Pre-exploratory well location design method and device based on well control resource quantity proportion, medium and equipment

Abstract

The invention relates to a pre-exploratory well location design method and device based on a well control resource quantity ratio, a medium and equipment. The method comprises the following steps: S1, determining target horizon of a to-be-drilled trap, and determining a corresponding target spot for each target horizon; and S2, the well control resource quantity ratio of the to-be-drilled well trap is calculated, the well control resource quantity ratio is compared with a preset standard interval to serve as a basis for judging whether the position of the target spot is appropriate or not, and if the position is not appropriate, the corresponding target spot is adjusted. And S3, solving the well trajectory of the pre-exploratory well based on the predetermined top surface structure grid and the adaptive target point of each target horizon. According to the method, a quantitative basis is provided for target spot position selection work by rapidly calculating the key parameter, namely the well control resource quantity ratio; through programming integrated design, a pure manual design process is centralized and programmed, so that the exploratory well design can be quickly realized, and the working efficiency and precision are improved.

Description

Technical Field

[0001] This invention relates to the field of oil and gas exploration technology, and in particular to a method, apparatus, medium and equipment for designing exploratory well locations based on the proportion of well-controlled resources. Background Technology

[0002] Exploratory well location design is a crucial step in oil and gas exploration. The general process for exploratory well location design is as follows: 1) Gridding is performed using seismic interpretation layers and fault polygons to obtain the structural grid for each layer to be drilled (gridization); 2) Traps to be drilled are located and identified, and the trap elements and predicted trap resources (hereinafter referred to as trap resources) for each target layer are statistically analyzed; 3) Drilling points (target points) are designed and determined for each target layer, and the predicted well-controlled resources (hereinafter referred to as well-controlled resources) are calculated; 4) Based on the spatial location of the target points, the well trajectory is designed and submitted to the drilling engineering department; 5) The engineering department, considering subsurface geological conditions and drilling technology, designs the final well trajectory. In actual production, target point selection is a critical task, typically requiring exploration personnel to comprehensively manage multiple factors such as reserves, geological risks, and engineering difficulty. Traditional well trajectory design methods have the following two problems: 1) The design of target points in the target stratigraphy is highly subjective and lacks objective and quantitative reference standards; 2) Although well-controlled resources can serve as a good quantitative reference standard, manual calculation of well-controlled resources is cumbersome and time-consuming, making it difficult to use in practice; 3) In actual exploration work, the target points need to be changed frequently, and the traditional manual well trajectory design method is inefficient, especially when the spatial overlap of the target stratigraphy is poor and multiple well directional drilling designs are required. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method, device, medium and equipment for designing the location of exploratory wells based on the proportion of well-controlled resources.

[0004] The technical solution adopted by this invention to solve its technical problem is: a method for designing the location of exploratory wells based on the proportion of well-controlled resources, the method comprising the following steps: S1. Determine the target formation to be drilled and trap, and determine the corresponding target point for each target formation; S2. Calculate the proportion of well-controlled resources to be closed in the well to be drilled, and compare the proportion of well-controlled resources with a preset standard range as a basis for judging whether the target location is appropriate; if the location is not appropriate, adjust the corresponding target point. Wherein, the well-controlled resource ratio is the ratio of well-controlled resource volume to trap resource volume; the trap resource volume is the potential resource volume of the trap calculated before drilling; the potential resource volume of the trap is the volume of crude oil or natural gas in the trap's storage space; and the well-controlled resource volume is the expected controllable resource volume. S3. Based on the pre-determined top surface structure grid of each target layer and the matching target points, the well trajectory of the exploratory well is obtained.

[0005] Furthermore, in the exploratory well location design method based on the proportion of well-controlled resources described in this invention, step S2 includes: If the proportion of well-controlled resources is too small, the target point is determined to be too high, and the target point is adjusted to a lower position. If the proportion of well-controlled resources is too large, exceeding the predicted fill rate of the trap, the target point is determined to be too low, and the risk of an empty well is relatively high. In this case, the target point is adjusted to a higher position.

[0006] Furthermore, in the exploratory well location design method based on the proportion of well-controlled resources described in this invention, step S2, calculating the proportion of well-controlled resources, includes: The percentage of well-controlled resources is calculated using the following formula: In the formula, Q represents the proportion of well-controlled resources; The area of ​​the trap; A well For the well-controlled area; It is the ratio of well control amplitude to trap closure amplitude, where well control amplitude is the difference between the depth of the drilled top surface and the depth of the highest point of the trap.

[0007] Furthermore, in the exploratory well location design method based on the proportion of well-controlled resources described in this invention, in step S2, the proportion of well-controlled resources is calculated. The formula for calculating the value is: = In the formula, To control the thickness of the well; To close the thickness of the ring; To flatten the proportions; The coefficient for leveling the trap; This is the well control leveling coefficient.

[0008] Furthermore, in the exploratory well location design method based on the proportion of well-controlled resources described in this invention, step S2, calculating the proportion of well-controlled resources, includes: The corresponding sand-to-land ratio is obtained based on the sandstone and mudstone thicknesses of the surrounding traps of the well to be drilled, and the obtained sand-to-land ratio is used as the sand-to-land ratio of the well to be drilled; the selected surrounding trap formations and the formations of the well to be drilled have a preset similarity; the sand-to-land ratio is the ratio of the total sandstone thickness to the total formation thickness. The corresponding leveling thickness is calculated based on the average formation thickness, sand-to-soil ratio, and corresponding leveling coefficient; the leveling thickness includes well-controlled leveling thickness and trap leveling thickness.

[0009] Furthermore, in the exploratory well location design method based on the proportion of well-controlled resources described in this invention, step S3 includes: Based on the pre-determined top surface grid of each target layer, the azimuth and dip angle of the pre-exploration well are calculated according to the coordinate and depth values ​​of the adapted target points. The well trajectory is designed based on the azimuth and dip angles so that the well trajectory passes through all suitable target points.

[0010] In addition, the present invention also provides a device for designing the location of exploratory wells based on the proportion of well-controlled resources, comprising: The target point pre-determination module is used to determine the target layer to be drilled and trap, and to determine the corresponding target point for each target layer; The target point adaptation determination module is used to calculate the proportion of well-controlled resources to be trapped in the well to be drilled, and compare the proportion of well-controlled resources with a preset standard range as a basis for determining whether the target point position is suitable; if the position is not suitable, the corresponding target point is adjusted. Wherein, the well-controlled resource ratio is the ratio of well-controlled resource volume to trap resource volume; the trap resource volume is the potential resource volume of the trap calculated before drilling; the potential resource volume of the trap is the volume of crude oil or natural gas in the trap's storage space; and the well-controlled resource volume is the expected controllable resource volume. The well trajectory design module is used to determine the well trajectory of the exploratory well based on the pre-determined top surface grid of each target layer and the matching target points.

[0011] In addition, the present invention also provides a computer-readable storage medium storing a computer program adapted for loading by a processor to execute the steps of the above-described method for designing exploratory well locations based on the proportion of well-controlled resources.

[0012] In addition, the present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the steps of the pre-exploratory well location design method based on the proportion of well-controlled resources as described above by calling the computer program stored in the memory.

[0013] The method, apparatus, medium, and equipment for designing exploratory well locations based on the proportion of well-controlled resources of the present invention have the following beneficial effects: The present invention provides a quantitative basis for the selection of target locations by quickly calculating the key parameter of the proportion of well-controlled resources. Through integrated programming design, the purely manual design process is centralized and proceduralized, enabling exploratory well design to be realized quickly, thereby improving work efficiency and accuracy. Attached Figure Description

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings: Figure 1 These are schematic diagrams of vertical and inclined well structures provided in some embodiments of the present invention; Figure 2 This is a flowchart illustrating the method for designing exploratory well locations based on the proportion of well-controlled resources provided in an embodiment of the present invention. Figure 3 These are seismic profiles provided in some embodiments of the present invention; Figure 4 This is a schematic diagram of a computing unit according to some embodiments of the present invention; Figure 5 These are schematic diagrams of edge-water reservoirs and bottom-water reservoirs according to some embodiments of the present invention; Figure 6 This is a schematic diagram of the resource quantity of the exploration stage traps in some embodiments of the present invention; Figure 7 These are schematic diagrams illustrating target selection in some embodiments of the present invention; Figure 8 This is a schematic diagram illustrating the calculation of the trapped resource quantity and well-controlled resource quantity of the present invention; Figure 9 This is a structural diagram of the A-loop control layer according to some embodiments of the present invention; Figure 10 yes Figure 9 The diagram shows the target selection for trap A. Figure 11 yes Figure 9 Comparison of target location differences between T1 and T2 layers; Figure 12 yes Figure 9 The diagram shows the well inclination design between the closed target points in loop A. Figure 13 This is a schematic diagram of the exploratory well location design device based on the proportion of well-controlled resources provided in an embodiment of the present invention. Detailed Implementation

[0015] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the invention are now described in detail with reference to the accompanying drawings. In the following description, specific details such as particular system structures and techniques are set forth for illustrative purposes rather than for limiting the scope of the invention, in order to provide a thorough understanding of the embodiments. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted to avoid unnecessary detail that could obscure the description of the invention.

[0016] Oil and gas wells can be categorized into several types based on their exploration and development stages, including exploratory wells (pre-exploration wells), appraisal wells, and development wells. Exploratory wells typically refer to the first well drilled in a trap, their purpose being to investigate the oil and gas content of the trap. Oil and gas wells can also be classified into vertical wells and deviated wells based on their well trajectory geometry. A vertical well is a well designed to maintain a vertical or near-vertical wellbore trajectory from the wellhead to the target formation (usually an oil and gas layer). Ideally, the wellbore of a vertical well is a vertical line. A deviated well, also known as a directional well, is a well intentionally drilled using specialized tools and techniques to ensure the wellbore trajectory follows a pre-designed direction and angle to reach the underground target. Since it is difficult to guarantee a perfectly vertical well trajectory during actual drilling, in the oil industry, wells with a maximum inclination angle (the angle between the stable inclination section and the vertical line) of less than 5 degrees can be considered vertical wells. Figure 1 As can be seen in (a), the structure of a vertical well is relatively simple, while that of an inclined well requires the design and construction of an inclination (…). Figure 1 (b) shows a deviated well with only one start-up point (in actual production, multiple start-ups can be made to meet geological objectives), thus the well structure is relatively complex. In the exploration field, vertical wells are typically used when the vertical overlap of each target layer trap is good; while deviated wells are typically used when the vertical overlap of each target layer trap is poor. Since the structure of a vertical well is relatively simple (it can be considered as a deviated well with an inclination angle of less than 5 degrees), this patent application will provide a detailed introduction to the rapid design of deviated wells.

[0017] In the field of petroleum exploration, a trap refers to a location that prevents oil and gas from migrating further and allows them to accumulate. It is an organic whole composed of reservoirs, caprocks, and shielding structures (see the national standard "Classification of Oil and Gas Mineral Resources Reserves" (GB / T19492-2020)). Typically, not all strata within a trap are reservoirs. For example, in common clastic rock formations, the reservoir is usually sandstone, with oil and gas stored in the pores between the sandstone matrix. Mudstone, on the other hand, usually serves as a caprock or barrier, preventing oil and gas from escaping. Therefore, the potential resource quantity of a trap (according to the national standard "Classification of Oil and Gas Mineral Resources Reserves" (GB / T 19492-2020), the trap resource quantity calculated before drilling is called the trap potential resource quantity, hereinafter referred to as the trap resource quantity) is the volume of crude oil or natural gas in the trap's reservoir space.

[0018] In a preferred embodiment, reference Figure 2 The exploratory well location design method based on the proportion of well-controlled resources in this embodiment includes the following steps: S1. Determine the target formation to be drilled and trap, and identify the corresponding target point for each target formation.

[0019] S2. Calculate the proportion of well-controlled resources to be closed in the well to be drilled, and compare the proportion of well-controlled resources with the preset standard range as a basis for judging whether the target location is appropriate; if the location is not appropriate, adjust the corresponding target location.

[0020] The well-controlled resource ratio is the ratio of well-controlled resources to trap resources. Trap resources refer to the potential resources of the trap calculated before drilling. Potential trap resources are the volume of crude oil or natural gas in the trap's reservoir space. Well-controlled resources refer to the resources that are expected to be controllable according to the existing drilling design. For example... Figure 7 As shown, theoretically, the target point can be arbitrarily chosen between the depth of the highest point of the trap and the overflow depth. Given a fixed trap shape, the amount of well-controlled resources depends primarily on the chosen location. The farther the target point is from the highest point, the larger the controlled volume and the greater the controlled resources (usually calculated based on bottom water model, without considering edge water conditions). However, if the trap is not fully filled, the farther the target point is from the highest point, the greater the risk of exploration failure due to deviation from the oil (gas)-water interface. Ideally, the first drilling operation should encounter the oil (gas)-water interface, but since the location of the oil (gas)-water interface is difficult to predict, a trade-off must often be made between the size of the well-controlled resources and the level of risk (in addition, sedimentary and geophysical characteristics, such as bright spots, must be considered).

[0021] Specifically, in step S2, if the proportion of well-controlled resources is too small, the controlled reserves are too small, and the target point is determined to be too high. In this case, the target point is adjusted to a lower position. If the proportion of well-controlled resources is too large, exceeding the predicted fill rate of the trap, the target point is determined to be too low, and the risk of an empty well is high. In this case, the target point should be adjusted to a higher position. Generally speaking, this value should be determined with reference to nearby wells.

[0022] The percentage of well-controlled resources is calculated using the following formula (1-1): In the formula, Q represents the proportion of well-controlled resources. The area is the enclosed area. A well The area controlled by the well. It is the ratio of well control amplitude to trap closure amplitude, where well control amplitude is the difference between the depth of the top surface encountered and the depth of the highest point of the trap.

[0023] It can be understood that equation (1-1) is derived from the following equation (1-2): Since the terms related to reservoir parameters in the numerator and denominator of equation (1-2) are the same, they can be canceled out to obtain equation (1-1).

[0024] The advantage of the well-controlled resource ratio parameter is that it is less affected by factors such as sand body thickness and trap height, and is almost entirely related only to the well-controlled area, trap area, and the ratio of well-controlled amplitude to trap closure amplitude. The significance of the well-controlled resource ratio parameter is as follows: 1) If the calculated well-controlled ratio after target point determination is too small (close to 0), it indicates that the target point is too high, the controlled reserves are small, and the target point needs to be adjusted to a lower location; 2) Conversely, if the parameter is too large, especially if it exceeds the predicted filling degree, it indicates a higher risk, and the target point needs to be adjusted to a higher location. As mentioned above, well-controlled resources are related to the target point location; therefore, if the Q value can be quickly obtained, it can provide a quantitative basis for target point selection. Specific examples will be used to illustrate this below.

[0025] Furthermore, in step S2, the proportion of well-controlled resources is calculated. The formula for calculating the value is: = In the formula, To control the thickness of the well. The thickness of the closed loop is flattened. To flatten the proportions. The coefficient for compaction is denoted as truncation coefficient. This is the well control leveling coefficient.

[0026] S3. Based on the pre-determined top surface structure grid of each target layer and the matching target points, the well trajectory of the exploratory well is obtained.

[0027] Specifically, step S3 includes: constructing a grid on the top surface of each target layer based on pre-determined parameters, and calculating the azimuth and dip angles of the exploratory well according to the coordinates and depth values ​​of the matching target points. The well trajectory is designed based on the azimuth and dip angles to ensure the well trajectory passes through all matching target points. This method can be understood to complete dip angle estimation in seconds at the drilling site, locking the build-up angle within the 30° upper limit and minimizing it. This directly reduces the difficulty of well trajectory control and drilling costs; reduces downhole complexity and shortens the well construction cycle; minimizes the costs and risks of subsequent logging, testing, and production data acquisition; and meets the stringent "exploration well ≤30°" requirements of companies like CNOOC, enabling safe, economical, and efficient vertical-micro-inclination well drilling decisions.

[0028] This embodiment provides a quantitative basis for target location selection by quickly calculating the key parameter of the proportion of well-controlled resources. Through integrated programming design, the purely manual design process is centralized and proceduralized, enabling exploration well design to be realized quickly and improving work efficiency and accuracy.

[0029] It's understandable that in the oil and gas exploration field, calculating resources (reserves) is a process of modeling underground reservoir space, and the final result is an approximation of the actual reserves. Typically, in determining resources, the underground target area is divided into multiple calculation units based on stratigraphic sedimentary characteristics, lithological features, and other factors. During the trap exploration stage, relevant data is relatively scarce (especially well data), and the geological understanding of the area is relatively superficial; therefore, the calculation unit division is relatively coarse, such as at the third-order sequence stratigraphy or sandstone group level. However, in the trap evaluation and development stage, with increased data and a deeper understanding, the calculation unit division is relatively finer, usually at the single sand body level. Figure 3 The image shows a seismic profile. Continuous axes in the profile are called phase axes, representing one or more strata. In trap exploration, due to a lack of data, it is neither possible nor necessary to calculate the resource volume of a single sand body; therefore, multiple phase axes are usually divided into the same calculation unit. The two main principles for dividing calculation units are: 1) Multiple sets of approximately parallel phase axes with similar reflection characteristics can be divided into one calculation unit. For example... Figure 3 In (a), assuming a structural trap is developed at this location, if we want to calculate the resource quantity between interface 1 and interface 4, since interfaces 1 and 2 are approximately parallel, interfaces 3 and 4 are approximately parallel, and the internal phase axis is also approximately parallel to the two interfaces, interface 1 and interface 2 can be divided into one calculation unit, and the same applies to interfaces 3 and 4. The thickness between interface 2 and interface 3 gradually increases from left to right, so it is divided into a separate calculation unit. However, since the thickness change is small, the method used to calculate 1 and 3 can still be used for approximate calculation; 2) Seismic reflection characteristics similar to these can be divided into the same calculation unit. For example Figure 3 In (b), if the resource quantity between interface 1 and interface 4 is required, although the two interfaces and their phase axes are basically parallel, it can be inferred from the reflection characteristics that the lithological and physical parameters of the underground medium will differ vertically. Therefore, interface 2 and interface 3 can be manually selected to divide the strata into three calculation units.

[0030] The commonly used method for calculating the resource volume of a trap (including post-drilling calculated reserves) is the volumetric method. The calculation formula is as follows: (1-3) Where A is the trap area (or the oil and gas-bearing area if calculating reserves). To flatten the reservoir thickness, For reservoir porosity, Water saturation For oil and gas density, This represents the oil and gas volume coefficient. However, formula (1-3) is only a theoretical formula, and several additional parameters need to be added for calculation in practical applications. The commonly used formula for calculating the resource volume of a trap is: (1-4) Where R is the sand ratio, P is the filling coefficient, and T is the net-to-gross ratio (all dimensional parameters are in international standard units, and the dimensionless quantity is a proportion).

[0031] The enclosed area refers to the planar area bounded by the lowest enclosed line. For formula (1-4), the first two terms... The product is equivalent to Figure 5 The volume of the green portion in (a) (for bottom-water reservoirs, the volume enclosed by the bottom of the oil layer and the lowest trap line needs to be subtracted for edge-water reservoirs), or formula (1-4) can be understood as flattening an irregular volume into a cylinder for calculation. Therefore, it is called the flattening thickness. The ratio of the flattening thickness to the trap closure amplitude varies depending on the trap shape, expressed by the formula: ,in The closing amplitude of the loop. The flattening coefficient is given. The trap in the diagram is a simple anticline trap, which can be approximated as a cone. That is, the flatness coefficient .

[0032] In step S2, the calculation method for the leveling thickness involves obtaining the corresponding sandstone-to-soil ratio based on the sandstone and mudstone thicknesses of the surrounding traps already drilled, and using this ratio as the sandstone-to-soil ratio for the trap to be drilled. The selected surrounding trap formations and the trap formation to be drilled achieve a preset similarity in structure. The sandstone-to-soil ratio is the ratio of the total sandstone thickness to the total formation thickness. The corresponding leveling thickness is calculated based on the average formation thickness, the sandstone-to-soil ratio, and the corresponding leveling coefficient. The leveling thickness includes the well-controlled leveling thickness and the trap leveling thickness.

[0033] Understandably, during the trap exploration phase, the resource quantity of a single reservoir is often not calculated separately. Instead, the exploration is divided into calculation units, and then the resource quantity of the entire stratigraphic suite is calculated as an approximation. Figure 4Taking a specific calculation unit as an example, this unit contains two sandstone layers serving as reservoirs and two mudstone layers serving as caprock and interlayers. When calculating the resource volume of a trap, since the underground stratigraphic structure is unknown, the sandstone and mudstone layers are generally not distinguished. Instead, the average thickness of the entire formation is multiplied by the sandstone-to-soil ratio to obtain an approximate thickness of the sandstone. Finally, this thickness is multiplied by a leveling coefficient to obtain the leveled thickness. The mathematical derivation process will be provided below to demonstrate its rationality. The sandstone-to-soil ratio is the ratio of the sandstone thickness to the total formation thickness, and in the absence of wells, it is generally calculated from the wells drilled within the surrounding trap. For example... Figure 6 As shown, suppose there is an existing well in a surrounding trap that is similar in formation structure to the trap in the seismic profile. This trap encounters two sandstone layers and two mudstone layers. The thicknesses of the two sandstone layers (which can be either surface thickness or regional average thickness, the same below) are hq1 and hq2, and the thicknesses of the two mudstone layers are hs1 and hs2, respectively. Then, the surface sandstone formation ratio (referred to as sandstone-soil ratio) can be calculated using the following formula (since the underground formation structure cannot be determined, it is usually calculated based on a bottom water reservoir): The following section provides an introduction to the reservoir's lithological and physical properties as well as its fluid parameters.

[0034] (1) Filling coefficient: Oil and gas traps are formed during geological history. In the early stages of formation, the initial filling liquid is usually water. Oil and gas are then injected into the trap, and there are usually multiple filling processes throughout the geological history. After entering the trap, the oil and gas, because their density is less than that of water, will accumulate at the top of the trap and displace the water out of the trap. The ratio of the volume of oil and gas in the trap to the volume of the total reservoir space in the trap is usually called the filling coefficient. This coefficient is usually between 0 and 1 (it can also be greater than 1, such as if the filling intensity is too high, and the oil and gas rushes out of the lowest trap line, forming a stratigraphic lithology trap outside the trap range. This situation is usually not considered in the exploration stage).

[0035] (2) Reservoir Net-to-Gas Ratio: In clastic rock formations, sandstone is usually used as a reservoir, but not all sandstone has reservoir capacity. Some sandstone is too dense, resulting in poor physical properties, or the pores of sandstone are blocked by cement, making it difficult to store oil and gas. Therefore, this part of the sandstone should be excluded when calculating resources. The reservoir net-to-gasture ratio is the ratio of sandstone with reservoir capacity to all sandstone.

[0036] (3) Reservoir porosity: Sandstone is usually composed of matrix and cement, with the matrix generally consisting of various minerals. Pores exist between the matrix, and oil and gas are stored in these pores. Sandstone porosity is the ratio of sandstone pore volume to sandstone total volume. Since sandstone pores are divided into ineffective pores (dead pores) and connected pores (effective pores), only connected pores have reservoir properties. Therefore, the porosity used in resource calculation is the effective porosity.

[0037] (4) Water saturation: As mentioned above, after oil and gas are injected into the trap, they will displace the water in the trap. However, in reality, due to capillary pressure and other reasons, oil and gas often do not displace all the water in the pores, but rather a situation where multiple fluids coexist. Water saturation is the ratio of the volume of water in the pores to the sum of the volumes of all liquids. Considering only oil and water, water saturation + oil saturation = 1.

[0038] (5) Oil and gas density: This item is required when calculating the mass of oil and gas. If only the volume of oil and gas needs to be calculated, this coefficient does not need to be considered. The density of natural gas is usually around 0.4, crude oil is around 0.8, and heavy oil can be close to 1.

[0039] (6) Oil and gas volume factor: Under high temperature and high pressure conditions underground, the volume of oil and gas usually decreases. The oil and gas volume factor refers to the ratio of the volume of oil and gas underground (under reservoir conditions) to the volume of oil and gas under standard surface conditions (after separation).

[0040] The above reservoir physical and fluid parameters are usually obtained from logging data of drilled wells. In the absence of wells, surrounding drilled wells or empirical values ​​can be used as a reference.

[0041] refer to Figure 8 , Figure 8 A schematic diagram illustrating the calculation of trapped resources and well-controlled resources is shown.

[0042] First, we assume the calculation unit is a single layer, the strata are all sandstone, and we do not consider edge water reservoirs; we calculate it as a bottom water reservoir. Based on the above, the trap resource quantity formula (1-5) is: in For the enclosed area, R is the reservoir thickness after leveling, P is the sand-to-soil ratio, P is the filling factor, and T is the net-to-gross ratio. For reservoir porosity, Water saturation For oil and gas density, This is the oil and gas volume coefficient.

[0043] The formula for well-controlled resource quantity (1-6) is: in For well control area, The thickness of the reservoir is determined by the flattening process, and other parameters are the same as those in formula (1-5).

[0044] In formulas (1-5) and (1-6), , That is, the thickness of the trap leveling is equal to the trap closure amplitude multiplied by the leveling coefficient, and the thickness of the well control leveling is equal to the difference between the depth of the drilled top surface and the depth of the highest point of the trap multiplied by the leveling coefficient.

[0045] Extending formulas (1-5) and (1-6) to multiple layers, we assume that the calculation unit contains M layers of sand bodies with identical trap areas and structural morphologies, and each layer has a thickness of [missing information]. Then, for the amount of confined resources, we have the following formula (1-7): In the formula: , ,in, This is for calculating the thickness of the cell.

[0046] Therefore, the formula for calculating the amount of resources in a confined area (1-8) is: in For the enclosed area, The flatness coefficient is... To calculate the thickness of the leveled strata in a given unit, R is the sand-to-soil ratio, P is the filling factor, and T is the net-to-gross ratio. For reservoir porosity, Water saturation For oil and gas density, This is the oil and gas volume coefficient.

[0047] For well-controlled resources, the same formula (1-9) applies: It can make In other words, the well control amplitude is directly proportional to the trap closure amplitude. Each calculation unit corresponds to one... Therefore, the formula for calculating the well-controlled resource quantity (1-10) is as follows: Understandably, in actual calculations, since it is necessary to calculate the well-controlled resources and the resources of the trap, it is not deliberately sought out. Instead of using the value, the well-controlled resource quantity is directly obtained by using parameters such as the well-controlled area and the leveling ratio.

[0048] It should be noted that the statistical calculation methods for the trapping elements required to determine the amount of trapped resources, such as trapping volume, trapping area, and closure radius, in this application can refer to existing technologies. For example, the statistical method for trapping elements in patent number 202111534467.0 can quickly determine the amount of constructed trapped resources. Further details will not be elaborated here.

[0049] The following example illustrates the process and effect of this method. Figure 9 As shown, the target trap is structural trap A in the Heshan main depression of the Zhujiangkou Basin in the eastern South China Sea, specifically within the Zhujiang-Siping Depression. The trap type is a fault trap. This trap exhibits good longitudinal superposition, with all strata present. This patent selects the Neogene T1 and T2 layers as examples. It can be seen that the northern part of this trap is controlled by a large, near-east-west trending fault. Two high points are developed within the trap: the southern high point is an anticline dissected by a fault, and the northern high point is a fault-corroded anticline.

[0050] As mentioned above, target selection requires consideration of many factors. For example... Figure 9 The selection of target points for the target traps considered the following factors: 1) The structural morphology of the southern high point is more favorable than the northern high point; 2) The southern block of the southern high point is higher than the northern block; 3) The direction of hydrocarbon migration in this region is from south to north; 4) To control a certain reserve scale, the target point needs to be at a certain distance from the highest point; 5) To reduce risk, the target point should be within the range of the southern high point. Therefore, considering the above factors, two high points were selected for traps T1 and T2 respectively, as follows: Figure 10 As shown.

[0051] Figure 11 A comparison diagram showing the differences in target point locations between layers T1 and T2 is provided. The target points in layer T1 (blue) and T2 (white) differ in planar location, necessitating the design of an inclined well. Since there are only two target layers, a single inclined well design is sufficient. Because the two target points correspond to two points in the underground space, the azimuth and inclination angles need to be designed to ensure the well trajectory passes through both target points. Figure 12 As shown. The system can automatically assign depth values ​​to the two target points based on their positions on the control layer grid. In this example, the layer depth corresponding to the target point in layer T1 is -2274.6 meters, and the depth corresponding to the target point in layer T2 is -2428.4 meters. Therefore, based on the target point's coordinates and depth values, the system can automatically calculate the azimuth and dip angles. In this embodiment, the azimuth is 49.6 degrees and the dip angle is 64.9 degrees. If multiple wellbore drillings are required, the dip and azimuth angles of each wellbore segment can be calculated sequentially as described above. It is understandable that different oil companies have certain restrictions on the dip and azimuth angles of the well trajectory. For example, offshore oil fields typically require the dip angle to not exceed 30 degrees; otherwise, not only will the engineering be more difficult and costly, accidents are more likely to occur, but it will also be detrimental to subsequent logging and coring operations. Therefore, in this example, the positions of the two target points can be modified and the system resubmitted for calculation until the well inclination angle meets the requirements. Then, after providing data such as the length of the stable inclination section and the completed drilling depth, the well trajectory scheme can be obtained.

[0052] Drilling design involves complex considerations. In addition to achieving geological objectives, engineering feasibility must also be taken into account. Therefore, after the geological team conducts the initial design, the plan will be submitted to the engineering team for professional design and final well trajectory submission. This plan will not elaborate further.

[0053] First, calculate the first calculation unit, namely the area between layers T1 and T2. Quickly calculate the trap area, leveling thickness, and closure amplitude of layer T1, and calculate the ratio of leveling thickness to closure height, i.e., the leveling coefficient (this parameter is generally between 2 and 4; quality control can be performed at this point, and a large deviation from this range indicates that the structural morphology may be special); 2) Obtain the grid depth corresponding to the target point coordinates, and then quickly calculate the well-controlled area using the method in the patent; 3) Calculate the average thickness of the strata between T1 and T2 as the sand body thickness (a thickness value can also be given manually), and provide parameters such as predicted filling degree and sand-soil ratio, so that the trap resource quantity and well-controlled resource quantity can be calculated respectively; 4) Compare the well-controlled resource quantity with the trap resource quantity to obtain the well-controlled proportion value. It is worth noting that, according to the national standard, the trap resource quantity calculation is not a single value, but several probability values ​​(usually calculated using the Monte Carlo method for P10, P50, and P90). In actual operation, the resource quantity corresponding to the lowest trap line is similar to the P10 resource quantity. Therefore, further calculations of P50 and P90 are required.

[0054] This embodiment can quickly calculate the well trajectory by constructing a grid on the top surface of each computing unit and providing a given target point. Compared with traditional manual operation, it has the advantages of high efficiency and high accuracy, especially when the constructed grid and target point positions need to be changed frequently. The concept of well-controlled resource proportion is proposed, along with a method for quickly calculating the well-controlled resource proportion based on the aforementioned patent. Compared with traditional fixed target point design methods, this method can provide a quantitative parameter to better guide the design of exploratory wells.

[0055] In another preferred embodiment, reference Figure 13 The exploratory well location design device based on the proportion of well-controlled resources in this embodiment includes: The target point pre-determination module is used to determine the target layer to be drilled and trap, and to determine the corresponding target point for each target layer.

[0056] The target point adaptation and determination module calculates the proportion of well-controlled resources to be trapped in the well to be drilled, compares this proportion with a preset standard range, and uses this as a basis for determining whether the target point location is suitable. If the location is not suitable, the corresponding target point is adjusted.

[0057] The well-controlled resource ratio is the ratio of well-controlled resources to trap resources. Trap resources are the potential resources of the trap calculated before drilling. Potential trap resources are the volume of crude oil or natural gas in the trap's reservoir space. Well-controlled resources are the expected amount of resources that can be controlled.

[0058] The well trajectory design module is used to determine the well trajectory of the exploratory well based on the pre-determined top surface grid of each target layer and the matching target points.

[0059] This embodiment provides a quantitative basis for target location selection by quickly calculating the key parameter of the proportion of well-controlled resources. Through integrated programming design, the purely manual design process is centralized and proceduralized, enabling exploration well design to be realized quickly and improving work efficiency and accuracy.

[0060] In another preferred embodiment, the computer-readable storage medium of this embodiment stores a computer program adapted for loading by a processor to perform the steps of the exploratory well location design method based on the proportion of well-controlled resources as described in the above embodiments.

[0061] In another preferred embodiment, the computer device of this embodiment includes a memory and a processor. The memory stores a computer program, and the processor executes the steps of the exploratory well location design method based on the proportion of well-controlled resources as described in the above embodiment by calling the computer program stored in the memory.

[0062] The computer-readable storage medium of the present invention can be any computer-readable storage medium capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a magnetic disk, or an optical disk.

[0063] The processor of this invention provides computing and control capabilities to support the operation of the entire device. It should be understood that, in the embodiments of this application, the processor may be a Central Processing Unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0064] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0065] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0066] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A method for designing exploratory well locations based on the proportion of well-controlled resources, characterized in that, The method includes the following steps: S1. Determine the target formation to be drilled and trap, and determine the corresponding target point for each target formation; S2. Calculate the proportion of well-controlled resources to be closed in the well to be drilled, and compare the proportion of well-controlled resources with a preset standard range as a basis for judging whether the target location is appropriate; if the location is not appropriate, adjust the corresponding target point. Wherein, the well-controlled resource ratio is the ratio of well-controlled resource volume to trap resource volume; the trap resource volume is the potential resource volume of the trap calculated before drilling; the potential resource volume of the trap is the volume of crude oil or natural gas in the trap's storage space; and the well-controlled resource volume is the expected controllable resource volume. S3. Based on the pre-determined top surface structure grid of each target layer and the matching target points, the well trajectory of the exploratory well is obtained.

2. The method for designing exploratory well locations based on the proportion of well-controlled resources according to claim 1, characterized in that, Step S2 includes: If the proportion of well-controlled resources is too small, the target point is determined to be too high, and the target point is adjusted to a lower position. If the proportion of well-controlled resources is too large, exceeding the predicted fill rate of the trap, the target point is determined to be too low, and the risk of an empty well is relatively high. In this case, the target point is adjusted to a higher position.

3. The method for designing exploratory well locations based on the proportion of well-controlled resources according to claim 1, characterized in that, In step S2, the calculation of the proportion of well-controlled resources includes: The percentage of well-controlled resources is calculated using the following formula: In the formula, Q represents the proportion of well-controlled resources; The area of ​​the trap; A well For well-controlled area; It is the ratio of well control amplitude to trap closure amplitude, where well control amplitude is the difference between the depth of the top surface encountered and the depth of the highest point of the trap.

4. The method for designing exploratory well locations based on the proportion of well-controlled resources according to claim 3, characterized in that, In step S2, the proportion of well-controlled resources is calculated. The formula for calculating the value is: = In the formula, To control the thickness of the well; To close the thickness of the ring; To flatten the proportions; The coefficient for leveling the closed loop; This is the well control leveling coefficient.

5. The method for designing exploratory well locations based on the proportion of well-controlled resources according to claim 4, characterized in that, In step S2, the calculation of the proportion of well-controlled resources includes: The corresponding sand-to-land ratio is obtained based on the sandstone and mudstone thicknesses of the surrounding traps of the well to be drilled, and the obtained sand-to-land ratio is used as the sand-to-land ratio of the well to be drilled; the selected surrounding trap formations and the formations of the well to be drilled have a preset similarity; the sand-to-land ratio is the ratio of the total sandstone thickness to the total formation thickness. The corresponding leveling thickness is calculated based on the average formation thickness, sand-to-soil ratio, and corresponding leveling coefficient; the leveling thickness includes well-controlled leveling thickness and trap leveling thickness.

6. The method for designing exploratory well locations based on the proportion of well-controlled resources according to claim 1, characterized in that, Step S3 includes: Based on the pre-determined top surface grid of each target layer, the azimuth and dip angle of the pre-exploration well are calculated according to the coordinate and depth values ​​of the adapted target points. The well trajectory is designed based on the azimuth and dip angles so that the well trajectory passes through all suitable target points.

7. A device for designing exploratory well locations based on the proportion of well-controlled resources, characterized in that, include: The target point pre-determination module is used to determine the target layer to be drilled and trap, and to determine the corresponding target point for each target layer; The target point adaptation determination module is used to calculate the proportion of well-controlled resources to be trapped in the well to be drilled, and compare the proportion of well-controlled resources with a preset standard range as a basis for determining whether the target point position is suitable; if the position is not suitable, the corresponding target point is adjusted. Wherein, the well-controlled resource ratio is the ratio of well-controlled resource volume to trap resource volume; the trap resource volume is the potential resource volume of the trap calculated before drilling; the potential resource volume of the trap is the volume of crude oil or natural gas in the trap's storage space; and the well-controlled resource volume is the expected controllable resource volume. The well trajectory design module is used to determine the well trajectory of the exploratory well based on the pre-determined top surface grid of each target layer and the matching target points.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program adapted for loading by a processor to perform the steps of the exploratory well location design method based on the proportion of well-controlled resources as described in any one of claims 1 to 6.

9. A computer device, characterized in that, It includes a memory and a processor, wherein the memory stores a computer program, and the processor executes the steps of the exploratory well location design method based on the proportion of well-controlled resources as described in any one of claims 1 to 6 by calling the computer program stored in the memory.

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