A method for partitioning the attributes of a reservoir grid model

Abstract

The present invention discloses a method for dividing the connected attributes of a reservoir grid model, and the present invention relates to the field of computer algorithms. The method comprises: obtaining reservoir grid data; merging connected oil-bearing grids into blocks; dividing blocks into new blocks according to necks; reclassifying the removed necks into the reservoir grid and blocks; and redrawing the reservoir grid. The method solves the problem that the distribution of remaining oil is highly scattered and complex, which is not conducive to deepening the understanding of the distribution law of remaining oil, accurately locating the potential type and distribution scale of remaining oil, and provides a direct basis for the design of personalized potential tapping schemes such as stratum well network, comprehensive adjustment, and special well types.

Description

Technical Field

[0001] The invention relates to the field of computer algorithms, in particular to a method for segmenting oil reservoir grid models into connected attributes. Background Art

[0002] With the development of the national economy, the demand for oil has increased year by year, and the contradiction between supply and demand has become increasingly prominent. my country is the country with the highest proportion of water-injected oil fields in the world. Most oil fields have entered the high water-content oil production stage in the middle and late stages of development, especially in the eastern oil fields. In addition, the geological conditions of my country's oil fields are complex, the properties of crude oil vary greatly, and the reservoir heterogeneity is serious. After water-injection development, 60% to 70% of the oil in the ground is still unextracted and becomes residual oil. The distribution of residual oil is highly scattered and complex, and it is increasingly difficult to tap the potential of oil field production capacity.

[0003] The reservoir grid model discretizes the reservoir by using grids of equal or unequal spacing on the plane and dividing the grids into several geological layers in the vertical direction, thus reproducing the structural morphology of the reservoir; dividing the grids containing residual oil in the reservoir grid model into different oil-bearing blocks is an effective method and means to study the distribution of residual oil; there is currently no unified method for merging and dividing the oil-bearing blocks of residual oil, and different methods and rules are adopted for different understandings of geological structures. Such methods and rules will be continuously adjusted and improved with the continuous understanding of geological structures. Summary of the invention

[0004] The purpose of the present invention is to provide a method for segmenting the properties of a reservoir grid model into blocks, so as to solve the problem of merging and segmenting the oil-bearing blocks of residual oil, and to provide an effective quantitative method for further deepening the understanding of the distribution law of residual oil, accurately locating the potential type and distribution scale of residual oil.

[0005] The present invention provides a reservoir grid model joint attribute block method, comprising:

[0006] Step 1: Obtain reservoir grid data, including grid data, oil content data, and geological fault data;

[0007] Preferably, the oil-containing data obtained in step 1 is grid data processed based on the original data, which only expresses whether the grid contains oil, but does not express the specific oil content value; the geological fault data obtained is grid data processed based on the original data, which only expresses whether there is a fault between the grids, but does not express other characteristic values ​​of the fault.

[0008] Step 2: Merge the connected oil-bearing grids into initial oil-bearing blocks. According to the connectivity of the oil-bearing grids and the distribution of faults, merge the connected oil-bearing grids into many internally connected initial oil-bearing blocks.

[0009] Preferably, the connectivity of the oil-containing grids in step 2 is judged in the order of the left side, upper left side, upper side, and upper right side. When one connectivity condition is met, the judgment is completed and the grids are merged into an oil-containing block, and the connectivity in other directions is no longer judged.

[0010] Step 3: Divide the block into new blocks according to the neck, identify the neck in the oil-bearing block, temporarily remove the neck, and thus divide the original block into different blocks at the neck;

[0011] Preferably, the neck in step 3 is a special oil-bearing grid for identifying the inside of the oil-bearing block. The method for identifying the neck is that the oil-bearing grid at a specific position is called the neck. The identification of the neck needs to meet two conditions at the same time, that is, there must be at least one connected oil-bearing grid between the current oil-bearing grid and the adjacent grid, and there must be no connected oil-bearing grid in at least one direction of the longitudinal, transverse and diagonal directions. The oil-bearing block can be further divided according to the neck to achieve the purpose of optimizing the oil-bearing block.

[0012] Step 4: Reclassify the removed necks into the reservoir grid and then the block. According to the number of oil-bearing grids in the adjacent blocks of the necks, classify the necks into the blocks with more oil-bearing grids.

[0013] Preferably, in step 4, there is at least one oil-containing grid in the block adjacent to the neck that is connected to the neck. After the neck is included in the block with a large number of oil-containing grids, the characteristics of the neck disappear, and the neck will no longer appear inside the oil-containing block.

[0014] Step 5: Redraw the reservoir grid. The grids of adjacent oil-bearing blocks are drawn using different legends to intuitively distinguish different oil-bearing blocks.

[0015] Preferably, the grids of adjacent oil-bearing blocks in step 5 are drawn using different legends, and the legends are only used to visually distinguish adjacent oil-bearing blocks. The legends of the oil-bearing blocks of the entire reservoir grid will be displayed repeatedly, but the legends of adjacent oil-bearing blocks will not be the same.

[0016] The present invention has the following beneficial effects:

[0017] The present invention provides a method for segmenting the properties of a reservoir grid model, which can provide an effective quantitative method for further deepening the understanding of the distribution law of remaining oil, accurately locating the potential type and distribution scale of remaining oil, and developing from the traditional qualitative and semi-quantitative description to precise quantitative description. After using the method provided by the present invention, combined with the research results of numerical simulation, it is possible to carry out the tracking calculation of the plane distribution scale of remaining oil at different levels, realize the quantitative evaluation of remaining oil at different levels, obtain the plane distribution scale of a single potential object, and provide a direct basis for the design of personalized oilfield production capacity potential tapping plans such as stratum well network, comprehensive adjustment, and special well types. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 : A flow chart of a method for segmenting reservoir grid models into connected attributes;

[0019] Figure 2 : Drawing reservoir grid schematic diagram on computer screen;

[0020] Figure 3 : Schematic diagram of oil-bearing grid connectivity position determination;

[0021] Figure 4 : Schematic diagram of disconnection of oil-bearing grids caused by geological faults;

[0022] Figure 5 : Schematic diagram of oil-bearing grids merged into oil-bearing blocks;

[0023] Figure 6 : Schematic diagram of neck identification inside oil-bearing blocks;

[0024] Figure 7 : The effect diagram of the oil-bearing area before and after neck recognition processing. DETAILED DESCRIPTION

[0025] By describing the embodiments of the present invention with reference to the accompanying drawings, the purpose, features and advantages of the present invention are more clearly understood. The present invention is described below based on the embodiments, but it is worth noting that the present invention is not limited to these embodiments. In the following detailed description of the present invention, some specific details are described in detail; however, for the parts not described in detail, those skilled in the art can also fully understand the present invention.

[0026] In addition, those skilled in the art should understand that the drawings are only provided to illustrate the purpose, features and advantages of the present invention, and the drawings are not actually drawn to scale.

[0027] At the same time, unless the context clearly requires otherwise, the words "include", "comprises" and similar words throughout the specification and claims should be interpreted as inclusive rather than exclusive or exhaustive; that is, the meaning is "including but not limited to".

[0028] In an embodiment of the present invention, it includes:

[0029] Step 1: Obtain reservoir grid data; including grid data, oil content data, and geological fault data.

[0030] like Figure 1 As shown, after obtaining the reservoir grid data, the reservoir grid is directly drawn;

[0031] The grid data is the grid division of the entire area, and the number of horizontal grids and vertical grids are obtained. The origin of the grid coordinates O (0,0) is located in the upper left corner of the entire grid. The grid attributes include X, Y, N, F, K, etc. X represents the horizontal coordinate of the grid, Y represents the vertical coordinate of the grid, N represents whether it contains oil, for example, the oil-containing attribute value is -2, and the oil-free attribute value is 0, F represents the oil-containing block code, K represents the legend code, and the legend corresponding to the legend code can be defined by yourself, for example, 0 represents blank, 1 represents solid sphere, 2 represents hollow triangle, etc. The specific meaning of the attribute value is agreed in the legend library; when the computer draws the reservoir grid model on the screen, the grid is drawn with fine grid lines, and the oil-containing grid will draw a legend inside the grid, such as a solid sphere, and the grid with a blank legend represents an oil-free grid. The thick line represents a geological fault, indicating that the grids on both sides of the fault are not connected, such as Figure 2 shown.

[0032] The oil-bearing data is a set of grid data sets, each set element is a grid coordinate, and the coordinates of the oil-bearing grids will appear in the set.

[0033] Geological fault data is a set of grid data. Each set element is a pair of grid coordinates, such as {(2,3), (3,3)}, which means that there is a fault between the two grids (2,3) and (3,3). Because of the existence of the fault, the adjacent oil-bearing grids are not connected, such as Figure 4 There are 10 disconnected situations shown, with the faults represented by thick lines on the screen.

[0034] Step 2: Merge connected oil-bearing grids into blocks. According to the connectivity of the oil-bearing grids and the distribution of faults, the connected oil-bearing grids are merged into many internally connected oil-bearing blocks.

[0035] Starting from the coordinate origin in the upper left corner of the screen, traverse each grid from left to right and from top to bottom; when the grids on the left side, upper left side, upper side, and upper right side of the oil-bearing grid contain oil, and there is no fault between the grids, the adjacent oil-bearing grids are merged into an oil-bearing block.

[0036] like Figure 3 , Figure 4 As shown in the figure, the C grid is an oil-bearing grid. When it is merged with other oil-bearing grids into an oil-bearing block, it needs to be judged in sequence. When a condition is met, the judgment ends and the merging of the C grid is completed. If it is not met, the next condition is judged. After completing the judgment of the current grid, the next grid is traversed for judgment and merging. After executing step 2, as shown in the figure, Figure 4 As shown, the entire reservoir grid will be divided into multiple oil-bearing blocks. The order of conditions judged in step 2 is:

[0037] (1) Whether the grid C4 on the left side contains oil and there is no fault between the grids. If the condition is met, grid C and grid C4 are merged into an oil-bearing block, and the oil-bearing block code of grid C is assigned. The oil-bearing block code is the same as that of grid C4, and the judgment of grid C ends; if the condition is not met, grid C proceeds to the next condition judgment.

[0038] (2) Whether the upper left grid C1 contains oil and there is no fault between grids. If the condition is met, grid C and grid C1 are merged into an oil-bearing block, and the oil-bearing block code of grid C is assigned. The oil-bearing block code is the same as that of grid C1, and the judgment of grid C ends; if the condition is not met, grid C proceeds to the next condition judgment.

[0039] (3) Whether the upper grid C2 contains oil and there is no fault between the grids. If the condition is met, grid C and grid C2 are merged into an oil-bearing block, and the oil-bearing block code of grid C is assigned. The oil-bearing block code is the same as that of grid C2, and the judgment of grid C ends; if the condition is not met, grid C proceeds to the next condition judgment.

[0040] (4) Whether the upper right grid C3 contains oil and there is no fault between the grids; if the condition is met, grid C and grid C3 are merged into an oil-bearing block, and the oil-bearing block code of grid C is assigned. The oil-bearing block code is the same as that of grid C3, and the judgment of grid C ends; if the condition is not met, grid C proceeds to the next condition judgment.

[0041] (5) If none of the above conditions 1-4 are met, grid C is defined as a separate block, and the oil-bearing block code of grid C is assigned a value equal to the total number of existing oil-bearing blocks plus 1.

[0042] Step 3: Split the block into new blocks based on the neck. Identify the neck in the oil-bearing block and temporarily remove the neck, thereby dividing the original block into different blocks at the neck.

[0043] The neck is a special oil-containing grid defined in the present invention. Any oil-containing grid in a specific position can be called a neck. Figure 6As shown, there must be at least one connected oil-bearing grid between the current oil-bearing grid and the adjacent grid, and there must be no connected oil-bearing grid in at least one direction of the longitudinal, transverse, and diagonal directions. In step 2, the merging of oil-bearing grids has been preliminarily completed to form multiple oil-bearing blocks. However, the oil-bearing grids in many oil-bearing blocks are unevenly distributed and too loose, which is not conducive to the future research and calculation of the plane distribution law of remaining oil, well location deployment and other research work. Therefore, it is necessary to further divide the blocks to obtain relatively compact and relatively balanced oil-bearing blocks with internal oil-bearing grids; step 3 will traverse all oil-bearing blocks and find the neck in the oil-bearing blocks. If there is a neck, the block will be divided from the neck to form different adjacent blocks, and the oil-bearing grid at the neck will be included in a block after division in step 4.

[0044] Step 3 The specific steps are:

[0045] (1) Identify the neck in the oil-bearing block. The position of the neck is determined as follows: Figure 6 shown.

[0046] (2) When a neck is identified, the adjacent two sides are defined as new and different blocks, and the oil-bearing grid at the neck is temporarily removed.

[0047] (3) Continue to identify other necks in the oil-bearing blocks. Each time a neck is identified, its two adjacent sides are defined as new and different blocks, and the oil-bearing grid at the neck is temporarily removed. This cycle continues until all necks in the oil-bearing blocks are removed.

[0048] Step 4: Re-classify the removed necks into the reservoir grid and then into the block; based on the number of oil-bearing grids in the blocks adjacent to the necks, classify the necks into the blocks with more oil-bearing grids.

[0049] In step 3, all the necks have been temporarily removed, and the oil-bearing blocks have reached the point where they no longer need to be segmented. At this point, it is necessary to determine which block the temporarily removed oil-bearing grids should be assigned to. The specific order of determination in step 4 is as follows:

[0050] (1) Traverse the first neck that is removed. The oil-bearing grids at the original neck will be adjacent to two blocks. Calculate the number of oil-bearing grids inside the two blocks. The block with the larger number will be assigned to it. If the numbers are the same, then it can be assigned to one of the blocks.

[0051] (2) Traverse the next removed neck and assign the oil-bearing grid at its location to one of its adjacent blocks.

[0052] (3) Traverse all the removed necks and return all the oil-bearing grids at the necks to the oil-bearing blocks.

[0053] Step 5: Redraw the reservoir grid. The grids of adjacent oil-bearing blocks are drawn using different legends to intuitively distinguish different oil-bearing blocks.

[0054] For reservoir grid models, whether or not to use the neck identification method in the process of processing oil-bearing grid concatenation and block division has a significant difference in the final processing results. Figure 7 As shown in the figure, in the a1 area, there was originally a butterfly-shaped oil-bearing block, which was divided into two oil-bearing blocks after neck recognition; in the a2 area, there was originally a narrow and long oil-bearing block, which was divided into two oil-bearing blocks after neck recognition, because one of the oil-bearing blocks was smaller than the specified value and merged into the adjacent block, so it was still one oil-bearing block in the end; in the a3 area, there was originally a circuitous oil-bearing block, which was divided into two oil-bearing blocks after neck recognition. Before and after neck recognition, the compactness and distribution balance of the internal oil-bearing grid of the oil-bearing block have been significantly improved.

[0055] The above-described embodiments are merely embodiments of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, without departing from the concept of the present invention, several modifications, equivalent substitutions, improvements, etc. can be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A method for segmenting reservoir grid models into blocks, characterized by: include: Step 1: Obtain reservoir grid data, including grid data, oil content data, and geological fault data; Step 2: Merge the connected oil-bearing grids into the initial oil-bearing block, and judge whether two adjacent oil-bearing grids are connected in the order of the left side, upper left side, upper side, and upper right side of the oil-bearing grid. If the two oil-bearing grids are connected to each other and there is no fault between the two oil-bearing grids, then the two oil-bearing grids are judged to be connected, and the two oil-bearing grids are merged. The connectivity in other directions is no longer judged. Each oil-bearing grid is judged in turn according to the above method, and finally the connected oil-bearing grids are merged into many internally connected initial oil-bearing blocks; Step 3: If the current oil-bearing grid has at least one connected oil-bearing grid with the adjacent grid, and there is no connected oil-bearing grid in at least one direction of the longitudinal, transverse, and diagonal directions, the current oil-bearing grid is identified as a neck, and the block is divided into a new block according to the neck. The neck in the oil-bearing block is identified and the neck is temporarily removed, thereby dividing the original block into different blocks at the neck; Step 4: Reclassify the removed necks into the reservoir grid and then the block. According to the number of oil-bearing grids in the adjacent blocks of the necks, classify the necks into the blocks with more oil-bearing grids. Step 5: Redraw the reservoir grid. The grids of adjacent oil-bearing blocks are drawn using different legends to intuitively distinguish different oil-bearing blocks.

2. According to claim 1, a reservoir grid model contiguous attribute block method is characterized by: The oil content data obtained in step 1 is grid data processed based on the original data, which only expresses whether the grid contains oil, but not the specific oil content value; the geological fault data obtained is grid data processed based on the original data, which only expresses whether there is a fault between the grids, but not other characteristic values ​​of the fault.

3. According to claim 1, a reservoir grid model attribute segmentation method is characterized by: In step 3, the neck is a special oil-bearing grid for identifying the inside of the oil-bearing block. The oil-bearing block can be further divided according to the neck to achieve the purpose of optimizing the oil-bearing block.

4. The method for segmenting reservoir grid models into blocks according to claim 1, characterized in that: In step 4, there will be at least one oil-bearing grid in the adjacent blocks of the neck connected to the neck. After the neck is included in the block with a large number of oil-bearing grids, the characteristics of the neck will disappear, and the neck will no longer appear inside the oil-bearing block.

5. The method for segmenting reservoir grid models into blocks according to claim 1, characterized in that: In step 5, the grids of adjacent oil-bearing blocks are drawn using different legends, which are only used to visually distinguish adjacent oil-bearing blocks. The legends of the oil-bearing blocks of the entire reservoir grid will be displayed repeatedly, but the legends of adjacent oil-bearing blocks will not be the same.

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