KR102064557B1 - Platform for developing borehole elemental concentration logging sonde - Google Patents

Abstract

The present invention relates to a platform for developing a rock component logging probe. The rock component logging probe includes a housing module, a neutron source, a gamma ray detector, and a shielding material module as key components. According to the present invention, in the probe platform, a test can be carried out while the material, size, installation position, and the like of the key components are being changed in various manners. Accordingly, the platform can be very useful in self-developing and optimizing the rock component logging probe. Moreover, an important technical issue of rock components is to secure standard gamma ray spectra by rock and chemical components, and the platform easily enables a variety of experiments, thereby being able to work very advantageously for data securement and standardization.

Description

Platform for rock formation with rock composition with adjustable neutron source type and shielding thickness {PLATFORM FOR DEVELOPING BOREHOLE ELEMENTAL CONCENTRATION LOGGING SONDE}

The present invention relates to a physical exploration and physical logging technology for detecting the physical and chemical properties of the underground, and more particularly, to a technique for the rock sphere composition logging for detecting the chemical composition of the rock.

Geophysical well logging inserts a logging device (sonde, sonde) into the borehole excavated in the ground to be investigated to determine the physical properties of the rock such as temperature, pressure, density, porosity, water saturation, and electrical resistivity. The technology of detecting the state of the. In order to detect various properties of the rock, physical logging is subdivided into various logging methods such as density logging, electrical resistivity logging, sonic logging, and neutron logging.

The physical logging started from understanding oil reserves, productivity, etc., but the scope of application is now expanding to groundwater, carbon dioxide disposal, mineral resource exploration, and engineering.

As mentioned earlier, physical logging was a technique for identifying the "physical" properties of rock, but has recently been developed to understand the "chemical" properties of the rock, that is, its chemical composition. This logging method is called "rock component logging" for convenience of explanation.

The rock component logging is a method of detecting the chemical components of the strata by detecting gamma rays generated when 1795 neutrons emitted from the neutron source mounted on the sonde (collager) collide with the components of the strata. It is a method of logging chemical components, not physical properties of strata, and it is the latest in physical logging technology, and its scope of application is very wide.

These rock component logs are used exclusively by a few major physical logging companies, such as Schlumberrger, Baker-Hughes and Halliburton. Not only do these global physical logging companies sell equipment, they do not disclose equipment specifications, data processing algorithms, etc., and provide only expensive rock component logging services.

In other words, with regard to rock component logging, the technology such as Sonde's physical specifications, logging manual, and the interpretation and processing algorithms of the logging data do not have benchmarking targets, which leads to a lot of difficulties in independent development.

The present invention has been made in order to solve the above-mentioned problems, in order to develop a rock component logging layer sonde, an object of the present invention is to provide a platform for the development of sonde.

On the other hand, the Sonde development platform according to the present invention can perform the function of the sonde as it is, the present invention has another object to provide a rock component logging layer Sonde.

On the other hand, other unspecified objects of the present invention will be further considered within the range that can be easily inferred from the following detailed description and effects.

According to an embodiment of the present invention, there is provided a platform for developing a rock component logging zone Sonde, including: a housing module installed in close contact with a ball wall of a borehole formed in a crust; A neutron beam source detachably coupled to the front end of the housing module to emit neutrons; A gamma ray detector coupled to the housing module as a high-speed neutron emitted from the neutron source to sense gamma rays generated by reacting with the strata; A shielding module installed between the neutron source and the gamma ray detector in the housing module to prevent the fast neutrons emitted from the neutron source from directing to the gamma ray detector and having a variable thickness; And a communication module coupled to the housing module to transmit a gamma ray signal sensed by the gamma ray detector to an external controller.

In the present invention, the shielding module is a stack of a plurality of shielding material is fixed to the housing module, it is preferable that the thickness of the shielding module can be adjusted according to the number of the shielding material is laminated.

In one embodiment of the present invention, the housing module includes an outer housing, and an inner housing inserted into the outer housing and in which the gamma ray detector is installed. In particular, the outer housing is formed of a plurality of segments coupled to each other, the length can be adjusted according to the number of segments.

In one embodiment of the present invention, the neutron source is any one of a neutron generator (PNG) for generating neutrons only by a chemical source of Am-Be material or a predetermined signal.

Using the Sonde platform for rock component logging according to the present invention, experiments can be made while freely varying the material and length of the housing module, the type of neutron source, the type and location of the gamma ray detector, the type, size, and thickness of the shielding material. Can be done.

The most important technical issue is that rock constituent samples have data about gamma rays emitted from each rock (stratum) in response to high-speed neutrons through numerous experiments. The rock component logging sonde development platform according to the present invention enables the experiment in various environments and conditions, it can be very useful in the development of sonde.

On the other hand, even if the effects are not explicitly mentioned herein, it is added that the effects described in the following specification and the provisional effects expected by the technical features of the present invention are treated as described in the specification of the present invention.

Figure 1 shows the rock component sample layer Sonde is installed on the hollow wall.
2 and 3 are diagrams for explaining the principle of rock component logging.
Figure 4 is a schematic exploded perspective view of the rock constituent logging zone Sonde development platform according to an embodiment of the present invention.
FIG. 5 is a schematic longitudinal sectional view of the rock component logging sonde development platform shown in FIG. 4.
6 and 7 show experimental results for selecting the type of neutron source.
8 to 10 show the experimental results for selecting the type, size and location of the gamma ray detector.
11 and 12 show the flux of neutrons and gamma rays according to the type and thickness of the shielding material.
The accompanying drawings show that they are illustrated as a reference for understanding the technical idea of the present invention, by which the scope of the present invention is not limited.

The present invention relates to a platform for rock component component sonde development. Prior to describing the present invention in detail, the rock component sample layer will be briefly described with reference to FIG. 1.

Referring to FIG. 1, the rock component logging layer excavates a borehole (h) in the ground (g) to be irradiated, and then suspends (9, sonde) to the winch (not shown) through the cable (8). Insert into the borehole (h). When the sonde 9 reaches the depth to be investigated, the sonde 9 is brought into close contact with the borehole wall to perform the logging.

In the neutron source 1 disposed at the bottom of the sonde 9, high energy fast neutrons are emitted. Referring to FIG. 2, the fast neutrons lose energy at a high speed as they react with the strata and decelerate to a thermal energy level. At this time, the high-speed neutrons emit inelastic scattering interactions with the strata until the energy drops below about 1 MeV (within microseconds). In other words, the fast neutrons collide with the nucleus of the material in the layer to excite the nucleus, and emit the inelastic scattering gamma rays when the excited nucleus is restored to its original state. On the other hand, when neutrons lose more energy and fall to 0.025 eV to become thermal neutrons, the thermal neutrons are absorbed by the neutron capture phenomenon that is absorbed by the atomic nuclei of the material in the strata as shown in FIG. appear. In the process of neutron capture in the nucleus, the nucleus is excited and emits capture gamma ray as it is restored.

Inelastic scattering gamma rays and capture gamma rays emitted from the strata due to interaction with neutrons are measured at the detector 2 of the sonde 9 as shown by arrow (a) of FIG.

The detector 2 implements a spectrum of the measured gamma rays and compares the spectrum with an elemental standard spectrum, which is a unique property of each chemical element, to identify rock components in the strata.

The standard spectrum of each element is not defined as a standard but is obtained through separate experiments. For example, the standard spectrum of silicon can be obtained experimentally through neutron emission and gamma ray detection after making a model stratified block of pure sandstone (SiO2). Similarly, standard spectra of calcium can be obtained by experimenting with model strata blocks made of pure limestone (CaCO3). Standard spectra of hydrogen, carbon and oxygen can also be obtained by experimenting in tanks filled with water or in tanks filled with oil (CnHm). In other words, the standard spectrum of the element is not determined separately, but the experiment is performed using a rock block which already knows the components to make data. Experiments with various elements and rock blocks ensure a standard database as shown in FIG. 3. However, since the standard spectrum also appears differently depending on the type of neutron source or detector, it is more accurate to view the spectrum as being obtained from a specific sonde such as a neutron source or detector rather than an element-specific spectrum. Therefore, standard spectra appear differently depending on the components and properties of Sonde, and these standard spectra are used separately by manufacturers.

The basic principle of rock component logging is to obtain the gamma ray spectrum from the rock component in the actual strata and then to compare the data with the standard data to determine the components of the strata.

As mentioned earlier, rock component logging is the latest technology in physical logging and is developed and used by only a few global companies that provide oil / resource exploration / development services. Sonde's design, as well as the standard spectral data of the elements are obtained and used only by itself, and are not disclosed to the outside. Therefore, latecomers are not subject to benchmarking in the development of rock component logging technology and must rely solely on their own development.

The present invention relates to a platform used to develop Sonde itself. In other words, it relates to a kind of platform that enables the design of the optimal sonde by allowing the experiment to be carried out while variously changing the material, performance, installation location, etc. of the various components constituting the sonde.

Meanwhile, the Sonde development platform can function as a rock component logging sonde by itself, adding that the platform according to the present invention can be utilized as sonde.

Hereinafter, with reference to the drawings, the rock constituent sample logging sonde design platform according to the present invention (hereinafter referred to as "Zonde platform") will be described in more detail.

However, in the following description of the present invention, if it is determined that the subject matter of the present invention may be unnecessarily obscured by those skilled in the art with respect to the known functions related to the present invention, detailed description thereof will be omitted.

4 is a schematic exploded perspective view of the Sonde platform 100 according to an embodiment of the present invention, Figure 5 is a schematic longitudinal cross-sectional view.

4 and 5, the Sonde development platform 100 according to an embodiment of the present invention includes a housing module 30, a neutron source 40, a gamma ray detector 50, a shielding module 60, and a communication module. (70).

The housing module 10 is to be installed in close contact with the borehole wall as a main body of the Sonde platform 100, and has an outer housing 20 and an inner housing 30. The outer housing 20 is formed long in a cylindrical shape. In the present invention, the outer housing 20 is characterized in that the length of the sonde according to the number of the segment 21 is composed of a plurality of segments 21 can be assembled. Coupling between segments 21 is possible in a variety of ways, for example, threads are formed at both ends of the segments so that the segments can be screwed together. The rear end of the outer housing 20 is the cap 22 is coupled to seal the inside of the outer housing 20. The cap 22 may have a through hole through which a power line, a communication line, or the like may pass. The winch cable is also connected. The outer housing 20 may be made of stainless steel and may be adjusted to a thickness of approximately 1 to 5 mm. Since the gamma ray detector 50 to be described later is mounted inside the outer housing 20, the thickness of the outer housing 20 should be such that the gamma ray is least shielded. However, since the sonde is disposed in the deep underground, too thin thickness is not preferable because the pressure resistance and temperature resistance is poor. In the present invention, the experiment proposed a thickness of 1 to 5 mm in consideration of minimization and pressure resistance of the gamma ray, and in particular, it was confirmed that having a thickness of 1 mm is most suitable for minimizing gamma ray shielding.

In addition, the Zonde platform 100 according to the present invention can be equipped with a neutron detector in addition to the gamma ray detector, it is also important to minimize the neutron shielding, it was confirmed that 1mm thickness is most effective in minimizing the neutron shielding. In terms of material, stainless 316L is the most effective for neutrons and stainless 401 is the most effective for gamma rays. Since the main object of the present invention is gamma ray detection, the outer housing 20 was made of stainless 401 having a thickness of 1 mm.

The inner housing 30 is inserted and installed inside the outer housing 20 and is where various components described below are mounted. In this embodiment, the inner housing 30 is formed in a semi-circular or arc-shaped longitudinal section.

A gamma ray detector 50 is mounted at the center of the inner housing 30. The location of the gamma ray detector 50, more specifically the distance from the neutron source 40, is a very important factor in the rock component detection layer. That is because the position where the gamma rays emitted from the strata are concentrated depends on the components of the strata, the type of source, and the type of detector. The Sonde platform 100 according to the present invention allows the installation position of the gamma ray detector 50 to be varied so that the optimum position of the gamma ray detector can be tested under various conditions and environments. The mounting position variable structure can be adopted in various ways, in this embodiment, the guide rails 31 are installed on both sides of the inner circumferential surface of the inner housing 30 along the longitudinal direction, and the gamma ray detector 50 is mounted on the guide rails 31. It was fitted so that it could slide. The guide rail 31 has a length of about 1m, and the distance between the neutron source and the gamma ray detector can be changed at about 20 ~ 120cm. Once the position is determined, the gamma ray detector 50 may be fixed using a screw or the like.

The front end of the inner housing 30 is where the shielding module 60 is installed. A relative position is between the neutron source 40 and the gamma ray detector 50. This portion is formed with a recess groove 32 concavely at regular intervals. Cutting groove 32 is to adjust the thickness of the shield, it will be described again when explaining the shield module.

The neutron source 40 radiates the neutrons into the strata and is mounted at the tip of the housing module 10. In the present embodiment, a screw thread is formed at the rear end of the neutron source 40, and may be mutually screwed with the screw thread formed at the front end of the housing module 10. Of course, through the various removable structure in addition to the screw coupling, the neutron source 40 can be detachable to the housing module (10). In order to select the optimal neutron source according to various stratum conditions, experiments with various sources are required, so that the neutron source can be attached and detached to the housing module.

Thus, by attaching and detaching various neutron sources, experiments were carried out using chemical source and PNG (Pulsed Neutron Generator) source using the Sonde platform according to the present invention. The PNG source is a source that can be adjusted to emit neutrons only when a pulse is applied, and the chemical source continuously emits neutrons through self-reaction such as fission. As a chemical source, an americium-beryllium Am-Be source was used. For reference, in the case of the PNG source, electronic components, a power source, and a cable are required for control. Only a source source that directly emits neutrons is detached from the outside, and a power source and a cable are installed in the housing module.

For reference, the experimental results using the Am-Be source and the experimental results using the PNG source are shown in FIGS. 6 and 7. 6 and 7, the experiment was performed in a sandstone block, and the distance between the neutron source and the gamma ray detector was set to 60 cm. The total gamma ray flux (1 / cm ² ) was 4.79E-05 for the DT PNG source, 3.45E-05 for the Am-Be source, which was higher for the PNG source, and higher for the chemical source. Experimental results themselves are not important, rather, using the Sonde platform 100 according to the present invention has a significant meaning that it is possible to experiment with various neutron sources under various conditions to select the optimal neutron source for each condition.

The gamma ray detector 50 is for detecting gamma rays (capturing gamma rays and inelastic scattering gamma rays) emitted from the strata through interaction with neutrons. On both sides of the gamma ray detector 50, slits 51 which are fitted to the guide rails 31 of the housing module 10 are formed. The gamma ray detector 50 may be inserted into the guide rail 31 to be slid to change its position, and may be fixed by a screw or the like when the position is determined.

An important point in the present invention is that the gamma ray detector 50 is detachably attached to the housing module 10 so that the gamma ray detector 50 can be replaced and the gamma ray detector can be moved within the housing module. In this embodiment, the position shift through the guide rail and the slit structure, but can be selected in addition to the various position movement structure. The gamma ray detector may be a scintillator or a semiconductor method using germanium, which uses an inorganic or organic scintillator as a scintillator. As the inorganic scintillator, NaI, LaBr 3, bismuth germanate (BGO), gadolinium oxyorthosilicate (GSO), or the like can be used. In particular, using the present invention it was possible to perform a variety of experiments while changing the flash material. For reference, the experimental results are introduced in FIGS. 8 to 10. 8 to 10 show the experimental results for selecting the type, size and location of the gamma ray detector.

Referring to FIG. 8, the above four types of gamma ray detectors were tested at a sandstone block with a neutron source at a distance of 50 cm, and gamma ray spectra of the detector types were confirmed. Experimental results showed that the detector with the most similar spectrum to the gamma ray flux spectrum was a scintillator detector using BGO as scintillation material.

9 is a result of measuring the capture gamma rays of silicon and calcium by changing the position of the detector in the shale, sandstone, limestone, basalt, granite environment. In the case of silicon, the capture gamma ray was high when the gamma detector was 50cm away from the neutron source and the calcium was 40cm apart.

Referring to FIG. 10, the experiment was performed by changing the length of the cylindrical BGO detector, which was determined to be the best in the experiment result of FIG. 8, in a range of 2 to 6 inches (diameter is fixed to the housing module). The distance from the neutron source was divided into 40cm and 50cm. As a result of capturing gamma-ray of silicon and calcium, it was confirmed that the gamma-ray detector was the best when the length was 6 inch.

Using the Sonde platform 100 according to the present invention has the advantage that the experiment can be performed while varying the conditions, such as the type, length, distance to the neutron source of the gamma ray detector as described above. In the absence of benchmarking, a variety of experiments are required to develop the rock component logging sonde, but it is not possible to produce a new experimental sonde each time. Using the Sonde platform according to the present invention has the advantage that can be performed by a variety of experiments by a single device, as a result of which the optimum design of the sonde conditions are possible.

The shielding module 60 is installed in the housing module 10 and is disposed between the neutron source 40 and the gamma ray detector 50. The shielding module is for preventing neutrons emitted from the neutron source from directly entering the gamma ray detector 50. In the rock component logging zone, what kind of shielding material is used and how to set the thickness is very important.

The shielding material can be divided into neutron absorbing material and neutron scattering material. The neutron absorbing material includes boron, natural boron, boron-containing polyethylene, etc., and tungsten is mainly used as the neutron scattering material. In the present invention, by adopting a structure that can vary the thickness of the shielding material to enable a variety of experiments.

In this example, the shielding material is used by laminating a plurality of shielding disks 61. The thickness of the shielding material varies depending on the number of shielding disks 61. Referring to FIG. 5, the shielding module 60 stacks three shielding disks 61 in a row, and then fixes the position by inserting the stoppers 62 only at both ends or the rear ends thereof. The stopper 62 may also be manufactured in the form of a thin disk and fitted into the cutout groove 32 of the inner housing 30. A plurality of cutout grooves 32 are formed along the longitudinal direction of the inner housing 30, and the stopper 62 is inserted into the cutout grooves 32 according to the number of shielding disks 61 to shield the shielding disk 61. Can be prevented from moving up and down. In the present embodiment, the shielding disk 61 is fixed by using the cutout groove 32 and the stopper 62, but various methods of fixing the shielding disk 61 to the inner housing may be adopted. An important point in the present invention is that the shielding material can be manufactured in the form of a plurality of disks to control the thickness of the entire shielding material.

11 and 12 show the results of experiments performed while changing the type and thickness of the shielding material. 11 and 12 show the flux of neutrons and gamma rays according to the type and thickness of the shielding material.

Referring to the results of FIGS. 11 and 12, it was found that a tungsten shield that scatters neutrons is more effective than a neutron shield, compared to a shield that absorbs neutrons such as boron, and has a thickness of at least 20 cm. Could. According to the present invention, by performing experiments according to various shielding materials and their thicknesses, an optimal shielding design is possible.

Finally, the Sonde platform 100 includes a data processing module (not shown) and a communication module 70. Both modules are mounted to the housing module 10. The data processing module stores data obtained through data processing such as amplifying a signal measured by the gamma ray detector 50. Alternatively, raw data may be recorded in the data processing module without data processing. The communication module 70 transmits the data obtained from the data processing module to an external controller through a wired or wireless communication network.

As described above, using the Johnde platform 100 having the above-described configuration, the experiment is carried out under various conditions while changing the length of the housing module, the type and location of the type of neutron source gamma ray detector, and the material and thickness of the shielding module. can do. The most important technical issue is that the rock component collection collects a large amount of data on gamma rays generated by reacting with neutrons for each rock and increases the reliability by standardizing them. Accordingly, the Sonde platform according to the present invention is expected to be very useful in developing the rock component logging layer Sonde.

In the present invention, a neutron detector (not shown) may be provided in addition to the gamma ray detector. This is to detect neutrons emitted from the neutron source and then returning through the strata. The neutron detector may selectively perform neutron logging, one of physical logging techniques, and may assist in rock component logging. The neutron detector is also preferably mounted to be movable in the housing module in the same structure as the aforementioned gamma ray detector.

The Sonde development platform described above aims to experiment with various changes to the parts, but adds that it can function as a rock component logging sonde by itself.

The protection scope of the present invention is not limited to the description and the expression of the embodiments explicitly described above. In addition, it is further noted that the scope of protection of the present invention may not be limited due to obvious changes or substitutions in the technical field to which the present invention pertains.

100... Rock component logging sonde development platform
10... Housing module, 20.. External housing
30…. Internal housing, 40... Neutron source
50…. Gamma ray detector, 60. Shielding Module
70... Communication module

Claims (6)

To identify the chemical composition of the strata,
A housing module installed in close contact with the ball wall of the borehole formed in the crust;
A neutron beam source detachably coupled to the front end of the housing module to emit neutrons;
A high-speed neutron emitted from the neutron source for detecting a gamma ray generated by reacting with the strata, the gamma ray detector coupled to the housing module to be movable along the longitudinal direction of the housing module is adjustable to the neutron source ;
A shielding module installed between the neutron source and the gamma ray detector in the housing module so as to prevent the fast neutron emitted from the neutron source from directing to the gamma ray detector and having a variable thickness; And
And a communication module coupled to the housing module to transmit a gamma ray signal detected by the gamma ray detector to an external controller.
The shielding module is a stack of a plurality of shielding material is fixed to the housing module, the thickness of the shielding material module is adjustable according to the number of the shielding material is laminated,
The outer housing is formed of a plurality of segments coupled to each other, the length can be adjusted according to the number of segments,
A guide rail is installed along the longitudinal direction of the housing module, and the gamma ray detector is mounted on the guide rail and is movable in the longitudinal direction, thereby controlling the separation distance from the neutron source.
The gamma ray detector measures gamma rays generated by reacting with the strata, implements a spectrum of gamma rays, and compares the spectra with standard spectra of chemical elements to determine the chemical composition of the rock strata. Platform. delete The method of claim 1,
The housing module and the outer housing,
A rock component component zonde development platform, comprising: an inner housing inserted into the outer housing and having the gamma ray detector installed therein. delete The method of claim 1,
The housing module is a platform for rock component component sonde development, characterized in that the stainless material. The method of claim 1,
The neutron source is a rock component zonde development platform, characterized in that any one of the neutron generator (PNG, Pulsed Neutron Generator) to generate neutrons only by a chemical signal source or a predetermined signal of Am-Be material.

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