Quantitative evaluation method for geological success rate of multi-target oil-gas exploration block

Abstract

The invention relates to the technical field of petroleum and natural gas exploration geological evaluation, and discloses a geological success rate quantitative evaluation method for a multi-target oil and gas exploration block, which comprises the following steps of: explaining potential traps and analyzing reservoir-forming geological conditions in an exploration block mine right range through well drilling and seismic data; based on the relationship between the reservoir forming geological condition of the adjacent region of the exploration block and oil and gas display, obtaining a sufficient condition of oil and gas reservoir forming of the regional geological unit, and scoring the reservoir forming geological condition of the potential trap; calculating the geological success rate P of the potential trap based on the reservoir-forming geological condition scoring result; calculating the geological success rate PL of the exploration target based on the geological success rate evaluation result of the potential trap; and calculating the geological success rate Pg of the exploration block based on the geological success rate evaluation result of the exploration target. In the evaluation process, the exploration target data reliability and the geological resource quantity are introduced as evaluation parameters, and the problem of potential evaluation result deviation in the multi-target oil-gas exploration block in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of geological evaluation of oil and gas exploration projects, and in particular to a method for quantitatively evaluating the geological success rate of a multi-target oil and gas exploration block. Background Art

[0002] Geological evaluation of oil and gas exploration blocks is the technical basis for feasibility studies of oil and gas exploration projects. Geological success rate evaluation is an important part of geological evaluation, which helps the management of oil companies understand the potential risks of oil and gas exploration projects from the perspective of geological conditions and make favorable business decisions.

[0003] In recent years, my country's oil companies have actively participated in the bidding projects of oil and gas exploration blocks in overseas resource countries. Unlike domestic oil and gas exploration blocks, overseas oil and gas exploration blocks usually have low exploration degree and lack of geological data on the one hand, but have great exploration potential on the other hand, and the mining rights contain multiple exploration targets located in different strata and with different geological resource quantities.

[0004] The geological success rate of an oil and gas exploration block means the probability that the block contains oil and gas. When actually conducting geological exploration work, the exploration targets that may contain oil and gas within the mining rights of the block are first interpreted, the geological success rates of these targets are analyzed, and then the probability that at least one exploration target in the block contains oil and gas is calculated. When calculating, the existing methods assign the same weight to the geological success rates of the exploration targets in the block, without considering the potential bias in the evaluation results caused by the reliability of the exploration target data and the difference in geological resources. However, when the geological resources between the exploration targets vary greatly, the correlation between the geological resources and the geological success rate should not be ignored. At the same time, under the condition of less research data, the data basis of different exploration targets usually varies greatly. When conducting geological success rate analysis, the data reliability of the exploration target should be used as one of the evaluation parameters.

[0005] In view of this, this application is hereby filed. Summary of the invention

[0006] In order to solve the problems of the above-mentioned prior art, the present invention provides a quantitative evaluation method for the geological success rate of multi-target oil and gas exploration blocks. In the evaluation process, the reliability of exploration target data and the amount of geological resources are introduced as evaluation parameters, and the influence of the data reliability of the exploration target and the difference in the amount of geological resources on the deviation of the geological success rate evaluation result is considered. At the same time, the scoring basis of the reservoir geological conditions is the relationship between the reservoir geological conditions and the oil and gas shows in the adjacent areas. It can reflect the geological potential of the closure according to local conditions, and reflect the influence of geological conditions in different regions on oil and gas accumulation, so as to provide the project management with more accurate geological success rate evaluation results of multi-target oil and gas exploration blocks, thereby improving the success probability of oil and gas exploration project management decisions.

[0007] The present invention is achieved through the following technical solutions: The present invention provides a method for quantitatively evaluating the geological success rate of a multi-target oil and gas exploration block, comprising the following steps: S1, interpret potential traps within the scope of exploration block mineral rights through drilling and seismic data, and analyze the geological conditions of potential trap formation; S2, based on the relationship between the reservoir-forming geological conditions and oil and gas shows in the neighboring areas of the exploration block, the sufficient conditions for oil and gas accumulation in the regional geological units are obtained, and the reservoir-forming geological conditions of potential traps are scored; S3, based on the scoring results of reservoir geological conditions, calculate the geological success rate P of potential traps; S4, based on the geological success rate evaluation results of potential traps, calculate the geological success rate P of the exploration target L ; S5, based on the geological success rate evaluation results of the exploration target, calculate the geological success rate P of the exploration block g .

[0008] In a specific implementation, in step S2, the reservoir-forming geological conditions include trap conditions, reservoir conditions, transport conditions and preservation conditions.

[0009] In a specific embodiment, when scoring the geological conditions of potential trap formation, The trap conditions are scored based on structural closure and data reliability; The reservoir conditions are scored based on the sedimentary facies conditions and the predicted reservoir thickness; The transport conditions are scored based on the distance between the oil source fault development and the oil and gas display ratio in the adjacent area; The preservation conditions are scored based on the development distance of the Tongtian Fault and the sealing capacity of the caprock.

[0010] In a specific embodiment, in the trap condition, data reliability is analyzed based on the number of seismic lines that explain the trap and the quality of seismic data display.

[0011] In a specific implementation, in step S2, when scoring the reservoir-forming geological conditions of the potential trap, the scoring is based on the relationship between the reservoir-forming geological conditions of the adjacent area and the oil and gas show.

[0012] In a specific embodiment, in step S3, the geological success rate P of the potential trap of the jth layer of the i-th exploration target is ij The calculation formula is: ij =P Tij *P Rij *P Cij *P Sij , where P Tij , P Rij , P Cij , PSij They are the scores of the trap conditions, reservoir conditions, transport conditions and preservation conditions of the j-th potential trap of the ith exploration target, respectively.

[0013] In a specific embodiment, the geological success rate of the exploration target P L The calculation is the probability of at least one potential trap containing oil and gas in a single exploration target; assuming that there are n exploration targets in the exploration block, and the i-th exploration target has m exploration layers, the calculation formula for the geological success rate of the i-th exploration target is: , Where P ij is the geological success rate of trapping the jth potential layer of the ith target.

[0014] In a specific embodiment, the geological success rate P of the exploration block g The calculation is the probability that at least one exploration target in the block contains oil and gas after being weighted by the geological resources: the probability that the exploration target does not contain oil and gas , taking the geological resource volume Q as the weight for geometric averaging; assuming that there are n exploration targets in the exploration block, the calculation formula for the geological success rate of the exploration block is: , Where P Li is the geological success rate of the jth potential trap of the i-th exploration target, Q i is the geological resource volume of the i-th exploration target.

[0015] In a specific implementation, the geological resources are calculated by volumetric method using the following formula: Q=A o *h*φ*S oi / B oi Where: Q - geological resources, 10 6 t; A o - Oil-bearing area, km 2 ; h - effective thickness of crude oil reservoir, m; φ - effective porosity of crude oil reservoir, dimensionless; S oi - The original oil saturation of the crude oil reservoir, dimensionless; B oi -Original volume coefficient of crude oil, m 3 / m 3 .

[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. A quantitative evaluation method for the geological success rate of a multi-target oil and gas exploration block provided in an embodiment of the present invention introduces the reliability of exploration target data and the amount of geological resources as evaluation parameters in the evaluation process, thereby solving the potential evaluation result deviation problem when the prior art solution is applied to the multi-target oil and gas exploration block, and providing a scientific basis for the operation decision-making and risk control of oil and gas exploration projects; 2. An embodiment of the present invention provides a quantitative evaluation method for the geological success rate of a multi-target oil and gas exploration block. The scoring basis of the geological conditions of reservoir formation is the relationship between the geological conditions of the adjacent areas and the oil and gas shows. It can reflect the geological potential of the closure according to local conditions, and reflect the influence of geological conditions in different regions on oil and gas accumulation. It provides the project management with a more accurate geological success rate evaluation result of the multi-target oil and gas exploration block, thereby improving the success probability of the operation decision of the oil and gas exploration project. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A schematic flow chart of a method for quantitatively evaluating geological success rates of multi-target oil and gas exploration blocks provided by an embodiment of the present invention; Figure 2 The geological data and exploration target distribution map of oil and gas exploration block A and its adjacent areas provided in Example 2 of the present invention. DETAILED DESCRIPTION

[0019] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0020] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is apparent to one of ordinary skill in the art that these specific details need not be employed to practice the present invention. In other embodiments, in order to avoid confusing the present invention, well-known materials or methods are not specifically described.

[0021] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment," "an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. In addition, it will be appreciated by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] Example 1 like Figure 1 As shown, an embodiment of the present invention provides a method for quantitatively evaluating the geological success rate of a multi-target oil and gas exploration block, comprising the following steps: S1, interpret potential traps within the scope of exploration block mineral rights through drilling and seismic data, and analyze the geological conditions of potential trap formation; S2, based on the relationship between the reservoir-forming geological conditions and oil and gas shows in the neighboring areas of the exploration block, the sufficient conditions for oil and gas accumulation in the regional geological units are obtained, and the reservoir-forming geological conditions of potential traps are scored; S3, based on the scoring results of reservoir geological conditions, calculate the geological success rate P of potential traps; S4, based on the geological success rate evaluation results of potential traps, calculate the geological success rate P of the exploration target L ; S5, based on the geological success rate evaluation results of the exploration target, calculate the geological success rate P of the exploration block g .

[0023] In a specific implementation, in step S2, the reservoir-forming geological conditions include trap conditions, reservoir conditions, transport conditions and preservation conditions.

[0024] In a specific embodiment, when scoring the geological conditions for the formation of potential traps, The trap conditions are scored based on structural closure and data reliability; The reservoir conditions are scored based on the sedimentary facies conditions and the predicted reservoir thickness; The transport conditions are scored based on the distance between the oil source fault development and the oil and gas display ratio in the adjacent area; The preservation conditions are scored based on the development distance of the Tongtian Fault and the sealing capacity of the caprock.

[0025] In a specific embodiment, in the trap condition, data reliability is analyzed based on the number of seismic lines that explain the trap and the quality of seismic data display.

[0026] In a specific implementation, in step S2, when scoring the reservoir-forming geological conditions of the potential trap, the scoring is based on the relationship between the reservoir-forming geological conditions of the adjacent area and the oil and gas show.

[0027] In a specific embodiment, in step S3, the geological success rate P of the potential trap of the jth layer of the i-th exploration target is ij The calculation formula is: ij =P Tij *P Rij *P Cij *P Sij , where P Tij , P Rij , P Cij , P Sij They are the scores of the trap conditions, reservoir conditions, transport conditions and preservation conditions of the j-th potential trap of the ith exploration target, respectively.

[0028] In a specific embodiment, the geological success rate of the exploration target P L The calculation is the probability of at least one potential trap containing oil and gas in a single exploration target; assuming that there are n exploration targets in the exploration block, and the i-th exploration target has m exploration layers, the calculation formula for the geological success rate of the i-th exploration target is:

[0029] Where P ij is the geological success rate of closure of the jth potential layer of the i-th exploration target.

[0030] In a specific embodiment, the geological success rate P of the exploration block g The calculation is the probability that at least one exploration target in the block contains oil and gas after being weighted by the geological resources: the probability that the exploration target does not contain oil and gas , taking the geological resource volume Q as the weight for geometric averaging; assuming that there are n exploration targets in the exploration block, the calculation formula for the geological success rate of the exploration block is:

[0031] Where P Li is the geological success rate of the jth potential trap of the i-th exploration target, Q i is the geological resource volume of the i-th exploration target.

[0032] In a specific implementation, the geological resources are calculated by volumetric method using the following formula: Q=A o *h*φ*Soi / B oi， Where: Q - geological resources, 10 6 t; A o - Oil-bearing area, km 2 ; h - effective thickness of crude oil reservoir, m; φ - effective porosity of crude oil reservoir, dimensionless; S oi - The original oil saturation of the crude oil reservoir, dimensionless; B oi -Original volume coefficient of crude oil, m 3 / m 3 .

[0033] Example 2 This example takes the quantitative evaluation of the geological success rate of oil and gas exploration in Block A of a certain overseas country as an example. In this example, there is no drilling and 3D seismic data within the mining rights of Block A, and only 2D seismic lines with a grid density of about 4km×4km can be used for exploration target interpretation. In addition, the resource country provides geological data of an oil field (Z oil field) and two wells (X well, Y well) around Block A (such as Figure 2 ).

[0034] S1, through drilling, seismic and other data, interpret the potential closures within the block mining rights and analyze their geological conditions for reservoir formation.

[0035] Since there is no drilling and 3D seismic data within the mining rights of Block A, 2D seismic data was used to interpret three potential traps in the J3 layer by leading the layers from Well X and Well Y, and two potential traps were interpreted in the K1 and K2 layers respectively. They overlap each other vertically to form three favorable exploration targets, such as Figure 2 As shown, they are named as exploration targets 1, 2 and 3 respectively, among which exploration target 1 has three potential traps, J3, K1 and K2, exploration target 2 has two potential traps, J3 and K1, and exploration target 3 has two potential traps, K1 and K2.

[0036] The geological conditions for reservoir formation of potential traps are analyzed from four aspects: trap conditions, reservoir conditions, transport conditions and preservation conditions.

[0037] The trap conditions include structural closure and data reliability. The structural closure is measured by the interpretation results of 2D seismic data. The data reliability is analyzed based on the number of seismic lines used to interpret the trap and the quality of the seismic data display.

[0038] Reservoir conditions include sedimentary phase conditions and predicted reservoir thickness, which are obtained through comprehensive analysis and prediction of regional drilling and seismic data.

[0039] The transport conditions include the development distance of oil-source faults and the oil and gas indication ratio of adjacent areas. The development distance of oil-source faults is obtained through two-dimensional seismic structural interpretation, and the oil and gas indication ratio of adjacent areas is obtained through statistics of oil and gas indications of adjacent drilling wells.

[0040] The preservation conditions include the development distance of the Tongtian Fault and the sealing capacity of the cap rock. The development distance of the Tongtian Fault is obtained through two-dimensional seismic structural interpretation, and the sealing capacity of the cap rock is obtained through the study of the lithology and thickness of the regional cap rock.

[0041] The geological conditions of the potential traps under each exploration target are shown in Table 1: Table 1 Exploration targets and potential trap formation geological conditions in Block A

[0042] S2, based on the relationship between the geological conditions of hydrocarbon accumulation in the adjacent areas and hydrocarbon shows, the sufficient conditions for hydrocarbon accumulation in the regional geological units are obtained, and the geological conditions for hydrocarbon accumulation in the potential traps are scored.

[0043] In this embodiment, the geological conditions of the adjacent areas to be investigated are the same as the potential trap geological conditions of the block mineral rights analysis, that is, the trap conditions, reservoir conditions, transport conditions and preservation conditions, and the target horizons for the investigation are the J3, K1, and K2 layers with potential traps. The geological and oil and gas display data show that the sufficient conditions for oil and gas accumulation in the J3, K1, and K2 layers of the regional geological units of Block A are: ① Trap conditions: structural closure ≥ 30m; ② Reservoir conditions: development of shoal sedimentary phases, reservoir thickness ≥ 10m; ③ Transport conditions: oil source fault development distance ≤ 15km, adjacent area oil and gas display ratio ≥ 0.5; ④ Preservation conditions: Tongtian fault development distance ≥ 30km, caprock plugging capacity ≥ 0.8. Thus, the scoring criteria table of reservoir geological conditions of the J3, K1, and K2 layers of the regional geological units of Block A can be obtained, as shown in Table 2.

[0044] Table 2 Evaluation criteria for reservoir geological conditions of J3, K1 and K2 layers in the regional geological units of Block A

[0045] Comparing the scoring criteria in Table 1 with those in Table 2, the geological conditions for the formation of potential traps are scored, as shown in Table 3.

[0046] (1) J3 trap of exploration target 1: In terms of trap conditions, the structural closure is 65 m > 30 m (score 1), 3 seismic survey lines for interpreting the trap are > 2 (score 1), and the seismic data show a quality score of 0.7, with a comprehensive score of 1 × 1 × 0.7 = 0.7; in terms of reservoir conditions, a shoal sedimentary facies is developed (score 1), and the reservoir thickness is 20 m > 10 m (score 1), so the score is 1 × 1 = 1; in terms of transport conditions, the oil and gas display ratio in the adjacent area is 0.8 > 0.5 (score 1), but the development distance of the oil source fault is 30 km = 15 km ÷ 0.5 (score 0.5), and the comprehensive score is 1 × 0.5 = 0.5; in terms of preservation conditions, the caprock sealing capacity is 0.9 > 0.8 (score 1), but the development distance of the Tongtian fault is 15 km = 30 km * 0.5 (score 0.5), and the comprehensive score is 1 × 0.5 = 0.5.

[0047] (2) K1 trap of exploration target 1: In terms of trap conditions, the structural closure is 60 m > 30 m (score 1), 3 seismic survey lines for interpreting the trap are > 2 (score 1), combined with the seismic data display quality score of 0.7, the comprehensive score is 1×1×0.7=0.7; in terms of reservoir conditions, shoal sedimentary facies is developed (score 1), the reservoir thickness is 15 m > 10 m (score 1), so the score is 1×1=1; in terms of transport conditions, the oil and gas display ratio in the adjacent area is 0.6>0.5 (score 1), but the development distance of the oil source fault is 30 km = 15 km ÷ 0.5 (score 0.5), the comprehensive score is 1×0.5=0.5; in terms of preservation conditions, the sealing capacity of the cap rock is 0.9>0.8 (score 1), but the development distance of the Tongtian fault is 15 km = 30 km * 0.5 (score 0.5), the comprehensive score is 1×0.5=0.5.

[0048] (3) K2 trap of exploration target 1: In terms of trap conditions, the structural closure is 55 m > 30 m (score 1), 3 seismic survey lines for interpreting the trap are > 2 (score 1), combined with the seismic data display quality score of 0.7, the comprehensive score is 1×1×0.7=0.7; in terms of reservoir conditions, platform sedimentary facies is developed (score 0.6), the reservoir thickness is 10 m (score 1), so the score is 0.6×1=0.6; in terms of transport conditions, the oil and gas display ratio in the adjacent area is 0.3=0.5*0.6 (score 0.6), and the development distance of the oil source fault is 30 km=15 km÷0.5 (score 0.5), the comprehensive score is 0.6×0.5=0.3; in terms of preservation conditions, the sealing capacity of the cap rock is 0.9>0.8 (score 1), but the development distance of the Tongtian fault is 15 km=30 km*0.5 (score 0.5), the comprehensive score is 1×0.5=0.5.

[0049] (4) J3 trap of exploration target 2: In terms of trap conditions, the structural closure is 45 m > 30 m (score 1), 4 seismic survey lines for interpreting the trap are > 2 (score 1), and the seismic data show a quality score of 0.8, with a comprehensive score of 1 × 1 × 0.8 = 0.8; in terms of reservoir conditions, a shoal sedimentary facies is developed (score 1), and the reservoir thickness is 18 m > 10 m (score 1), so the score is 1 × 1 = 1; in terms of transport conditions, the oil and gas display ratio in the adjacent area is 0.8 > 0.5 (score 1), and the development distance of the oil source fault is 10 km < 15 km (score 1), with a comprehensive score of 1 × 1 = 1; in terms of preservation conditions, the caprock sealing capacity is 0.8 (score 1), and the development distance of the Tongtian fault is 40 km > 30 km (score 1), with a comprehensive score of 1 × 1 = 1.

[0050] (5) K1 trap of exploration target 2: In terms of trap conditions, the structural closure is 40 m > 30 m (score 1), 4 seismic survey lines for interpreting the trap are > 2 (score 1), and the seismic data show a quality score of 0.8, with a comprehensive score of 1 × 1 × 0.8 = 0.8; in terms of reservoir conditions, a shoal sedimentary facies is developed (score 1), and the reservoir thickness is 13 m > 10 m (score 1), so the score is 1 × 1 = 1; in terms of transport conditions, the oil and gas display ratio in the adjacent area is 0.6 > 0.5 (score 1), and the development distance of the oil source fault is 10 km < 15 km (score 1), with a comprehensive score of 1 × 1 = 1; in terms of preservation conditions, the caprock sealing capacity is 0.8 (score 1), and the development distance of the Tongtian fault is 40 km > 30 km (score 1), with a comprehensive score of 1 × 1 = 1.

[0051] (6) K1 trap of exploration target 3: In terms of trap conditions, the structural closure is 30 m (score 1), there are 2 seismic survey lines that interpret the trap (score 1), and the seismic data show a quality score of 0.6, with a comprehensive score of 1×1×0.6=0.6; in terms of reservoir conditions, a shoal sedimentary facies is developed (score 1), and the reservoir thickness is 20 m>10 m (score 1), so the score is 1×1=1; in terms of transport conditions, the oil and gas display ratio in the adjacent area is 0.6>0.5 (score 1), and the development distance of the oil source fault is 12 km<15 km (score 1), with a comprehensive score of 1×1=1; in terms of preservation conditions, the caprock sealing capacity is 0.9>0.8 (score 1), and the development distance of the Tongtian fault is 45 km>30 km (score 1), with a comprehensive score of 1×1=1.

[0052] (7) K2 trap of exploration target 3: In terms of trap conditions, the structural closure is 24m=30m*0.8 (score 0.8), there are 2 seismic survey lines that interpret the trap (score 1), combined with the seismic data display quality score of 0.6, the comprehensive score is 0.8×1×0.6=0.48; in terms of reservoir conditions, platform sedimentary facies is developed (score 0.6), the reservoir thickness is 8m=10m*0.8 (score 0.8), so the score is 0.6×0.8=0.48; in terms of transport conditions, the oil and gas display ratio in the adjacent area is 0.3=0.5*0.6 (score 0.6), but the development distance of the oil source fault is 12km<15km (score 1), the comprehensive score is 0.6×1=0.6; in terms of preservation conditions, the caprock sealing capacity is 0.9>0.8 (score 1), and the development distance of the Tongtian fault is 45km>30km, the comprehensive score is 1×1=1.

[0053] Table 3. Scoring table of reservoir-forming geological conditions for potential traps in Block A

[0054] S3, based on the scoring results of reservoir geological conditions, calculate the geological success rate P of potential traps.

[0055] In this embodiment, according to the geological success rate P of the potential trap of the jth layer of the i-th exploration target, ij The calculation formula is: ij =P Tij *P Rij *P Cij *P Sij , where P Tij , P Rij , P Cij , P Sij The trap, reservoir, transport and preservation conditions of the jth potential trap of the i-th exploration target were scored respectively, and the geological success rate of each potential trap in Block A was calculated respectively, and the calculation results are shown in Table 4. The geological success rate of J3 and K1 traps of exploration target 1 = 0.7 × 1 × 0.5 × 0.5 = 0.175; the geological success rate of K2 trap of exploration target 1 = 0.7 × 0.6 × 0.3 × 0.3 = 0.063; the geological success rate of J3 and K1 traps of exploration target 2 = 0.8 × 1 × 1 × 1 = 0.8; the geological success rate of K1 trap of exploration target 3 = 0.6 × 1 × 1 × 1 = 0.6; the geological success rate of K2 trap of exploration target 3 = 0.48 × 0.48 × 0.6 × 1 = 0.13824.

[0056] S4, based on the geological success rate evaluation results of potential traps, calculate the geological success rate P of the exploration target L .

[0057] In this embodiment, the geological success rate of the exploration target P LThe calculation is the probability that at least one potential trap in a single target contains oil and gas. Assuming there are n exploration targets in total, and the i-th exploration target has m exploration layers, the calculation formula for the geological success rate of the i-th exploration target is , where P ij is the geological success rate of the jth potential trap of the i-th exploration target. The geological success rates of the three exploration targets are calculated according to the formula. The calculation process and results are shown in Table 4. The geological success rate of exploration target 1 is 0.362, the geological success rate of exploration target 2 is 0.960, and the geological success rate of exploration target 3 is 0.655.

[0058] Table 4 Geological success rate P of three exploration targets in Block A L Calculation results

[0059] S5, based on the geological success rate evaluation results of the exploration target, calculate the geological success rate P of the exploration block g .

[0060] In this embodiment, the geological success rate of the exploration block P g The calculation is the probability that at least one exploration target in the block contains oil and gas after being weighted by the geological resources. , taking the geological resource volume Q as the weight for geometric averaging. Assuming there are n exploration targets, the calculation formula is:

[0061] Where P Li is the geological success rate of trapping the jth potential layer of the i-th target, Q i is the geological resource volume of the ith target.

[0062] Geological success rate of exploration target P L As calculated in step S104, the geological resources are calculated by volumetric method, and the calculation formula is: Q = A o *h*φ*S oi / B oi .

[0063] Where: Q - geological resources of crude oil, 10 6 t; A o - Oil-bearing area, km 2 ; h - effective thickness of crude oil reservoir, m; φ - effective porosity of crude oil reservoir, dimensionless; S oi - The original oil saturation of the crude oil reservoir, dimensionless; B oi -Original volume coefficient of crude oil, m 3 / m 3 .

[0064] The values ​​of relevant parameters and calculation results are shown in Table 5. The geological resources of exploration target 1 are 61.65 million tons, the geological resources of exploration target 2 are 39.2 million tons, and the geological resources of exploration target 3 are 16.4 million tons.

[0065] Table 5 Calculation table of geological resources for exploration target in Block A

[0066] Calculate the geological success rate of Block A based on the geological success rate of the exploration target and the geological resources 0.987524073. Therefore, the final evaluation of the geological success rate of oil and gas exploration in Block A is about 0.99 (retain two decimal places).

[0067] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A quantitative evaluation method for geological success rate of multi-target oil and gas exploration blocks, characterized in that: The steps include: S1, interpret potential traps within the scope of exploration block mineral rights through drilling and seismic data, and analyze the geological conditions of potential trap formation; S2, based on the relationship between the reservoir-forming geological conditions and oil and gas shows in the neighboring areas of the exploration block, the sufficient conditions for oil and gas accumulation in the regional geological units are obtained, and the reservoir-forming geological conditions of potential traps are scored; S3, based on the scoring results of reservoir geological conditions, calculate the geological success rate P of potential traps; S4, based on the geological success rate evaluation results of potential traps, calculate the geological success rate P of the exploration target L ; S5, based on the geological success rate evaluation results of the exploration target, calculate the geological success rate P of the exploration block g .

2. The method for quantitatively evaluating geological success rate of a multi-objective oil and gas exploration block according to claim 1 is characterized in that: In step S2, the reservoir-forming geological conditions include trap conditions, reservoir conditions, transport conditions and preservation conditions.

3. The method for quantitatively evaluating geological success rate of a multi-objective oil and gas exploration block according to claim 2 is characterized in that: When scoring the geological conditions for the formation of potential traps, The trap conditions are scored based on structural closure and data reliability; The reservoir conditions are scored based on the sedimentary facies conditions and the predicted reservoir thickness; The transport conditions are scored based on the distance between the oil source fault development and the oil and gas display ratio in the adjacent area; The preservation conditions are scored based on the development distance of the Tongtian Fault and the sealing capacity of the caprock.

4. The method for quantitatively evaluating geological success rate of a multi-objective oil and gas exploration block according to claim 3 is characterized in that: Among the trap conditions, data reliability is analyzed based on the number of seismic lines that interpret the trap and the quality of seismic data display.

5. The method for quantitatively evaluating geological success rate of a multi-objective oil and gas exploration block according to claim 1, characterized in that: In step S2, when scoring the reservoir-forming geological conditions of the potential trap, the scoring is based on the relationship between the reservoir-forming geological conditions of the adjacent area and the oil and gas show.

6. The method for quantitatively evaluating geological success rate of a multi-objective oil and gas exploration block according to claim 3 is characterized in that: In step S3, the geological success rate P of the potential trap of the jth layer of the i-th exploration target is ij The calculation formula is: ij =P Tij *P Rij *P Cij *P Sij , where P Tij , P Rij , P Cij , P Sij They are respectively the scores of the trap conditions, reservoir conditions, transport conditions and preservation conditions of the j-th potential trap of the ith exploration target.

7. A method for quantitatively evaluating geological success rate of a multi-objective oil and gas exploration block according to claim 6, characterized in that: In step S4, the exploration target geological success rate P L The probability that at least one potential trap in a single exploration target contains hydrocarbons is calculated; In step S5, the geological success rate P of the exploration block is g What is calculated is the probability that at least one exploration target in the block contains oil and gas, weighted by the amount of geological resources.

8. The method for quantitatively evaluating geological success rate of a multi-objective oil and gas exploration block according to claim 7, characterized in that: Assuming that there are n exploration targets in the exploration block, and the i-th exploration target has m exploration layers, the geological success rate calculation formula for the i-th exploration target is: ， Where P ij is the geological success rate of closure of the jth potential layer of the i-th exploration target.

9. The method for quantitatively evaluating geological success rate of a multi-objective oil and gas exploration block according to claim 7, characterized in that: Assuming that there are n exploration targets in the exploration block, the formula for calculating the geological success rate of the exploration block is: ， Where P Li is the geological success rate of the jth potential trap of the i-th exploration target, Q i is the geological resource volume of the i-th exploration target.

10. A method for quantitatively evaluating geological success rate of a multi-objective oil and gas exploration block according to claim 9, characterized in that: The geological resources are calculated by volumetric method using the following formula: Q=A o *h*φ*S oi / B oi Where: Q - geological resources, 10 6 t; A o - Oil-bearing area, km 2 ; h - effective thickness of crude oil reservoir, m; φ - effective porosity of crude oil reservoir, dimensionless; S oi - The original oil saturation of the crude oil reservoir, dimensionless; B oi -Original volume coefficient of crude oil, m 3 / m 3 .

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