Review of the development history of nuclear geophysical exploration in our institute

Li came to his office 1957. He used to be the temporary head of the nuclear technology room of our institute. 1985 Aviation Geophysical Exploration Corps of the Ministry of Geology and Mineral Resources.

Zhang Yujun came here in 1957. He used to be the head of the nuclear technology room of our institute. 1983 Aviation Geophysical Exploration Corps of the Ministry of Geology and Minerals, currently the director of the research institute of the team.

The application research of nuclear geophysical exploration in our institute began at 1956, when it was still the laboratory of Geophysical Exploration Bureau. In the past 30 years, the work focused on the research of nuclear logging method and nuclear analysis technology of ground samples, and the corresponding instruments were developed. Many comrades devote themselves to this cause with enthusiasm and spare no effort. Natural gamma and neutron gamma logging in oil field, natural gamma and gamma gamma logging in coal field and natural gamma spectrum logging in potassium salt have played a very good role in production, withstood the test of history and created remarkable economic and social benefits. In the next few years, modern instruments and equipment were introduced and a special nuclear technology laboratory was established. The quantity and accuracy of elements determined by neutron activation multi-element analysis of geochemical exploration standard samples have reached the advanced level of similar work abroad. ..... All these achievements are condensed with the painstaking efforts and wisdom of many comrades.

However, looking at the course of these 30 years, the steps are difficult and the road is tortuous, which is influenced by both subjective factors and objective conditions. The waves of political life in the past 30 years have directly affected the progress of scientific research. At the stage when the overall situation is stable, scientific research is guaranteed and personnel are relatively stable, the progress of scientific research projects will be smoother, and only on this premise can individual efforts be exerted.

1956 Encouraged by the call of the CPC Central Committee to March into science and technology, the laboratory of Geophysical Exploration Bureau took the first step of nuclear geophysical exploration. On August 20th, 1956, Xinhua News Agency broadcasted a telegram from Yumen, "China Explores Oil with Atomic Energy for the First Time", which was published in some newspapers. Under the eye-catching title, the natural gamma and neutron gamma logging experiments carried out by Geophysical Exploration Bureau and Yumen Oil Mine are reported.

China used atomic energy to detect oil for the first time.

(Xinhua News Agency, Yumen, 20th) Yumen Oil Mine began to test the latest achievement of oil exploration technology-atomic radioactivity logging in laojunmiao Oilfield. This is the first time that China has used atomic energy to detect oil.

Recently, the radioactive logging test in downhole casing has achieved good results, and the geological conditions of underground sandstone and clay have been obviously analyzed. At present, radioactive logging tests are conducted by gamma logging and neutron logging. This is to put a set of special downhole instruments into the well, and use the natural radioactivity of rocks or the reaction to artificial radioactive elements to detect underground geology and oil-bearing water layers. Compared with ordinary electrical logging, it has great advantages: it can be measured in wells passing through casing; When the mud resistivity is very low, the change of underground strata can be accurately measured; It can solve the problem of oil-water interface in oilfield exploitation. These problems cannot be completely solved by the past technology. Before liberation, due to the low technical level, many old wells in laojunmiao Oilfield were not clear about the depth and quality of the reservoir. Now it can be solved by radioactive logging.

The radioactive logging test will be carried out for three months. This test was jointly conducted by the radioactive logging test team of Geophysical Exploration Bureau of the Ministry of Geology and the logging brigade of Geophysical Exploration Department of Yumen Mining Bureau.

(1956.8.2 1. news daily)

At that time, the nuclear reactor in China was under construction, and the first application of atomic energy in geological exploration also attracted the attention of all parties. The Central News Documentary Studio also filmed a documentary at the experimental site. The experiment was organized by the laboratory of Geophysical Exploration Bureau, with Lan Benjie as the team leader and Russian expert Muchev as the specific guidance. Comrade Li also had the honor to participate in this historic experiment. After the experiment, a training course on radioactive logging technology was held, which was taught by Professor Mucheyer and trained the first batch of oilfield radioactive logging talents for China. Neutron gamma logging will play an important role in petroleum logging in the next 30 years.

Following the oilfield test, the gamma-gamma logging method and natural gamma logging method were tested in 1957 coalfield. The experimental team was led by Lan Benjie from Suixi, Anhui Province, and Zhang Yujun from Fengfeng, Hebei Province. From 1958, Zhu Chengren from the Institute of Geology of the Coal Research Institute fully cooperated. The average age of this experimental team is only 22 years old, but it fully demonstrates the ability of young people to forge ahead and overcome technical difficulties. 195810 ~1,the Geophysical Exploration Bureau held a national coal field radioactive logging training course in Fengfeng Coal Mine, and trained 133 radioactive logging personnel for the Ministry of Geology and the Ministry of Coal. At the end of the same year, the repair institute of Geophysical Exploration Bureau also successfully copied portable radioactive logging tools and manufactured a number of instruments. In addition, reactors in China have started to produce cobalt -60 radioactive sources. Professionals, special instruments and radioactive sources are three indispensable conditions for the rapid popularization of coalfield radioactive logging. With these three conditions, by 1959, more than 50% of the national coalfield logging teams have popularized the gamma-gamma logging method. In the future, gamma-gamma logging method was quickly used as the dominant method by coalfield logging team without exception, and the economic benefits created in the past 30 years could not be estimated. Therefore, in the National Science Conference of 1978, the coal field γ -γ logging method was recommended as an award-winning project by the Ministry of Coal.

The research of radioactive logging in oil and gas fields is carried out on the basis of introducing advanced technology from the Soviet Union. The combination of learning from foreign countries and training our own professional team, as well as importing equipment and imitation, bought us time, quickly filled the gap in radioactive logging in China's oil and coal fields, and formed the basic technical force of method research, instrument manufacturing and production.

196 1, there are only two people left in the nuclear team. In addition, the Soviet Union stopped exporting neutron sources to China, so many tasks were interrupted and nuclear geophysical exploration was on the verge of cancellation. In order to find a way out, after investigation, people know that there is an urgent shortage of potash deposits in China. According to the radioactive characteristics of K-40 isotope and through theoretical calculation, Zhang Yujun put forward the idea of using energy spectrum to determine the natural weak radioactivity of K-40 in borehole (see the research report of Nuclear Group 1963). It is reported abroad that potassium spectrum logging did not appear until five years later (1968). Therefore, the proposal of this idea marks that the nuclear geophysical exploration work in our institute has entered the "innovation" period from the "imitation" stage.

1965, we obtained the conditions for developing 205 single-channel electron tube energy spectrum logging tool in cooperation with Shanghai Geological Instrument Factory. The ground analyzer is based on the design of Wu Zhenyuan in 1958.

After the end of 1965, we went to Mengyejing sylvite mining area in Yunnan for method experiment and instrument test. Five wells have been measured, and the interpretation of measurement technology and method has been solved. It can identify the potassium salt layer with a thickness of 0.5m and a potassium chloride content of more than 2% (the mining grade is 6%), and find the missing 1 1 horizon in production, in which 10 horizon has been confirmed by geological verification. Just as the research work needs to be further deepened, the turbulent "Cultural Revolution" that began in 10 seriously interfered with this work. Although comrades tried several times to continue experiments in the field on the charge of "grasping production and suppressing revolution", they were all hindered by serious wars and had to be interrupted.

It was not until 1972, the so-called right-wing reversal period, that scientific research took a little turn for the better. The Academy of Geological Sciences and Jianghan Oilfield organized a campaign to find potassium. As a subsidiary of the Academy of Geological Sciences, we undertook the task of searching for potassium by logging together with the oilfield logging battalion. After half a year's efforts, the key technologies of 3000m pulse transmission and 100℃ high temperature of downhole tools have been solved. Finally, in the favorable area of potassium formation pointed out by the comprehensive analysis of geology and logging, the anomaly of potassium salt layer was detected, and it was confirmed by coring in the same layer of adjacent boreholes that this layer was a 0.8-meter-thick potassium nitrate layer containing 16.8% potassium chloride. This is the discovery of a potash layer in an unknown mining area, and energy spectrum logging has played an effective role, which also shows the necessity of potassium exploration for oil and salt. Therefore, Jianghan Oilfield used this instrument to conduct a productive survey of potassium. The Ministry of Petroleum held 1975 technical promotion meeting in Jianghan Oilfield, and awarded 1986 the third prize of scientific and technological progress in this campaign.

After that, in order to improve the performance of the instrument, we continued to develop the following three types of instruments; The NC-75 dual-channel energy spectrum logging tool for integrated circuits has developed from 1974 to 1975. 1976, in order to meet the urgent need of potassium prospecting in Sichuan, Yunnan, Shandong, Xinjiang and other provinces, NC-76 dual-channel energy spectrum logging tool was developed. 1978 ~ 1979 JHW- 1 small diameter deep well four-channel energy spectrum logging tool developed in cooperation with Chongqing geological instrument factory was listed as a national key scientific research project, and was put into production by Chongqing factory after passing the appraisal. The main technical breakthroughs in instrument development are: pulse transmission of 3600-meter-long cable, downhole instrument that can withstand high temperature of 100℃ and energy spectrum peak position stabilizer. The developed instrument has developed from electron tube to integrated circuit, from single channel to four channels, and its performance has been continuously improved. The resolution (CS- 137) has been improved from about 15% to 10%, and its sensitivity has been more than doubled. JHW- 1 Instruments were included in 1983 National Atomic Energy Application Technology Exhibition.

In order to popularize this method in our department, I went to Sichuan, Yunnan and Xinjiang several times to carry out experiments with the production team. When expanding the trial production of NC-76 instrument, I invited the technicians of production teams to participate, so these production teams mastered the methods, technologies and instruments well and played a certain role in production. For example, the energy spectrum logging used by Sichuan 7 10 team can effectively identify the marker layers of the stratigraphic boundary between Lower Triassic and Middle Triassic in Sichuan Basin-potassium-bearing polyhalite and mung bean rock (tuff). Another example is the energy spectrum logging of Well Chuan 25 1979 and 1983. Regression analysis excluded the interference of uranium and thorium, and revealed the potassium-rich brine and its existing position. This paper tries to estimate the relative potassium content between brine layers, which explains why the natural gamma logging intensity in active brine layers increases in 1983 due to uranium enrichment over time, in order to find out whether there is solid phase.

In a word, the method and technology of finding potassium by natural gamma-ray spectrometry logging are our own creation, and the instrument is our own design. Practice has proved that finding potassium is effective.

In addition to searching for potassium by energy spectrum logging, Li Shoutian and other comrades also developed a ground single-channel energy spectrometer together with Chongqing Geological Instrument Factory, which was tested in Qinghai Salt Lake and can effectively indicate the deposited potassium ore bodies.

The catastrophe of 10 killed the development of science and technology. At that time, science and technology of the world's industrial powers advanced by leaps and bounds. At the end of 1970s, large-scale integrated circuits, computer technology and new detector elements were adopted in nuclear technology, and great progress was made, and intelligent multichannel spectrometers for field ground, oil wells, aviation and laboratories appeared. New breakthroughs have been made in the application of geological exploration.

Faced with this situation abroad, it is imperative to introduce foreign advanced technology, train a group of technicians, establish professional laboratories and raise the application of nuclear technology to a new level. After two years of premise experiments and sufficient technical demonstration, the latest product-Jupiter multichannel spectrometer was introduced from the United States at the end of 1979. Before Langfang Laboratory was completed, it was installed in the Institute of Low Energy of Beijing Normal University and used by two companies.

The technical route of introducing this set of equipment is: "one machine can be used for two purposes"; "Start near, focus far away" and "give consideration to scientific research and production". "One machine can be used for two purposes" means that the system can measure both gamma rays (which can be used for neutron activation and natural radioactivity measurement) and X rays (which can be used for isotope source excitation energy dispersion X-ray fluorescence measurement). "Hands near, eyes far away" refers to the newly developed neutron activation and X-ray fluorescence analysis of ground samples, as well as other methods and instruments prepared for the application of nuclear technology. "Taking both scientific research and production into consideration" means that this large-scale equipment is the basic tool for the application and research of nuclear technology. It maintains its long-term operation with productive work and gives full play to its role, making the scientific research foundation more solid.

We have conducted neutron activation logging of copper deposits in 1960 ~ 1962, neutron activation sample experiments in 1967 and fast neutron activation sample experiments in 197 1 and 65438+. Neutron activation analysis of stacked ground samples has the advantages of multi-elements, high sensitivity and high accuracy, and has broad application prospects in geoscience, which can quickly establish itself in cattle production. Although the sensitivity of X-ray fluorescence analysis excited by isotope source is not high, it has the characteristics of rapid analysis and can complement neutron activation analysis. This method can also be developed to on-site elemental determination. Because of its wide energy range, high resolution and practical spectral analysis software, the equipment is also a basic tool for developing nuclear technology methods and instruments.

By the end of 1984, a number of scientific research achievements had been made. The geochemical standard sample GSD 1-8 has submitted 32 element content data and granularity analysis data. The analytical sensitivity of gold reaches 0.05ppb, and 12 element can be detected by neutron activation analysis of preconcentrated rare earth elements, and some production samples are analyzed. X-ray fluorescence analysis excited by isotope source is preliminarily tested. A group of young technicians grew up, and Song Linshan was also selected to study in Britain. Scientific research results are published in professional magazines at home and abroad. 1985 Geophysical Exploration Bureau organized the appraisal of equipment digestion, absorption and development achievements.

Because radioactive work involves personal safety and environmental pollution, it is very important to establish a professional nuclear technology laboratory. In the past, there were no professional laboratories, and some experiments had to be carried out in basements, core warehouses and remote places, which not only affected the progress of experiments, but also affected the application of scientific research results. For example, after obtaining the research results of boron determination by neutron absorption approach and beryllium determination by photoinduced neutron analysis, one of the important reasons why we can't undertake production is that there is no professional laboratory. Therefore, in the process of designing and constructing Langfang Nuclear Technology Laboratory, we specially dispatched technicians to work.

1August, 985, according to the decision of the leaders, the installation task of moving Jupiter system to Langfang was completed.

The 30-year history of nuclear technology application research in our hospital was written by dozens of comrades. Due to the limitation of time and space, it's a pity that I'm in a hurry to write, and I can't always do my best. In particular, I didn't show the comrades' spirit of being diligent and eager to learn and forgetting their roots. Even if this article is a reflection on the rugged road, it is also a nostalgia for many comrades who were in the same boat in the past.

In the history of scientific development, 30 years is only a brief glimpse. The past is the past. We sincerely hope that our leaders will pay enough attention to the application of nuclear technology and make timely decisions on the basis of summing up historical experience. Radioactive geophysical exploration is an indispensable branch of geophysical exploration, and we hope it can produce more fruitful results in geophysical exploration.

(Beijing, June 1987)

Special issue of the 30th anniversary celebration of Geophysical Exploration Institute, 1987.