CN106291727B - Method and device for qualitatively evaluating magnesium element in stratum - Google Patents
Method and device for qualitatively evaluating magnesium element in stratum Download PDFInfo
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- CN106291727B CN106291727B CN201610559816.7A CN201610559816A CN106291727B CN 106291727 B CN106291727 B CN 106291727B CN 201610559816 A CN201610559816 A CN 201610559816A CN 106291727 B CN106291727 B CN 106291727B
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- 239000011777 magnesium Substances 0.000 title claims abstract description 153
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 title claims abstract description 152
- 229910052749 magnesium Inorganic materials 0.000 title claims abstract description 152
- 238000000034 method Methods 0.000 title claims abstract description 39
- 238000001228 spectrum Methods 0.000 claims abstract description 159
- 230000015572 biosynthetic process Effects 0.000 claims abstract description 47
- 238000011156 evaluation Methods 0.000 claims abstract description 31
- 230000008859 change Effects 0.000 claims abstract description 21
- 230000005251 gamma ray Effects 0.000 claims abstract description 19
- 238000012545 processing Methods 0.000 claims description 25
- 238000010606 normalization Methods 0.000 claims description 18
- 238000007781 pre-processing Methods 0.000 claims description 10
- 230000003595 spectral effect Effects 0.000 claims description 8
- 238000005755 formation reaction Methods 0.000 claims 4
- 239000010459 dolomite Substances 0.000 abstract description 11
- 229910000514 dolomite Inorganic materials 0.000 abstract description 11
- 238000004364 calculation method Methods 0.000 abstract description 9
- 235000019738 Limestone Nutrition 0.000 abstract description 5
- 239000006028 limestone Substances 0.000 abstract description 5
- 239000011435 rock Substances 0.000 abstract description 5
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 abstract description 4
- 230000008569 process Effects 0.000 description 8
- 238000010586 diagram Methods 0.000 description 7
- 238000010183 spectrum analysis Methods 0.000 description 7
- 238000006243 chemical reaction Methods 0.000 description 6
- 238000000342 Monte Carlo simulation Methods 0.000 description 4
- 229910021532 Calcite Inorganic materials 0.000 description 3
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 3
- 239000011148 porous material Substances 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- 239000010703 silicon Substances 0.000 description 3
- 238000004088 simulation Methods 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 2
- 229910052622 kaolinite Inorganic materials 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 239000010453 quartz Substances 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 241000933832 Broussonetia Species 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000004590 computer program Methods 0.000 description 1
- 238000005094 computer simulation Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000013505 freshwater Substances 0.000 description 1
- 238000000084 gamma-ray spectrum Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
- G01V5/00—Prospecting or detecting by the use of ionising radiation, e.g. of natural or induced radioactivity
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- High Energy & Nuclear Physics (AREA)
- Life Sciences & Earth Sciences (AREA)
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- General Physics & Mathematics (AREA)
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- Geophysics And Detection Of Objects (AREA)
- Measurement Of Radiation (AREA)
Abstract
The invention relates to the technical field of geological exploration, in particular to a method and a device for qualitatively evaluating a formation magnesium element. The method comprises the following steps: acquiring inelastic scattering gamma energy spectrum data of a target stratum; determining gamma ray energy reflecting inelastic scattering characteristics of magnesium elements according to the inelastic scattering gamma energy spectrum data, and determining an energy window reflecting the magnesium elements according to the gamma ray energy; acquiring gamma energy spectrum counts in the energy window reflecting the magnesium element according to the inelastic scattering gamma energy spectrum data; and qualitatively evaluating the magnesium element of the target stratum according to the gamma energy spectrum counting to obtain relative content change data of the magnesium element in the target stratum. The method is simple, the calculation amount is small, the rapid qualitative evaluation of the formation magnesium element is achieved, and the requirement for distinguishing limestone from dolomite in the carbonate rock formation is met.
Description
Technical Field
The invention relates to the technical field of geological exploration, in particular to a method and a device for qualitatively evaluating a formation magnesium element.
Background
In the dolomite diagenesis process of the carbonate reservoir, magnesium replaces calcium in calcite, the reservoir shrinks to a certain degree to generate a micro-crack system, so that the storage space is greatly increased, and therefore, in the exploration of the dolomite diagenesis stratum, magnesium is a key element for distinguishing limestone from dolomite in the carbonate reservoir.
The formation element logging is to measure a gamma energy spectrum generated by the reaction of neutrons emitted to the formation by a neutron source and the formation element atomic nucleus, and the content of the formation elements can be accurately obtained by utilizing a gamma energy spectrum analysis method. The magnesium content of the stratum can be obtained through inelastic scattering gamma-ray spectrum analysis of stratum element logging measurement, and therefore limestone and dolomite can be distinguished. In the qualitative evaluation of the logging of the formation lithology, the gamma energy spectrum measured underground needs to be subjected to spectrum decomposition by using a standard gamma energy spectrum measured in a standard calibration tank by a logging instrument in the prior art, and then the spectrum decomposition result is further processed to obtain the formation magnesium element content. Therefore, how to evaluate the content of the magnesium element in the stratum rapidly and qualitatively is still a problem to be solved urgently in the exploration of the dolomite lithification stratum.
Disclosure of Invention
The embodiment of the application provides a method and a device for qualitatively evaluating formation magnesium elements, so that the formation magnesium elements can be quickly and qualitatively evaluated.
In order to achieve the above object, in one aspect, an embodiment of the present application provides a method for qualitatively evaluating a magnesium element in a formation, where the method includes:
acquiring inelastic scattering gamma energy spectrum data of a target stratum;
determining gamma ray energy reflecting inelastic scattering characteristics of magnesium elements according to the inelastic scattering gamma energy spectrum data, and determining an energy window reflecting the magnesium elements according to the gamma ray energy;
acquiring gamma energy spectrum counts in the energy window reflecting the magnesium element according to the inelastic scattering gamma energy spectrum data;
and qualitatively evaluating the magnesium element of the target stratum according to the gamma energy spectrum counting to obtain relative content change data of the magnesium element in the target stratum.
Further, the gamma ray energy reflecting the inelastic scattering characteristic of magnesium element is 2.75 Mev.
Furthermore, the energy window reflecting the magnesium element is 2.63-2.84 MeV.
Further, obtaining gamma spectrum counts within the energy window reflecting magnesium elements from the inelastic scattering gamma spectrum data, including:
preprocessing the inelastic scattering gamma energy spectrum data to obtain preprocessed inelastic scattering gamma energy spectrum data;
normalizing the preprocessed inelastic scattering gamma energy spectrum to obtain normalized inelastic scattering gamma energy spectrum data;
and acquiring the gamma energy spectrum count in the energy window reflecting the magnesium element according to the inelastic scattering gamma energy spectrum data after normalization processing.
Further, normalizing the preprocessed inelastic scattering gamma energy spectrum to obtain normalized inelastic scattering gamma energy spectrum data, including:
and normalizing the total spectral band of the preprocessed inelastic scattering gamma energy spectrum to obtain the inelastic scattering gamma energy spectrum data after normalization processing.
Further, before qualitatively evaluating the magnesium element in the target formation according to the gamma energy spectrum counting and acquiring the relative content change data of the magnesium element in the target formation, the method further comprises the following steps:
adjusting the data weight of the gamma energy spectrum counting to obtain the adjusted gamma energy spectrum counting;
correspondingly, performing qualitative evaluation on the magnesium element in the target stratum according to the adjusted gamma energy spectrum counting to obtain relative content change data of the magnesium element in the target stratum.
On the other hand, the embodiment of the application also provides a device for qualitatively evaluating the magnesium element in the formation, and the device further comprises:
the acquisition unit is used for acquiring inelastic scattering gamma energy spectrum data of the target stratum;
the energy window determining unit is used for determining gamma ray energy reflecting inelastic scattering characteristics of magnesium elements according to the inelastic scattering gamma energy spectrum data and determining an energy window reflecting the magnesium elements according to the gamma ray energy;
the gamma energy spectrum counting acquisition unit is used for acquiring gamma energy spectrum counting in the energy window reflecting the magnesium element according to the inelastic scattering gamma energy spectrum data;
and the qualitative evaluation unit is used for qualitatively evaluating the magnesium element in the target stratum according to the gamma energy spectrum counting to obtain the relative content change data of the magnesium element in the target stratum.
Further, the gamma ray energy reflecting the inelastic scattering characteristic of magnesium element is 2.75 Mev.
Furthermore, the energy window reflecting the magnesium element is 2.63-2.84 MeV.
Further, the gamma spectrum count acquisition unit includes:
the preprocessing subunit is used for preprocessing the inelastic scattering gamma energy spectrum data to obtain preprocessed inelastic scattering gamma energy spectrum data;
the normalization processing subunit is configured to perform normalization processing on the preprocessed inelastic scattering gamma energy spectrum to obtain normalized inelastic scattering gamma energy spectrum data;
and the gamma energy spectrum counting subunit is used for acquiring the gamma energy spectrum counting in the energy window reflecting the magnesium element according to the inelastic scattering gamma energy spectrum data after the normalization processing.
Further, normalizing the preprocessed inelastic scattering gamma energy spectrum to obtain normalized inelastic scattering gamma energy spectrum data, including:
and normalizing the total spectral band of the preprocessed inelastic scattering gamma energy spectrum to obtain the inelastic scattering gamma energy spectrum data after normalization processing.
Further, the apparatus further comprises:
the data weight adjusting unit is used for adjusting the data weight of the gamma energy spectrum counting to obtain the adjusted gamma energy spectrum counting;
correspondingly, the qualitative evaluation unit is used for qualitatively evaluating the magnesium element in the target stratum according to the adjusted gamma energy spectrum counting, and obtaining relative content change data of the magnesium element in the target stratum.
In the embodiment of the application, the energy window reflecting magnesium elements is determined by obtaining inelastic scattering gamma energy spectrum data of a target stratum, then gamma energy spectrum counting in the energy window reflecting magnesium elements is obtained, then rapid qualitative evaluation of the magnesium elements in the stratum is achieved through gamma energy spectrum calculation in the energy window reflecting magnesium elements, and stratum magnesium element relative content change data is obtained. Compared with the energy spectrum analysis in the prior art, the method provided by the embodiment of the application utilizes the processing of inelastic scattering gamma energy spectrum data, and then utilizes the gamma counting which can reflect the energy window of the magnesium element to directly qualitatively evaluate the content of the magnesium element in the stratum.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, it is obvious that the drawings in the following description are only some embodiments described in the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without any creative effort.
FIG. 1 is a flow chart of a method for qualitative evaluation of formation magnesium in an embodiment of the present application;
FIG. 2 is a schematic diagram of a petrophysical volume model 1 according to an embodiment of the present application;
FIG. 3 is a schematic diagram of a Monte Carlo simulation technique model of an embodiment of the present application;
FIG. 4 is a schematic view of an inelastic scattering gamma energy spectrum of an embodiment of the present application;
FIG. 5 is a schematic diagram of a petrophysical volume model 2 according to an embodiment of the present application;
FIG. 6 is a graph of gamma ray count rate versus mass percent of magnesium in the formation within an energy window reflecting magnesium in accordance with an embodiment of the present application;
FIG. 7 is a diagram illustrating the results of rapid qualitative evaluation of formation Mg for actual well log data processing according to an embodiment of the present application;
fig. 8 is a structural diagram of an apparatus for qualitative evaluation of magnesium element in a formation according to an embodiment of the present application.
Detailed Description
In order to make those skilled in the art better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The following describes embodiments of the present application in further detail with reference to the accompanying drawings.
Referring to fig. 1, an embodiment of the present application provides a method for qualitatively evaluating magnesium in a formation, where the method includes:
and S1, acquiring inelastic scattering gamma energy spectrum data of the target stratum.
In the embodiment of the application, the inelastic scattering gamma energy spectrum of the target stratum can be acquired through logging data recorded by a stratum element logging instrument utilizing a pulse neutron source.
S2, determining gamma ray energy reflecting inelastic scattering characteristics of magnesium elements according to the inelastic scattering gamma energy spectrum data, and determining an energy window reflecting the magnesium elements according to the gamma ray energy;
in the embodiment of the application, the energy of the inelastic gamma ray of the magnesium element is 2.75MeV, and the energy window of the magnesium element is reflected to be 2.63-2.84 MeV.
And S3, acquiring the gamma energy spectrum count in the energy window reflecting the magnesium element according to the inelastic scattering gamma energy spectrum data.
In an embodiment of the present application, acquiring a gamma spectrum count in the energy window reflecting the magnesium element includes:
preprocessing the inelastic scattering gamma energy spectrum data to obtain preprocessed inelastic scattering gamma energy spectrum data;
normalizing the preprocessed inelastic scattering gamma energy spectrum to obtain normalized inelastic scattering gamma energy spectrum data;
and acquiring the gamma energy spectrum count in the energy window reflecting the magnesium element according to the inelastic scattering gamma energy spectrum data after normalization processing.
In the embodiment of the application, the preprocessing includes processing of deducting, capturing, and correcting the radiation reaction influence, filtering, spectrum drift and the like on the inelastic gamma energy spectrum data. And normalizing the total spectral band of the preprocessed inelastic scattering gamma energy spectrum to obtain the inelastic scattering gamma energy spectrum data after normalization processing. In the embodiment of the application, the normalization processing is to accumulate the energy spectrum counts of the whole energy section and then divide each calculation by the energy spectrum calculation, so that the normalized data is between 0 and 1, and the sum of the energy spectrum data of the whole energy section is 1. The normalization treatment is to make the magnesium element qualitative calculation value after treatment reflect the change of the whole well section. In the embodiment of the application, the gamma count of the energy window reflecting the magnesium element can be determined by normalizing the processed inelastic scattering gamma energy spectrum data.
S4, normalizing the total spectral band of the preprocessed inelastic scattering gamma energy spectrum to obtain normalized inelastic scattering gamma energy spectrum data.
In the embodiment of the application, the gamma energy spectrum counting in the energy window of the magnesium element is reflected, so that the qualitative evaluation of the magnesium element can be realized, and the relative content change data of the magnesium element can be obtained through the qualitative evaluation; secondly, standard energy spectrum data are required to be used in the energy spectrum analysis process, and the standard energy spectrum data are obtained by measuring in a standard calibration tank by a professional through a logging instrument, so that the obtaining process is complicated; meanwhile, after the relative yield of the elements is obtained through energy spectrum analysis, the content of the elements can be obtained only after a series of data conversion is carried out on the relative yield, so that the data processing process in the prior art is very complex, and professional technicians are also required to analyze the relative yield. According to the method and the device, the magnesium element of the target stratum is qualitatively evaluated by reflecting the gamma energy spectrum counting in the energy window of the magnesium element, so that the change data of the relative content of the magnesium element in the obtained target stratum can reflect the change of limestone and dolomite, and compared with the prior art, after the gamma energy spectrum is preprocessed, the gamma energy spectrum counting in the energy window of the magnesium element can be qualitatively evaluated to evaluate the magnesium element content of the stratum, a complex spectrum resolving process is not needed, a standard gamma energy spectrum in the spectrum resolving process is not needed, and a complex process of converting the relative yield of the element to the element content is also not needed. The method provided by the embodiment of the application has the advantages of small calculation amount, simplicity and high efficiency, and can realize qualitative evaluation of the formation magnesium element, so that the requirement of accurately and qualitatively distinguishing limestone from dolomite in a carbonate rock formation can be met.
In the embodiment of the present application, before step S5, the method further includes:
adjusting the data weight of the gamma energy spectrum counting to obtain the adjusted gamma energy spectrum counting;
correspondingly, performing qualitative evaluation on the magnesium element in the target stratum according to the adjusted gamma energy spectrum counting to obtain relative content change data of the magnesium element in the target stratum.
In the embodiment of the application, the gamma energy spectrum counting value in the energy window reflecting the magnesium element is very small, so that the data volatility is very small, and the data volatility can be increased by adjusting the data change weight, thereby being beneficial to subsequent qualitative evaluation. In an embodiment of the present application, adjusting the data weight of the gamma spectrum counts may uniformly subtract a certain base number from the gamma spectrum counts in the energy window reflecting the magnesium element, and then amplify the gamma spectrum counts by a certain factor, so as to increase the volatility of the gamma spectrum counts in the energy window reflecting the magnesium element.
In the embodiment of the application, the gamma energy spectrum counting in the energy window reflecting the magnesium element is obtained by preprocessing and normalizing the acquired inelastic scattering gamma energy spectrum data of the target stratum, then the rapid qualitative evaluation of the magnesium element in the stratum is realized by the gamma energy spectrum counting in the energy window reflecting the magnesium element, and the relative content change data of the magnesium element in the stratum is acquired. Compared with the energy spectrum analysis in the prior art, the method provided by the embodiment of the application utilizes the processing of inelastic scattering gamma energy spectrum data, and then utilizes the gamma counting which can reflect the energy window of the magnesium element to directly qualitatively evaluate the content of the magnesium element in the stratum.
For clarity of illustrating the beneficial effects of the embodiments of the present application, the following is exemplified:
FIG. 2 is a rock physical volume model 1 set for research of rapid qualitative evaluation of magnesium element in a formation in an embodiment of the present application. As shown, the petrophysical volume model 1 includes 5 parts: calcite 201, dolomite 202, quartz 203, kaolinite 204 and kerogen 205.
Fig. 3 is a schematic diagram of a monte carlo simulation calculation model set for studying rapid qualitative evaluation of formation magnesium in the embodiment of the present application, where the simulation calculation conditions are as follows: a pulse neutron source 311 in the pulse neutron stratum element logging instrument 31 adopts a D-T pulse neutron generator, the pulse width of the pulse neutron generator is 40 mus, the shielding body 312 is made of tungsten, the gamma detector 313 adopts a Broussonetia crystal, and the distance between the pulse neutron source 311 and the gamma detector 313 is 35 cm; the wellbore fluid 32 is fresh water, the wellbore diameter being 20 cm; the measurement formation 33 is cylindrical with a radial thickness and height of 90cm and 150cm, respectively.
The measured formation 33 is set according to the rock volumetric physics model shown in FIG. 2 using the Monte Carlo simulation computational model shown in FIG. 3, where: the volume percentages of calcite 201, dolomite 202, quartz 203, kaolinite 204 and kerogen 205 are respectively 30%, 10%, 20% and 10%, the time window for recording the gamma energy spectrum is set to be 0-40 mus, and the inelastic scattering gamma energy spectrum is recorded by simulation by using a neutron truncation method, as shown in fig. 4.
The inelastic scattering reaction of the fast neutrons and the atomic nucleus of the magnesium element mainly has 4 characteristic gamma energy peaks, and the energy is as follows: 1.36MeV, 1.8MeV, 2.75MeV and 4.23 MeV. As can be seen from fig. 4, two characteristic gamma energy peaks of magnesium with energy of 1.36MeV and 4.23MeV on the inelastic scattering gamma energy spectrum are not obvious, and therefore, the two characteristic gamma energy peaks are not suitable for reflecting the content of magnesium in the formation; because the fast neutrons and silicon element atomic nuclei generate inelastic scattering reaction to generate characteristic gamma rays with energy of 1.8MeV, and the section of the silicon element subjected to inelastic scattering reaction is much larger than that of magnesium, the characteristic gamma energy peak of the magnesium element with energy of 1.78MeV is greatly influenced by the characteristic gamma energy peak of the silicon element with energy of 1.80 MeV; near the characteristic gamma energy peak of magnesium element with energy of 2.75MeV, only influenced by the second escape peak of the characteristic gamma energy peak of calcium element with energy of 3.74 MeV; relatively, the characteristic gamma energy peak of magnesium element having an energy of 2.75MeV is least affected by other gamma energy peaks among the 4 characteristic gamma energy peaks of magnesium element. Therefore, the characteristic gamma energy peak of the magnesium element with the energy of 2.75MeV is used for reflecting that the content of the magnesium element is better than that of the characteristic gamma energy peaks with other energies. Therefore, the inelastic scattering characteristic gamma energy peak of the magnesium element with the energy of 2.75MeV is determined to reflect the content of the magnesium element in the stratum in the embodiment of the application.
Based on the range of gamma energy peaks characteristic of inelastic scattering for magnesium element with an energy of 2.75MeV in FIG. 4, the energy window for reflecting the magnesium element in the formation in the present invention is selected to be 2.63-2.84 MeV.
To verify the feasibility of using gamma spectral counts within the 2.63-2.84MeV energy window to reflect the formation magnesium element, a petrophysical volume model 2 as shown in fig. 5 was set up. As shown, the petrophysical volume model 2 includes two parts: dolomite 501 and pores 502.
By using the monte carlo simulation calculation model shown in fig. 3, the measured formation 33 is set according to the rock volume physical model shown in fig. 5, the pore 502 is saturated with oil, 9 different formation models with the volume percentages of the pore 502 being 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35% and 40% respectively are set, the time window for recording gamma energy spectra is set to be 0-40 μ s, and the inelastic scattering gamma energy spectra under 9 different formation conditions are recorded in a simulation manner by using a neutron truncation method, so that the relationship between the gamma energy spectrum count and the magnesium content in the 2.63-2.84MeV energy window reflecting magnesium elements is obtained as shown in fig. 6.
As can be seen from FIG. 6, the gamma spectrum counts within the 2.63-2.84MeV energy window reflecting the magnesium element of the formation increase with the increase of the magnesium element content and show a good linear relationship with the magnesium element content. Therefore, the feasibility of reflecting the formation magnesium element by utilizing the gamma spectral counting in the energy window of 2.63-2.84MeV is further verified.
Fig. 7 is a result diagram of rapid qualitative evaluation of formation magnesium element obtained by processing formation element logging data measured at a 3840-3880-meter well section of a sichuan X well in the embodiment of the present application. As can be seen from FIG. 7, the variation trend of the formation magnesium element rapid qualitative evaluation result obtained by the processing of the invention is basically consistent with the variation trend of the formation magnesium element content obtained by using a complex energy spectrum analysis process in the formation element logging, and the correlation of the two is up to 0.95.
As shown in fig. 8, an embodiment of the present application further provides an apparatus for qualitatively evaluating magnesium in a formation, the apparatus further includes:
the data acquisition unit 21 is used for acquiring inelastic scattering gamma energy spectrum data of the target stratum;
an energy window determining unit 22, configured to determine, according to the inelastic scattering gamma energy spectrum data, gamma ray energy reflecting inelastic scattering characteristics of magnesium element, and accordingly determine an energy window reflecting magnesium element;
a gamma spectrum count obtaining unit 23, configured to obtain, according to the inelastic scattering gamma spectrum data, a gamma spectrum count in the energy window reflecting the magnesium element;
and the qualitative evaluation unit 24 is configured to perform qualitative evaluation on the magnesium element in the target formation according to the gamma energy spectrum counting, and acquire relative content change data of the magnesium element in the target formation.
The components of the apparatus of this embodiment are respectively used to implement the steps of the method of the foregoing embodiment, and since the steps have been described in detail in the method embodiment, no further description is given here.
In the embodiment of the application, the gamma energy spectrum counting in the energy window reflecting the magnesium element is obtained by preprocessing and normalizing the acquired inelastic scattering gamma energy spectrum data of the target stratum, then the rapid qualitative evaluation of the magnesium element in the stratum is realized by the gamma energy spectrum counting in the energy window reflecting the magnesium element, and the relative content change data of the magnesium element in the stratum is acquired. Compared with the energy spectrum analysis in the prior art, the method provided by the embodiment of the application utilizes the processing of inelastic scattering gamma energy spectrum data, and then utilizes the gamma counting which can reflect the energy window of the magnesium element to directly qualitatively evaluate the content of the magnesium element in the stratum.
In one or more exemplary designs, the functions described in the embodiments of the present application may be implemented in hardware, software, firmware, or any combination of the three. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media that facilitate transfer of a computer program from one place to another. Storage media may be any available media that can be accessed by a general purpose or special purpose computer. For example, such computer-readable media can include, but is not limited to, RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store program code in the form of instructions or data structures and which can be read by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor.
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present application in further detail, and it should be understood that the above-mentioned embodiments are only examples of the embodiments of the present application and are not intended to limit the scope of the present application, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present application should be included in the scope of the present application.
Claims (8)
1. A method for qualitatively evaluating magnesium element in a stratum is characterized by comprising the following steps:
acquiring inelastic scattering gamma energy spectrum data of a target stratum;
determining gamma ray energy reflecting inelastic scattering characteristics of magnesium elements according to the inelastic scattering gamma energy spectrum data, and determining an energy window reflecting the magnesium elements according to the gamma ray energy;
acquiring gamma energy spectrum counts in the energy window reflecting the magnesium element according to the inelastic scattering gamma energy spectrum data;
performing qualitative evaluation on the magnesium element in the target stratum according to the gamma energy spectrum counting to obtain relative content change data of the magnesium element in the target stratum; wherein,
the obtaining of the gamma spectrum counts within the energy window reflecting magnesium elements from the inelastic scattering gamma spectrum data comprises:
preprocessing the inelastic scattering gamma energy spectrum data to obtain preprocessed inelastic scattering gamma energy spectrum data;
normalizing the preprocessed inelastic scattering gamma energy spectrum to obtain normalized inelastic scattering gamma energy spectrum data;
acquiring gamma energy spectrum counts in the energy window reflecting magnesium elements according to the inelastic scattering gamma energy spectrum data after normalization processing;
before qualitatively evaluating the magnesium element of the target stratum according to the gamma energy spectrum counting and acquiring relative content change data of the magnesium element in the target stratum, the method further comprises the following steps:
adjusting the data weight of the gamma energy spectrum counting to obtain the adjusted gamma energy spectrum counting;
correspondingly, performing qualitative evaluation on the magnesium element in the target stratum according to the adjusted gamma energy spectrum counting to obtain relative content change data of the magnesium element in the target stratum.
2. The method for qualitative evaluation of magnesium in formation according to claim 1, wherein the gamma ray energy reflecting the inelastic scattering characteristic of magnesium is 2.75 Mev.
3. The method for qualitatively evaluating magnesium element in stratum according to claim 2, wherein the energy window reflecting magnesium element is 2.63-2.84 MeV.
4. The method for qualitatively evaluating magnesium in the stratum according to claim 1, wherein the normalization processing is performed on the preprocessed inelastic scattering gamma energy spectrum to obtain normalized inelastic scattering gamma energy spectrum data, and the method comprises the following steps:
and normalizing the total spectral band of the preprocessed inelastic scattering gamma energy spectrum to obtain the inelastic scattering gamma energy spectrum data after normalization processing.
5. An apparatus for qualitative evaluation of formation magnesium, the apparatus comprising:
the acquisition unit is used for acquiring inelastic scattering gamma energy spectrum data of the target stratum;
the energy window determining unit is used for determining gamma ray energy reflecting inelastic scattering characteristics of magnesium elements according to the inelastic scattering gamma energy spectrum data and determining an energy window reflecting the magnesium elements according to the gamma ray energy;
the gamma energy spectrum counting acquisition unit is used for acquiring gamma energy spectrum counting in the energy window reflecting the magnesium element according to the inelastic scattering gamma energy spectrum data;
the qualitative evaluation unit is used for qualitatively evaluating the magnesium element in the target stratum according to the gamma energy spectrum counting to obtain relative content change data of the magnesium element in the target stratum; wherein,
the gamma energy spectrum counting acquisition unit comprises:
the preprocessing subunit is used for preprocessing the inelastic scattering gamma energy spectrum data to obtain preprocessed inelastic scattering gamma energy spectrum data;
the normalization processing subunit is configured to perform normalization processing on the preprocessed inelastic scattering gamma energy spectrum to obtain normalized inelastic scattering gamma energy spectrum data;
the gamma energy spectrum counting subunit is used for acquiring the gamma energy spectrum counting in the energy window reflecting the magnesium element according to the inelastic scattering gamma energy spectrum data after the normalization processing;
the device further comprises:
the data weight adjusting unit is used for adjusting the data weight of the gamma energy spectrum counting to obtain the adjusted gamma energy spectrum counting;
correspondingly, the qualitative evaluation unit is used for qualitatively evaluating the magnesium element in the target stratum according to the adjusted gamma energy spectrum counting, and obtaining relative content change data of the magnesium element in the target stratum.
6. The apparatus for qualitative evaluation of magnesium in earth formations according to claim 5, wherein the gamma ray energy reflecting the inelastic scattering characteristic of magnesium is 2.75 Mev.
7. The apparatus for qualitative evaluation of magnesium element in stratum according to claim 6, wherein said energy window reflecting magnesium element is 2.63-2.84 MeV.
8. The apparatus for qualitative evaluation of magnesium in formation according to claim 5, wherein the normalization processing is performed on the preprocessed inelastic scattering gamma energy spectrum to obtain normalized inelastic scattering gamma energy spectrum data, and comprises:
and normalizing the total spectral band of the preprocessed inelastic scattering gamma energy spectrum to obtain the inelastic scattering gamma energy spectrum data after normalization processing.
Priority Applications (1)
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