Geological exploration: stages and stages

Geology as a science has passed a long and thorny path, constantly developing on the basis of many years of experience of bold and persistent practitioners. Since ancient times, they have begun the craft of mining minerals from the earth's interior, gradually exploring new resources and discovering methods for their development. Geologists-contemporaries went far ahead in terms of knowledge and technology. However, with all the current progress, this work still requires considerable mental, physical and financial costs.

A comprehensive work package for strategic purposes

Searches, detection and complex technical preparation for the further development of mineral deposits are the most comprehensive description of the entire complex of geological exploration work, the complex and multifaceted structure of which makes this sphere rather closed to those who do not have the slightest specialized knowledge.

The main goal of geological exploration is to study methods of exploration and extraction of minerals with the most effective and economically rational results. At the same time, the state of the environment is also taken into account - the rules of geological exploration that are harmful to it are minimized.

In addition, geological services and organizations often find adjacent exploration services for the construction of various underground structures, conduct geotechnical studies of individual territories privately, prepare sites for the harmless disposal of hazardous industrial waste.

A Brief Historical Essay

Search and exploration of minerals (in particular, noble and non-ferrous metals, and later also black) was carried out by man since antiquity. The earliest and full experience in geological exploration on the lands of medieval Europe was presented in his works by the German scientist Georg Agricola.

The first documented geological exploration in Russia was conducted on the Pechora River in 1491. The most powerful impetus to the development of this industry in domestic practice was given only a couple of centuries later, in 1700. This was facilitated by the publication of the "Order of Miner Deeds" of Peter I. A further bias on the more scientific basis of Russian geological exploration was laid by Mikhail Lomonosov. In 1882 the first state geological institution of Russia was created - the Geological Committee. His employees, after ten years, in 1892, managed to create the first geological map of the European part of the country at a scale of 1: 2 520 000. Around the same period, the theory of reconnaissance of oil, underground waters, solid minerals and placers begins to form.

With the onset of the Soviet period, the geological service underwent significant changes. State priorities shifted more towards oil exploration, as a result of which not only the old oil and gas bearing areas (in particular, the North Caucasus) were expanded, but new deposits were also explored. So, in 1929 geological exploration was set up in the Volga-Ural region, widely known as the "Second Baku".

By the beginning of 1941 Soviet geology could boast with impressive results: most of the known minerals were explored and prepared for exploitation. During the Great Patriotic War (1941-1945) the geological exploration was sharply translated into accelerated searches and development of areas with the most important resources from a strategic point of view (in particular, in the Urals, Siberia, Central Asia and the Far East). As a result, the reserves of oil, iron ore, nickel, tin and manganese were significantly increased. In the postwar years, the exhausted deposits were offset by intensive exploration of new ones.

In modern Russia, the state emphasis of geological exploration has shifted more towards private investment. However, the budgetary share also allows building long-term strategic programs for the development of the country's mineral and raw stock of the country. So, for the period 2005-2020 receipts from the treasury for geological surveys in the total amount of 540 billion rubles are expected. Almost half of them will be allocated to the allocation of hydrocarbon exploration.

Phase one - initial training

All stages and stages of geological exploration work in total are composed of three successive sets of actions.

Initial - the first stage - includes only geophysical work on the ground with geological surveys of the territory. In this case, drilling of support wells is often carried out. The whole region under consideration is closely monitored, including the possibility of earthquakes and other factors negative for the geological exploration.

The result is the preliminary determination of promising deposits. At the same time, a set of maps of the captured area is necessarily created for various scales and purposes. The state of the surrounding geological environment for stability and its possible changes is also assessed.

The second stage is the search for deposits and their evaluation

A deeper and more detailed collection of information on deposits of minerals on a scale of a certain territory begins precisely at this stage.

Stage 2 consists in works of a search character on promising areas of the first stage: the identification of specific deposits of minerals, a more accurate assessment of their volumes. A complex of geological, geophysical and geochemical works is being carried out, aerospace materials are being deciphered, boreholes are being built (or surface workings are simply made) for detailed study of deep rocks. As a result, another set of geological maps is compiled (on a scale of 1: 50000 - 1: 100000), geologists receive detailed statistical summaries on their hands.

At the third stage of geological exploration, the expediency of further exploration of the discovered deposits is determined. It is from the results obtained that the next stage will depend, during which the extraction of the required resources begins. Geologists estimate the economic potential of all found deposits, culling all the invaluable accumulations.

No less important is the fact that after carrying out this set of works, a feasibility study of the value of the deposits is made. And only with positive results, the object is finally transferred to further exploration and exploitation.

The final (third) stage - mastering

The reason for this is the painstaking collection of geological information on the discovered deposits. As in the case of the previous one, the rules of geological exploration divide this stage into two stages.

Stage 4 (exploration) begins exclusively on the assessed deposits (those whose development is recognized as economically viable). The geological structure of the object is specified in detail, the engineering-geological conditions are evaluated for its further development, the technological properties of minerals located in it are clarified. As a result, all valued deposits must be technically prepared for further operation. It is equally important to take into account the resources falling under the categories A, B, C2 and C1 in the field exploration.

Finally, at the fifth stage of geological exploration, operational exploration is carried out. It occupies the entire period of development of the deposit, due to which specialists have the opportunity to have reliable data on available deposits (morphology, internal structure and condition of occurrence of minerals).

In search of underground water

By analogy with the extraction of solid minerals, geological exploration for water is carried out exactly for the same four stages (regional geological survey, a complex of prospecting works, evaluation and exploration of the deposit). However, in connection with the specifics of this resource and the conditions for its formation, extraction is carried out with a considerable number of nuances.

In particular, the operational water reserves are calculated and approved in completely different units of measurement. They represent the volumes of this resource that can be extracted under the given conditions per unit of time - m ³ / day; L / s, etc.

The modern instruction on geological prospecting allocates 4 types of groundwater :

1. Drinking and technical - they are used in water supply systems, they are used to irrigate the soil, flood pastures.
2. Mineral waters with medicinal properties - this type is used in the manufacture of beverages and also for preventive purposes.
3. Thermal energy (in the same subset includes steam-water mixtures) - they are used for heat supply of industrial, agricultural and civil objects.
4. Industrial water - serves only as a source for the subsequent extraction of valuable substances and components from it (salts, metals, various chemical microelements).

The high risks of incidents, complications and sometimes catastrophic consequences always make one particularly anxious to observe the safety of geological exploration aimed at searching for groundwater. Development of a field by an open method can often be accompanied by suffusion, landslides, landslides and caving. The conduct of underground development can always be associated with sudden breakthroughs in water, floes and floods. In addition to the obvious danger to humans, nearby clusters of other minerals are also adversely affected - they simply soak.

Exceptional nuances for finding oil and gas

The extraction of these resources is divided into two stages. The first - the search engine - is aimed at obtaining data on fossils falling under categories C1 and C2. At the same time, geological and economic assessment of the appropriateness of developing certain deposits is also given. The stage itself is conducted in three alternating stages:

1. Geological and geophysical work of the regional plan - includes small-scale surveys of the surveyed area. A qualitative and quantitative assessment of oil and gas bearing prospects in the area under investigation is being carried out. On the basis of this information, the priority objects for geological prospecting of oil and gas will be determined.
2. Preparation of the basis for deep exploratory drilling - in the agreed order, the sites of the search wells are selected. Includes a detailed seismic survey, in some cases also gravity / electrical prospecting.
3. Exploratory work - in the course of drilling and testing of exploratory wells, prospects and oil and gas characteristics are also estimated, reserves of open deposits are counted. In addition, the geological and geophysical properties of the adjacent horizons and layers are clarified.

Any exploration project also implies the possibility of drilling on the already developed fields. This allows to find more deposits on the exploited object, which for many reasons could not be noticed during the search phase.

The next stage is exploration. It is conducted with the aim of preparing all the prospective deposits of gas and oil for further development. The structure of the discovered deposits is studied in detail, productive strata are noted, and condensate, groundwater, pressure and many other parameters are calculated.

The result of the exploration stage is the calculation of oil and gas reserves. On this basis, the economic expediency of further exploitation of the fields is being decided.

A hopeless bottom or a prospect for exploration?

The waters of the seas and oceans, in spite of their relative lack of knowledge in our time, are also widely adopted. First of all, the underwater shelf presents quite impressive prospects for the extraction of various mineral salts (in particular, sea salt, amber, etc.), oil and gas. All the minerals of a similar locality are divided into three types:

1. Contained in sea water.
2. Solid resources, which are located on the bottom / bottom layer.
3. Fluids (oil with gas, thermal waters), lying in the depths of the continental and oceanic crust of the Earth.

By location, they are classified as:

• Deposits of the near and far shelf.
• Deposits of deep-sea depressions.

At the bottom, offshore exploration for oil and gas production is carried out exclusively by drilling wells. Usually these resources are located not less than 2-3 kilometers deep into the shelf. Given the distance to the fields, various types of sites are used, from where geological exploration will be conducted:

• At a depth of up to 120 meters - pile foundations.
• At a depth of 150-200 meters - floating platforms on the anchor system.
• Hundred meters / pair kilometers - floating drilling rigs.

Western practice of private business

Abroad, geological exploration of minerals is carried out mainly with the initiative of private firms, leaving behind the state's needs only systematic geological survey and prospecting works at the regional level. Processes for the preparation of deposits for their further development begin in the overwhelming majority only after obtaining the first positive results from exploratory workings (artificially created cavities in the earth's crust formed as a result of geological exploration).

They, in turn, subject to detailed drilling and opening the largest deposits, for the industrial development of which will require significant financial investment. In operational exploration, high category fossils are built up exclusively in those volumes that are required to ensure current production. The depth at which work is carried out in such normal cases does not exceed 2-3 operational horizons (a set of exploration workings on one level).

However, for the sake of reliability it is worth noting that this practice does not guarantee insurance against serious mistakes and errors in the search for minerals. The Western approach to geological exploration is, to a large extent, reduced to extracting information, from which the discovered deposits will be evaluated in their economic feasibility and, if successful, immediately put into operation. In this plan, it is quite problematic to identify the maximum volume of all types of minerals at the site, and also to forecast the resource for explored reserves.

Sources of financing of geological exploration in the Russian Federation

The Russian practice of prospecting for minerals can be carried out both with government support and with private investment. In cases related to public needs, all geological exploration work is provided in the form of orders. Depending on the direction and volume, contractors receive funds from the corresponding budget level: federal, regional or local.

Before the beginning of geological exploration in any locality at the expense of budgetary funds, the state selects applicants on a competitive basis. The process itself is quite simple:

1. Each territory where the state plans to conduct geological exploration work is exhibited for the relevant competition. In this case, the customer (state entity) is developing a geological task and a starting price for the expected results from the project geological exploration work. It takes into account both the regulatory costs of production, and the planned level of profit.
2. The winner who offered the most suitable option at the most reasonable price, in accordance with the established procedure, obtains a license to conduct work within the specified object.
3. During the issuance of the permit, the customer also signs a contract with the winner of the competition for the exploration. The work execution period is determined either by the results of the competition, or by additional negotiations and agreements with the contractor.

The main points in the scheme for financing the geological exploration project at the governmental level are as follows:

1. The Ministry of Natural Resources receives from the Ministry of Finance annual allocations with quarterly breakdown and plans their distribution among state customers. After that, the Ministry sends relevant information to the General Directorate of the Federal Treasury.
2. The Federal Treasury notifies its respective territorial subdivisions about the approved finances for the customers they serve.
3. The Ministry of Natural Resources thus sends the approved amount of finance to the customer, simultaneously handing it the "Contract on the transfer of functions of the state customer" in accordance with established standards.
4. The means and contract made to the customer are the basis for the immediate planning of geological exploration.

The contractor receives payment for geological exploration work quarterly (also provides for the possibility of paying advances). And only if the report on the completed geological task fully satisfies the subsequent state expertise, then it is successfully received in the repository of the territorial geological fund and geological exploration is considered complete.