Because the prospecting object is usually buried deep underground, it is not only difficult to observe its appearance but also often impossible to find its existence only by human sensory organs, which requires the help of scientific theories, technical methods and various prospecting equipment and instruments to explore the minerals we are looking for. In order to reduce the risk and improve the success rate of prospecting, we need the guidance of scientific theory and the help of advanced technical methods. Especially in the current situation, on the one hand, the demand for resources of all mankind is increasing, and China's socialist modernization is also increasing; On the other hand, with the improvement of geological work, it is more and more difficult and the cost of prospecting is higher and higher. For example, during the Sixth Five-Year Plan period, there were 1 586 newly discovered mineral areas in China, while during the Seventh Five-Year Plan period, there were only 1 newly discovered mineral areas, a decrease of 9%. In 1950s and 1960s, the depth of oil drilling was generally1000 ~ 2000m, but now it is 3000m ~ 5000m. In 1970s, the drilling cost of solid minerals was generally 53 yuan per meter, and now it is 280 yuan. In order to improve the effect and economic benefit of mineral exploration, it is more necessary to rely on scientific and technological progress and give full play to the role of science and technology as the primary productive force in mineral exploration.
The importance of science and technology to ore prospecting is not only fully based on theory, but also confirmed in mineral exploration practice.
Taking geochemical exploration as an example, not only a set of scientific working procedures has been formed: regional scanning → anomaly inspection → anomaly detailed investigation → prospecting engineering verification, but also a set of effective methods have been formed in sampling, analysis, data processing, interpretation and inference. Geochemical exploration technology itself has also made great progress. For example, regional geochemical exploration methods and techniques in special landscape areas, rapid analysis techniques of some trace and ultra-trace elements, computer mapping and processing techniques of regional geochemical data, etc. Due to the improvement and progress of geochemical exploration methods, the development of prospecting work has been effectively promoted. During the period from1979 to1990, 3.57 million square kilometers of second-generation regional geochemical exploration were completed in China, and 440,000 square kilometers of1:200,000 regional geochemical exploration were completed. Nearly 3.6 million samples have been collected. Due to the progress of testing and analysis technology, 39 elements can be quantitatively analyzed in each sample, thus obtaining a lot of prospecting information and finding more than 24,000 geochemical anomalies. After three-level anomaly verification, further general survey and detailed investigation, * * * found 676 producing areas of various minerals, of which *** 158 was confirmed as industrial deposits. The progress of analysis and testing technology is not only manifested in the quantitative analysis of 39 elements in trace geochemical samples, but also the accuracy of element analysis is greatly improved. In the past, the accuracy of gold analysis could only reach the level of ppm (10-6), but now it has reached the level of ppb (10-9), which can clearly reflect the weak mineralization of gold and silver and greatly improve the ability of gold and silver discovery. Therefore, of the 676 occurrences and deposits discovered by geochemical anomalies in 12, 459 are gold occurrences and deposits, accounting for 68% (Table 26). A series of large-scale gold deposits have been discovered in western Henan, Shandong Jiaodong, Xinjiang, Yunnan, Guangxi and Guizhou by geochemical exploration. The geological survey team of Liaoning Province discovered Paishanlou large gold deposit in Fuxin through1∶ 200,000 and1∶ 50,000 geochemical exploration, using the field rapid analysis of gold and combining with geological observation, and realized the "four-year" rapid evaluation. That is, when anomalies were discovered, mines were verified, general surveys were conducted, and detailed investigation basis was submitted.
Table 26 1979 ~ 1990 Mineral deposits and mineral distribution of mineral deposits identified according to1∶ 200,000 regional geochemical anomalies.
(According to Sun Huanzhen, Zhou Qinglai 199 1)
In drilling technology, in recent years, great progress has been made in drilling equipment, drilling technology, bit, mud flushing fluid and so on. With the wide application of small-caliber diamond drilling technology, wireline coring technology, various high-quality drill bits and high-quality mud technology in solid mineral exploration, the drilling efficiency has been greatly improved and the labor intensity has been reduced. Before the popularization of small diameter diamond drilling technology, the monthly efficiency of drilling platform was 273 meters, and after the popularization, it was 399 meters. The Fujian Provincial Bureau of Geology and Mineral Resources popularized the diamond hydraulic percussion rotary drilling in Zijinshan mining area of Shanghang, and the platform efficiency increased by 33% ~ 135%, and the core recovery rate reached 93.7% ~ 100%. Xinjiang Bureau of Geology and Mineral Resources used diamond rope coring drilling in Huangshan copper-nickel mine area, with an average depth of 928.6 meters, 30 boreholes, the deepest hole 1506 meters, an average platform efficiency of 664 meters, and a high-quality hole-forming rate of 93.3%, which ensured the quality and shortened the construction period. In recent years, the success of controlled directional drilling technology test has made it possible to drill multiple wells (that is, to drill several inclined wells in different directions in the deep part of a well site), which has greatly improved drilling efficiency and economic benefits. In Dongguashan Copper Mine, Anhui Province, controlled directional branching technology was used to drill, and 1 main hole and four branch holes were completed, with a depth of more than 840 meters, which saved the workload of 4090 meters, the monthly cost was 30%, and the quality met the requirements. Jilin Provincial Bureau of Geology and Mineral Resources adopted air reverse circulation center sampling (CSR) drilling technology, which changed the situation that the heart rate of placer gold mine was not up to standard for many years, and completed the exploration task quickly and with high quality.
Using advanced geophysical methods, especially aerial geophysical exploration and aerial remote sensing technology, we can quickly display geological structures in a large range and obtain a lot of prospecting information. Since the founding of New China, more than 30,000 aeromagnetic anomalies have been discovered, including more than 450 mineral anomalies. After ground verification, a number of important mineral deposits have been discovered. During the "Seventh Five-Year Plan" period, the second generation airborne geophysical methods and techniques, spectrum induced polarization techniques, digital logging techniques and borehole geophysical techniques have all made new progress and played an important role in prospecting. In petroleum geophysical exploration, digital seismograph has been widely used and played an important role in improving the level and effect of oil and gas exploration. Many achievements have been made in searching for metals and nonmetals by geophysical methods. Geothermal geophysical prospecting has achieved remarkable results in geothermal exploration of high-temperature geothermal fields in the neotectonic active area of Yunnan and Tibet, moderate-temperature geothermal fields in Mesozoic magmatic areas along the southeast coast, and low-temperature geothermal fields in Beijing-Tianjin buried hill. Aerial remote sensing technology has been widely used in ore prospecting in recent years, which has played a very good role in quickly identifying geological bodies related to mineralization in a large range and looking for prospecting clues.
Computer technology has been widely used in mineral exploration, playing an increasingly important role in mineral information collection, data interpretation, processing and storage, data sorting and mapping, and greatly improving the prospecting effect and economic benefits of exploration work.
In the aspect of pit exploration, due to the successful popularization and application of "NATM" technology and some innovations, some tunnel excavation problems in complex strata that were difficult to construct in the past have been solved. For example, the exploration of Yangshikeng mercury mine in Sichuan needs to cross the Chen Shan Ya fault zone, but the old method failed several times, and later this new technology was adopted for one pass. This technology has achieved good results in Laowangzhai Gold Mine in Yunnan, Shanggong Gold Mine in Henan and Shuangwangjin Gold Mine in Shaanxi. It not only ensures safety, but also saves time and investment.
The progress of experimental analysis and testing technology has strongly promoted the geological prospecting work. 10 years ago, a trace element analysis system for rock and mineral samples and a major, minor and trace analysis system for some minerals suitable for China's national conditions were established, which met the needs of geochemical work widely carried out during the Sixth Five-Year Plan and the Seventh Five-Year Plan, and then a number of new standard samples and standard analysis methods for rock and mineral were developed, reaching the international level. It has played an important role in geological prospecting. Among them, the geological prospecting units and laboratories affiliated to the Henan Provincial Department of Geology and Mineral Resources took the lead in making breakthroughs in the analysis technology of trace and ultra-trace gold. They used chemical-spectrometry to detect trace gold in rocks, and 0. 1n gram (that is, one billion) of gold can be detected in 10g samples, which reached the international advanced level and provided an effective method for rapid gold discovery in China. In recent years, the discovery of many gold deposits is closely related to the breakthrough of gold analysis technology.
In geological surveying and mapping, geological mapping and geological report printing, relying on scientific and technological progress, not only the speed is greatly accelerated, but also the quality is significantly improved. If the dot film subtractive method is used to print multi-color geological maps, the number of colors used will be reduced from 20 to 30 to 4 to 6, which will also ensure the color separation effect of geological maps, improve the printing efficiency 1/3, reduce the cost by 20% and achieve remarkable results.
Relying on scientific and technological progress, China's mineral exploration has achieved fruitful results, especially in oil and gas. For example, since 10, the department of geology and mineral resources has carried out the second round of oil and gas exploration with "four innovations" (new fields, new types, new fields and new depths) as the main content, which has not only made new major breakthroughs and progress in two key exploration areas in the northern Tarim Basin and the East China Sea, but also made major breakthroughs in shallow gas exploration in the southern Songliao Basin. A number of important exploration bases have been opened up and a number of significant oil and gas geological achievements have been made. The geological exploration team of the petroleum industry department has also made a series of major breakthroughs in several aspects. The remarkable achievements made by the geological and mineral departments and the petroleum industry departments in oil and gas exploration also depend on the achievements of scientific and technological progress. As summarized by the vast number of petroleum geologists, they relied on the "four innovations" of science and technology (new theory, new technology, new method and new technology) and persisted in exploring the "four innovations" of the second round of oil and gas exploration, and the exploration work has made new progress and success.
During the Seventh Five-Year Plan period, the progress and perfection of oil and gas exploration techniques and methods played an extremely important role in obtaining various oil and gas geological achievements. For example, in geophysical exploration, methods and techniques of trap exploration, three-dimensional techniques and data processing under complex terrain and geological conditions, and methods and techniques of man-machine interactive interpretation and seismic data in oil and gas field reserve calculation and rapid evaluation; Logging technology aiming at reservoir characteristics in different areas; Research and application of new techniques and methods of multi-parameter oil and gas geochemical exploration: In drilling, a set of drilling techniques for deep exploration wells, including high-pressure jet drilling, balanced pressure drilling and optimized parameter drilling, sidetracking and directional drilling around accident intervals, and low-density cement slurry cementing technology for deep wells have been tried out. Deep well testing technology and unstable testing technology in oil and gas testing; During the construction of Pinghu No.4 well in the East China Sea, the wellhead was successfully retrieved on the seabed entirely by our own strength, and this technical difficulty of offshore drilling was mastered. The progress of these technical methods has effectively promoted the improvement of production efficiency and produced good economic benefits. According to statistics, the average success rate of exploration wells (the proportion of discovered wells to the total number of exploration wells) increased from 13.8% in the Sixth Five-Year Plan to 15. 17% in the Seventh Five-Year Plan, with the highest success rate in the East China Sea, with 50% in the whole basin and 63% in Xihu sag. The average controlled reserve of exploration wells1170,000 tons/well is the highest in the East China Sea, which is 3.55 million tons/well according to the approved number 1990, and the gas storage is 4.9 billion cubic meters/well (7.5 billion cubic meters/well in the Pearl River estuary and 450,000 tons/well in the sea area). During the "Seventh Five-Year Plan" period, 3 15 local structures were discovered by seismic exploration and other methods, with a total area of 9,264 square kilometers, of which 72 were drilled, and 22 industrial oil and gas streams were obtained, and the success rate of trap drilling was 30%. There are 50 structures showing oil and gas, accounting for 69% of the proven structures.
During the Seventh Five-Year Plan period, the department of geology and mineral resources also carried out bilateral technical cooperation with foreign counterparts in some aspects. For example, natural gas exploration in deep ultra-high pressure zone in western Sichuan failed to achieve high and stable production in 10, and the main problem was deep drilling technology. During the Seventh Five-Year Plan period, by introducing equipment and technical experts and combining with our own strength, the high and stable oil and gas production of He Chuan 100 well was finally realized, which opened up a new situation. There are also Sino-Japanese Ordos oil and gas exploration projects, Sino-German Guangning Tantalum and Niobium exploration projects, Sino-US cooperation projects on gold-bearing anomalies in arid areas, Sino-Canadian gold mines, Sino-British diamonds, Sino-Dutch Yellow River Delta, Sino-Japanese Xinjiang groundwater and other cooperative research projects, all of which have achieved important geological prospecting results.
In short, for decades, especially since the reform and opening up of 12, due to the emphasis on relying on scientific and technological progress, advanced prospecting theories, advanced prospecting techniques and methods and advanced prospecting tools have been adopted for prospecting, giving full play to the role of science and technology as the primary productive force, and the prospecting work has achieved fruitful results. According to statistics, the number of minerals with proven reserves has increased from 144 in the Sixth Five-Year Plan to 149, with 20 new proven reserves, equivalent to the sum of proven reserves in the previous 35 years.