Exploration work

The general goal of exploration is the scientifically sound, systematic and cost-effective provision of the mining industry with proven mineral reserves, the study of methods for their complete, integrated and economically rational extraction in the process of exploitation of deposits, taking into account environmental protection. Geological services, geological organizations also provide services for the study of mineral resources for the construction and operation of underground structures , for agricultural needs. An engineering and geological study of certain areas and territories is also necessary for the preparation of underground burial of harmful substances and industrial wastes, discharge of wastewater and other issues.

Geological exploration involves a comprehensive conduct of work, that is, along with the search and exploration of mineral deposits , all related mineral components are also studied, the possibilities of their utilization are determined, hydrogeological , mining, geotechnical and other studies are carried out, natural-climatic, geo-economic, socio-economic, geological and economic conditions for the development of deposits.

Exploration work includes:

• Regional and large-scale types of surveys: geological , topographic , geodetic , geophysical , geochemical , aerial photography , space and others;
• Various types of prospecting, exploration, hydrogeological and engineering-geological works, analytical-mineralogical-technological, geological-economic, scientific-thematic and other studies.

Depending on the goals, the process of geological exploration of mineral resources is divided into 3 stages and 5 stages ^[4] :

Stage I. Works of general geological and mineralogenetic purpose

Stage 1. Regional geological study of the subsoil and forecasting of minerals.

Stage II. Search and evaluation of deposits

Stage 2. Search work.

Stage 3. Evaluation work.

Stage III. Exploration and development of the field

Stage 4. Exploration of the field.

Stage 5. Operational intelligence.

Previously, the work was carried out in 6 stages:

1. The first stage included regional geological survey and geophysical work . According to their results, large structures, strata and areas recommended for setting up specialized prospecting works that were promising for the discovery of minerals were distinguished.
2. The second stage of geological exploration - directly the search for deposits - was aimed at the discovery of deposits of certain types of minerals. The search for deposits was carried out in three stages:
   • General searches in order to identify areas and sites potentially promising for finding mineral deposits;
   • Detailed searches in areas where prospective mineral deposits were discovered or the likelihood of their discovery has received sufficient geological justification;
   • Exploration and assessment work is a complex of structural-geological, geophysical and geochemical studies using mine workings and boreholes . Based on the results of this stage, an assessment was made of the possible industrial significance of the identified deposit (or manifestations of minerals that did not have such significance were rejected). With positive results, reserves of category C2 were calculated, a quantitative assessment of the predicted mineral resources was given, a feasibility study was made on the desirability of continuing further exploration work.
3. The third stage of exploration is preliminary exploration , during which the industrial significance of the deposit was determined: the general parameters of the deposit, the shapes and sizes of the main bodies of minerals, the main features of their occurrence conditions, the quality and technological properties of minerals, a preliminary description of the development conditions, etc. . Based on the results of the work performed, C1 and C2 categories were calculated for mineral reserves , temporary conditions for mineral raw materials were developed and approved, and a feasibility study was made for the feasibility of conducting detailed exploration.
4. The fourth stage - detailed exploration - was carried out only at deposits or their individual sections, the industrial value of which was proved by preliminary exploration. The sequence of detailed exploration at each field was coordinated with the interested mining ministries and departments and was carried out in accordance with the plan for the industrial development of individual objects and their parts. As a result of detailed exploration, the field should have been prepared for industrial development in accordance with the requirements for its degree of study, established classifications of reserves of deposits and predicted mineral resources. For deposits of solid minerals, the reserves identified as a result of detailed exploration were calculated for categories A, B, C1 and C2.
5. The fifth stage - additional exploration of deposits - was carried out within the mining allotment on insufficiently studied parts of mineral deposits involved in industrial development. The stage included work on the consistent (in conjunction with the development plans for operational work) transfer of reserves of categories C1 and C2 to higher categories, as well as the calculation of newly discovered reserves.
6. The sixth stage - operational exploration - is combined with the excavation of mining and development workings . Production exploration precedes treatment works and serves to ensure the current extraction of minerals in the developed fields. At this stage, the data obtained by detailed exploration on the morphology, internal structure, conditions of occurrence of mineral bodies and their quality are clarified.

Based on the results of geological exploration, mineral reserves are calculated and approved in the established manner, a predictive assessment of mineral resources is made.

Exploration for oil and gas consists of two stages: prospecting and exploration.

1. The search stage is divided into three stages:
   • A - Regional geological and geophysical work. They include small-scale geological and structural-geomorphological surveys in combination with geochemical, hydrogeological and other studies, aeromagnetic and gravimetric surveys, electrical exploration and seismic exploration, as well as drilling of reference, parametric and structural wells;
   • B - Preparation of areas (structures) for deep exploratory drilling. Includes medium and large-scale structural geological surveys, detailed seismic surveys, as well as gravity exploration , electrical exploration , gas surveys, structural and parametric drilling, assessment of forecast resources and reserves of category C2;
   • B - Searches for deposits (deposits). This stage includes drilling , comprehensive geological and geophysical studies and testing of exploratory wells. Based on the results obtained at the search stage, reserves of categories C1 and C2 are calculated and preliminary geological and economic assessment of deposits and deposits is carried out to justify the conduct or termination of further exploration.
2. The task of the exploration phase is to prepare the field for development. Using complex geophysical and other methods in the drilled wells, the structure of the field is studied, productive formations are identified, possible flow rates of oil, gas, condensate, water, reservoir pressure and other indicators are determined. These indicators are used for designing field development, substantiating capital investments.

Geological exploration for groundwater is carried out similarly to the first four stages for deposits of solid minerals, but taking into account the formation conditions specific to them, the features of occurrence in the bowels, and the techniques and technologies for extraction and use. In particular, unlike all other types of minerals, groundwater reserves are calculated and approved, measured in units of volume, which can be extracted under given conditions per unit time (m3 / day, l / s, etc.). Hydrogeological studies are an indispensable part of the study and exploration of all types of mineral deposits, so this allows you to determine the degree of water cut, the calculation of possible water inflows during field development, and the solution of issues of providing water supply to the designed enterprises.

Since the 1970s, exploration work on the offshore shelf (especially for oil, gas, and placers of heavy minerals) and in the deep water areas of the seas and oceans, where accumulations of ferromanganese nodules, polysulfide ores, metal-bearing brines and silts have been greatly developed, has been widely developed. The methodology for prospecting and exploration of minerals on the shelf of the seas, the bottom of the seas and oceans is in the process of formation and development.

Along with the sequence of geological exploration and the multi-stage described above, which, for example, was adopted in the CCCP, methods are used for accelerated exploration of individual mineral deposits of important economic or commercial importance. In this case, the stages of preliminary and detailed exploration, detailed exploration with the design of mining enterprises can be combined.

As of 2010, the content of subsoil only in 20% of the country’s territory is reflected by state geological maps of 1: 200,000 scale that meet modern requirements, while 55% of the territory needs geological exploration, and 25% needs to be completed with the entire modern complex of geological mapping . ^[5] In 2018, the LF-230 Boart Longyear rig was sent to the Krasnoyarsk Territory north of the Arctic Circle. ^[6]

According to the long-term program for the reproduction of the mineral resource base of Russia for 2005-2020, it is proposed to invest about 540 billion rubles in geological research. budgetary funds, of which 47% are for the exploration of hydrocarbons. ^[7]

In Russia , exploration financing is carried out both at the expense of budgetary funds and by private companies. In 2009, the volume of budget funding for geological exploration amounted to 18,931 million rubles. (in 2008 - 21 975 million rubles). In 2009, total hydrocarbon deposits were explored for 620 million tons, in 2008 - 589 million tons. ^[8]

The total volume of investment in exploration in 2010 consisted of funds from private investors aimed directly at exploration - research activities, appraisal, prospecting and exploration work worth 24.5 billion rubles; for additional exploration and monitoring of existing fields - 6 billion rubles; state budget funds - 5.4 billion rubles. Funds from the budgets of the constituent entities of the Federation - 200 million rubles. Total total investment in exploration amounted to 36.1 billion rubles. ^[9]

• Mineral Exploration

• http://geoekonomica.ru/ - portal of the Federal Agency for Subsoil Use on the planning and design of exploration work, with a database of Rosnedr standards
• Map of geologists throughout the country 2015 (portvein777tm (c)) http://pervokarta.ru/klassif/test7.jpg