Method and system for correcting hydrocarbon content of shale oil gas rock stratum

Abstract

The invention provides a hydrocarbon content correction method and system for a shale oil gas rock stratum. The method comprises the following steps: dividing sub-layer sections based on different coring layer sections, and respectively collecting rock cores by adopting a pressure-maintaining closed coring mode and a common coring mode; respectively carrying out pyroelectric detection on the collected samples to obtain hydrocarbon contents at different temperatures; taking a relation curve between the hydrocarbon content of the single temperature interval corresponding to the pressure-maintaining closed coring mode and the total oil content as a standard rope hydrocarbon content relation; taking a relation curve of the hydrocarbon content in the single temperature interval corresponding to the common coring mode and the total oil content as a to-be-measured hydrocarbon content relation; analyzing the slope of a to-be-measured and permissible-line hydrocarbon content relation curve, judging the hydrocarbon content needing to be corrected, and determining a correction coefficient according to the slope; and determining a hydrocarbon content correction operation model of different coring layer sections in a common coring mode according to the correction coefficient. According to the scheme, the problems of large time and manpower resource consumption and insufficient data accuracy of a hydrocarbon recovery technology in the prior art are effectively solved, and reliable hydrocarbon loss correction is realized by adopting simple operation.

Description

Technical Field

[0001] The present invention relates to the technical field of resource exploration and development evaluation, and particularly to a hydrocarbon content correction method and system for shale oil and gas rock formations. Background Art

[0002] Free hydrocarbons are one of the key parameters in the evaluation of shale oil resource potential. Light hydrocarbons, due to their low viscosity and good fluidity, make an important contribution to improving the fluidity of free hydrocarbons. However, they have the characteristics of instability and easy volatilization loss. Therefore, the free hydrocarbon content measured by conventional experiments is quite different from the true content due to the loss of light hydrocarbons. Moreover, generally, the higher the maturity of mud shale, the more serious the loss of free hydrocarbons, resulting in distortion of the oil-bearing evaluation results.

[0003] Currently, the industry generally adopts a method of recovering the light hydrocarbon content based on the light hydrocarbon loss curve (the correlation curve between light hydrocarbon content and time). In addition, some technologies use the comparison between crude oil chromatography and chloroform bitumen "A" chromatography to determine the light hydrocarbon recovery coefficient; some technologies use solvent extraction to determine the light hydrocarbon content in samples of different maturities and establish the light hydrocarbon recovery coefficient during the extraction process; some technologies use the hydrocarbon generation kinetics method to simulate the light hydrocarbon content at different maturation stages to obtain the light hydrocarbon recovery coefficient.

[0004] Most of these light hydrocarbon recovery methods do not consider the light hydrocarbon loss during the sample acquisition process, and the acquisition of crude oil samples can only be said to be fortuitous. In addition, since each light hydrocarbon recovery method is only effective for the research samples, and these light hydrocarbon recovery methods all require separate experimental procedures, a large amount of time and manpower are needed to obtain the light hydrocarbon recovery coefficient. Therefore, it is difficult to widely promote and apply the above-mentioned light hydrocarbon recovery methods.

[0005] The information disclosed in the background art part of the present invention is only intended to deepen the understanding of the general background art of the present invention, and should not be regarded as an admission or any form of implication that this information constitutes the prior art known to those skilled in the art. Summary of the Invention

[0006] To solve the above problems, the present invention provides a hydrocarbon content correction method for shale oil and gas rock formations, a method for in-situ hydrocarbon content correction of shale formations by combining the core acquisition method and on-site sealed pyrolysis analysis, which corrects the light hydrocarbon content of other core samples according to the light hydrocarbon content of pressure-maintained sealed core samples, and evaluates the light hydrocarbon loss caused by other coring methods; it abandons the phenomenon of shale hydrocarbon content loss under surface normal temperature and pressure conditions, and can effectively correct the hydrocarbon loss under underground high temperature and high pressure conditions caused by different coring methods; preferably, in one embodiment, the method includes:

[0007] Distribution sampling step: For the target well, based on different coring intervals, the pressure-retaining closed coring intervals and ordinary coring intervals are divided according to the set rules respectively, and core samples are collected by pressure-retaining closed coring and ordinary coring methods respectively;

[0008] Pyrolysis detection step: For the samples collected by different coring methods, weighing and sub-sampling and pyrolysis detection are carried out according to the matching standards respectively to obtain the hydrocarbon content data at different detection temperatures;

[0009] Standard data extraction step: Select the hydrocarbon content data of the samples corresponding to the pressure-retaining closed coring method, establish the correlation curve between the hydrocarbon content in a single temperature range and the total oil content, and use it as the reference hydrocarbon content relationship;

[0010] Data to be measured processing step: Based on the samples corresponding to the ordinary coring method, obtain the hydrocarbon content data respectively, and establish the correlation curve between the hydrocarbon content in a single temperature range and the total oil content, and use it as the hydrocarbon content relationship to be measured;

[0011] Calibration model determination step: Compare and analyze the curve slopes of different hydrocarbon content relationships to be measured and the reference hydrocarbon content relationship, determine whether calibration is required, if calibration is required, determine the calibration coefficient according to the curve slope, and determine the hydrocarbon content calibration operation model for the samples of the ordinary coring method according to the calibration coefficient;

[0012] Calibration execution step: For the well sections with calibration requirements, calculate the calibrated hydrocarbon content data based on the hydrocarbon content of the ordinary core samples using the matching hydrocarbon content calibration operation model.

[0013] Optionally, in one embodiment, in the distribution sampling step, for each divided coring interval, the pressure-retaining closed coring method is used in the 1 / 3 section of the unit coring interval, and the ordinary coring method is used in the remaining sections, and the ordinary coring method includes the closed coring method and the conventional coring method.

[0014] Furthermore, in one embodiment, in the pyrolysis detection step, the closed pyrolysis detection is carried out by continuously heating a sample to a set temperature range and maintaining a set time period, wherein the hydrocarbon content data in the following experimental temperature ranges are obtained: temperature t = 0, 0 < t ≤ 90 °C and 90 °C < t ≤ 300 °C, and the maintained time period is correspondingly matched according to different temperature ranges.

[0015] Preferably, in one embodiment, the method further includes:

[0016] Pressure-retaining closed sample pretreatment step: Before the pyrolysis detection step, after the coring barrel using the pressure-retaining closed coring method reaches the surface, it is immediately placed in liquid nitrogen for freezing treatment for a set duration, and then used as the sample for the pyrolysis detection step.

[0017] Optionally, in one embodiment, in the calibration model determination step, if the correlation value of the slope of the fitting curve between the hydrocarbon content relationship to be measured and the standard hydrocarbon content relationship is greater than 0.05, it is determined that the hydrocarbon content data to be measured needs to be calibrated.

[0018] Specifically, in a preferred embodiment, in the calibration model determination step, the calibration coefficient c is determined according to the following formula based on the curve slope:

[0019] c = k p / k s

[0020] In the formula, k p is the relevant slope corresponding to the pressure-retaining closed coring, and k s is the slope corresponding to the closed coring.

[0021] Furthermore, in one embodiment, in the calibration model determination step, the hydrocarbon content calibration operation model described below is determined:

[0022] S' = S * c

[0023] In the formula, S is the hydrocarbon content measured from the sample of the ordinary coring method with calibration requirements, c is the calibration coefficient for the coring interval corresponding to the current sample, and S' is the hydrocarbon content after calibration for the current coring interval.

[0024] In a preferred embodiment, according to the engineering calibration requirements, multiple drilling intervals of various types in multiple blocks are respectively selected as the target sample intervals, and the corresponding hydrocarbon content calibration operation models are respectively determined to form a hydrocarbon content calibration operation model set. The block code, geological period parameter, rock formation maturity, and organic matter type corresponding to each hydrocarbon content calibration operation model are recorded and stored in association with the hydrocarbon content calibration operation model.

[0025] In an optional embodiment, in the calibration execution step, a hydrocarbon content calibration operation model that meets the set conditions for both the block code, geological period, rock formation maturity, and organic matter type of the drilling interval to be measured is selected as the matching hydrocarbon content calibration operation model.

[0026] Based on other aspects of the method described in any one or more of the above embodiments, the present invention also provides a storage medium, on which program code for implementing the method described in any one or more of the above embodiments is stored.

[0027] Based on the application aspect of the method described in any one or more of the above embodiments, the present invention also provides a hydrocarbon content calibration system for shale oil and gas rock formations, and the system executes the method described in any one or more of the above embodiments.

[0028] Compared with the closest prior art, the present invention also has the following beneficial effects:

[0029] A hydrocarbon content correction method and system for shale oil and gas rock formations provided by the present invention. The method collects core samples by using pressure-maintained closed coring and ordinary coring methods respectively for sub-sections divided based on different coring sections; performs thermal release detection respectively to obtain hydrocarbon contents at different detection temperatures; takes the correlation curve between the hydrocarbon content in a single temperature range corresponding to the pressure-maintained closed coring method and the total oil content as the benchmark hydrocarbon content relationship; takes the correlation curve between the hydrocarbon content in a single temperature range corresponding to the ordinary coring method and the total oil content as the to-be-detected hydrocarbon content relationship; compares and analyzes the curve slopes of different to-be-detected hydrocarbon content and benchmark hydrocarbon content relationships, determines the hydrocarbon content to be corrected, and determines the correction coefficient according to the curve slope; thereby determines the hydrocarbon content correction operation model for the ordinary coring method in different coring sections according to the correction coefficient, and realizes hydrocarbon content correction and restoration operations; adopting this solution can achieve hydrocarbon loss correction during the oil and gas exploration process, save a large amount of costs in terms of time, and avoid designing experiments separately, saving a large amount of testing costs;

[0030] In addition, this solution corrects the light hydrocarbon content of other core samples according to the light hydrocarbon content of the pressure-maintained closed core samples, evaluates the light hydrocarbon loss caused by other coring methods, can effectively make up for the defect that the traditional light hydrocarbon restoration method cannot accurately evaluate the light hydrocarbon loss during the coring stage, helps to accurately evaluate the in-situ oil content of shale, and can provide strong support for objectively evaluating the in-situ gas-oil ratio, predicting the physical properties of formation fluids and formation pressure anomalies.

[0031] Other features and advantages of the present invention will be described in the following description, and in part will be obvious from the description, or understood by implementing the present invention. The objectives and other advantages of the present invention can be realized and obtained through the structures specifically pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings are used to provide a further understanding of the present invention, and constitute a part of the description, and are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention. In the drawings:

[0033] Figure 1 is a schematic flow chart of a hydrocarbon content correction method for shale oil and gas rock formations provided by an embodiment of the present invention;

[0034] Figure 2 is a schematic flow chart of a hydrocarbon content correction method for shale oil and gas rock formations provided by another embodiment of the present invention;

[0035] Figure 3 is a coring method section distribution and gas logging curve diagram of a hydrocarbon content correction method for shale oil and gas rock formations provided by an embodiment of the present invention;

[0036] Figure 4It is the comparison diagram of the relationship distribution between the pressure-maintained sealed core and the sealed core S g value and the total thermally released hydrocarbon content in the hydrocarbon content correction method for shale oil and gas rock formations provided by the embodiments of the present invention;

[0037] Figure 5 It is the comparison diagram of the relationship distribution between the pressure-maintained sealed core and the sealed core S 0 * value and the total thermally released hydrocarbon content in the hydrocarbon content correction method for shale oil and gas rock formations provided by the embodiments of the present invention;

[0038] Figure 6 It is the comparison diagram of the relationship distribution between the pressure-maintained sealed core and the sealed core S 1 value and the total thermally released hydrocarbon content in the hydrocarbon content correction method for shale oil and gas rock formations provided by another embodiment of the present invention;

[0039] Figure 7 It is the comparison diagram of the relationship distribution between the pressure-maintained sealed core and the sealed core S g value after correction and the total thermally released hydrocarbon content in the hydrocarbon content correction method for shale oil and gas rock formations provided by the embodiments of the present invention;

[0040] Figure 8 It is the structural schematic diagram of the hydrocarbon content correction system for shale oil and gas rock formations provided by the embodiments of the present invention. Detailed implementation manners

[0041] The following will combine the drawings and embodiments to detail the implementation manners of the present invention, so that the implementers of the present invention can fully understand how the present invention uses technical means to solve technical problems and achieve the implementation process of technical effects, and specifically implement the present invention according to the above implementation process. It should be noted that as long as there is no conflict, each embodiment in the present invention and each feature of each embodiment can be combined with each other, and the formed technical solutions are all within the protection scope of the present invention.

[0042] Although the flowchart describes the operations as sequential processing, many of the operations can be performed in parallel, concurrently, or simultaneously. The order of the operations can be rearranged. When the operations are completed, the processing can be terminated, but there can also be additional steps not included in the drawings. The processing can correspond to a method, function, procedure, subroutine, subprogram, etc.

[0043] Computer devices include user devices and network devices. Among them, user devices or clients include, but are not limited to, computers, smart phones, PDAs (Personal Digital Assistants), etc.; network devices include, but are not limited to, a single network server, a server group composed of multiple network servers, or a cloud composed of a large number of computers or network servers based on cloud computing. The computer device can run alone to implement the present invention, or can be connected to a network and implement the present invention through interactive operations with other computer devices in the network. The network where the computer device is located includes, but is not limited to, the Internet, wide area network, metropolitan area network, local area network, VPN network, etc.

[0044] Here, terms such as "first", "second", etc. may be used to describe various units, but these units should not be limited by these terms. These terms are only used to distinguish one unit from another. The term "and / or" used herein includes any and all combinations of one or more of the listed associated items. When a unit is referred to as being "connected" or "coupled" to another unit, it can be directly connected or coupled to the other unit, or there may be an intermediate unit.

[0045] The terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms "a", "an" used herein are also intended to include the plural. It should also be understood that the terms "comprises" and / or "comprising" used herein specify the presence of the stated features, integers, steps, operations, units and / or components, and do not preclude the presence or addition of one or more other features, integers, steps, operations, units, components and / or their combinations.

[0046] Free hydrocarbons are one of the key parameters in the evaluation process of shale oil resource potential, and are generally characterized by the pyrolysis parameter S. 1 Light hydrocarbons (hydrocarbon substances with elements before C10) have an important contribution to improving the fluidity of free hydrocarbons due to their low viscosity and good fluidity, but they have the characteristics of instability and easy volatilization loss. Therefore, the free hydrocarbon content measured by conventional experiments has a large difference from the true content due to the loss of light hydrocarbons, and usually, the higher the maturity of the mud shale, the more serious the loss of its free hydrocarbons, resulting in distortion of the oil-bearing evaluation results.

[0047] Currently, the industry generally adopts a method of recovering the light hydrocarbon content based on the light hydrocarbon loss curve (the correlation curve between the light hydrocarbon content and time). In addition, some technologies use the comparison of crude oil chromatography and chloroform bitumen "A" chromatography to determine the light hydrocarbon recovery coefficient; some technologies use solvent extraction to determine the light hydrocarbon content in samples with different maturities and establish the light hydrocarbon recovery coefficient during the extraction process; some technologies use the hydrocarbon generation kinetics method to simulate the light hydrocarbon content at different maturation stages to obtain the light hydrocarbon recovery coefficient.

[0048] Most of these light hydrocarbon recovery methods do not consider the light hydrocarbon loss during the acquisition of fresh samples, and the acquisition of crude oil samples can only be said to be a matter of chance. In addition, since each light hydrocarbon recovery method is only effective for the studied samples, and these light hydrocarbon recovery methods all require separate experimental procedures, a large amount of time and manpower are needed to obtain the light hydrocarbon recovery coefficient. Therefore, it is difficult to widely promote and apply the above light hydrocarbon recovery methods.

[0049] It should be noted that the researchers of the present invention found that during the process of core acquisition where the sample experiences drilling extraction - out of the barrel - normal temperature placement, the rapid drop and release of temperature and pressure will cause a large amount of hydrocarbons to precipitate and disperse. Most of the flowable hydrocarbons will volatilize completely during this stage. Data shows that the loss amount can account for more than 90% of the total loss amount.

[0050] Based on this, the researchers of the present invention propose that the light hydrocarbon content of fresh samples can be detected without loss first, and then the light hydrocarbon loss during the acquisition of fresh samples can be scientifically recovered by considering the content data without light hydrocarbon loss. Such an approach has special significance for the research on light hydrocarbon loss and recovery in the field. Currently, on - site closed - system thermal desorbed hydrocarbon detection can basically achieve the detection of light hydrocarbon content without loss; by combining the analysis of rock samples with different core acquisition methods, a reliable analysis of the light hydrocarbon loss during core acquisition can be carried out, thus providing strong support for the research on the hydrocarbon content of oil and gas rock formations.

[0051] The pressure - maintaining coring or conventional coring methods cannot maintain the pressure inside the rock. While the pressure is lost, hydrocarbon substances are also lost, and the loss degree is affected by comprehensive factors such as coring time, formation pressure, and rock pore structure. In addition, after the core reaches the surface and is exposed to the atmospheric environment, hydrocarbon loss is constantly occurring. The high - pressure loss and surface low - pressure loss of hydrocarbon substances during coring have different characteristics. Under high - pressure conditions, it is rapid seepage loss, and under low - pressure conditions, it is slow diffusion. It is obviously unscientific to estimate the high - pressure seepage loss during coring using the loss law under surface low - pressure conditions, so it causes serious errors in the estimation of in - situ oil content.

[0052] To solve the above problems, the present invention provides a method and system for hydrocarbon content correction of shale oil and gas rock formations, which corrects the light hydrocarbon content of rocks based on the on-site sealed pyrolysis hydrocarbon detection data of different coring methods. By detecting the sealed pyrolysis hydrocarbon content of the core samples obtained by the pressure-maintained sealed coring method at the drilling site, the light hydrocarbon content under the original conditions is obtained as the true light hydrocarbon content of the rock formation, and the same sealed pyrolysis hydrocarbon content detection is carried out on the core samples obtained by other coring methods. The light hydrocarbon content of other core samples is corrected according to the light hydrocarbon content of the pressure-maintained sealed core samples, and the light hydrocarbon loss caused by other coring methods is evaluated; this method can effectively make up for the defect that the traditional light hydrocarbon recovery method cannot accurately evaluate the light hydrocarbon loss in the coring stage, and has important reference significance for the evaluation of shale oil resources.

[0053] Next, the detailed process of the method of the embodiment of the present invention will be described in detail based on the accompanying drawings. The steps shown in the flowchart of the accompanying drawings can be executed in a computer system including a set of computer-executable instructions. Although the logical order of the steps is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0054] Embodiment 1:

[0055] Figure 1 The schematic flowchart of the hydrocarbon content correction method for shale oil and gas rock formations provided by Embodiment 1 of the present invention is shown. Referring to Figure 1 It can be seen that the method includes the following steps.

[0056] Distribution sampling step: Based on different coring intervals of the target well, the pressure-maintained sealed coring intervals and ordinary coring intervals are divided according to the set rules respectively, and the core samples are collected by the pressure-maintained sealed coring and ordinary coring methods respectively;

[0057] Pyrolysis detection step: For the samples collected by different coring methods, weight sub-sampling and pyrolysis detection are carried out respectively according to the matching standards to obtain the hydrocarbon content data at different detection temperatures;

[0058] Standard data extraction step: Select the hydrocarbon content data of the samples corresponding to the pressure-maintained sealed coring method, and establish the correlation curve between the hydrocarbon content in a single temperature range and the total oil content as the criterion (standard) hydrocarbon content relationship;

[0059] Data to be measured processing step: Based on the samples corresponding to the ordinary coring method, the hydrocarbon content data are obtained respectively, and the correlation curve between the hydrocarbon content in a single temperature range and the total oil content is established as the hydrocarbon content relationship to be measured;

[0060] Calibration model determination step: Compare and analyze the curve slopes of the relationships between different hydrocarbon contents to be measured and the reference hydrocarbon content relationship, determine whether calibration is required, if calibration is required, determine the calibration coefficient based on the curve slope, and determine the hydrocarbon content calibration operation model for samples obtained by the ordinary coring method according to the calibration coefficient;

[0061] Calibration execution step: For the drilling intervals with calibration requirements, calculate the calibrated hydrocarbon content data based on the hydrocarbon content of the ordinary coring samples using the matching hydrocarbon content calibration operation model.

[0062] In the same formation, the gas logging content is high in the sealed coring or conventional coring intervals, and low in the pressure-maintained sealed coring interval, and is several times lower than that in the sealed coring or conventional coring intervals. That is to say, the degree of light hydrocarbon loss is closely related to the coring method, and the coring method has a direct impact on the gas logging content. The pressure-maintained sealed coring method can effectively retain more light hydrocarbons.

[0063] The above embodiments of the present invention realize the calibration of the light hydrocarbon content of rocks based on the on-site sealed pyrolysis hydrocarbon detection data of different coring methods. By detecting the sealed pyrolysis hydrocarbon content of the core samples obtained by the pressure-maintained sealed coring method at the drilling site, the light hydrocarbon content under the original conditions is obtained as the reference hydrocarbon content of the rock formation. The same sealed pyrolysis hydrocarbon content detection is carried out on the core samples obtained by other coring methods to obtain the hydrocarbon content data, and the light hydrocarbon content of other core samples is calibrated according to the light hydrocarbon content of the pressure-maintained sealed core samples, and the light hydrocarbon loss caused by other coring methods is analyzed; this method can effectively overcome the defect that the traditional light hydrocarbon recovery method cannot accurately evaluate the light hydrocarbon loss during the coring stage and realize the precise study of the light hydrocarbon content of the rock formation.

[0064] Preferably, in one embodiment, in the distributed sampling step, for each divided coring interval, the pressure-maintained sealed coring method is adopted in the 1 / 3 coring interval of the unit coring interval, and the ordinary coring method is adopted for the rest of the interval. The ordinary coring method includes the sealed coring method and the conventional coring method. In actual application, samples are taken at intervals of one meter, and a sample is collected every one meter of well depth interval.

[0065] Among them, the division of the coring intervals is determined by the decision-making of the oilfield drilling design principle and is not restricted by on-site experiments; based on this, the subsequent on-site experimental work is naturally carried out under the conditions of the drilling design principle; in actual application, the drilling design principle is determined according to regional seismic and adjacent well data. The specific method for determining the drilling design principle can be realized by those skilled in the art using feasible solutions in the field according to the conditions of the drilling site, and the present invention does not specifically limit it.

[0066] Further, in one embodiment, in the pyrolysis detection step, for the samples collected by different coring methods, weight separation and pyrolysis detection are respectively carried out according to the matching standards to obtain the hydrocarbon content data at different detection temperatures;

[0067] Specifically, in an alternative embodiment, in the pyroelectric detection step, a closed pyroelectric detection is performed by continuously heating a sample to a set temperature range and maintaining it for a set time period. Among them, hydrocarbon content data in the following experimental temperature ranges are obtained: temperature t = 0, 0 < t ≤ 90 °C, and 90 °C < t ≤ 300 °C, and the maintained time period is set correspondingly according to different temperature ranges.

[0068] In actual application, the sample is weighed and taken for closed pyroelectric detection to obtain hydrocarbon content information of Sg (not heated), S0* (temperature ≤ 90 °C), and S1 (temperature between 90 - 300 °C); the maintained time period of the detection can be set by technicians according to actual detection requirements, and the maintained time periods in different test stages can be set to be the same or different. For example, it can be set as follows: keep it for 3 minutes without heating to test S g , heat it up to 90 degrees and keep it at a constant temperature for 3 minutes to test S 0 *, then heat it up to 300 degrees and keep it at a constant temperature for 12 minutes to test S 1 , and the heating rate is 50 degrees per minute.

[0069] Based on this, through closed pyroelectric detection and analysis, S g , S 0 *, and S 1 are obtained, and three pyroelectric peaks are obtained. The S g peak is mainly composed of C1 - C5 gaseous hydrocarbons, the S 0 * peak is mainly composed of C6 - C10 light hydrocarbons, and the S 1 peak is mainly composed of C10+ hydrocarbons; Total = S g +S 0 *+S 1 represents the total pyroelectric hydrocarbon amount.

[0070] In actual application, the on - site closed pyroelectric detection and analysis method can place the sample in a closed system to detect the hydrocarbon substances released by the sample, avoiding the problem of hydrocarbon loss caused by the sample contacting the atmospheric environment. The on - site closed pyroelectric analysis detects the content of hydrocarbon substances released by rocks ≤ 300 °C, that is, the so - called free oil content. Combining with pressure - maintained closed coring, sampling is carried out from the central position of the pressure - maintained closed core after liquid nitrogen freezing for closed pyroelectric analysis to obtain the true formation oil - bearing information. For the core samples obtained by ordinary coring methods, after reaching the ground, they are normally sub - sampled and weighed according to the requirements of pyroelectric detection to carry out closed pyroelectric analysis to obtain hydrocarbon content information at different temperatures.

[0071] Furthermore, in the standard data extraction step, the hydrocarbon content data of the samples corresponding to the pressure - maintained closed coring method are selected, and the correlation curve between the hydrocarbon content in a single temperature range and the total oil content is established as the standard hydrocarbon content relationship;

[0072] Execute the steps for processing the data to be measured, obtain the hydrocarbon content data for the samples corresponding to the ordinary coring method respectively, establish the correlation curve between the hydrocarbon content in a single temperature range and the total oil content, and use it as the relationship of the hydrocarbon content to be measured.

[0073] Next, compare the hydrocarbon content data of the pressure-maintained sealed core and the cores obtained by other coring methods. Taking the hydrocarbon content of the pressure-maintained sealed core as the criterion, determine the correction coefficient according to the slope of the correlation curve between the hydrocarbon content in a single temperature range and the total oil content, and correct the hydrocarbon content data of the cores obtained by other coring methods to obtain the true hydrocarbon content information of the formation. Based on this, execute the correction model determination step, compare and analyze the curve slopes of different relationships of the hydrocarbon content to be measured and the criterion hydrocarbon content relationship, and determine whether correction is required. If correction is required, determine the correction coefficient according to the curve slope.

[0074] Preferably, in one embodiment, in the correction model determination step, if the slope correlation value of the fitting curve between the relationship of the hydrocarbon content to be measured and the criterion hydrocarbon content relationship is greater than 0.05, it is determined that the hydrocarbon content data to be measured needs to be corrected; the slope correlation value uses the absolute value of the difference between the slopes of the two fitting curves, that is, |k p -k s |.

[0075] Specifically, in an optional embodiment, in the correction model determination step, the correction coefficient c is determined according to the following formula based on the curve slope:

[0076] c = k p / k s In the formula, k p is the relevant slope corresponding to the pressure-maintained sealed coring, and k s is the slope corresponding to the sealed coring.

[0077] Furthermore, execute the correction execution step, and according to the correction model, determine the hydrocarbon content correction operation model for the samples obtained by the ordinary coring method, which is used to calculate the corrected hydrocarbon content data based on the hydrocarbon content of the ordinary coring samples for the matching drilling intervals with correction requirements.

[0078] Specifically, in an optional embodiment, in the correction model determination step, determine the hydrocarbon content correction operation model as described below:

[0079] S’ = S * c

[0080] In the formula, S is the hydrocarbon content measured for the samples obtained by the ordinary coring method with correction requirements, c is the correction coefficient corresponding to the current sample's coring interval, and S’ is the corrected hydrocarbon content of the current coring interval.

[0081] In actual application, multiple types of drilling intervals in multiple blocks can be selected as target sample intervals according to the calibration application requirements in the project, and the corresponding hydrocarbon content calibration operation models can be determined respectively according to the operations in the above embodiments of the present invention, so as to constitute a hydrocarbon content calibration operation model set for diversified calibration application requirements.

[0082] Record the block code, geological period parameters, rock formation maturity, and organic matter type corresponding to each hydrocarbon content calibration operation model, and store them in association with the hydrocarbon content calibration operation model; in an optional embodiment, storage is implemented with the block code and geological period as indexes for convenient retrieval and call during subsequent application.

[0083] Therefore, based on the determined hydrocarbon content calibration operation model, when the drilling interval to be measured has a hydrocarbon content analysis requirement during actual application, after sampling and detection are carried out by using the ordinary coring method, the hydrocarbon content result consistent with the actual situation of the drilling interval can be calculated by using the hydrocarbon content calibration operation model determined in the embodiment of the present invention based on the detected hydrocarbon content data.

[0084] In actual application, first select the satisfied hydrocarbon content calibration operation model according to the block code and geological period of the drilling interval to be measured, and further determine the hydrocarbon content calibration operation model whose rock formation maturity and organic matter type are both satisfied with the set conditions compared with the rock formation maturity and organic matter type of the drilling interval to be measured from the selected one or more hydrocarbon content calibration operation models; as the hydrocarbon content calibration operation model matched with the current drilling interval to be measured.

[0085] Then, after sampling and detection are carried out on the current drilling interval to be measured by using the ordinary coring method, calibration operation is carried out by using the matched hydrocarbon content calibration operation model to obtain the hydrocarbon content result consistent with the actual situation of the drilling interval.

[0086] Generally, in the same sedimentary basin block, the strata with the same geological period and similar lithology, maturity, and organic matter type can be applied horizontally. Specifically, the lithology of the drilling strata can be judged according to the rock mineral composition, the rock formation maturity is usually represented by the vitrinite reflectance, and the organic matter type is usually determined according to the kerogen type and microscopic components.

[0087] On the other hand, if no matched hydrocarbon content calibration operation model is identified for the current drilling interval to be measured, it can be used as a sample drilling interval, and the distribution sampling step, pyrolysis detection step, standard data extraction step, measured data processing step, and calibration model determination step are carried out according to the method of the embodiment of the present invention to determine the corresponding calibration coefficient, and then the corresponding hydrocarbon content calibration operation model is obtained and stored in the hydrocarbon content calibration operation model set to enrich the model data of the hydrocarbon content calibration operation model set, so as to provide more comprehensive model support for subsequent application.

[0088] Using the hydrocarbon content correction method for shale oil and gas strata provided by the embodiments of the present invention, a method for in-situ hydrocarbon content correction of shale formations that combines core acquisition methods and on-site sealed pyrolysis analysis not only eliminates the phenomenon of hydrocarbon content loss in shale under surface normal temperature and pressure conditions, but also effectively corrects the hydrocarbon loss under underground high temperature and pressure conditions caused by different coring methods.

[0089] When applying the solution of the present invention, at least the following beneficial effects can be achieved:

[0090] (1) During the oil and gas exploration process, hydrocarbon loss correction can be achieved. The hydrocarbon loss correction process is included in the drilling coring and on-site testing processes, saving a large amount of costs in terms of time, avoiding separate experimental design, and saving a large amount of testing costs.

[0091] (2) Considering the hydrocarbon loss behavior during the storage of reference samples, based on accurate reference data, the hydrocarbon loss during the coring process is corrected. The corrected data represents the in-situ oil content under formation conditions and is closer to the true value. This method not only helps to accurately evaluate the in-situ oil content of shale, but also provides strong support for objectively evaluating the in-situ gas-oil ratio, predicting the physical properties of formation fluids, and formation pressure anomalies.

[0092] Embodiment 2:

[0093] Figure 2 The flow schematic diagram of the hydrocarbon content correction method for shale oil and gas strata provided by Embodiment 2 of the present invention is shown. Referring to Figure 2 it can be seen that this method includes the following steps.

[0094] Distribution sampling step: Based on different coring intervals of the target well, the pressure-retaining sealed coring intervals and ordinary coring intervals are divided according to set rules respectively, and core samples are collected by pressure-retaining sealed coring and ordinary coring methods respectively;

[0095] Pyrolysis detection step: For the samples collected by different coring methods, weighing and sub-sampling and pyrolysis detection are carried out respectively according to the matching standards to obtain the hydrocarbon content data at different detection temperatures;

[0096] Standard data extraction step: Select the hydrocarbon content data of the samples corresponding to the pressure-retaining sealed coring method, and establish the correlation curve between the hydrocarbon content in a single temperature range and the total oil content as the reference hydrocarbon content relationship;

[0097] Data to be measured processing step: Based on the samples corresponding to the ordinary coring method, the hydrocarbon content data are obtained respectively, and the correlation curve between the hydrocarbon content in a single temperature range and the total oil content is established as the hydrocarbon content relationship to be measured;

[0098] Calibration model determination step: Compare and analyze the curve slopes of the hydrocarbon content relationships of different samples to be measured and the reference hydrocarbon content relationship, determine whether calibration is required, if calibration is required, determine the calibration coefficient based on the curve slope, and determine the hydrocarbon content calibration operation model for samples obtained by the ordinary coring method according to the calibration model;

[0099] Calibration execution step: For the drilling intervals that require calibration, calculate the calibrated hydrocarbon content data based on the hydrocarbon content of the ordinary coring samples using the matching hydrocarbon content calibration operation model. Example 2 is a variant of the solution of Example 1, so the steps that are the same as or similar to those in Example 1 will not be described again, and only the different steps will be described.

[0100] Furthermore, in a preferred embodiment, the method further includes:

[0101] Pre-treatment step for pressure-maintained sealed samples: Before the thermal release detection step, after the coring barrel of the rock sample obtained by the pressure-maintained sealed coring method reaches the surface, it is immediately placed in liquid nitrogen for freezing treatment for a set duration, and then used as the sample for the thermal release detection step.

[0102] During the on-site exploration of shale oil, considering the loss of light hydrocarbons, the pressure-maintained sealed coring method has received increasing attention. In order to obtain the true oil-bearing information of the formation, after the oil and gas explorers take the core to the surface by the pressure-maintained sealed method, the entire pressure-maintained sealed coring barrel (with the core sealed) is frozen with liquid nitrogen for more than 4 hours, which can effectively prevent the volatilization loss of light hydrocarbon substances in the core and ensure to the greatest extent that the hydrocarbon content data obtained from the thermal release detection of the samples collected by the pressure-maintained sealed coring method is consistent with the true hydrocarbon content data.

[0103] The present invention will be further described below in conjunction with implementation cases. The scope of the present invention is not limited by the embodiments, and the scope of the present invention is set forth in the claims.

[0104] The following will take the shale coring interval of the Qingshankou Formation in a shale oil exploration well in the Songliao Basin as an example for analysis and description.

[0105] The set unit coring interval of the shale in the Qingshankou Formation of this well is 217 meters, of which 74 meters are cored by the pressure-maintained sealed method, and the remaining 143 meters are cored by the sealed method. In this implementation case, two coring methods, namely the pressure-maintained sealed coring and the sealed coring, are adopted in the coring interval, and the two coring methods are implemented at intervals.

[0106] Figure 3 Shows the coring method distribution and gas logging curves. The gas logging concentration can reflect the lost hydrocarbons; it can be clearly seen from the figure that the gas logging value of the pressure-maintained sealed coring interval is much lower than that of the sealed coring interval.

[0107] After the pressure-maintained sealed coring barrel reaches the ground, it is placed in liquid nitrogen for freezing for 4 hours, and then sampling is carried out.

[0108] In actual application, samples are taken at intervals of 1 meter, and then closed pyrolysis analysis is carried out.

[0109] The closed pyrolysis analysis method can be based on the scheme in the literature (Evaluation of shale oil-bearing characteristics by rock closed pyrolysis method - Taking the Jurassic Daanzhai section in the Sichuan Basin as an example, Petroleum Geology & Experiment, Luo Chao, Zhang Huanxu, etc.).

[0110] Closed pyrolysis analysis obtains S g , S 0 *, and S 1 Three pyrolysis peaks, the S g peak is mainly composed of C1-C5 gaseous hydrocarbons, and the S 0 * peak is mainly composed of C6-C10 light hydrocarbons, and the S 1 peak is mainly composed of C10+ hydrocarbons; during actual detection, the hydrocarbon content in different temperature segments can be obtained by continuously heating a sample. For example, in a certain embodiment, it can be to keep the temperature at 3 minutes without heating to test S g , heat up to 90 degrees and keep the temperature constant for 3 minutes to test S 0 *, then heat up to 300 degrees and keep the temperature constant for 12 minutes to test S 1 , and the heating rate is 50 degrees / minute.

[0111] After the closed core reaches the ground, samples are taken for closed pyrolysis analysis under the same conditions to obtain the same parameters. Total = S g +S 0 *+S 1 represents the total pyrolysis hydrocarbon amount.

[0112] Figure 4 , Figure 5 and Figure 6 respectively represent the correlation between the S g , S 0 *, and S 1 content of each single type of hydrocarbon in the pressure-maintained closed core and the closed core and the total pyrolysis hydrocarbon content (oil content); taking Figure 4 as an example, the ordinate in the figure represents Sg, that is, the gaseous hydrocarbon content, and the abscissa represents the total oil content. The total oil content = S g +S 0 *+S 1 .

[0113] From Figure 5 and Figure 6 it can be seen that the S 0 *, and S 1 data of the pressure-maintained closed core and the closed core are closely intertwined, and the slopes of the correlation curves with the total pyrolysis hydrocarbon content are very close, indicating that both the pressure-maintained closed and closed coring methods have well retained the S 0 *, and S 1, the two coring methods have good consistency, indicating that the S of the current layer in this implementation case 0 * and S 1 data do not require correction. However, in actual applications, there may be cases where the S 0 * and S 1 data need to be corrected.

[0114] Figure 4 clearly reflects that the pressure-maintained sealed core S g is greater than the sealed core S g value. The slopes of the correlation curves of the two with the total thermally released hydrocarbon content differ by nearly a factor of 1, indicating that the sealed coring method has caused the loss of gaseous hydrocarbons.

[0115] The correction coefficient is determined by the slope to be 1.78. Figure 7 shows the relationship between the corrected S g value and the total thermally released hydrocarbon content. The S g of different coring methods are closely intertwined, indicating that the corrected S g value has good consistency with the true hydrocarbon content data.

[0116] The calculation of the correction coefficient can be expressed by the formula:

[0117] c = k p / k s

[0118] In the formula, k p is the relevant slope corresponding to the pressure-maintained sealed coring, and k s is the slope corresponding to the sealed coring.

[0119] Further, based on the correction coefficient c, the corrected data S' is calculated according to the following formula:

[0120] S' = S * c

[0121] In the formula, S is the hydrocarbon content measured from the sample of the ordinary coring method that requires correction, c is the correction coefficient corresponding to the coring layer of the current sample, and S' is the hydrocarbon content corrected for the current coring layer.

[0122] For the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0123] It should be noted that in other embodiments of the present invention, the method can also be combined with one or several of the above embodiments to obtain a new hydrocarbon content correction method for shale oil and gas formations, so as to achieve accurate research on the true hydrocarbon content data of oil and gas formations.

[0124] It should be noted that based on the method in any one or more of the above embodiments of the present invention, the present invention also provides a storage medium, on which program codes capable of implementing the method described in any one or more of the above embodiments are stored. When the codes are executed by an operating system, the hydrocarbon content correction method for shale oil and gas formations as described above can be implemented.

[0125] Embodiment 3:

[0126] In the above embodiments disclosed by the present invention, the method is described in detail. The method of the present invention can be implemented by various forms of devices or systems. Therefore, based on other aspects of the method in any one or more of the above embodiments, the present invention also provides a hydrocarbon content correction system for shale oil and gas formations, which is used to execute the hydrocarbon content correction method for shale oil and gas formations described in any one or more of the above embodiments. Specific embodiments are given below for detailed description.

[0127] Specifically, Figure 8 shows a schematic structural diagram of the hydrocarbon content correction system for shale oil and gas formations provided in the embodiments of the present invention. As Figure 8 shown, the system includes:

[0128] A distributed sampling module, configured to divide a pressure-retaining and airtight coring section and a common coring section respectively according to a set rule based on different coring sections of a target well, and collect core samples by using pressure-retaining and airtight coring and common coring methods respectively;

[0129] A thermal release detection module, configured to perform weighing and sub-sampling and thermal release detection on the samples collected by different coring methods respectively according to matching standards, and obtain hydrocarbon content data at different detection temperatures;

[0130] A standard data extraction module, configured to select the hydrocarbon content data of the samples corresponding to the pressure-retaining and airtight coring method, establish a correlation curve between the hydrocarbon content in a single temperature range and the total oil content thereof, and use it as a criterion hydrocarbon content relationship;

[0131] A to-be-tested data processing module, configured to obtain hydrocarbon content data based on the samples corresponding to the common coring method respectively, establish a correlation curve between the hydrocarbon content in a single temperature range and the total oil content thereof, and use it as a to-be-tested hydrocarbon content relationship;

[0132] A calibration model determination module configured to comparatively analyze the curve slopes of different hydrocarbon content relationships to be measured and the reference hydrocarbon content relationship, determine whether calibration is required, if calibration is required, determine a calibration coefficient based on the curve slope, and determine a hydrocarbon content calibration operation model for samples in the ordinary coring method according to the calibration coefficient;

[0133] A calibration execution module configured to calculate calibrated hydrocarbon content data for a well drilling section with a calibration requirement based on the hydrocarbon content of ordinary coring samples using a matching hydrocarbon content calibration operation model.

[0134] Optionally, in one embodiment, the distributed sampling module is configured to: for each divided coring section, use the pressure-retaining and airtight coring method in the 1 / 3 section of the unit coring section, and use the ordinary coring method for the remaining section, and the ordinary coring method includes the airtight coring method and the conventional coring method.

[0135] Further, in one embodiment, the thermal release detection module performs airtight thermal release detection by continuously heating a sample to a set temperature range and maintaining a set time period, and obtains hydrocarbon content data in the following experimental temperature ranges: temperature t = 0, 0 < t ≤ 90 °C, and 90 °C < t ≤ 300 °C, and the maintained time period is correspondingly and matchedly set according to different temperature ranges.

[0136] Preferably, in one embodiment, the system further includes:

[0137] A pressure-retaining and airtight sample pretreatment module configured to, before performing thermal release detection, immediately place the core barrel using the pressure-retaining and airtight coring method in liquid nitrogen for freezing treatment for a set duration after reaching the surface, and then use it as a sample for the thermal release detection module to perform thermal release detection.

[0138] Optionally, in one embodiment, the calibration model determination module is configured to: if the correlation value of the slope of the fitting curve of the hydrocarbon content relationship to be measured and the reference hydrocarbon content relationship is greater than 0.05, determine that the hydrocarbon content data to be measured needs to be calibrated.

[0139] Specifically, in a preferred embodiment, the calibration model determination module determines the calibration coefficient c according to the following formula based on the curve slope:

[0140] c = k p / k s

[0141] In the formula, k p is the relevant slope corresponding to the pressure-retaining and airtight coring, and k s is the slope corresponding to the airtight coring.

[0142] Further, in one embodiment, the calibration model determination module determines the following hydrocarbon content calibration operation model:

[0143] S’ = S * c

[0144] Wherein, S is the hydrocarbon content measured from the samples in the ordinary coring method with calibration requirements, c is the calibration coefficient for the coring interval corresponding to the current sample, and S’ is the hydrocarbon content after calibration for the current coring interval.

[0145] In practical applications, in a preferred embodiment, multiple types of drilling intervals in multiple blocks are respectively selected as target sample intervals according to engineering calibration requirements, and the corresponding hydrocarbon content calibration operation models are respectively determined to form a hydrocarbon content calibration operation model set. The block code, geological period parameters, rock formation maturity, and organic matter type corresponding to each hydrocarbon content calibration operation model are recorded and stored in association with the hydrocarbon content calibration operation model.

[0146] In an alternative embodiment, the calibration execution module is configured to select a hydrocarbon content calibration operation model that meets the set conditions for the block code, geological period, rock formation maturity, and organic matter type of the drilling interval to be measured as the matching hydrocarbon content calibration operation model.

[0147] In the hydrocarbon content calibration system for shale oil and gas rock formations provided by the embodiments of the present invention, each module or unit structure can operate independently or in combination according to actual sample processing requirements and detection operation requirements to achieve corresponding technical effects.

[0148] It should be understood that the embodiments disclosed in the present invention are not limited to the specific structures, processing steps, or materials disclosed herein, but should extend to equivalent alternatives of these features understood by those of ordinary skill in the relevant art. It should also be understood that the terms used herein are only for the purpose of describing specific embodiments and do not imply limitation.

[0149] The phrase "an embodiment" mentioned in the specification means that the specific features, structures, or characteristics described in connection with the embodiment are included in at least one embodiment of the present invention. Therefore, the phrase "an embodiment" that appears throughout the specification does not necessarily refer to the same embodiment.

[0150] Although the disclosed embodiments of the present invention are as above, the described content is only an embodiment adopted for the convenience of understanding the present invention and is not intended to limit the present invention. Any person skilled in the technical field to which the present invention pertains can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed by the present invention. However, the scope of patent protection of the present invention shall still be subject to the scope defined by the appended claims.

Claims

1. A method for correcting hydrocarbon content in shale oil and gas formations, characterized in that: The method includes: Distribution sampling step: Based on different coring intervals of the target well, the pressure-maintained closed coring intervals and ordinary coring intervals are divided according to set rules respectively, and core samples are collected by pressure-maintained closed coring and ordinary coring methods respectively; Pyrolysis detection step: For the samples collected by different coring methods, weighing and sub-sampling and pyrolysis detection are carried out according to the matching standards respectively to obtain hydrocarbon content data at different detection temperatures; Standard data extraction step: Select the hydrocarbon content data of the samples corresponding to the pressure-maintained closed coring method, and establish a correlation curve between the hydrocarbon content in a single temperature range and the total oil content as the reference hydrocarbon content relationship; Data to be measured processing step: Based on the samples corresponding to the ordinary coring method, hydrocarbon content data are obtained respectively, and a correlation curve between the hydrocarbon content in a single temperature range and the total oil content is established as the hydrocarbon content relationship to be measured; Calibration model determination step: Compare and analyze the curve slopes of different hydrocarbon content relationships to be measured and the reference hydrocarbon content relationship, determine whether calibration is needed, if calibration is needed, determine the calibration coefficient according to the curve slope, and determine the hydrocarbon content calibration operation model for the samples of the ordinary coring method according to the calibration coefficient; Calibration execution step: For the drilling intervals with calibration requirements, calculate the calibrated hydrocarbon content data based on the hydrocarbon content of the ordinary core samples using the matching hydrocarbon content calibration operation model.

2. The method according to claim 1, characterized in that In the distribution sampling step, for each divided coring interval, the pressure-maintained closed coring method is used in the 1 / 3 interval of the unit coring interval, and the ordinary coring method is used in the remaining intervals. The ordinary coring method includes the closed coring method and the conventional coring method.

3. The method according to claim 1, characterized in that In the pyrolysis detection step, the closed pyrolysis detection is carried out by continuously heating a sample to a set temperature range and maintaining a set time period. Among them, the hydrocarbon content data in the following experimental temperature ranges are obtained: temperature t = 0, 0 < t ≤ 90 °C, and 90 °C < t ≤ 300 °C, and the maintained time period is correspondingly set according to different temperature ranges.

4. The method according to claim 1, characterized in that: The method further includes: Pressure-maintained closed sample pretreatment step: Before the pyrolysis detection step, after the core barrel using the pressure-maintained closed coring method reaches the surface, it is immediately placed in liquid nitrogen for freezing treatment for a set duration and then used as the sample for the pyrolysis detection step.

5. The method according to claim 1, characterized in that In the calibration model determination step, if the correlation value of the slope of the fitting curve between the hydrocarbon content relationship to be measured and the reference hydrocarbon content relationship is greater than 0.05, it is determined that the hydrocarbon content data to be measured needs calibration.

6. The method according to claim 1, characterized in that In the calibration model determination step, the calibration coefficient c is determined according to the following formula based on the curve slope: c=k p / k s The hydrocarbon content calibration operation model is determined according to the calibration coefficient as follows: S’ = S * c In the formula, k p is the relevant slope corresponding to the pressure-maintained closed coring, k s is the slope corresponding to the closed coring; S is the hydrocarbon content measured by the sample of the ordinary coring method with correction requirements, c is the correction coefficient of the coring layer corresponding to the current sample, and S' is the corrected hydrocarbon content of the current coring layer.

7. The method according to claim 1, characterized in that According to the engineering calibration requirements, multiple types of drilling intervals in multiple blocks are respectively selected as the target sample intervals, and the corresponding hydrocarbon content calibration operation models are respectively determined to form a hydrocarbon content calibration operation model set. Record the block code, geological period parameters, rock maturity, and organic matter type corresponding to each hydrocarbon content calibration operation model, and store them in association with the hydrocarbon content calibration operation model.

8. The method according to claim 1, characterized in that In the correction execution step, a hydrocarbon content correction calculation model that meets the set conditions for the block code, geological period, rock formation maturity and organic matter type of the drilling layer section to be measured is selected as the matching hydrocarbon content correction calculation model.

9. A storage medium, characterized in that: The storage medium stores program codes that can implement the method as claimed in any one of claims 1 to 8.

10. A hydrocarbon content correction system for shale oil and gas formations, characterized in that: The system executes the method according to any one of claims 1 to 8.

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