Rock skeleton mass acquisition method and device based on thermal weight loss, electronic equipment and storage medium

Abstract

The invention relates to the technical field of rock skeleton quality monitoring, in particular to a rock skeleton quality obtaining method and device based on thermal weight loss, electronic equipment and a storage medium. According to the rock skeleton quality obtaining method based on thermal weight loss, the original rock skeleton quality, the shale content and the carbonate mineral content of a rock sample are utilized; and calculating the rock skeleton mass of the rock sample based on the skeleton mass correction model. Aiming at regions with high shale content and carbonate mineral content, the thermal weight loss method disclosed by the invention has a remarkable correction effect on the rock skeleton quality. According to the method, the shale and the ash are accurately corrected, so that the quality of the rock skeleton is effectively compensated, and the accuracy of the quality of the rock skeleton is improved. For subsequent reservoir physical property evaluation, the calculation results of the porosity and the permeability are more accurate due to more accurate rock skeleton quality, so that the oil storage capacity and the oil and gas flow condition of the reservoir are reflected more truly.

Description

Technical Field

[0001] The present invention relates to the technical field of rock skeleton quality monitoring, and is a method, device, electronic equipment and storage medium for obtaining rock skeleton quality based on thermal gravimetry. Background Art

[0002] In oil exploration, rock skeleton quality plays a key role. It can help determine rock type, as different rock skeletons have different mineral compositions and quality characteristics. It can also be used to assess reservoir properties, such as porosity and permeability. The quality of the skeleton and the density of its arrangement affect both porosity and permeability. Analyzing rock skeleton quality can also help understand rock mechanical properties and aid in drilling plan design. Rock skeleton quality is also related to formation pressure and can indirectly reflect formation pressure distribution. Furthermore, it can be combined with other geological data to predict oil and gas distribution, assist in well logging interpretation, and improve the accuracy of formation parameter determination. However, the current process of obtaining rock skeleton quality is susceptible to loss of rock skeleton quality due to factors such as the removal of interlayer water from layered clay minerals and the high-temperature decomposition and degassing of carbonate minerals, which in turn affects the calculation of relevant parameters, leading to problems such as large calculation errors.

[0003] Patent publication number CN119164823A discloses a method for obtaining the porosity of rock cuttings while drilling. The method subjects rock cuttings samples to initial thermal catalysis, saturation treatment, and later thermal catalysis. The dry weight coefficient is calculated using the mass of the initial thermal catalysis rock cuttings sample and the mass of the later thermal catalysis rock cuttings sample. Finally, the rock cutting porosity of each rock cutting sample is calculated using a wet-dry weight difference model. The rock cutting porosity of all rock cuttings samples is averaged, and this average is used as the rock cutting porosity while drilling. The mass of the later thermal catalysis rock cuttings sample obtained during the later thermal catalysis is used as the rock skeleton mass. This rock skeleton mass does not take into account the mass loss caused by the removal of interlayer water from clay minerals during pyrolysis and the degassing of carbonate minerals due to high-temperature decomposition. Therefore, the resulting rock skeleton mass has a certain degree of error. Summary of the Invention

[0004] The present invention provides a method, device, electronic device and storage medium for obtaining rock skeleton mass based on thermal gravimetry, which overcomes the shortcomings of the above-mentioned existing technologies. It can effectively solve the problem that the existing rock skeleton mass acquisition method does not take into account the mass loss caused by the interlayer water removed by clay minerals and the high-temperature decomposition and degassing of carbonate minerals during pyrolysis, resulting in a certain error in the rock skeleton mass obtained.

[0005] The present invention uses the thermogravimetric method to correct mud and ash (i.e., carbonate minerals) in areas with high mud and carbonate mineral contents (mud content ≥ 20%, carbonate mineral content ≥ 30%), and compensate for the rock skeleton quality, thereby improving the accuracy of rock skeleton quality and providing an important basis for all aspects of oil exploration.

[0006] One of the technical solutions of the present invention is achieved through the following measures: a method for obtaining rock skeleton mass based on thermal gravimetry, comprising: Obtain the original rock skeleton quality of the rock sample; Obtain the mud content of rock samples; Obtaining the carbonate mineral content of rock samples; The original rock skeleton mass, mud content, and carbonate mineral content of the rock sample are used to calculate the rock skeleton mass of the corrected rock sample based on the skeleton mass correction formula. The skeleton mass correction formula is as follows: w r =w d +K1a+K2b Where w r is the rock skeleton mass of the rock sample after correction; w d is the original rock skeleton mass of the rock sample; a is the mud content of the rock sample, %; b is the carbonate mineral content of the rock sample, %; K1 is the thermal weight loss rate of mud; K2 is the thermal weight loss rate of carbonate minerals.

[0007] The following is a further optimization and / or improvement of one of the above-mentioned technical solutions: For sandstone, in the skeleton mass correction formula, K1=0.14, K2=0.09, then the skeleton mass correction formula is as follows: w r =w d +0.14a+0.09b Where w r is the rock skeleton mass of the rock sample after correction; w d is the original rock skeleton mass of the rock sample; a is the mud content of the rock sample, %; b is the carbonate mineral content of the rock sample, %.

[0008] The mud content of the above rock samples is calculated according to the following formula: Where a is the mud content of the rock sample, %; GR is the gamma value of the rock, GR max is the maximum value of the gamma value of the rock; GR min is the minimum gamma value of the rock.

[0009] The original rock skeleton mass of the rock sample is the mass of the later thermal catalysis rock cuttings sample recorded in the patent document with publication number CN119164823A (named "Method for Obtaining Porosity of Rock Cuttings While Drilling").

[0010] The second technical solution of the present invention is achieved by the following measures: a device using the method for obtaining rock skeleton mass based on thermal gravimetry as described in the first technical solution, comprising: The first acquisition module: obtains the original rock skeleton mass of the rock sample; The second acquisition module: obtains the mud content of the rock sample; The third acquisition module: obtains the carbonate mineral content of the rock sample; Calculation module: Calculate the rock skeleton mass of the corrected rock sample based on the skeleton mass correction formula using the original rock skeleton mass, mud content, and carbonate mineral content of the rock sample. The skeleton mass correction formula is as follows: w r =w d +K1a+K2b Where w r is the rock skeleton mass of the rock sample after correction; w d is the original rock skeleton mass of the rock sample; a is the mud content of the rock sample, %; b is the carbonate mineral content of the rock sample, %; K1 is the thermal weight loss rate of mud; K2 is the thermal weight loss rate of carbonate minerals.

[0011] The following is a further optimization and / or improvement of the second technical solution of the above invention: The above calculation module includes sandstone calculation unit: Sandstone calculation unit: For sandstone, in the skeleton mass correction formula, K1=0.14, K2=0.09, then the skeleton mass correction formula is as follows: w r =w d +0.14a+0.09b Where w r is the rock skeleton mass of the rock sample after correction; w d is the original rock skeleton mass of the rock sample; a is the mud content of the rock sample, %; b is the carbonate mineral content of the rock sample, %.

[0012] The above calculation module includes a mud content calculation unit, Mud content calculation unit: The mud content of the rock sample is calculated according to the following formula: Where a is the mud content of the rock sample, %; GR is the gamma value of the rock, GR max is the maximum value of the gamma value of the rock; GR min is the minimum gamma value of the rock.

[0013] In the above calculation module, the original rock skeleton mass of the rock sample is the mass W2 of the later thermally catalyzed rock cuttings sample recorded in the patent document with publication number CN119164823A (named "Porosity Acquisition Method for Rock Cuttings While Drilling").

[0014] The third technical solution of the present invention is achieved through the following measures: an electronic device, including a processor and a memory, wherein the memory stores a computer program, and the computer program is loaded and executed by the processor to implement the method for obtaining rock skeleton mass based on thermal gravimetry as described in one of the technical solutions.

[0015] The fourth technical solution of the present invention is achieved through the following measures: a storage medium, on which a computer program that can be read by a computer is stored, and the computer program is configured to execute the method for obtaining rock skeleton mass based on thermal gravimetry as described in one of the technical solutions when it is run.

[0016] For areas with high mud content and carbonate mineral content, the thermogravimetric method of the present invention has a significant correction effect on the rock skeleton quality. It effectively compensates for the rock skeleton quality by accurately correcting the mud and gray matter, thereby improving the accuracy of the rock skeleton quality. For subsequent reservoir physical property assessments, the calculation results of porosity and permeability will be more accurate due to the more accurate rock skeleton quality, thereby more realistically reflecting the oil storage capacity and oil and gas flow of the reservoir. At the same time, the analysis of formation pressure distribution is also more reliable, reducing safety hazards caused by misjudgment of pressure. In the future, when predicting oil and gas distribution and assisting well logging interpretation, high-precision rock skeleton quality will make geological model construction more realistic, providing a solid and reliable basis for all aspects of oil exploration. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Attachment Figure 1 This is the heating dehydration weight loss curve of kaolinite.

[0018] Attachment Figure 2 This is the heating dehydration weight loss curve of montmorillonite.

[0019] Attachment Figure 3 This is the heating dehydration weight loss curve of illite.

[0020] Attachment Figure 4 The figure is a comparison of weights before and after correction.

[0021] Attachment Figure 5 This is a comparison chart of porosity before and after correction. DETAILED DESCRIPTION

[0022] The present invention is not limited to the following embodiments, and specific implementation methods can be determined based on the technical solutions of the present invention and actual conditions.

[0023] In the present invention, it should be noted that the terms "first", "second", "third", etc. are only used to facilitate the description of the present invention and simplify the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, they cannot be understood as limiting the present invention.

[0024] The percentages in the present invention are all by mass unless otherwise specified.

[0025] In the method for obtaining rock skeleton mass based on thermal weight loss of the present invention, the thermal weight loss rate is specifically as follows: Step 1: Thermogravimetric analysis of clay minerals Clay minerals mainly include kaolinite, montmorillonite, illite, chlorite, etc. Their common feature is that they have a layered structure and contain interlayer water and structural water. The results of heating and dehydration experiments of different types of clay minerals show that: The H2O in kaolinite exists in the lattice in the form of structural water. The heating dehydration weight loss curve shows that between 100℃ and 525℃, the structural water is lost and the weight is reduced. Before 400℃, the weight changes slowly and there is no significant dehydration phenomenon. Figure 1 .

[0026] The nH2O in the molecular structure of montmorillonite is interlayer water, which can increase or decrease due to different external humidity and the amount of water absorbed, thereby causing the crystal to expand or contract, but its lattice structure does not change. The heating dehydration weight loss curve of montmorillonite can be divided into two stages. The first stage is between 100℃ and 350℃, which is caused by the loss of a large amount of interlayer water; the second stage starts from 300℃ to 400℃, and the change is most intense between 400℃ and 600℃, which is caused by the loss of structural water. Figure 2 .

[0027] The heating dehydration weight loss curve of illite can be divided into two stages: the first stage is around 100℃, which is the stage of removing interlayer water; the second stage is between 200℃ and 500℃, which is the stage of losing structural water. Figure 3 .

[0028] Taking kaolinite as an example, the following reactions occur during the pyrolysis and heating process of the rock: In the above reaction equation, the molecular weight of Al₂O₃·2SiO₂·2H₂O is 258, the molecular weight of Al₂O₃·2SiO₂ is 222, and the molecular weight of 2H₂O is 36. The thermal weight loss (i.e., percent weight loss) of kaolinite after dehydration is 14%. The thermal weight loss of similar clay minerals due to dehydration during pyrolysis (maximum temperature of 600°C) is shown in Table 1. In practical applications, 14% (i.e., 0.14) can be used as the average thermal weight loss of clay minerals.

[0029] Step 2: Thermogravimetric analysis of carbonate minerals Carbonate minerals are the most important cementing components besides clay minerals, mainly including calcite, dolomite, siderite, etc. Taking calcite as an example, its thermal gravimetric reaction is: According to the above reaction equation, after CaCO3 decomposes, CO2 escapes, and the thermal weight loss rate is 44%. Currently, many oil fields use this reaction equation to correct the thermal weight loss of carbonate minerals. However, the thermal decomposition temperature of calcite (gray matter) is 550°C to 850°C, and the thermal decomposition temperature of dolomite (cloudy matter) is 520°C to 820°C. However, the maximum temperature reached by the programmed temperature of the pyrolysis furnace is only 600°C. At this temperature, the actual thermal weight loss rates of calcite and dolomite are only 10% and 8%, respectively. The average value of 9% (i.e., 0.09) is used here as the thermal weight loss rate of carbonate minerals.

[0030] Step 3: Determination of rock skeleton quality Since the thermal weight loss of clay mineral matrix and carbonate minerals does not contribute to the porosity of sandstone, when using thermal weight loss data to calculate reservoir porosity, it is necessary to correct the content of mud (i.e. clay minerals) and calcium (i.e. carbonate minerals) to compensate for the mass of the rock skeleton, that is, to form the skeleton mass correction formula: w r =w d +K1a+K2b Where w r is the rock skeleton mass of the rock sample after correction; w d is the original rock skeleton mass of the rock sample; a is the mud content of the rock sample, %; b is the carbonate mineral content of the rock sample, %; K1 is the thermal weight loss rate of mud; K2 is the thermal weight loss rate of carbonate minerals.

[0031] The present invention will be further described below in conjunction with the embodiments: Example 1: The method for obtaining rock skeleton mass based on thermal gravimetry comprises: Obtain the original rock skeleton quality of the rock sample; Obtain the mud content of rock samples; Obtaining the carbonate mineral content of rock samples; The original rock skeleton mass, mud content, and carbonate mineral content of the rock sample are used to calculate the rock skeleton mass of the corrected rock sample based on the skeleton mass correction formula. The skeleton mass correction formula is as follows: w r =w d +K1a+K2b Where w r is the rock skeleton mass of the rock sample after correction; w dis the original rock skeleton mass of the rock sample; a is the mud content of the rock sample, %; b is the carbonate mineral content of the rock sample, %; K1 is the thermal weight loss rate of mud; K2 is the thermal weight loss rate of carbonate minerals.

[0032] Example 2: As an optimization of the above example, for sandstone, in the skeleton mass correction formula, K1=0.14, K2=0.09, then the skeleton mass correction formula is as follows: w r =w d +0.14a+0.09b Where w r is the rock skeleton mass of the rock sample after correction; w d is the original rock skeleton mass of the rock sample; a is the mud content of the rock sample, %; b is the carbonate mineral content of the rock sample, %.

[0033] Example 3: As an optimization of the above example, the mud content of the rock sample is calculated according to the following formula: Where a is the mud content of the rock sample, %; GR is the gamma value of the rock, GR max is the maximum value of the gamma value of the rock; GR min is the minimum gamma value of the rock.

[0034] The carbonate content can be obtained by conventional carbonate analysis (such as a carbonate meter).

[0035] Example 4: As an optimization of the above example, the original rock skeleton mass of the rock sample is obtained according to the method for obtaining the mass W2 of the late thermal catalytic rock cuttings sample described in the patent document with publication number CN119164823A (named "Method for Obtaining Porosity of Rock Cuttings While Drilling").

[0036] Example 5: A device using the method for obtaining rock skeleton mass based on thermal gravimetry as described in the above embodiment, comprising: The first acquisition module: obtains the original rock skeleton mass of the rock sample; The second acquisition module: obtains the mud content of the rock sample; The third acquisition module: obtains the carbonate mineral content of the rock sample; Calculation module: Calculate the rock skeleton mass of the corrected rock sample based on the skeleton mass correction formula using the original rock skeleton mass, mud content, and carbonate mineral content of the rock sample. The skeleton mass correction formula is as follows: w r =w d +K1a+K2b Where w r is the rock skeleton mass of the rock sample after correction; wd is the original rock skeleton mass of the rock sample; a is the mud content of the rock sample, %; b is the carbonate mineral content of the rock sample, %; K1 is the thermal weight loss rate of mud; K2 is the thermal weight loss rate of carbonate minerals.

[0037] Example 6: As an optimization of the above-mentioned Example 5, the calculation module includes a sandstone calculation unit: Sandstone calculation unit: For sandstone, in the skeleton mass correction formula, K1=0.14, K2=0.09, then the skeleton mass correction formula is as follows: w r =w d +0.14a+0.09b Where w r is the rock skeleton mass of the rock sample after correction; w d is the original rock skeleton mass of the rock sample; a is the mud content of the rock sample, %; b is the carbonate mineral content of the rock sample, %.

[0038] Example 7: As an optimization of the above-mentioned Example 5, the calculation module includes a mud content calculation unit, Mud content calculation unit: The mud content of the rock sample is calculated according to the following formula: Where a is the mud content of the rock sample, %; GR is the gamma value of the rock, GR max is the maximum value of the gamma value of the rock; GR min is the minimum gamma value of the rock.

[0039] Example 8: As an optimization of the above-mentioned Example 5, in the calculation module, the original rock skeleton mass of the rock sample is obtained according to the method of obtaining the mass W2 of the later thermal catalytic rock cuttings sample recorded in the patent document with publication number CN119164823A (named "Method for Obtaining Porosity of Rock Cuttings While Drilling").

[0040] Example 9: An electronic device includes a processor and a memory, wherein the memory stores a computer program, and the computer program is loaded and executed by the processor to implement the method for obtaining rock skeleton mass based on thermal gravimetry as described in the above embodiment.

[0041] Embodiment 10: A storage medium having stored thereon a computer program readable by a computer, wherein the computer program is configured to execute, when running, the method for obtaining rock skeleton mass based on thermal gravimetry as described in the above embodiment.

[0042] Example 11: The method for obtaining rock skeleton mass based on thermal gravimetry comprises: Obtain the original rock skeleton quality of the rock sample; The original rock skeleton mass of the rock sample is the mass W2 of the later thermally catalyzed rock cuttings sample recorded in the patent document with publication number CN119164823A (named "Method for Obtaining Porosity of Rock Cuttings While Drilling").

[0043] Obtain the mud content of rock samples; The mud content of the rock sample is calculated according to the following formula: Where a is the mud content of the rock sample, %; GR is the gamma value of the rock, GR max is the maximum value of the gamma value of the rock; GR min is the minimum gamma value of the rock.

[0044] Obtaining the carbonate mineral content of rock samples; The carbonate mineral content can be obtained by conventional carbonate analysis (such as carbonate meter).

[0045] The original rock skeleton mass, mud content, and carbonate mineral content of the rock sample are used to calculate the rock skeleton mass of the corrected rock sample based on the skeleton mass correction formula. The skeleton mass correction formula is as follows: w r =w d +K1a+K2b Where w r is the rock skeleton mass of the rock sample after correction; w d is the original rock skeleton mass of the rock sample; a is the mud content of the rock sample, %; b is the carbonate mineral content of the rock sample, %; K1 is the thermal weight loss rate of mud; K2 is the thermal weight loss rate of carbonate minerals.

[0046] Example 12: The rock skeleton mass acquisition method based on thermal gravimetric loss described in Example 11 is applied to the rock skeleton mass calculation of each rock sample in a certain section of Well Q9 (as shown in Table 2), and the corresponding porosity (i.e., corrected porosity) is calculated using the rock skeleton mass.

[0047] Well Q9: Section 2918.39m to 2921.34m, lithology: gray fine sandstone, 20% argillaceous content, 1.4% carbonate mineral content. This section is sandstone, so the skeleton quality correction formula uses the following formula: w r =w d +0.14a+0.09b Where w r is the rock skeleton mass of the rock sample after correction; w d is the original rock skeleton mass of the rock sample; a is the mud content of the rock sample, %; b is the carbonate mineral content of the rock sample, %.

[0048] The original weight of each rock sample (i.e., wet sample weight), the original rock skeleton mass of the rock sample (i.e., mass before correction), the rock skeleton mass of the rock sample after correction (i.e., mass after correction), the porosity before correction, and the porosity after correction are shown in Table 2. Figure 4 and Figure 5 .

[0049] The porosity before correction is calculated in the same manner as described in the patent document with publication number CN119164823A (entitled "Method for Obtaining Porosity of Rock Cuttings While Drilling"). The rock cuttings porosity of the rock cuttings sample is calculated as follows: Where Φ represents the porosity of the cuttings sample; W1 represents the mass of the saturated cuttings sample; W2 represents the mass of the later thermally catalyzed cuttings sample (i.e., the mass of the cuttings skeleton); k represents the slope of the linear fitting formula; ρ r represents the rock fragment skeleton density; C represents the dry weight coefficient.

[0050] The calculation method of the corrected porosity is the same as that of the uncorrected porosity, except that the mass of the rock skeleton of the corrected rock sample is used instead of the mass W2 of the late thermal catalytic rock cuttings sample in the calculation formula.

[0051] From Table 2, Figure 4 and Figure 5 It can be seen that the porosity after correction is closer to the porosity interpreted by logging (i.e., logging porosity), which means that the porosity after correction is closer to the actual porosity value, and indirectly means that the rock skeleton mass of the rock sample after correction is closer to the actual value of the rock skeleton mass of the rock sample, thus indicating that the method of the present invention improves the accuracy of rock skeleton mass calculation.

[0052] The above technical features respectively constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or removed according to actual needs to meet the requirements of different situations.

[0053] Table 1 Thermal weight loss rate of common clay minerals .

[0054] Table 2 .

Claims

1. A method for obtaining rock skeleton mass based on thermal gravimetry, characterized in that: include: Obtain the original rock skeleton quality of the rock sample; Obtain the mud content of rock samples; Obtaining the carbonate mineral content of rock samples; The original rock skeleton mass, mud content, and carbonate mineral content of the rock sample are used to calculate the rock skeleton mass of the corrected rock sample based on the skeleton mass correction formula. The skeleton mass correction formula is as follows: In r =in d +K1a+K2b Where w r is the rock skeleton mass of the rock sample after correction; w d is the original rock skeleton mass of the rock sample; a is the mud content of the rock sample, %; b is the carbonate mineral content of the rock sample, %; K1 is the thermal weight loss rate of mud; K2 is the thermal weight loss rate of carbonate minerals; The mud content of the rock sample is calculated according to the following formula: Where a is the mud content of the rock sample, %; GR is the gamma value of the rock, GR max is the maximum value of the gamma value of the rock; GR min is the minimum gamma value of the rock.

2. The method for obtaining rock skeleton mass based on thermal gravimetry according to claim 1, characterized in that: For sandstone, in the skeleton mass correction formula, K1=0.14, K2=0.09, then the skeleton mass correction formula is as follows: In r =in d +0.14a+0.09b Where w r is the rock skeleton mass of the rock sample after correction; w d is the original rock skeleton mass of the rock sample; a is the mud content of the rock sample, %; b is the carbonate mineral content of the rock sample, %.

3. A device using the method for obtaining rock skeleton mass based on thermal gravimetric analysis according to any one of claims 1 to 2, characterized in that: include: The first acquisition module: obtains the original rock skeleton mass of the rock sample; The second acquisition module: obtains the mud content of the rock sample; The third acquisition module: obtains the carbonate mineral content of the rock sample; Calculation module: Calculate the rock skeleton mass of the corrected rock sample based on the skeleton mass correction formula using the original rock skeleton mass, mud content, and carbonate mineral content of the rock sample. The skeleton mass correction formula is as follows: In r =in d +K1a+K2b Where w r is the rock skeleton mass of the rock sample after correction; w d is the original rock skeleton mass of the rock sample; a is the mud content of the rock sample, %; b is the carbonate mineral content of the rock sample, %; K1 is the thermal weight loss rate of mud; K2 is the thermal weight loss rate of carbonate minerals; The calculation module includes a mud content calculation unit, Mud content calculation unit: The mud content of the rock sample is calculated according to the following formula: Where a is the mud content of the rock sample, %; GR is the gamma value of the rock, GR max is the maximum value of the gamma value of the rock; GR min is the minimum gamma value of the rock.

4. The device according to claim 3, characterized in that The calculation module includes sandstone calculation unit: Sandstone calculation unit: For sandstone, in the skeleton mass correction formula, K1=0.14, K2=0.09, then the skeleton mass correction formula is as follows: In r =in d +0.14a+0.09b Where w r is the rock skeleton mass of the rock sample after correction; w d is the original rock skeleton mass of the rock sample; a is the mud content of the rock sample, %; b is the carbonate mineral content of the rock sample, %.

5. An electronic device, characterized in that The method comprises a processor and a memory, wherein a computer program is stored in the memory, and the computer program is loaded and executed by the processor to implement the method for obtaining rock skeleton mass based on thermal gravimetry as described in any one of claims 1 to 2.

6. A storage medium, characterized in that The storage medium stores a computer program that can be read by a computer, and the computer program is configured to execute the method for obtaining rock skeleton mass based on thermal gravimetry according to any one of claims 1 to 2 when running.

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