The survival and development of human beings are closely related to the development and utilization of natural resources such as rocks, soil, minerals, salt and water from the beginning. The division of Paleolithic Age, Neolithic Age (including clay-fired pottery), Bronze Age and Iron Age in human history is determined according to the level of human development and utilization of mineral products (the symbol of productivity development). In the process of exploitation and utilization of various mineral resources, exploration technology and engineering have gradually formed.
China is an ancient civilization with a long history and culture of more than 5,000 years, and the development of exploration technology has a long history. Written in BC 180, Guanzi Dishu clearly records: "Where there is a mountain, there is iron under it; There is lead on the top and silver on the bottom; There is cinnabar on the top and gold on the bottom; Those who have compassion stones on the top have copper and gold on the bottom, and those who see glory in this mountain are also. " It not only reveals the facts and laws of gold and mercury, iron, copper and gold, lead and silver, but also provides enlightenment for modern geochemical exploration and utilization of indicator minerals (indicator elements) for prospecting. In the Natural History written by Zhang Hua in the Western Jin Dynasty in China, there is a description that "absinthe has been accumulated for three years, and lead and tin have flowed down from combustion and body fluids, and there have been experiments", which is actually the original idea and method of modern biogeochemical prospecting (Zhu Xun's Geological Science and Geology and Minerals, 1997).
As for the drilling and excavation technology for finding groundwater and extracting salt, it developed earlier and achieved more brilliant results. As early as the Xia Dynasty in China, there was a saying that "Bo Yi made a well". By the Northern Song Dynasty, in order to extract brine from underground to make salt, the drilling depth of Zhuotong well in Suining, Sichuan Province had reached 3000 m, and a whole set of drilling engineering, technology and related technologies were exhibited, which were widely used in Zigong, Suining and Wutongqiao. This salt drilling technology is known as "the father of modern oil drilling" and "the fifth great invention in ancient China" (Sichuan Volume of China Mining, 1998).
During the Warring States Period, China used natural magnets to grind compasses, resulting in one of the four great inventions of ancient china. This is an early understanding and concrete application of rock magnetism and earth magnetic field. Later, Queen Elizabeth I's doctor (william Gilbert) made further research on the compass pointing to the north, and came to the conclusion that the earth itself is a huge irregular magnet. This conclusion inspired Newton to think about why the apples on the tree fell to the ground to some extent. He believed that there must be gravity between objects, and finally his famous theory of gravity (A.E.Mussett et al., 2000) came into being. The establishment of geomagnetic field and gravity field theory has laid the foundation for modern geophysical gravity and magnetic exploration. Zhang Heng, a famous scholar of the Eastern Han Dynasty in China, invented the seismograph Hou Feng in A.D. 132, which is an outstanding contribution of Chinese scholars to the understanding of earthquakes and earthquake disasters and the development of earthquake observation technology. Figure 0-4 is a schematic diagram of the shape and inertia principle of the seismograph, which makes the inverted pendulum swing in the direction of seismic wave propagation and makes the longkou spit out the ball in this direction.
0.3.2 Modern exploration technology
Modern exploration technology began to develop from the end of 19 to the beginning of the 20th century. 1888, Hungarian scholar baron Roland von e? Television? S invented the torsion balance; 1900 Europe draws structural maps with torsion scale. 1922 discovered gravity anomaly of salt dome structure in Dezhou, 1926 discovered oil in salt dome structure for the first time by geophysical torsion balance method.
Figure 0-4 Houfeng Seismograph and Schematic Diagram
The seismic exploration method is developed from the theoretical study of seismic waves, natural earthquakes and sound waves. In 1905, L.P.Garret suggested using seismic refraction wave method to find salt dome structure. 19 12 years, after the British Titanic collided with an underwater iceberg and sank in the Atlantic Ocean, R.A. Fessenden immediately began to study the detection of underwater icebergs, which led to the underwater acoustic wave detection method and obtained the US patent. The patent authorization number is 19 17, which is the first patent in the world to use seismic waves for exploration. The seismic exploration method with more practical application value was put forward by German scholar Mintrop. He invented the mechanical seismograph in 19 14. Based on this instrument, he applied for a German patent at 19 19, entitled "Method for determining rock structure". The patent was published in 1926, which claimed that mechanical waves could be generated by artificial explosion and received by seismic instruments. By analyzing the depth, travel time and distance of various seismic waves propagating underground, we can determine the thickness and density of the stratum, as well as the strike and dip angle of the stratum structure (R.E. Sharif, 1995), which involves almost all the important contents of modern seismic exploration.
1879, professor R. Salem published the book "magnetic prospecting for iron ore", and then successfully manufactured Salem-Tibberg magnetometer and Thomson-Salem magnetometer in Sweden, forming a practical method to determine the buried depth, strike and dip angle of underground magnetic dikes (W.M.Telford et al., 1990).
Electrical prospecting also has a long history of development. In 18 15, R. Fox discovered that some minerals have self-polarization characteristics, and predicted that this effect can be used to find some minerals. It takes about 65,438+000 years to manufacture the corresponding instruments. In 65,438+0,965,438+03, C. Schlumberger discovered sulfide deposits with this instrument, and later he invented resistivity method and equipotential line method with practical exploration value (M.B. Doblin, 65,438+0,976).
People not only study the physical properties and structure of crustal materials, but also attach great importance to their chemical composition, and have conducted long-term research on elements and their abundance. From 65438 to 0889, American scholar F.W. Clark published a famous paper "Relative Abundance of Chemical Elements", which initiated the study of modern geochemistry. At present, people usually refer to the abundance of elements in the crust as Clark value.
0.3.3 Modern exploration technology and its development trend
The formation and development of modern exploration techniques and methods began after the Second World War in the West and after the establishment of China 1949 People's Republic of China (PRC).
According to the progress of exploration technology and the change of application field, the development of modern exploration technology can be divided into two periods: the first period is the rapid development and maturity of exploration technology in the 1940s and 1980s, and the application field is centered on mineral exploration. The second period, from the 1980s to the present, is a period of constant change and expansion in the field of application.
In the first period with prospecting as the center, exploration techniques were mainly divided into oil and gas exploration techniques and solid mineral exploration techniques.
Typical oil and gas exploration technologies are seismic exploration and underground geophysics. Through their development, we can understand the development process and general situation of the whole oil and gas exploration technology. The development of seismic exploration has gone through the following three stages.
In the first stage (1940s-1950s), seismic instruments used electronic tube components, obtained seismic records with special photographic paper as the medium through optical photography, and manually sorted, processed and interpreted the data. Many large oil fields, including Daqing oil field in China, were discovered for the first time with this instrument and technical method. The main disadvantages of this kind of equipment are large size, poor maneuverability, inability to reprocess data, small recording dynamic range (20 dB, only 10 times the amplitude difference) and low data processing efficiency.
In the second stage (1950s-1970s), seismic instruments used transistor devices and took magnetic tape as the medium to obtain seismic records. This recording can be played back repeatedly, and can be processed by analog electronic computer or digital computer after analog-to-digital (A/D) conversion. The dynamic range of recording is increased by 1 order of magnitude (40 dB, which can identify signals with a phase difference of 100 times). With the appearance of magnetic tape instruments, the horizontal stacking technology of multiple coverage of reflected earthquakes has been applied and developed, and it is still in effective use today, greatly improving the ability and effect of seismic exploration.
The third stage (1970s-1980s) is characterized by digital tape recording, digital computer processing, multi-channel (above 1000 channels), high coverage observation and large dynamic range (above 100 dB, which can identify signals with a difference of more than 65438+ million times). This has promoted the rapid development of digital processing technology. Electronic computers used in seismic data processing in advanced countries in the world are no less than military and meteorological departments, even more so, in terms of operation speed, superior performance and large storage capacity.
In addition to seismic exploration, other oil and gas exploration techniques and methods have also developed rapidly. In gravity measurement, the heavy torsion scale is no longer used, and it is replaced by a high-precision and lightweight gravimeter. It can measure underwater, underground and airborne gravity. The accuracy of ground gravity measurement can reach microgravity level, and such high-precision measurement is also very useful in other aspects. For example, in the early 1970s, the Moon -4 gravimeter used in the Apollo-17 moon landing spacecraft and the high-precision gravimeter used in the exploration came from the same designer of the same company, and their accuracy was at the microgravity level. The purpose of the experiment is to take the moon as the reference mass and simultaneously measure the gravity of the earth and the moon to confirm Einstein's prediction about the existence of gravity waves. Unfortunately, because of some minor design errors, this experiment failed, and the accuracy and high resolution of the gravimeter are very certain.
During this period, oil and gas drilling technology also developed rapidly, and ultra-deep wells, deviated wells, horizontal wells and multi-directional drilling cluster wells in the same well location appeared, as well as seismic while drilling technology with bit as the source.
In the application of solid mineral exploration, exploration instruments, equipment and methods are developing towards portability, digitalization, high precision and high efficiency. In the 1950s and 1960s, more accurate aeronuclear magnetometers and optically pumped cesium rubidium vapor magnetometers appeared. Aeromagnetic survey is fast, efficient, convenient for large-scale survey, and easy to explore in areas that are difficult to access on the ground, such as deserts, mountains, polar regions and oceans, and plays an important role in iron ore exploration and basement description of oil-gas-bearing basins. During this period, remote sensing, aerial photography, satellite positioning, airborne electromagnetic method, airborne gamma, airborne gravity and other aerial exploration methods appeared, as well as various new methods, technologies and instruments such as radioactivity, geochemistry, electrical method and ground penetrating radar on the ground and underground, which improved the technical level of mineral exploration as a whole, comprehensively enhanced the exploration function and expanded the prospecting effect.
From 1980s to now, it is the second period of the development of modern exploration technology engineering, and the methods and technologies in this period also represent the development trend of exploration technology to a certain extent. Its remarkable feature is that with the continuous development of exploration technology, the field of activities has expanded from prospecting as the center to serving not only the exploration of resources and energy, but also the ecological environment, towns and large-scale engineering construction. The change of the active field is determined by the following factors.
First of all, people gradually realize the importance of environmental protection. While developing and utilizing nature and enjoying the modern material civilization created by high technology, human beings have brought serious damage to nature and ecological environment. Environmental problems have attracted the attention of all countries in the world, and new exploration technology engineering branches such as environmental geophysics and environmental geochemistry have gradually adjusted their positions and directions.
Second, the construction speed and scale of large-scale projects are constantly expanding, including the construction of roads, railways, subways, airports, mines, pipelines, dams, buildings, nuclear power plants and docks. The quality and safety of these facilities and their corresponding environmental protection have become an unprecedented concern. Therefore, engineering geophysics, an older discipline, has also received special attention, and a new discipline, environmental engineering geochemistry, began to appear in the 1990s.
Environmental engineering geochemistry is a science and technology to improve the environment through geochemical action. Its main task is to prevent pollution, improve the physical and chemical properties of rocks and soil, and improve water quality.
Thirdly, with the acceleration of urbanization and the increase of urban population, the market demand for urban geophysics, geographic information system (GIS), remote sensing (RS) and water resources exploration technology for groundwater is rapidly expanding.
The above new exploration technologies and methods from different application fields are still composed of those shown in the middle of Figure 0-2 and Figure 0-3, and the applicable scope of each method should still refer to Table 0- 1. This table is mainly determined according to the performance of technical methods. In practical application, we should also pay attention to the use of cost performance to choose the appropriate method, and high proportion is preferred. The economic cost of doing the same job in various ways is different.
Since 1980s, with the progress of information technology and the change of social demand, exploration technology has the following main development trends.
Make full use of information, network and computer to make exploration technology more modern in data acquisition, transmission, storage, processing, interpretation and display. Giant parallel computers, mass storage, high-speed transmission and communication of network data, various interpretation workstations and three-dimensional visual display will be widely used.
Exploration technology engineering will continuously improve the ability to solve complex problems according to the complexity of the research object. The earth is a complex and huge system. At present, it can only be described by an ideal and simple mathematical and physical model. According to this ideal model and the limited data observed by exploration technicians on the surface or above, it is inaccurate to invert or explain the interior of the earth. It can only partially solve some simple problems, and it will be an arduous and long-term task to show people a complex and real interior of the earth.
Strengthen the function of exploration technology and adjust the investment structure. Some new application fields of exploration technology are pointed out, and how to make substantial progress in these fields is another problem that people should pay attention to. The development of water resources is an urgent problem. The investment in groundwater exploration in the world (199 1 year) only accounts for 0.1%of the total investment in exploration (R.E. Sheriff, 1995). Changing the unreasonable investment structure like this can promote the development of technology in the corresponding direction.