Oilfield brine resource quantity estimation method, system, equipment and medium

Abstract

The invention relates to an oil field brine resource quantity estimation method, system, equipment and medium, the oil field brine resource quantity estimation method comprises the following steps: obtaining key parameters; constructing an oil field deep brine starting index; comparing the key parameter with the oil field deep brine starting index, judging whether the key parameter reaches the standard or not, and if yes, substituting the key parameter into an oil field brine resource quantity estimation formula for calculation to obtain an oil field brine resource quantity estimation value. According to the oil field deep brine occurrence rule and the characteristic that oil and gas coexist in the same trap and are fluid, the oil and gas volume method is used for calculating the oil field deep brine resource mineral product, and the method is more mature and easy to implement; through technical methods such as earthquakes, logging, analysis and test and the like, key parameters for resource evaluation can be effectively valued, and the reliability is high.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield exploitation, and in particular relates to an oilfield brine resource estimation method, system, equipment and medium. Background Art

[0003] In recent years, some scholars have conducted sporadic research on deep brine in oil fields, proposed an improved model for calculating the amount of deep underground brine resources (traditionally the volumetric method), and used a brine storage structure in the northeast of the Sichuan Basin as an example to calculate the amount of resources in the structure, and achieved good results; they also derived two methods for calculating salinity using logging data, the formation water resistivity method and the neutron lifetime logging method (suitable for low-salinity and high-salinity brines, respectively), and used these two methods to calculate the salinity of deep brine in the Qianjiang Formation of the Qianjiang Sag in the Jianghan Basin, and achieved good results. However, whether the value parameters are truly operational in exploration and evaluation has not been considered from the perspective of workload and investment, and the feasibility of evaluation has only been studied theoretically. Summary of the invention

[0004] The purpose of the present invention is to provide a method, system, equipment and medium for estimating the amount of brine resources in an oil field in order to solve the above-mentioned problem.

[0005] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0006] A method for estimating oilfield brine resources comprises the following steps:

[0007] Obtaining key parameters, including water-bearing area, effective thickness of water layer, effective porosity, original water saturation, original brine volume coefficient, brine density and mineral grade;

[0008] Construct the calculation index of deep brine in oil fields;

[0009] The key parameters are compared with the oilfield deep brine calculation index to determine whether the key parameters meet the standards. If so, the key parameters are substituted into the oilfield brine resource estimation formula to calculate and obtain the oilfield brine resource estimation value.

[0010] As a further optimization scheme of the present invention, the specific process of obtaining the effective thickness of the water layer is as follows:

[0011] Divide the plane calculation unit and the vertical calculation unit, and delineate the water-bearing area according to the top boundary structure map of the target water layer.

[0012] As a further optimization scheme of the present invention, the specific process of obtaining the effective thickness of the water layer is as follows:

[0013] The physical, electrical and saturation lower limit standards are established to divide the reservoirs of the corresponding fluids. The core, conventional and special logging methods are used to obtain the reservoir thickness of the part of the aquifer system with water production capacity that meets the starting standard. Referring to the lower limit standards of the region, the natural gamma and natural potential curves are used to divide the water layer thickness and eliminate the thickness of the interlayer in the water layer. The average effective thickness of the water layer in each well in the same calculation unit is obtained by taking the arithmetic average.

[0014] As a further optimization scheme of the present invention, the specific process of obtaining the effective porosity is as follows:

[0015] Using core measured scale logging, the average effective porosity of a single well in the same calculation unit is calculated weighted by effective thickness, and the effective porosity of each calculation unit is conservatively determined by arithmetic mean and effective thickness trade-off method.

[0016] As a further optimization scheme of the present invention, the specific process of obtaining the original water saturation is as follows:

[0017] It is determined by means of well logging interpretation, closed core analysis and conventional core mercury injection analysis, and the ratio of the volume of water contained in the effective reservoir in the formation to the volume of rock pores is obtained; the weighted average of effective thickness and effective porosity is adopted for single wells in the same calculation unit, and comprehensive conservative values ​​such as arithmetic average and pore thickness trade-off method are adopted for each calculation unit.

[0018] As a further optimization scheme of the present invention, the specific process of obtaining the volume coefficient of the original brine is as follows:

[0019] The volume coefficient of the original brine under the corresponding pressure conditions is calculated by means of high-pressure physical property sampling. If there is no actual measurement of the mineral deposit, it can be used by analogy with neighboring areas.

[0020] As a further optimization scheme of the present invention, the specific process of obtaining the brine density and the mineral grade is as follows:

[0021] According to the actual water samples collected at the wellhead, the samples are sent to a laboratory with MA qualification, and internal and external inspections are carried out in parallel for sampling and analysis. When sampling, the analysis results that can reflect the true value are retained and the arithmetic average is calculated.

[0022] As a further optimization scheme of the present invention, the estimation formula is as follows:

[0023] Pw=100×A×h×φ×Sw×ρ×C / Bw;

[0024] Where: Pw represents the estimated value of oilfield brine resources, A represents the water-bearing area, H represents the effective thickness, Φ represents the effective porosity, Sw represents the original water saturation, Bw represents the original brine volume coefficient, ρ represents the brine density, and C represents the mineral grade.

[0025] An oilfield brine resource estimation system, comprising:

[0026] An acquisition module is used to acquire key parameters, wherein the key parameters include water-bearing area, effective thickness of water layer, effective porosity, original water saturation, original brine volume coefficient, brine density and mineral grade;

[0027] Index construction module, used to construct the initial calculation index of deep brine in oil fields;

[0028] A judgment module is used to compare the key parameters with the oilfield deep brine calculation index to determine whether the key parameters meet the standards.

[0029] The calculation module is used to substitute the key parameters into the oilfield brine resource estimation formula to calculate and obtain the oilfield brine resource estimation value.

[0030] An electronic device comprises a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus;

[0031] Memory, for storing computer programs;

[0032] The processor is used to implement the method for estimating the amount of brine resources in the oil field when executing the program stored in the memory.

[0033] A computer-readable storage medium stores a computer program, which implements a method for estimating oilfield brine resources when executed by a processor.

[0034] The beneficial effects of the present invention are:

[0035] According to the occurrence law of deep brine in oil fields, the present invention coexists with oil and gas in the same trap and has the same fluid characteristics. The oil and gas volume method is used to calculate the deep brine resources and minerals in oil fields, which is more mature and feasible. Through technical methods such as seismic, well logging, analysis and testing, the key parameters of resource evaluation can be effectively determined with high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a flow chart of the method of the present invention;

[0037] Figure 2 It is a diagram of the division principle of the plane estimation unit of the present invention;

[0038] Figure 3 It is a diagram showing the principle of dividing the longitudinal estimation units of the present invention;

[0039] Figure 4 It is a block method water-bearing area real point connection and well control boundary extrapolation diagram of the present invention;

[0040] Figure 5 It is the fault boundary map of the oil (gas / water) area of ​​the present invention;

[0041] Figure 6 It is the water layer and interlayer deduction curve diagram of the well logging interpretation of the present invention;

[0042] Figure 7 It is the well logging qualitative and quantitative interpretation chart of the present invention;

[0043] Figure 8 It is a core porosity calibration logging porosity processing result diagram of the present invention;

[0044] Fig. 9 It is a comparison diagram of the porosity modeling and core logging pore reliability of the present invention;

[0045] Fig.10 The present invention is a graph showing the relationship between the water saturation calculation resistance increase rate and saturation, gas reservoir formation factors and porosity;

[0046] Fig.11 It is a reliability comparison diagram of the well logging water saturation and the core water saturation of the present invention;

[0047] Fig.12 The method of obtaining the brine volume coefficient by using the adjacent area gas-oil ratio and volume coefficient regression chart of the present invention;

[0048] Fig.13 It is a system structure block diagram of the present invention;

[0049] Fig.14 It is a block diagram of the device structure of the present invention. DETAILED DESCRIPTION

[0050] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0051] Existing problems: There is currently no resource evaluation method for deep brine in oil fields at home and abroad. The current research on deep brine potassium salt tends to be based on the solid block method of surface salt lakes, which requires the deployment of well networks according to regular engineering grids, and the exploration and evaluation method of coring the entire well section and systematic analysis of rock and water samples for each well. The workload and investment are too large, and the operability is not strong.

[0052] Technical problems to be solved: To obtain key parameter values ​​through mature seismic, logging processing and interpretation methods for oil and gas evaluation at home and abroad, instead of the huge investment and workload of establishing a regular engineering network and taking core samples from the entire well section at each node well to carry out reservoir thickness division and porosity analysis and testing, so as to enhance operability and ensure the reliability of key parameter values ​​and resource evaluation results.

[0053] The purpose of this invention is to establish a mature technology for the evaluation method of deep brine resources in oil fields, and simultaneously promote the promulgation of resource reserve standards and specifications, so as to achieve a full combination of theory and practice and provide a technical reference for the resource evaluation and subsequent comprehensive development and utilization of such minerals.

[0054] like Figure 1 As shown, a method for estimating the amount of brine resources in an oil field comprises the following steps:

[0055] Obtaining key parameters, including water-bearing area, effective thickness of water layer, effective porosity, original water saturation, original brine volume coefficient, brine density and mineral grade;

[0056] Construct the calculation index of deep brine in oil fields;

[0057] The key parameters are compared with the oilfield deep brine calculation index to determine whether the key parameters meet the standards. If so, the key parameters are substituted into the oilfield brine resource estimation formula to calculate and obtain the oilfield brine resource estimation value.

[0058] Specifically, it includes the following:

[0059] Step 1: How to obtain the values ​​of key parameters

[0060] (1) Water-bearing area: First, the horizontal and vertical calculation units must be determined and the division method (see Figure 2 , Figure 3 ). The water-bearing area is delineated based on the top structural map of the target water layer. The technical methods used in the block method are mainly real hole connection and infinite extrapolation. According to the layered development of the water layer in this area, the top structural map of the layer is used as the base map, and the extrapolation method is used to extrapolate 1 / 4 of the engineering spacing along the water well exploration line and the vertical exploration line defense line to delineate (see Figure 4 In the oil and gas volume method, within the same trap, the focus is on identifying and determining the water-bearing boundary and the blocking boundary (such as faults, lithology, and strata). If the estimated controlled or proven resource volume shows that the edge of the mine is far from the structural contour line, it is extrapolated according to the well spacing (see Figure 5 ).

[0061] (2) Effective thickness of water layer: Determination principle: The thickness of the reservoir with water production capacity in the aquifer system that meets the starting standard is mainly determined by means of core logging, conventional logging and special logging. The key is to establish physical, electrical and saturation lower limit standards to divide the reservoir corresponding to the fluid.

[0062] Establishment of lower limit standards: Using the test or trial production data of existing wells in the area, establish the identification chart of the lower limits of physical and electrical properties in this area, and thus establish various lower limit standards to divide oil, gas and water layers (see Figure 7 ).

[0063] Principles for effective thickness division: refer to the lower limit standard of the region, use natural gamma and natural potential curve (half-width point) to divide the water layer thickness, remove the interlayer thickness (impermeable layer) in the water layer, and the interlayer deduction can be based on the actual situation (starting thickness 0.2m), among which the oil (gas) water layer reservoir thickness is converted at 50%, and the water-bearing oil (gas) layer is converted at 75% (see Figure 6 ).

[0064] Effective thickness value: The average effective thickness of each well water layer in the same estimation unit is obtained by arithmetic average. Each estimation unit adopts a comprehensive conservative value by arithmetic average, well point area trade-off, and contour area trade-off method.

[0065] (3) Effective porosity: using core scale logging (see Figure 8 ) Well logging porosity calculation and error verification: Use core measured calibration logging to meet the requirement that the relative error between the porosity calculated by well logging and the porosity analyzed by core analysis does not exceed ±8% (see Fig. 9 ).

[0066] Effective porosity value: The average effective porosity of a single well in the same estimation unit is calculated by weighting the effective thickness, and the effective porosity of each estimation unit is conservatively determined by arithmetic mean and effective thickness trade-off method.

[0067] (4) Initial water saturation

[0068] It is mainly determined by logging interpretation, closed core analysis, conventional core mercury injection analysis, etc. The ratio of the volume of water contained in the effective reservoir to the volume of rock pores in the formation is obtained.

[0069] Conventional core measurement calibration: Use core measurement calibration logging to establish a water saturation interpretation model and conduct quantitative interpretation (see Fig.10 ).

[0070] Closed coring verification: The reliability of the oil saturation calculated by logging is verified through the closed coring analysis results. The oil saturation calculated by logging in the effective reservoir section is consistent with the oil saturation result of closed coring (see Fig.11 ).

[0071] Water saturation value: The weighted average of effective thickness and effective porosity is adopted for single wells in the same calculation unit, and each estimation unit adopts comprehensive conservative values ​​such as arithmetic mean and pore thickness trade-off method.

[0072] (5) Original brine volume coefficient

[0073] It is defined as the ratio of the unit volume of underground brine to the volume after it reaches the surface. Due to the influence of underground dissolved gas and thermal expansion, the actual volume of oilfield brine exceeds the influence of elastic compression coefficient, so the volume coefficient of oilfield brine is generally greater than 1 (dimensionless). At present, the volume coefficient under the corresponding pressure conditions is mainly calculated by high-pressure physical property sampling. If there is no actual measurement of the mineral deposit, it can be used by analogy based on the neighboring area (see Fig.12 ).

[0074] (6) Brine density and mineral grade: Based on the water samples actually collected at the wellhead, the samples are sent to a laboratory with MA qualification, and internal and external inspections are carried out to verify the reliability of the analysis results. When sampling, the false values ​​are eliminated and the true values ​​are retained, and the analysis results that reflect the true values ​​are retained, and the arithmetic average is calculated (see Table 3).

[0075] The determination of these parameters is reliable in terms of data sources, technical methods, and operability evaluation, so the resource calculation results are also reliable.

[0076] Table 3 Statistics of brine density and mineral content

[0077]

[0078] Step 2: Oilfield deep brine calculation index requirements

[0079] The estimation refers to the estimation of salt mineral resources in the "Mineral Geological Exploration Specifications Salt Part 4: Deep Brine Salt" DZ / T0212.4-2020. The general industrial indicators and comprehensive evaluation index table (see Table 1 and Table 2) must be met before the calculation can begin.

[0080] Table 1 General industrial indicators of oilfield brine associated minerals

[0081]

[0082] Table 2 Reference indicators for comprehensive evaluation of oilfield brine associated minerals

[0083]

[0084] Step 3: Evaluation method of deep brine water resources in oil fields

[0085] 1. The reserves of brine resources in deep brine deposits are estimated by the fluid ore calculation method (oil and gas volumetric method).

[0086] The oil and gas volumetric method is a widely used method at home and abroad. The brine found in the oil field coexists with oil and gas, has the same fluid properties, similar mineralization conditions and laws, and exploration and evaluation runs through the entire process of oil and gas exploration and development. Compared with other methods, its calculation is more scientific and accurate. Therefore, it is recommended to use the oil and gas volumetric method to estimate the reserves of oilfield brine resources.

[0087] The formula for estimating oilfield (brine) water resource reserves using the oil and gas volume method is as follows:

[0088] Pw=100×A×h×φ×Sw×ρ×C / Bw

[0089] Where: Pw-deep brine reserves, 10 4 t;

[0090] A-water-containing area, km 2 ;

[0091] H-effective thickness, m;

[0092] Φ-effective porosity, f;

[0093] Sw-original water saturation, %;

[0094] Bw-original brine volume coefficient, dimensionless;

[0095] ρ-Brine density (t / m 3 );

[0096] C-mineral grade, % or mg / L.

[0097] The examples are as follows:

[0098] Nanyi Mountain is located in the western northern area of ​​the Qaidam Basin in Qinghai Province. It is under the jurisdiction of Mangya City, Haixi Mongolian and Tibetan Autonomous Prefecture, Qinghai Province. Its geographical extreme coordinates are 91°15′~91°45′ east longitude and 38°10′~38°30′ north latitude. It is 57km away from Huatugou Town. The ground is mostly saline-alkali Gobi and wind-eroded residual hills, with an average altitude of 2,800m. The climate is a typical inland desert hyperarid climate. The surface water system is extremely underdeveloped, with only a small number of seasonal flood gullies and occasional temporary torrents in the rainy season.

[0099] 1. Geological characteristics of the deposit

[0100] The Nanyishan structure is a third-order anticline structure extending in the northwest-southeast direction in the Mangya Sag sub-area of ​​the western depression area of ​​the Qaidam Basin. Its two wings are basically symmetrical, with a dip angle of about 20°. The northern wing is slightly steep, with an "S" shape, a long axis of about 50km, a short axis of 15km, a closed height of 820m, and a closed area of ​​620km. 2 Its south and north are controlled by two groups of faults, the south wing and the north wing respectively, with a "two faults and one uplift" pattern, presenting a large and gentle long-axis box-shaped anticline structure.

[0101] The anticline is formed by the superposition of two anticline structures, deep and shallow. The structural cores (high points) of the two anticlines are basically the same, showing the characteristics of inherited development. There are many northeast-southwest normal faults on the ground, extending 1.5 to 2 km, the longest of which is 4 km, accompanied by tensional joints. In the deep layer of the anticline structure, two faults, the south wing and the north wing, are mainly developed, trending NW-SE (see Table 4). Among them, the south wing fault is a north-dipping reverse fault, constituting the south wing fault zone; the north wing is a south-dipping reverse fault, constituting the north wing fault zone. Studies have shown that the two main faults were formed early, forming the prototype of the fault in the early stage of the Xia Ganchaigou Formation (E3) and the lower Youshashan Formation (N2 1 ) fault, the Upper Youshashan Formation (N2 2 ) fault continued to move, resulting in a series of secondary faults. Drilling core sampling confirmed that there were three main types of fractures: vertical fractures, layered fractures, and oblique fractures (with an inclination of 75-85°). The formation age of the E3g formation fractures was measured to be 20.8±2.17ma using the calcite fission track filling the fractures, and the age was N2 2 The overall performance is that it extends for a long length and breaks through many layers. It is a primary fault that controls the structural pattern and the development of the sedimentary system (Table 2).

[0102] Table 4 Main fault elements in Nanyishan mining area

[0103]

[0104] 2. Hydrogeological characteristics of the mining area

[0105] The mining area has revealed the Lulehe Formation (E 1+2 ), the lower section of Xiaganchaigou Formation (E3 1 ), the upper part of Xiaganchaigou Formation (E3 2 ), Upper Ganchaigou Formation (N1), Lower Youshashan Formation (N2 1 ), Upper Youshashan Formation (N2 2 ), Shizigou Formation (N2 3 ) There are seven strata in total (see Table 5). The upper part of the Xiaganchaigou Formation (E3 2 ), Upper Ganchaigou Formation (N1), Lower Youshashan Formation (N2 1 ), Upper Youshashan Formation (N2 2 ) Four sets of brine reservoirs, all of which are oil and gas reservoirs. 2 -N1 can be classified as structural fracture-pore brine, N2 1 -N2 2 It can be classified as porous brine.

[0106] Table 5 Brief Strata Table of Nanyishan Mining Area

[0107]

[0108] (1) Nanyi Mountain is far away from the provenance area, E3 2 -N2 2 The overall sedimentation is mainly semi-deep lake to shallow lake phase, the sedimentary environment is relatively stable, and the overall lithology is not very different. It is mainly limestone, followed by algal limestone and sandstone. The mixed characteristics of sand, mud and ash are obvious, but the physical properties are obviously different. 2 The reservoir has developed fractures, and the microscopic pores are dissolution pores, intercrystalline pores and intergranular pores. The porosity is distributed between 3.5% and 8.0%, with an average of 5.8%; most of the permeabilities are less than 0.5mD, which is a low-porosity and ultra-low-permeability reservoir. Under the combined influence of fractures and microscopic pores, there are many deep high-yield wells (Nan 13 well produces 401 cubic meters of water per day at 3040.6-3058.1m), showing the characteristics of high pressure (oil pressure 6.8Mpa, casing pressure 5Mpa), high yield (single well daily water production 100-401 cubic meters), stable production, gas and water co-production, with water as the main feature; N2 1 -N2 2 The reservoir is mainly composed of primary pores, followed by dissolution pores and fractures. The porosity distribution range is 25-35%, with an average of 29.0%; the permeability peak distribution range is 1-100mD, with a median of 9.0mD. It is a high-porosity and low-permeability reservoir with lower water production than the deeper layers, characterized by low pressure (oil pressure 0.8-1.3Mpa, casing pressure 4.4-7Mpa), low production (explaining that the oil-water layer produces 38-62 cubic meters of water per day), and the characteristics of oil, gas and water co-production (see Table 6).

[0109] Table 6 Statistics of oil and water production of single wells in Nanyishan (data as of the end of October 2021)

[0110]

[0111] (2) According to the test production and development data of Nanyishan oil and gas wells and the results of well logging interpretation, the vertical upper water layer is concentrated in the 1375-3518m well section, and there is no obvious thick aquiclude. The distribution of water production areas is different to a certain extent, among which the shallow N2 1 -N2 2 It is a low-saturation oil and gas reservoir with low oil and gas filling intensity, weak oil-water differentiation, and more original movable bound water. Oil (gas) and water phenomena are common in the high, middle and low parts of the structure, and the lateral distribution is relatively continuous. Deep E3 2 High-yield water is mainly located in the core of the Nanyi Mountain anticline structure, concentrated in the area of ​​South 13-South 6 wells. The brine reservoir is buried at a depth of 3030-3518m, with stable and continuous lateral distribution. It is in the groundwater retention area in the hydrogeological zone.

[0112] 3. Ore body characteristics

[0113] N2 2Ore body: The burial depth of the middle part of the brine reservoir is 678.0-1243.1m, the cumulative thickness of the single-hole brine reservoir is 93.5-267.4m, and the average thickness is 177.3m. The brine reservoir is distributed in thin layers and is developed in the high, middle and low parts of the structure. It is superimposed and interacts with the oil layer, with good lateral continuity. It is generally controlled by the structure. There is an obvious brine reservoir concentration section at the bottom of the ore body, and its thickness and continuity are more developed than those in the middle and upper parts.

[0114] N2 1 Ore body: The burial depth of the middle part of the brine reservoir is 1807.4-2172.3m, the cumulative thickness of the single-hole brine reservoir is 110.7-250.0m, and the average thickness is 165.9m. The brine reservoir is distributed in thin layers and is developed in the high, middle and low parts of the structure. The oil layer is concentrated on the top. It is generally controlled by the structure, with good lateral continuity. The brine reservoir in the low part of the structure has an obvious thickening trend.

[0115] N1 ore body: The burial depth of the middle part of the brine reservoir is 2490.9-2799.9m, the cumulative thickness of the single-hole brine reservoir is 80.9-145.9m, and the average thickness is 104.6m. The brine reservoir is distributed in thin layers and is developed in the high, middle and low parts of the structure. The oil layer is not developed. It is generally controlled by the structure and lithology, and is relatively continuous laterally. The brine reservoir in the low part of the structure has an obvious thickening trend.

[0116] E3 2 Ore body: The burial depth of the middle part of the brine reservoir is 3522.8-3690.9m, the cumulative thickness of the single-hole brine reservoir is 72.5-75.9m, and the average thickness is 74.3m. The brine reservoir is distributed in thick layers and is developed in the high, middle and low parts of the structure. It is more concentrated in the core of the structure, and oil and gas layers are developed on the top. It is generally controlled by the structure, with good lateral continuity and little difference in thickness variation (see Table 7).

[0117] Table 7 Statistics of characteristic parameters of Nanyishan ore body

[0118]

[0119]

[0120] 4. Hydrochemical characteristics of the mining area

[0121] From the sampling results of the oil wells of Nan 6 and Nan 2-3 (see Table 8), K + Content 1.68-8.09g / L, average content 5.07g / L; Li + Content 135.5-259.7mg / L, average content 197.5mg / L; I - The content is 6.0-39.25 mg / L, with an average of 27.3 mg / L; the mineralization is 173.0-298.5 g / L, with an average of 267.12 g / L, and Ca 2+The content is 8.38-17.51g / L, with an average of 12.43g / L. The water chemistry type is calcium chloride type, with K + 、Na + Mg 2+ and Cl － Brine characteristics of quaternary system. C Na / C Cl The value is 0.75~0.80,Br×10 3 / Cl value is 0.27~0.43, indicating that the origin of Nanyi Mountain brine is relatively complex, with the dual characteristics of sedimentary metamorphic brine and salt rock karst filtration brine. The calcium-magnesium coefficient value is 8.37~15.18, indicating that the deep brine of Nanyi Mountain has good sealing and high metamorphic degree, and the longer the formation time. Desulfurization coefficient 100×n(SO4 -2 ) / 2n(Cl - ) is 0.1~0.3, indicating that the deep brine in Nanyi Mountain is reduced by sulfate, resulting in the SO4 2- The content is low, and this environment is conducive to the generation and preservation of oil and gas. The beneficial components such as B, Br, and Li in the southern wing mountains are related to the formation of deep remelting magma caused by continental-continental collision since the Middle and Late Cenozoic, and are also affected by the secondary leaching enrichment and replenishment of hot water.

[0122] In summary, since the Paleogene, under the arid paleoclimate conditions, surface evaporation has caused a large amount of original surface water to be continuously concentrated and crystallized into salt. Some of the uncrystallized groundwater forms highly mineralized brine, which is stored in the pores of rock salt. Sedimentation continues, and the thickness of the sediment continues to increase. Under the formation pressure, it seeps into the surrounding sedimentary strata, reacts with the pore fluid of the surrounding rock in a reducing environment, changes its composition, and coexists with oil and gas. Groundwater uses fault fissures as migration channels to transport dissolved brine to tens of kilometers, or preserves it in fault fissures and formation pores. At the same time, deep elements such as Li and Br migrate into the strata along deep and large faults, mix with karst brine and eventually form oilfield (brine) water potassium-lithium mines.

[0123] Table 8 Water quality analysis statistics in Nanyishan area

[0124]

[0125] V. Development and Utilization

[0126] The pilot test results in 2012 were to build a salt field of 10,500 square meters using the Nanyishan South Well No. 13, and successfully carry out a small pilot test using the evaporation precipitation process, using 4419.13m of raw brine. 3 , obtained 285t of potassium mixed salt products and 210m of tail brine 3 , using 1.1m 3 Tail halogen (Li +Content 9.18g / L) was refined indoors to produce 40kg of lithium carbonate with a grade of 95.17%, indicating that the comprehensive evaluation of deep brine in Nanyi Mountain area has certain development and utilization value.

[0127] The results of the expanded pilot test in 2019-2020 are to conduct brine production tests using the 50,000 square meters of salt pan facilities in Nanyi Mountain, and obtain a set of parameters for the temperature, specific gravity, pH and salt pan brine production process in the oilfield lithium-potassium brine salt pan; divide the brine index control parameters of the three stages of sodium salt, potassium salt and carnallite in the oilfield brine salt pan brine production process; obtain the data on the change of the content of the main elements in the salt pan throughout the process, combined with the analysis of the precipitated solid phase minerals; summarize the complete change rules of the content of sodium, potassium, lithium, boron, bromine and other ions in the salt pan brine production process; prepare 28,000 tons of potassium-rich brine that meets the requirements of the subsequent pilot test as the raw material for the next step of extracting potassium mixed salt and lithium products. At present, it is still in the pilot test stage overall.

[0128] VI. Resource Reserve Estimation

[0129] Scope of reserves calculation:

[0130] The reserve calculation scope is the Nanyishan E3 within the scope of the prospecting right of the project "Survey of Deep Brine Potash Resources in Honggouzi-Nanyishan in the Western Qaidam Basin of Qinghai Province" 2 -I and II oil groups have ore layers. According to the distribution of drilling holes, they are mainly concentrated in the high parts of the structure in the plane, and the depth ranges from 2946 to 3992 meters in the vertical direction.

[0131] Objects and types of minerals for reserve calculation:

[0132] The project collected the South Wing Mountain E3 2 According to the available water quality analysis results, the beneficial minerals in deep brine are mainly KCl, LiCl, B2O3, and NaCl; followed by trace element minerals such as Rb, Cs, Br, and I.

[0133] Potash ore (KCl): It is the main mineral species for resource estimation in the mining area. It is consistent with the prospecting right certificate for deep brine.

[0134] B2O3, LiCl, NaCl: These three minerals are relatively abundant in the brine of the ore deposit, and all meet industrial targets. As symbiotic minerals, resource reserves are estimated based on reaching the minimum industrial target.

[0135] Rb, Cs, Br, I: The samples of the four minerals in the brine of the ore deposit are currently scattered and the content varies greatly. Some of them have reached the comprehensive utilization evaluation index and are regarded as associated minerals. The resource reserves are estimated according to the average value to understand the trace element resource base.

[0136] The estimated mineral types are KCl, B2O3, LiCl, NaCl, Rb, Cs, Br, and I, totaling 8 minerals, in order to fully grasp the resource base.

[0137] Reserves calculation industry indicators:

[0138] The industrial indicators for the calculation of the reserves of the liquid minerals in Nanyi Mountain are determined in accordance with the general industrial indicators in the "Mineral Deposit Geological Exploration Specifications Salts Part 4: Deep Brine Salts" (DZ / T0212.4-2020) issued by the Ministry of Natural Resources of the People's Republic of China (see Table 9), and the minerals and industrial indicators for the reserve calculation are shown in Table 7. Since the water sample analysis is for various ions, and the minerals of potassium, lithium, boron, sodium, and sodium minerals in the salt lake standard are KCl, LiCl, B2O3, and NaCl. In this work, the ion concentrations of potassium, lithium, and sodium ions are converted into the mineral concentrations of potassium chloride, lithium chloride, and sodium chloride, and B2O3 is calculated according to the actual measured concentration value.

[0139] From the analysis and testing results compared with the minimum industrial index, the mineral grade of each water-bearing layer of the deep brine in the Nanyishan mining area is far greater than the minimum industrial index of the salt lake, so all mineral types meet the starting standard. Deep brine is a liquid mineral and there is no minimum mineable thickness.

[0140] Table 9 Comparison of general industrial indicators of liquids used

[0141]

[0142] Calculation of deep brine resources by volumetric method:

[0143] The oil and gas volume method is a widely used method for evaluating oil and gas in oil fields. The brine found in oil fields coexists with oil and gas, has the same fluid properties, similar mineralization conditions and laws, and exploration and evaluation runs through the entire process of oil and gas exploration and development. Compared with other methods, its calculation is more scientific and accurate. Therefore, it is recommended to use the oil and gas volume method to estimate the reserves of oilfield brine resources.

[0144] a) Estimation formula for oilfield water resources:

[0145] 1) The calculation formula for oilfield (brine) water resources is as follows:

[0146] V=A×h×φ×Sw×C / B

[0147] If expressed in mass units:

[0148] Pw=V×ρ

[0149] 2) The water saturation calculation formula is as follows:

[0150] Oilfield water mixed with oil and gas or interbedded with oil and gas belongs to the same body of mineral products as oil and gas reservoirs. It is similar to oil and gas in terms of storage space, existence state, enrichment law, occurrence characteristics, etc., and coexists with underground oil and natural gas in liquid phase or gas-liquid phase. Therefore, according to the relationship between the storage characteristics of brine and hydrocarbons, the oil saturation can be used to obtain:

[0151] Sw=1-So;

[0152] The oilfield water that exists alone at the bottom and around the oil and gas is a heterogeneous mineral in the oil and gas reservoir, and exists in the stratum in the form of a single liquid phase. For this separately circled oilfield water ore body, the water saturation (Sw) is taken as 1.

[0153] b) Estimation formula for the amount of mineral resources associated with oilfield water:

[0154] For the mineral resources associated with oilfield water such as KCl, MgCl2, NaCl, Na2SO4 and Na2CO3, the calculation formula is:

[0155] P = Pw × C1;

[0156] For LiCl, B2O3, Br - 、Rb2O、Cs2O、I - The calculation formula for the amount of mineral resources associated with oilfield water is:

[0157] P=Pw×C2

[0158] Where:

[0159] V-deep brine resources, m 3 ;

[0160] Pw-deep brine resources, t;

[0161] P-deep brine associated mineral resources, t;

[0162] A-water-containing area, m 2 ;

[0163] h-effective thickness of brine layer, m;

[0164] Φ-effective porosity of brine layer, f;

[0165] Sw-water saturation, %;

[0166] So-oil saturation, %;

[0167] ρ-average density of brine, t / m 3 ;

[0168] Bw-brine volume coefficient, dimensionless;

[0169] C1-average grade of useful components, %;

[0170] C2-Average grade of useful components, t / m 3 .

[0171] Computational unit division

[0172] Nanyi Mountain E3 2 There is no fracture division on the planar structural map, and the whole is taken as one calculation unit; vertically it is divided into two calculation units according to the oil layers.

[0173] Determination of reserve calculation parameters

[0174] 1. Water-containing area (A)

[0175] Circumscription principle: E3 2 Brine deposits are structural water reservoirs under the lithological background, and the water layer is continuously distributed. Therefore, the contour line where the mine is located is followed according to the lowest part of the trap. If the mine is located within the contour line, the mine is taken as the standard and one development well distance (refer to the development well distance of 500m in Nanyishan E32) is extrapolated as the water-bearing boundary.

[0176] Evaluation of the top surface structure diagram of the computing unit

[0177] In order to meet the needs of calculation accuracy, the reserve calculation uses the 3D seismic fine target processing data combined with the fine stratigraphic comparison results to compile the E3 2 The 1:50000 structural map of the top of each calculation unit of the mineral deposit has been corrected by drilling geological stratification and has high accuracy. The selection of the structural map meets the requirements for delineating the oil-bearing area.

[0178] Determination of water-bearing boundary and area value

[0179] Nanyi Mountain E3 2 The distribution of mineral deposits is obviously controlled by the structure. The brine layer is continuous and partially affected by lithology and physical properties. The southern and northern boundaries are blocked by faults, and the eastern and western boundaries are the reserve calculation lines. The specific method for delineating the water-bearing area is as follows:

[0180] (1) The south and north are bounded by faults, which control the distribution of water layers;

[0181] (2) When there is no well control outside the water-bearing well, the boundary well is extrapolated 500m to determine the water-bearing boundary;

[0182] (3) When there is well control outside the water-bearing well, half of the well spacing is used to determine the water-bearing boundary.

[0183] 2. Thickness of ore layer (h)

[0184] Determination of effective thickness: Using core scale logging, a relationship model is established based on the measured porosity of the core section and the logging electrical properties. The reservoir porosity of the entire well is calculated through the parameter model. The arithmetic average is used for single project values, and the thickness weighting is used for the entire area.

[0185] 3. Average porosity (Φ)

[0186] Using core calibration logging, a relationship model is established based on the measured porosity of the core section and the logging electrical properties. The reservoir porosity of the entire well is calculated through the parameter model, and the arithmetic average is used for single project values, and the thickness weighted value is used for the entire area.

[0187] 4. Water saturation (Sw)

[0188] The established logging saturation interpretation model is used to quantitatively interpret all wells. The Archie formula is used to take the arithmetic mean for single-project thickness and the volume weighted method for water saturation in the entire area.

[0189] 5. Volume coefficient (B)

[0190] It is defined as the ratio of the unit volume of brine underground to the volume after it reaches the surface. At present, the volume coefficient under the corresponding pressure conditions is mainly calculated by high-pressure physical property sampling. If there is no actual measurement of the mineral deposit, it can be used by analogy based on neighboring areas.

[0191] 6. Brine density (ρ)

[0192] Based on the test values ​​of all samples in the mining area, the arithmetic average method is used to calculate the value for the entire area.

[0193] 7. Mineral grade (C)

[0194] Based on the test values ​​of all samples in the mining area, the arithmetic average method is used to calculate the value for the entire area.

[0195] like Fig.13 As shown, an embodiment of the present disclosure provides an oilfield brine resource estimation system, comprising:

[0196] An acquisition module 11 is used to acquire key parameters, wherein the key parameters include water-bearing area, effective thickness of water layer, effective porosity, original water saturation, original brine volume coefficient, brine density and mineral grade;

[0197] Index construction module 12, used to construct the initial calculation index of deep brine in oil fields;

[0198] The judgment module 13 is used to compare the key parameters with the oilfield deep brine calculation index to determine whether the key parameters meet the standards.

[0199] The calculation module 14 is used to substitute the key parameters into the oilfield brine resource estimation formula to perform calculations to obtain an estimated value of the oilfield brine resource.

[0200] The implementation process of the functions and effects of each module in the above system is specifically described in the implementation process of the corresponding steps in the above method, which will not be repeated here.

[0201] For the system embodiment, since it basically corresponds to the method embodiment, the relevant parts can refer to the partial description of the method embodiment. The system embodiment described above is only schematic, wherein the modules described as separate components may or may not be physically separated, and the components displayed as modules may or may not be physical modules, that is, they may be located in one place, or they may be distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of the present invention. Those of ordinary skill in the art can understand and implement it without paying creative labor.

[0202] In the above-mentioned embodiment, any multiple of all modules can be combined in one module for implementation, or any one of the modules can be split into multiple modules. Alternatively, at least some functions of one or more of these modules can be combined with at least some functions of other modules and implemented in one module. At least one of all modules can be at least partially implemented as a hardware circuit, such as a field programmable gate array (FPGA), a programmable logic array (PLA), a system on a chip, a system on a substrate, a system on a package, an application specific integrated circuit (ASIC), or can be implemented by hardware or firmware such as any other reasonable way of integrating or packaging the circuit, or implemented in any one of the three implementation modes of software, hardware and firmware or in a suitable combination of any of them. Alternatively, at least one of all modules can be at least partially implemented as a computer program module, and when the computer program module is run, the corresponding function can be executed.

[0203] See also Fig.14 , an electronic device provided by an embodiment of the present disclosure includes a processor 1110, a communication interface 1120, a memory 1130 and a communication bus 1140, wherein the processor 1110, the communication interface 1120, and the memory 1130 communicate with each other through the communication bus 1140;

[0204] Memory 1130, for storing computer programs;

[0205] The processor 1110 is used to implement the oilfield brine resource estimation method as shown below when executing the program stored in the memory 1130.

[0206] The communication bus 1140 may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The communication bus 1140 may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one thick line is used in the figure, but it does not mean that there is only one bus or one type of bus.

[0207] The communication interface 1120 is used for communication between the above electronic device and other devices.

[0208] The memory 1130 may include a random access memory (RAM) or a non-volatile memory, such as at least one disk memory. Optionally, the memory 1130 may also be at least one storage device located away from the processor 1110.

[0209] The above-mentioned processor 1110 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components.

[0210] The embodiment of the present disclosure further provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for estimating the amount of brine resources in an oil field as described above is implemented.

[0211] The computer-readable storage medium may be included in the device / apparatus described in the above embodiment; or it may exist independently without being assembled into the device / apparatus. The above computer-readable storage medium carries one or more programs, and when the above one or more programs are executed, the method for estimating the amount of oilfield brine resources according to the embodiment of the present disclosure is implemented.

[0212] According to an embodiment of the present disclosure, a computer-readable storage medium may be a non-volatile computer-readable storage medium, for example, may include but is not limited to: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present disclosure, a computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in conjunction with an instruction execution system, apparatus, or device.

[0213] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A method for estimating oilfield brine resources, characterized in that: The following steps are involved: Obtaining key parameters, including water-bearing area, effective thickness of water layer, effective porosity, original water saturation, original brine volume coefficient, brine density and mineral grade; Construct the calculation index of deep brine in oil fields; The key parameters are compared with the oilfield deep brine calculation index to determine whether the key parameters meet the standards. If so, the key parameters are substituted into the oilfield brine resource estimation formula to calculate and obtain the oilfield brine resource estimation value.

2. The method for estimating oilfield brine resources according to claim 1, characterized in that: The specific process of obtaining the effective thickness of the water layer is as follows: Divide the plane calculation unit and the vertical calculation unit, and delineate the water-bearing area according to the top boundary structure map of the target water layer.

3. The method for estimating oilfield brine resources according to claim 2, characterized in that: The specific process of obtaining the effective thickness of the water layer is as follows: The physical, electrical and saturation lower limit standards are established to divide the reservoirs of the corresponding fluids. The core, conventional and special logging methods are used to obtain the reservoir thickness of the part of the aquifer system with water production capacity that meets the starting standard. Referring to the lower limit standards of the region, the natural gamma and natural potential curves are used to divide the water layer thickness and eliminate the thickness of the interlayer in the water layer. The average effective thickness of the water layer in each well in the same calculation unit is obtained by taking the arithmetic average.

4. The method for estimating oilfield brine resources according to claim 1, characterized in that: The specific process of obtaining the effective porosity is as follows: Using core measured scale logging, the average effective porosity of a single well in the same calculation unit is calculated weighted by effective thickness, and the effective porosity of each calculation unit is conservatively determined by arithmetic mean and effective thickness trade-off method.

5. The method for estimating oilfield brine resources according to claim 1, characterized in that: The specific process of obtaining the original water saturation is as follows: It is determined by means of well logging interpretation, closed core analysis and conventional core mercury injection analysis, and the ratio of the volume of water contained in the effective reservoir in the formation to the volume of rock pores is obtained; the weighted average of effective thickness and effective porosity is adopted for single wells in the same calculation unit, and comprehensive conservative values ​​such as arithmetic average and pore thickness trade-off method are adopted for each calculation unit.

6. The method for estimating oilfield brine resources according to claim 1, characterized in that: The specific process of obtaining the original brine volume coefficient is as follows: The volume coefficient of the original brine under the corresponding pressure conditions is calculated by means of high-pressure physical property sampling. If there is no actual measurement of the mineral deposit, it can be used by analogy with neighboring areas.

7. The method for estimating oilfield brine resources according to claim 1, characterized in that: The specific process of obtaining the brine density and the mineral grade is as follows: According to the actual water samples collected at the wellhead, the samples are sent to a laboratory with MA qualification, and internal and external inspections are carried out in parallel for sampling and analysis. When sampling, the analysis results that can reflect the true value are retained and the arithmetic average is calculated.

8. The method for estimating oilfield brine resources according to claim 1, characterized in that: The estimation formula is as follows: Pw=100×A×h×φ×Sw×ρ×C / Bw; Where: Pw represents the estimated value of oilfield brine resources, A represents the water-bearing area, H represents the effective thickness, Φ represents the effective porosity, Sw represents the original water saturation, Bw represents the original brine volume coefficient, ρ represents the brine density, and C represents the mineral grade.

9. An oilfield brine resource estimation system, characterized in that: include: An acquisition module is used to acquire key parameters, wherein the key parameters include water-bearing area, effective thickness of water layer, effective porosity, original water saturation, original brine volume coefficient, brine density and mineral grade; Index construction module, used to construct the initial calculation index of deep brine in oil fields; A judgment module is used to compare the key parameters with the oilfield deep brine calculation index to determine whether the key parameters meet the standards. The calculation module is used to substitute the key parameters into the oilfield brine resource estimation formula to calculate and obtain the oilfield brine resource estimation value.

10. An electronic device, characterized in that: It includes a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; Memory, for storing computer programs; The processor is used to implement the oilfield brine resource estimation method described in any one of claims 1-8 when executing the program stored in the memory.

11. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method for estimating oilfield brine resources according to any one of claims 1 to 8 is implemented.

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