Sand body quantitative prediction method based on conservation of source and sink substances

Abstract

The invention discloses a sand body quantitative prediction method based on source and sink material conservation. The sand body quantitative prediction method comprises the steps that the annual average supply amount of material source areas around a sedimentary basin is calculated through a sedimentary flux calculation model; calculating the product of the stratum deposition time of the provenance area and the annual average supply quantity to obtain the supply quantity of the provenance area; calculating the total deposition amount of the deposition area in each object source direction of the deposition basin through a deposition amount calculation formula; the difference value between the material source supply amount of the material source area and the total deposition amount of the deposition area is calculated to serve as the deposition difference amount; substituting the deposition difference into a deposition calculation formula to reversely calculate the possible distribution area of the sand body under the condition of the maximum stratum thickness and the possible development thickness of the stratum under the condition of the maximum area of the sand body; and predicting the development scale of the depression area sand body based on the distribution area and the development thickness. The method can quantitatively predict the development scale of the sand body in the low-exploration-degree and low-data-quality area, and provides a geological basis for distribution and description of the sand body in the depression area of the coal measure strata and deployment of exploration and development well positions.

Description

Technical Field

[0001] The present invention relates to the technical field of sand body prediction for depression exploration in the field of oil and gas exploration and development, and in particular to a sand body quantitative prediction method based on source-sink material conservation, which is a technology for quantitatively predicting the scale of sand body development in areas with low exploration degree and low data quality. Background Art

[0002] When the oil and gas basin enters the middle and late stages of exploration, the exploration object changes from structural oil and gas reservoirs to lithological oil and gas reservoirs, the exploration field changes from the middle and shallow layers to the deep layers, and from the positive structural belt around the depression to the depression area. The exploration difficulty becomes increasingly greater. Therefore, the scale of sand body development in the depression area restricts the exploration and development of oil and gas in the sedimentary basin. At the same time, due to the low degree of exploration in the depression area and the lack of drilling data, it is difficult to predict the scale of sand body development by geological methods. For coal-bearing strata, due to the relatively low quality of seismic data, the credibility of predicting the scale of sand body development by seismic methods is low. Summary of the invention

[0003] The present invention aims to quantitatively predict the scale of sand body development in coal-bearing stratum depression areas through the relative conservation law of source-sink system materials. To this end, the present invention provides a sand body quantitative prediction method based on source-sink material conservation.

[0004] An embodiment of the present invention provides a sand body quantitative prediction method based on source-sink material conservation, which includes:

[0005] The average annual supply of the provenance area around the sedimentary basin is calculated by using the sediment flux calculation model;

[0006] Calculate the product of the stratigraphic deposition time of the provenance area and the average annual supply to obtain the supply of the provenance area;

[0007] Calculate the total amount of sedimentation in the sedimentary areas in each source direction of the sedimentary basin using a sedimentation calculation formula;

[0008] Calculating the difference between the material supply of the material source area and the total deposition amount of the deposition area as the deposition difference;

[0009] Substituting the sedimentation difference into the sedimentation calculation formula to reversely calculate the possible distribution area of ​​the sand body when the formation thickness is the largest, and the possible development thickness of the formation when the sand body area is the largest;

[0010] The development scale of the sand body in the depression area is predicted based on the distribution area and the development thickness.

[0011] Another aspect of an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the program implements the above method when executed by a processor.

[0012] Another aspect of an embodiment of the present invention provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above method when executing the program.

[0013] The embodiments of the present invention can quantitatively predict the scale of sand body development in areas with low exploration degree and low data quality, and provide a geological basis for the characterization of sand body distribution and the deployment of exploration and development wells in coal-bearing stratum depression areas.

[0014] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structure described in the written description, claims, and drawings.

[0015] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0017] Figure 1 The sedimentary facies and sand body distribution characteristics are shown;

[0018] Figure 2 This is a comparison chart of the calculation results of provenance supply and total sedimentation in different source-sink systems of the Jurassic Sangonghe Formation in the Turpan Depression;

[0019] Figure 3 This is a flow chart of a sand body quantitative prediction method based on source-sink material conservation described in an embodiment of the present invention. DETAILED DESCRIPTION

[0020] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0021] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0022] In the process of studying the problems in the prior art, the inventors found that: for areas with relatively high exploration levels at home and abroad, the sand body prediction methods are relatively mature, including sand-to-ground ratio, sandstone thickness mapping, grain size change or phase sequence evolution law, sedimentary model or sand body configuration, flume experiment or numerical simulation, etc.; even in areas without wells, various seismic attributes or seismic sedimentology methods can be used to characterize sedimentary boundaries and sand bodies when the quality of seismic data is relatively high. Therefore, for scale issues such as sand body development thickness and area in areas with low exploration levels and low data quality, traditional geological and geophysical methods are difficult to give quantitative answers.

[0023] The research on source-sink system and theory at home and abroad is at the stage of qualitative-semi-quantitative analysis. On the one hand, due to the limitation of research data or the influence of later tectonic evolution, the source-sink system during the sedimentary period and the mutual influence between them are uncertain. Secondly, the supply calculation of provenance areas in different basins mostly adopts empirical formulas, which have certain applicable conditions. Finally, the calculation formulas for sedimentation in different sedimentary systems are different, and there are a lot of uncertain factors or subjective adjustments. Therefore, various quantitative calculation methods of source-sink system are difficult to promote and apply.

[0024] Chinese patent CN112051626A discloses a quantitative characterization method for source-sink system. Based on the qualitative analysis of the sedimentary system, a sediment volume calculation formula based on three parameters, namely, terrain height difference, catchment area, and valley cross-sectional area, is proposed;

[0025] Chinese patent CN112327355A discloses a paleo-geomorphology restoration method based on the source-sink system, which restores the provenance and calculates the amount of erosion, thereby establishing the paleo-geomorphology and prototype basin during the sedimentary period;

[0026] Chinese patent CN113935153A discloses a method for quantitative restoration and picking of ancient river systems based on the source-sink-ArcGIS system, using remote sensing images and digital elevation models to obtain the source boundary and transportation channel characteristics;

[0027] Chinese patent CN113960288A discloses a source-sink system quantitative evaluation method, which is used to quantitatively evaluate the relative contribution of known sediments from different provenance areas in different time steps. The above patents are limited to the quantitative study of the supply of provenance in the provenance area, and have not yet carried out quantitative research on the sedimentation of sedimentary basins, let alone quantitative prediction of unknown sediments from the perspective of the law of conservation of source and sink materials.

[0028] In addition, many literatures have been published at home and abroad on the application of the BQART calculation model for sedimentation flux in provenance areas and the improvement of the model, as well as a large number of calculation formulas for sedimentation rates (Syvitski and Milliman, 2007; Nyberg et al., 2021; Wang Xuewen et al., 2022; Chen Xingyu et al., 2023). There is also no corresponding calculation method for the sedimentation amount of the sedimentary basin with the same dimension as the provenance supply amount of the provenance area. Therefore, it is impossible to achieve the purpose of predicting the scale of sand body development in the well-free area through quantitative calculation of the source-sink system.

[0029] This embodiment provides a sand body quantitative prediction method based on the law of conservation of source and sink matter. Figure 3 As shown, the following steps are included:

[0030] Step 100, the provenance system around the sedimentary basin is comprehensively determined by a variety of methods such as heavy mineral combination, rock fragment composition, parent rock tracing, zircon age comparison, sedimentary structural characteristics and modern sedimentary analogy, thereby determining the provenance area.

[0031] Step 200, calculating the average annual supply of the provenance area around the sedimentary basin by using a sediment flux calculation model.

[0032] The deposition flux calculation model is specifically a BQART model, as shown in the following formula:

[0033] Q s =ω×B×Q 0.31 ×A 0.5 ×R×T

[0034] Where: Q s is the deposition flux (Mt / a), ω is a constant (Q s The unit is Mt / a, which is 0.0006), B is the geological factor (taking into account the basement lithology, dimensionless), and Q is the runoff (km 3 / a), A is the basin area (km 2 ), R is the elevation difference (km), and T is the average annual temperature (℃).

[0035] Among them, parameters B and Q come from the empirical factors of the geological database, parameters A and R can be obtained according to the method provided by Chinese patent CN113935153A, and parameter T can be obtained by pollen analysis and trace element analysis of paleotemperature.

[0036] Step 300, calculating the product of the stratigraphic deposition time of the provenance area and the average annual supply to obtain the supply of the provenance area.

[0037] Specifically, as shown in the following formula:

[0038] P t =Q s ×T s

[0039] Where: P t is the source supply of the source area (Mt), Q s is the deposition flux (Mt / a), T s is the deposition time (Ma).

[0040] Among them, the parameter Ts is the formation deposition time.

[0041] Step 400, determining the deposition area in each source direction.

[0042] Specifically, the sedimentary system and sand body genesis type of the sedimentary basin are determined through drilling core, logging or seismic data, and the sand body comparison, sandstone thickness and sand-to-ground ratio distribution vertically or along the provenance direction are carried out; a lithofacies paleogeography map of the sedimentary period is compiled based on the results of the determination and the restoration of the prototype basin, paleogeographic characteristics, and seismic attributes; and the sedimentary areas in each provenance direction are determined based on the lithofacies paleogeography map of the sedimentary period.

[0043] Step 500: Calculate the total amount of sedimentation in the sedimentary areas in each source direction of the sedimentary basin using a sedimentation calculation formula.

[0044] The calculation formula of the deposition amount is as follows:

[0045] D t =a×b×S×H×ρ÷cosα

[0046] Where: D t is the total amount of sedimentation in the sedimentary area (Mt), a is the sedimentation factor (dimensionless), b is the structural factor (dimensionless), S is the area of ​​later erosion or residual strata (km 2 ), H is the formation thickness (m), ρ is the formation density (g / cm 3 ), α is the slope (°).

[0047] Among them, parameter a (sedimentation factor) comes from drilling data, parameter b (structural factor) comes from balanced profile recovery data, parameters S, H, and ρ are obtained based on drilling data, and parameter α can be obtained based on the slope of modern sedimentary analogy.

[0048] Step 600, calculating the difference between the material supply amount of the material source area and the total deposition amount of the deposition area as the deposition difference.

[0049] Among them, the sedimentation difference is obtained by subtracting the source supply from the total sedimentation according to the law of conservation of matter.

[0050] Specifically, according to the law of conservation of source and sink matter, it can be concluded that the total amount of deposition is equal to the amount of material supplied by the source, S t ≈P t , the difference between the provenance supply of each provenance area and the total deposition amount of the deposition area is calculated, which is the deposition difference, as shown in the following formula:

[0051] D d =P t -D t

[0052] Where: D d is the sedimentation difference (Mt), P t is the source supply of the source area (Mt), D t is the total amount of sedimentation in the sedimentary area (Mt).

[0053] The size of the sedimentary difference in different source-sink systems reflects the exploration degree and remaining exploration potential. The smaller the sedimentary difference, the higher the exploration degree; the larger the sedimentary difference, the greater the exploration potential of the depression area of ​​the source-sink system (the scale of the undiscovered sand body is large).

[0054] Step 700, substituting the deposition difference into the deposition calculation formula to reversely calculate the possible distribution area of ​​the sand body when the formation thickness is the largest, and the possible development thickness of the formation when the sand body area is the largest.

[0055] The calculation formula of the deposition amount is as shown above in step 500; the reverse calculation process in this step is as follows:

[0056] D d =a×b×S′×H′×ρ÷cosα

[0057] S′=(D d ×cosα)÷(a×b×ρ×H max )

[0058] H′=(D d ×cosα)÷(a×b×ρ×S max )

[0059] Where: S′ is the possible distribution area of ​​sand bodies in the depression area (km 2), indicating the possible sand body distribution area when the formation thickness is the largest; H′ is the possible development thickness of the formation in the depression area (m), indicating the possible development thickness of the formation when the sand body area is the largest. max is the known maximum stratum thickness in the study area, S max It is the maximum residual area of ​​the depression area.

[0060] Step 800: predicting the development scale of the sand body in the depression area based on the distribution area and the development thickness.

[0061] Specifically, the plan view and cross-sectional view of the sedimentary phase and the sand body distribution can be revised based on the distribution area and development thickness of the sand body, and the development scale can be predicted based on the plan view and cross-sectional view.

[0062] Step 900, verifying the reliability of the quantitative prediction method for source-sink material conservation sand bodies.

[0063] The first step is to verify the reliability of the calculation results. t ) is proportional to the total amount of sedimentation (D t ) are consistent with each other to verify whether the calculation results of the supply amount calculated in the above step 300 and the total deposition amount calculated in the above step 500 are relatively reliable.

[0064] The second step is to verify the reliability of the sand body prediction results. The reliability of the prediction results of the development scale in the above step 800 can be verified based on the sandstone thickness revealed by the later actual drilling and the sand body area depicted by the newly deployed three-dimensional data.

[0065] The method described in this embodiment can quantitatively predict the scale of sand body development in areas with low exploration degree and low data quality, and provide a geological basis for the characterization of sand body distribution and the deployment of exploration and development wells in coal-bearing stratum depression areas.

[0066] In order to verify the above technical effects, the inventor of the present application also takes the second section of the Sangonghe Formation of the Jurassic System in the Turpan Depression of the Tuha Basin as an example to elaborate on the present invention in detail:

[0067] 1. Comprehensive determination of four major sources using multiple methods

[0068] Through five methods including heavy mineral combination, rock fragment composition + parent rock tracing, zircon age comparison, sedimentary structure characteristics and modern sedimentary analogy, it was determined that there were four major provenance systems in the northwest, north, southeast and southwest during the deposition period of the Sangonghe Formation of the Jurassic in the study area.

[0069] The heavy mineral combination is mainly analyzed by analogy based on the pie chart made of heavy mineral data. The cuttings composition is mainly identified under the microscope and compared with the composition and content of cuttings from different wells. The parent rock tracing is mainly determined by the stratigraphic distribution and lithological characteristics in the cuttings composition and the current geological map of the basin periphery to determine the parent rock area. The zircon age comparison is mainly verified by comparing the zircon age and peak value of different wells with the characteristics of samples in the parent rock area. The sedimentary structural characteristics are mainly determined by the lithological combination, bedding scale and the ring-shaped distribution of mud and gravel to determine the source in multiple directions. The modern sedimentary analogy is mainly based on the runoff and sedimentary characteristics of the Barkol Basin, a modern intermountain basin.

[0070] 2. Quantitative calculation of the supply of four major provenance areas

[0071] First, the deposition flux is calculated using the BQART model:

[0072] Q s =ω×B×Q 0.31 ×A 0.5 ×R×T

[0073] Where: Q s is the deposition flux (Mt / a), ω is a constant (Q s The unit is Mt / a, which is 0.0006), B is the geological factor (taking into account the basement lithology, dimensionless), and Q is the runoff (km 3 / a), A is the basin area (km 2 ), R is the elevation difference (km), and T is the average annual temperature (℃).

[0074] The geological factor ranges from 1.5 to 1.8 according to the composition of the parent rock, and the runoff refers to the runoff characteristics of the modern intermountain basin in Barkol, with a value of 30-36 km 3 / a, the drainage area is estimated based on the old strata exposed in the geological map, the elevation difference is taken as 0.15-0.30km with reference to the modern elevation and the time of mountain uplift, and the annual average temperature is taken as 25℃ with reference to the warm-hot and humid climate (Table 1).

[0075] After obtaining the calculation results of sedimentation flux, the product of stratum deposition time and the annual average sedimentation flux of the provenance area is obtained to obtain the provenance supply of each provenance area:

[0076] P t =Q s ×T s

[0077] Where: P t is the source supply of the source area (Mt), Q s is the deposition flux (Mt / a), T s is the deposition time (Ma).

[0078] 3. Compile a lithofacies paleogeographic map of the sedimentary period based on existing data

[0079] Through the use of drilling cores, logging, seismic data, etc. to determine the sedimentary system and sand body genesis type, vertical or along the source direction of sand body comparison, sandstone thickness and sand-to-ground ratio distribution, combined with the prototype basin restoration, paleo-geomorphological characteristics, and seismic attributes, the sedimentary period lithofacies paleogeography map was compiled. The study area is mainly a braided river delta-lake sedimentary system, with five subfacies developed: upper plain, lower plain, front edge, and front delta-shallow lake ( Figure 1 ), there are eight braided river delta lobes in the Taipei sag, namely Pubei, Qialekan, Kekeya-Shanle, Zhaobishan, Xiaocaohu, Hongtai-Gedatai, Wenjisang, and Shengbei. Figure 1 As shown, the Sangonghe Formation has eight braided river delta lobes with four major provenances, and the front sand bodies are enriched in the depression. Both Qintan 1 and Ji 7 wells have confirmed the development of large-scale thick sand bodies in the depression area.

[0080] 4. Quantitative calculation of the sedimentation of 8 large bodies from 4 major sources

[0081] The sedimentation of different subfacies of each source in the study area is calculated according to the sedimentation calculation formula:

[0082] D t =a×b×S×H×ρ÷cosα

[0083] Where: D t is the total amount of sedimentation in the sedimentary area (Mt), a is the sedimentation factor (dimensionless), b is the structural factor (dimensionless), S is the area of ​​later erosion or residual strata (km 2 ), H is the formation thickness (m), ρ is the formation density (g / cm 3 ), α is the slope (°).

[0084] The sedimentation factor comes from drilling data and is the ratio of terrigenous supply to the total stratum in the sediment. Take the lower plain subfacies in the study area as an example. This subfacies contains coal-bearing strata. The coal seams are mainly deposited in situ. The thickness of the coal seams accounts for 40% of the total stratum thickness. The terrigenous supply is 60%, so the sedimentation factor of the lower plain subfacies is set to 0.6. The sedimentation factors of the upper plain, lower plain, front edge and front delta subfacies in the study area are 1.0, 0.6, 0.9 and 0.3 respectively.

[0085] The structural factor comes from the data restored from the balanced profile, in order to eliminate the stratigraphic duplication caused by structural thrust. Taking the northern foreland belt of the study area as an example, the northern Bogda Mountain thrusts about 12 km to the south, and the current north-south width of the study area is about 60 km. According to the ratio between the original width and the current width of the study area, the structural factor of the northern foreland belt is set to 1.2. The structural factors of the northern foreland belt, southern thrust belt and east-west direction in the study area are 1.2, 1.1 and 1.0 respectively.

[0086] The area of ​​each subfacies in the study area is inferred from the prototype basin boundary and the current residual stratigraphic boundary. The slope data of each subfacies in the study area comes from the modern intermontane basin survey, mainly referring to the Barkol Basin (similar to the Tuha Basin, also an intermontane basin), with the upper plain, lower plain and front slopes of 6.0°, 1.5° and 4.5° respectively. The stratigraphic thickness and stratigraphic density data come from drilling and logging.

[0087] The calculation results of the total amount of sedimentation in each source direction are shown in Table 2.

[0088] 5. Predicting the scale of sand body development based on the law of conservation of source and sink matter

[0089] According to the law of conservation of source and sink matter (D t ≈P t ), calculate the difference between the source supply in different source directions and the deposition in the deposition area (i.e., the deposition difference):

[0090] D d =P t -D t

[0091] Where: D d is the sedimentation difference (Mt), P t is the source supply of the source area (Mt), D t is the total amount of sedimentation in the sedimentary area (Mt).

[0092] After obtaining the sedimentation difference, the possible distribution area of ​​the sand body under the condition of maximum formation thickness and the possible development thickness of the formation under the condition of maximum sand body area are calculated according to the sedimentation calculation formula:

[0093] D d =a×b×S′×H′×ρ÷cosα

[0094] Where: S′ is the possible distribution area of ​​sand bodies in the depression area (km 2 ), H′ is the possible development thickness of the strata in the depression area (m).

[0095] The total amount of sedimentation calculated from the sources in the northwest and southeast directions is consistent with the source supply calculated by the BQART model. The source supply in the north and southwest directions is greater than the total amount of sedimentation, and the sedimentation difference is 0.2×10 6 Mt and 0.43×10 6 Mt (Table 3). After obtaining the sedimentation difference in the two provenance directions, the distribution scale of sand bodies in the depression area can be predicted. Taking the northern provenance of Xiaocaohu Depression as an example, the maximum possible additional sand body area is 400km 2 The maximum thickness of the sedimentary strata may reach 156m. Based on the average sand-to-ground ratio of 50%, the cumulative thickness of the sand body may reach 78m.

[0096] 6. Revise the sedimentary facies and sand body distribution plan

[0097] According to the predicted additional area of ​​sand bodies in the depression area, the sedimentary facies and sand body distribution map of the target layer are revised. There are 4 major provenances and 8 large braided river delta lobes in the study area. The Taipei Depression, including the 3 sub-depressions of Qiudong, Shengbei and Xiaocaohu, is characterized by full depression and rich sand. The predicted favorable exploration area of ​​the front without drilling is 1200km 2 The main sources are the southeast provenance of Qiudong Sag, the northwest provenance of Shengbei Sag, the north provenance of Shengbei Sag and the north provenance of Xiaocaohu Sag. At the same time, it is predicted that Shengbei Sag, Xiaocaohu Sag and Toksun Sag still have a certain scale of sand body development area.

[0098] 7. Reliability verification of the quantitative prediction method of source-sink material conservation sand body

[0099] According to the calculation results of the source supply and total deposition ( Figure 2 ), the supply of the northern provenance (northwest provenance + northern provenance) in the Taipei Sag is about twice that of the southern provenance (southeast provenance + southwestern provenance), and the total amount of sedimentation is also about twice, which shows the relative reliability of the calculation results. Secondly, the sedimentation difference of each source-sink system is generally small, which is consistent with the geological understanding that the Taipei Sag is full of sand. Among them, the sedimentation difference of the southeast provenance is the smallest, and the southwest provenance is the largest, which is consistent with the high exploration degree of the Qiudong Sag and the low exploration degree of the Xiaocaohu Sag, which once again shows the reliability of the calculation results ( Figure 2 ). This method was used to predict the development of large-scale sand bodies in the Qiudong Sag. Subsequently, six newly drilled exploration wells in the Ji7 block of the Qiudong Sag confirmed that the development thickness was 50-80m and the area was 270km. 2 The scale of sand bodies shows that the quantitative prediction method of source-sink material conservation sand bodies is reliable. Figure 2 As shown in the figure, the calculation results show that the supply and total deposition of the northern provenance (northwest provenance and northern provenance) are relatively large, while those of the southern provenance (southeast provenance and southwestern provenance) are relatively small; secondly, the deposition difference of each source-sink system is generally small, among which the deposition difference of the southeast provenance is the smallest and that of the southwestern provenance is the largest.

[0100] The above experimental examples show that the conclusion that the braided river delta of the coal-bearing strata is "full of sand" was drawn in the prediction of the sand body of the Sangonghe Formation in the Jurassic in the Tuha Basin, and this conclusion was confirmed after the completion of the drilling of 6 wells in the Ji7 block in the Qiudong Subsag. It is predicted that the northern source of the Xiaocaohu Subsag and the southwestern source of the Shengbei Subsag may each add 400km 2 The sand body area provides a basis for the next step of well site deployment.

[0101] The relevant data are shown in Tables 1 to 3 below:

[0102] Table 1 Statistics of the supply of materials from the four major provenance areas of the Sangonghe Formation in the Turpan Depression

[0103]

[0104] Table 1 shows the calculation results of the provenance supply of the provenance area. The northwest provenance area is equivalent to the northern provenance area, the southeast provenance area is equivalent to the southwestern provenance area, and the north (northwest provenance area and northern provenance area) is about twice that of the south (southeast provenance area and southwestern provenance area), which is consistent with the actual drilling data.

[0105] Table 2 Statistics of sedimentation of the Jurassic Sangonghe Formation in Turpan Depression

[0106]

[0107]

[0108] Table 2 shows the calculation results of the total amount of sedimentation in the sedimentary basin. The total amount of sedimentation from the northwest provenance area and the southeast provenance area is basically consistent with the provenance supply calculated in Table 1, and the proportion of the total amount of sedimentation is also consistent with the proportion of the provenance supply.

[0109] |Table 3 Sediment volume of the Sangonghe Formation in the Jurassic System in Turpan Depression and prediction of sand bodies in the well-free area

[0110]

[0111] Table 3 shows that there are differences in the total sedimentation and provenance supply between the north provenance and the southwestern provenance. According to the law of conservation of source and sink, taking the north provenance of Xiaocaohu Sag as an example, the maximum possible additional sand body area is 400km 2 The maximum thickness of the sedimentary strata may reach 156m. Based on the sand-to-ground ratio of 50%, the cumulative thickness of the sand body can reach 78m, which is consistent with the sand body thickness of the newly drilled well in Block 7 of the Qiudong Sag.

[0112] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program code.

[0113] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0114] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0115] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A sand body quantitative prediction method based on source-sink material conservation, characterized in that: include: The average annual supply of the provenance area around the sedimentary basin is calculated by using the sediment flux calculation model; Calculate the product of the stratigraphic deposition time of the provenance area and the average annual supply to obtain the supply of the provenance area; Calculate the total amount of sedimentation in the sedimentary area in each source direction of the sedimentary basin by using a sedimentation calculation formula; Calculating the difference between the material supply of the material source area and the total deposition amount of the deposition area as the deposition difference; Substituting the sedimentation difference into the sedimentation calculation formula to reversely calculate the possible distribution area of ​​the sand body when the formation thickness is the largest, and the possible development thickness of the formation when the sand body area is the largest; The development scale of the sand body in the depression area is predicted based on the distribution area and the development thickness.

2. The method according to claim 1, characterized in that The deposition flux calculation model is: Q s =ω×B×Q 0.31 ×A 0.5 ×R×T Where: Q s is the sedimentation flux, ω is a constant, B is a geological factor, Q is the runoff, A is the basin area, R is the elevation difference, and T is the average annual temperature.

3. The method according to claim 2, characterized in that The average annual temperature is obtained through pollen analysis and trace element analysis of paleotemperature.

4. The method according to claim 1, characterized in that The calculation formula for the deposition amount is: D t =a×b×S×H×ρ÷cosα Where: D t is the total amount of sedimentation in the sedimentary area, a is the sedimentation factor, b is the structural factor, S is the area of ​​later erosion or residual strata, H is the stratum thickness, ρ is the stratum density, and α is the slope.

5. The method according to claim 4, characterized in that The slopes are obtained from the slopes of modern sedimentary analogies.

6. The method according to claim 1, characterized in that The reverse calculation includes: D d =a×b×S′×H′×ρ÷cosα S′=(F d ×cosα)÷(a×b×ρ×H max ) H′=(D d ×cosα)÷(a×b×ρ×S max ) Where: S' is the possible distribution area of ​​the sand body in the depression area, H' is the possible development thickness of the stratum in the depression area, H max is the known maximum stratum thickness in the study area, S max It is the maximum residual area of ​​the depression area.

7. The method according to claim 1, characterized in that Before calculating the total amount of deposition, it also includes: Determine the sedimentary system and sand body genesis type of the sedimentary basin, vertical or along the provenance direction, sand body comparison, sandstone thickness and sand-to-ground ratio distribution through drilling core, logging or seismic data; Compile a sedimentary lithofacies paleogeographic map based on the results of the above judgments and the restoration of the prototype basin, paleogeomorphic features, and seismic attributes; The sedimentary areas in the directions of the various provenances are determined based on the lithofacies paleogeographic map of the sedimentary period.

8. The method according to claim 1, characterized in that Before calculating the average annual supply of the provenance area, it also includes: determining the provenance area through heavy mineral combination, rock fragment composition, parent rock tracing, zircon age comparison, sedimentary structure characteristics and modern sedimentary analogy.

9. The method according to claim 1, characterized in that: Predicting the development scale of the sand body in the depression area based on the distribution area and development thickness of the sand body includes: revising the plan view and cross-sectional view of the sedimentary phase and the sand body distribution based on the distribution area and development thickness of the sand body, and predicting the development scale according to the plan view and cross-sectional view.

10. The method according to claim 1, characterized in that Also includes: The reliability of the calculation results of the supply amount and the total amount of deposition is verified based on whether the size ratio between the supply amounts of different source areas is consistent with the size ratio between the total amount of deposition.

11. The method according to claim 1, characterized in that: Also includes: The reliability of the predicted results of the development scale is verified based on the sandstone thickness revealed by later actual drilling and the sand body area depicted by the newly deployed three-dimensional data.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 11 is implemented.

13. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the method according to any one of claims 1 to 11 is implemented.

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