RU2498358C1 - Method for remote searching of new oil and gas deposits - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: method involves performing geologic and seismic survey, as well as remote optical gas analysis using remote lidar. During gas analysis, a spectral image of the set of chemical components in the surface layer of the atmosphere is formed. Spatial selection of the spectral image of the area on given tracer substances is performed. The detected gas components are compared with the composition of the reference mixture of hydrocarbon components which corresponds to the geographical position of the area and the deposit. The area is mapped with spatial differentiation on the relief of the obtained spectral image of the probed area. The spectral image of the region of the authentic hydrocarbon deposit is selected on the map. A family of points with the measured concentration of heavy hydrocarbons is determined.

EFFECT: high accuracy of searching for hydrocarbons, low cost of search operations.

2 cl

Description

The invention relates to the field of exploration in the oil and gas industry and is aimed at a significant reduction in their cost and increased efficiency by supplementing traditional methods with new technology for the search and exploration of oil and gas fields using laser aerial sounding, which has high efficiency and increased sensitivity of measurements of extremely small concentrations of heavy hydrocarbon gases (UVG) in the surface layers of the atmosphere.

A known method [1] of exploration for exploration for oil and gas through seismic exploration. At the same time, seismic studies are carried out on a pre-selected network of profiles within the entire investigated territory. By processing and interpreting seismic data in the geological section of the territory, traps are searched for with which oil and gas deposits can be associated, and the presence of deposits is predicted.

This method of searching for oil and gas deposits is very expensive, as it requires seismic exploration and, accordingly, laying of seismic profiles with a width sufficient (at least 6 m) for the passage of heavy wheeled and tracked vehicles with increased cross-country ability, including in the conditions of the tundra, swampy, mountainous-wooded and taiga terrain, etc. cutting clearings, as well as drilling shallow wells for blasting and initiating elastic waves.

In this case, only seismic traps of a structural type can be successfully found through seismic exploration and, with a fairly high degree of reliability, to predict the presence of deposits of unique and large sizes. In the case of deposits of medium and small sizes, which currently constitute the bulk of the mass, significant difficulties arise, since the influence of these deposits on the wave pattern is comparable to or significantly lower than the influence of geological factors. In addition, in nature there are deposits associated with non-structural type traps, which in most cases cannot be detected by seismic exploration methods.

However, not every detected trap of a structural or non-structural type contains industrial accumulations of hydrocarbons (HC). In nature, there are so-called "empty traps" that do not contain hydrocarbons. Methods used for rejecting such structures, including ground-based geochemistry, require ground routes, either walking or using wheeled and tracked vehicles with increased cross-country ability and also have low productivity.

In this regard, for the rejection of unproductive traps identified by seismic data, a large number of deep search wells have to be drilled, for the conduct of which not only logging is required, but also the construction of temporary roads with leveling the terrain. Moreover, the features of the study area, for example, severe bogging and the absence of passable roads, can make seismic exploration very difficult and expensive.

Known geochemical methods of searching for oil and gas, which are direct search methods and can reliably assess the possibility of deposits in the bowels of the study area [2]. The disadvantage of geochemical methods is that, unlike seismic exploration, they cannot show the geological structure of the territory, but only assess the prospects for the presence of deposits in the bowels of the earth, that is, they show a picture in plan. The disadvantages of direct geochemical methods include the need for sampling throughout the study area, which complicates their use in hard-to-reach areas and in the study of vast territories.

Known methods for aerospace study of mineral deposits based on multi-zone remote sensing of the surface by electromagnetic radiation in order to study both landscape features and local electrical, magnetic and thermal anomalies [3, 4]. However, the effectiveness of aerospace methods based on technologies based on the fundamental physical interaction between elementary particles - electromagnetic radiation, remains low, since the probability of discovering deposits does not exceed 30–35%, and exploration depths are limited by the Earth’s surface horizons [5].

A combined method is known for the geological exploration of oil and gas [6], in which a geochemical survey is carried out in the study area by studying gases adsorbed on a clay matrix, according to the results of which zones of hydrocarbon anomalies are revealed, and then in areas of the area along the profiles within the identified hydrocarbon anomalies with By entering the normal field, electrical exploration is carried out, according to the results of which they are judged on the parameters of the reservoir at a depth from the surface geochemical anomaly to the desired reservoir. However, this method is not suitable for the search for oil and gas in very wetlands and to obtain the exact boundaries of the reservoir. Also the disadvantages of the method is the high complexity and high costs for the search for hydrocarbon deposits.

The closest method of the same purpose to the claimed invention according to the totality of features adopted as the closest prototype is an improved method for remote sensing of the earth’s surface in the interest of searching for mineral resources, in particular, due to the fact that multizone landscape sensing is supplemented by photographing vegetation in narrow zones of the electromagnetic spectrum at different times of the vegetation phases and determine the groups of chemical compounds that accumulate I am in the biomass of vegetation by the magnitude of the contrasts of the photographic images [7]. The method involves the transfer of images to the flight control center, their transformation and mapping, however, in principle, does not go beyond the scope of multi-zone remote sensing.

The principal disadvantage of the remote optical gas analysis method chosen as a prototype is that it does not allow detecting low concentrations of heavy hydrocarbon gases in the surface layers of the atmosphere, which are directly indicators of oil and gas deposits.

The objective of the invention is to ensure high reliability of searches for oil and gas fields, as well as reducing the cost of prospecting and increasing the accuracy of determining the location of oil and gas deposits.

The aim of the invention is to increase the efficiency of air search and exploration of oil and gas fields using aircraft in various territories - the Earth's surface (land), the continental shelf, namely:

- increasing the probability of discovering deposits;

- registration of extremely small concentrations of heavy hydrocarbons;

- a significant reduction in the duration of geophysical exploration, especially at the regional and exploratory stages of work;

- increase the pace of development and commissioning of deposits;

- reducing the economic costs of exploring new hydrocarbon deposits and reducing the cost of exploration and labor costs per unit of recoverable oil and gas reserves.

This goal is achieved by creating a method for remote search for new oil and gas fields, which allows registration and detailed analysis of the spectral characteristics of heavy hydrocarbon gases during laser sensing of the oil and gas region and combine with other methods, including with areal seismic survey. Unlike the prototype, the claimed remote method allows a high degree of accuracy to record and map the distribution of indicator HC molecules throughout the study area, to determine the presence of hydrocarbons in structural traps and their phase composition.

The inventive method should be used both at the regional stage of geological exploration in the study of promising areas located at the initial stages of exploration, as well as poorly studied and inaccessible territories that differ in difficult landscape conditions, and to increase the reliability of the data obtained as a result of seismic or gravimagnetic work in order to confirm (refute) the presence of oil and gas structures and the rationale for drilling exploratory wells.

Thus, the method of remote search for new oil and gas fields can have both independent and auxiliary value. In the first case, it is necessary to identify areas of development of ground-based geochemical anomalies in areas poorly studied by ground-based research and drilling, and to set expensive seismic and non-seismic search methods in their contours. In the second, it can be used to reject traps identified as a result of seismic exploration.

In addition, it is possible to assess the environmental and engineering conditions for designing, building and operating wells, laying pipelines, etc. This will significantly reduce the time required to conduct research on oil and gas industry facilities, eliminate pollution, and reduce expenses associated with exploration work.

The advantages of the laser sensing method include distance, proximity, the possibility of continuous areal and profile scanning, as well as a high detection rate. A detailed analysis of the spectral characteristics of oil and gas deposits during laser sensing is carried out under conditions significantly lower than the maximum level of sensitivity and spatial resolution of observing systems. Remote sensing by laser sensing can be applied around the clock and year-round.

The economic efficiency of the implementation of the invention is expressed in cost savings due to a significant reduction in the search area and high zoning speed with the allocation of promising oil and gas zones for further research.

The direct economic effect is expressed in:

- reducing unit costs for identifying and studying geophysical anomalies;

- reducing the time for geological, geophysical and prospecting work at promising regional facilities;

- prevention of unproductive costs for the study of unpromising objects.

The required result - a significant reduction in the time and economic costs of searching for new hydrocarbon deposits - is achieved through integrated geological surveys, seismic surveys and laser sensing.

The remote search method using an aircraft lidar solves the following functional tasks as intended.

1. Forms a spectral image of a set of chemical components in the surface layer of the atmosphere. The set includes substances whose spectral characteristics are contained in the database.

2. Conducts spatial differentiation of the spectral image of the area for a given indicator substances. The registered gas components are compared with the composition of the reference mixture of hydrocarbon components corresponding to the geographical location of the area and field.

3. Conducts terrain mapping (electronic maps) with spatial differentiation according to the relief of the obtained spectral image of the probed terrain. Areas of reliable hydrocarbon occurrence are distinguished on the map of the spectral image.

4. Defines a family of points with a low concentration of heavy hydrocarbons.

This method is suitable for air searches of oil and gas fields both in wetlands and in mountainous areas, and also differs in the accuracy of determining the boundaries and contours of deposits. In terms of the particle detection limit (10 ÷ 20 billion ^-1 ) of heavy hydrocarbon gases, the method of laser sensing and spectral diagnostics is two orders of magnitude superior to all known analogues.

Thus, we believe that the totality of the claimed features does not repeat the list of properties of individual features known from other methods.

Information sources.

1. The way to search for oil and gas deposits. RF patent 2078356 C1 dated 04/27/1997.

2. The geochemical method of searching for oil and gas. Patent 2039369 C1 of July 9, 1995.

3. Gotynin B.C. Theoretical background of remote research in the study of the geological structure of oil and gas territories. In the book. "Remote research in oil exploration." Min oil. prom USSR, USSR Academy of Sciences, Sat teach, works. M., 1985.

4. Gridin V.I. Dmitrievsky A.N. System-aerospace study of oil and gas areas. M., Science, 1994.

5. Physicochemical principles of direct searches for oil and gas deposits, VNIIAGG. M .: Nauka, 1986.

6. The combined method of geological exploration of oil and gas. Patent 2102781 C1 of 01.20.1998.

7. The method of remote sensing of the earth's surface. USSR patent 1716469, 1992

Claims (2)

1. A method for remote search for new oil and gas fields, including geological surveying, seismic surveying and a remote optical gas analysis method, characterized in that the remote optical gas analysis method is implemented using an aircraft lidar, and a spectral image of a set of chemical components in the surface layer is formed atmospheres, perform spatial selection of the spectral image of the area for given indicator substances, compare the registered gas components with the composition of the reference mixture of hydrocarbon components corresponding to the geographical position of the terrain and the field, conduct terrain mapping with spatial differentiation according to the relief of the obtained spectral image of the probed area, identify areas of reliable hydrocarbon occurrence on the spectral image map and determine a family of points with a measured concentration of heavy hydrocarbons. 2. The method for remote search for new oil and gas fields according to claim 1, characterized in that the information materials obtained are used to reject empty traps identified as a result of seismic exploration and to conduct detailed seismic studies, justify well laying and determine the oil and gas potential of the studied territories and objects.