, most of these oils are distributed in the offshore of China, the Middle East, the Persian Gulf, the Gulf of Mexico, the Gulf of Guinea in West Africa and the North Sea.
The chemical composition of oil and natural gas exposed their sources. It's all organic matter, it should be
When it is related to ancient creatures. Some scientists believe that oil and gas (oil and natural gas) are accompanied by deposition.
From the formation of rocks. In ancient times, prosperous creatures produced a lot of organic matter. Under the carrying of running water,
A large amount of organic matter is taken to low-lying lakes or basins. In these huge natural basins,
Organic matter is mixed with inorganic debris and deposited at the bottom of the basin. A quiet deep water body is an anoxic reduction ring.
In the environment, oxygen in organic matter is gradually lost, while carbon and hydrogen remain, forming new hydrocarbons, and
It forms petroleum source rocks with inorganic detritus.
In petroleum source rocks, oil and gas are dispersed, and there is no exploitable oil field at present. At this moment,
Under the action of gravity, the sediments at the bottom of the basin began to sink. Under the influence of underground pressure and high temperature,
Sediments are gradually compacted and eventually become sedimentary rocks. Liquid oil droplets refuse to turn into rocks and sink.
In the process of shrinking, they are squeezed out and gathered in one place. Because the density is lighter than water,
So oil began to migrate upward. With luck, the oil that passes through the cracks in the rock will eventually meet a layer.
Dense rocks, such as shale, mudstone, salt rock, etc. It was rejected because of the lack of cracks for oil to pass through.
Through the oil, the oil will stay under the dense rock formation and gradually enrich, forming an oil field. include
Rock layers containing oil are called reservoirs, and rocks that refuse to let oil pass through are called caprocks. If there is no cover,
Oil will rise back to the surface and eventually disappear into the dust of the earth's history until human beings appear. Content: The chemical composition of oil and natural gas exposes their sources. It's all organic matter, it should be
When it is related to ancient creatures. Some scientists believe that oil and gas (oil and natural gas) are accompanied by deposition.
From the formation of rocks. In ancient times, prosperous creatures produced a lot of organic matter. Under the carrying of running water,
A large amount of organic matter is taken to low-lying lakes or basins. In these huge natural basins,
Organic matter is mixed with inorganic debris and deposited at the bottom of the basin. A quiet deep water body is an anoxic reduction ring.
In the environment, oxygen in organic matter is gradually lost, while carbon and hydrogen remain, forming new hydrocarbons, and
It forms petroleum source rocks with inorganic detritus.
In petroleum source rocks, oil and gas are dispersed, and there is no exploitable oil field at present. At this moment,
Under the action of gravity, the sediments at the bottom of the basin began to sink. Under the influence of underground pressure and high temperature,
Sediments are gradually compacted and eventually become sedimentary rocks. Liquid oil droplets refuse to turn into rocks and sink.
In the process of shrinking, they are squeezed out and gathered in one place. Because the density is lighter than water,
So oil began to migrate upward. With luck, the oil that passes through the cracks in the rock will eventually meet a layer.
Dense rocks, such as shale, mudstone, salt rock, etc. It was rejected because of the lack of cracks for oil to pass through.
Through the oil, the oil will stay under the dense rock formation and gradually enrich, forming an oil field. include
Rock layers containing oil are called reservoirs, and rocks that refuse to let oil pass through are called caprocks. If there is no cover,
Oil will rise back to the surface and eventually disappear into the dust of the earth's history until human beings appear.
How is coal formed?
Coal is called black gold and industrial food. Since18th century, it has been one of the main energy sources used in the human world. Although its important position has been replaced by oil, it will inevitably decline in the future for a long time, and coal will become one of the irreplaceable energy sources in human production and life because of its huge reserves and rapid development of science and technology.
Coal is a very thick layer of black humus, which has been accumulated on the ground by the branches and roots of plants for millions of years. Due to the change of the earth's crust, it is buried underground for a long time and isolated from the air. After a series of complicated physical and chemical changes at high temperature and high pressure, black fossils are formed, which is the formation process of coal.
The thickness of coal seam in coal mine is related to the speed of crustal decline and the accumulation of plant residues in this area. The earth's crust is falling rapidly and the plant remains are piled thick, so the coal seam in this coal mine is thick. On the contrary, the earth's crust is slowly falling, and the plant remains are piled very thin, so the coal seam of this coal mine is very thin. Due to the tectonic movement of the earth's crust, the original horizontal coal seam was folded and fractured. Some coal seams are buried deep underground, while others are pushed out of the surface or even exposed to the ground, which is easy to be found. There are also some coal seams that are relatively thin and small in area and have no mining value. So far, there is no updated statement about the formation of coal.
Is coal formed in this way? Whether some expositions should be further studied and discussed. Large coal mines have thick coal seams and excellent coal quality, but the area is generally not very large. If it is formed by the natural growth of leaves and roots of plants for millions of years, its area should be very large. Because the earth was full of forests and grasslands in ancient times, there should be traces of coal storage everywhere underground; The coal seam is not necessarily very thick, because the leaves and roots of plants rot into humus, which will be absorbed by plants. If it is repeated, it will not be so concentrated when buried underground, and the boundary between soil layer and coal seam will not be so clear.
However, the undeniable fact and basis is that coal is indeed formed by the systematic evolution of plant residues, which is an unbreakable truth. As long as you look at the coal carefully, you can see the traces of leaves and roots of plants; If you slice coal and observe it under a microscope, you can find a very clear plant tissue structure. Sometimes things like tree trunks are still preserved in coal seams, and some coal seams are still wrapped with complete insect fossils. Why it is so concentrated and of such high quality is worth discussing.
I remember when I was in primary school, my family lived in a village not far from the city. Whenever the midsummer rainy season comes, after a rainstorm, there will be a rushing "stream" in the middle of the village, and many of our children will run into it to play. Due to the extension of heavy rain, this stream will become smaller and smaller and eventually dry up. But before the water is cut off, you will find that many water flows are blocked by floating objects such as wooden sticks and weeds, forming small water barriers. In order to make the water flow smoothly, we tear open those small water barriers from time to time, and sometimes build a "dam" on the stream. Even living in the city now, after a heavy rain, there will be all kinds of floating objects blocking the water flow and the sewer mouth in many places on the street, and many floating objects are concentrated in one place.
It can be inferred that the formation of coal may be directly related to the flood. Without such a powerful force and carrying function as flood, the formation of coal would never be so concentrated and of such high quality.
We can imagine that in the geological and historical period millions of years ago, because of the very suitable climatic conditions, lush and tall plants grew on the ground, and a large number of plants also grew in coastal and inland swamp areas. At that time, the rainfall was quite abundant. When natural disasters such as the once-in-a-century flood or tsunami come, grasslands and large forests will be flooded, and plants, large and small, there will be uprooted and floating on the water. The soil at the roots of plants will also be washed away. These trees and grass with roots and branches will also climb and entangle each other and go down the river. Once they are washed to shallows and bays, they will run aground, where they will settle down and screen out all the floating objects like a sieve. Soon, a barrier will be formed here, and this place will also be the accumulation place of plant remains (and many animal remains) in the next flood. When the flood recedes, a winding pile of plant debris will form here. After long-term geological changes, this pile of plant debris will gradually be buried underground and eventually evolve into today's coal mine.
Then some people may ask, why didn't this happen when China was hit by a rare flood in 1998? I think that's because the current forest coverage rate in China is very low. Most places with forests are at high altitudes, and the plains are full of grain fields, almost to the point where there is no forest to flood, but some farmland shelterbelts are flooded, and the trees in farmland shelterbelts are rare, and the roots of trees are well developed, so they can firmly grasp the land, and short-term soaking and impact will not cause much damage. The trees in the forest are different. Many trees live together. In order to absorb the energy of the sun, they grow up desperately, and their roots are underdeveloped. Once a tree is uprooted by the flood, it will be destroyed by the flood, just like putting a raft down the river, unstoppable, and finally all piled up in one place.
In addition, due to the enhancement of human understanding of nature, the ability to resist sudden natural disasters has been continuously improved. Building water conservancy projects, building strong dams and strengthening river embankments have greatly slowed down the impact of fierce floods, and the phenomenon of flooding has become less, even obediently obeying the call of human beings, turning fierce floods into electric energy, kinetic energy and heat energy, benefiting mankind and serving human society.
Not only floods have the ability to carry animals and plants, but tides, typhoons and tsunamis also have this ability. Tsunamis caused by earthquakes, volcanic eruptions and other factors can make the waves rise by more than 30 to 40 meters, and instantly wipe out the animals and plants on an island; Plunder all living things near the coastline.
Moreover, the material on the surface cannot wait for the earth to sink forever, and the material on the surface is constantly circulating. Therefore, whether the "flood theory" makes coal so concentrated and high-quality still makes sense, which is convincing and can be convincing.
The material on the earth's surface can't wait for the earth to sink forever. The material on the earth's surface is constantly circulating. Therefore, whether the "flood theory" makes coal so concentrated and high-quality still makes sense, which is convincing and can be convincing.
It is an irrefutable fact that coal is indeed formed by the systematic evolution of plant residues. As long as you look at the coal carefully, you can see the traces of leaves and roots of plants. If you slice coal and observe it under a microscope, you can find a very clear plant tissue structure. Sometimes things like tree trunks are still preserved in coal seams, and some coal seams are still wrapped with complete insect fossils. Why it is so concentrated and of such high quality is worth discussing.
Due to the deposition of a large number of ancient plants, they were buried deep underground, subjected to high pressure and high temperature, and turned into coal after hundreds of millions of years.
Coal mines, like other mines, are layered, not everywhere. If it is accumulated by surface plants, it will not be so concentrated, and it should be everywhere, so I think what the book says is wrong. Carbon exists in the earth. Most of the carbon on the surface exists in the form of compounds, while the carbon in the center of the earth exists in the form of simple substances. When the carbon in the center of the earth is sprayed to the surface, it is partly diamond, partly graphite and mostly coal (different substances are formed under different conditions), which is the same as the origin of most other mines.
Plants are pressed underground and will form coal under the condition of long-term hypoxia and high pressure.
In Carboniferous, the plants on the earth flourished, which provided a strong material basis for the formation of coal, and the subsequent orogeny provided external conditions for the formation of coal. Many years later, there was coal.