Oil reservoir longitudinal development dynamic monitoring method based on time-lapse earthquake

Abstract

The invention provides an oil layer longitudinal development dynamic monitoring method based on a time-lapse earthquake. The method comprises the steps that 1, stratum slice control horizon of a monitoring earthquake oil layer and a foundation earthquake oil layer are explained; 2, calculating the amplitude difference between a monitoring earthquake and a basic earthquake for the whole oil layer; 3, whether the overall amplitude difference of the oil layer and the dynamic data have a direct proportion relation or not is determined; 4, appropriate stratum slices with the same number are cut for the monitoring earthquake and the foundation earthquake respectively; 5, respectively solving amplitude or attribute differences before and after time shifting for each obtained earthquake slice and each obtained basic earthquake slice, and selecting a plurality of slice differences with most obvious monitoring oil reservoir longitudinal capability; and 6, comparing the obtained stratum slice differences, monitoring the development differences of different longitudinal parts of an oil layer, and guiding the adjustment of a development scheme. According to the method, the development scheme can be adjusted by adopting targeted technical measures, the oil reservoir longitudinal monitoring capability of the time-lapse earthquake is improved, and the oil reservoir recovery efficiency is further improved.

Description

Technical Field

[0001] This invention relates to the field of oil reservoir exploration and development technology, and in particular to a dynamic monitoring method for vertical development of oil reservoirs based on time-shifted seismic data. Background Technology

[0002] Reservoir dynamic monitoring refers to the measures and methods adopted during the development and production of oil reservoirs to understand and grasp the dynamics of fluid seepage within the reservoir and the changes in downhole reservoirs in production wells and various injection wells. Among these, remaining oil prediction is the main technical objective of reservoir dynamic monitoring. Currently, the commonly used methods for reservoir dynamic monitoring include: (1) development open-hole logging; (2) casing well logging; (3) development well testing; (4) analytical testing; and (5) inter-well monitoring. These technologies mainly utilize in-well and inter-well data, providing only a "one-hole view" or "one-line view," and have a relatively small scope for reservoir monitoring.

[0003] Time-shift seismic analysis is a relatively new reservoir dynamic monitoring technology. Theoretically, after subtracting the imaging results, time-shift seismic analysis can effectively remove the static properties of oil and gas reservoirs (such as structural and lithological properties), thereby obtaining direct imaging of the dynamic fluid properties of oil and gas reservoirs (fluid saturation, pressure, temperature, etc.), enabling large-scale reservoir monitoring. Applying time-shift seismic analysis to reservoir management can not only reveal the three-dimensional characteristics of oil and gas reservoirs, but also fully utilize the temporal differences in seismic response. Through calibration of well logging and development data, the location of remaining oil can be identified, providing valuable data for optimizing development plans and reducing dry wells.

[0004] Currently, time-shift seismic technology in China is still in the stage of in-depth research. Given the current need to further improve the accuracy of reservoir development, it is required not only to monitor the overall or most prominent changes in the reservoir, but also to monitor the development and activation of different parts of the reservoir vertically. This necessitates methods to improve the vertical monitoring capabilities of seismic reservoirs.

[0005] Chinese patent application CN202311585979.9 discloses a method and system for predicting remaining oil and gas based on time-lapse interpretation. The method includes: selecting any two periods of seismic data from time-lapsed seismic data, performing seismic data transformation based on slope calculation to obtain extreme value domain data for the two periods; performing time-lapse seismic time-lapse interpretation based on the extreme value domain data of the two periods; and predicting remaining oil and gas based on the time-lapse seismic time-lapse interpretation results. This invention innovatively develops a method to convert two periods of time-lapsed seismic data into extreme value volume data through slope, arctangent, and difference operations, effectively highlighting the detailed characteristics of vertical and horizontal variations in seismic data. The extreme value volume enables detailed interpretation of the target layer's stratigraphic position, thereby obtaining time-lapse attributes, overcoming the difficulty in obtaining traditional post-stack seismic time-lapse attributes.

[0006] Chinese patent application CN201010244645.1 discloses a method for determining whether time-shifted seismic activity can be implemented. The method includes the following steps: obtaining the energy change difference of the effective seismic signal caused by changes in reservoir parameters; obtaining the noise level in actual seismic data; comparing the energy change difference with the noise level; if the energy change difference is greater than the noise level, it indicates that time-shifted seismic activity can be implemented. By comparing the results of simulated energy change and signal-to-noise ratio analysis, it can be seen that the energy change (13.3%) of the effective seismic signal caused by reservoir parameter changes such as pressure drop in the gas field in the example is much higher than the noise level in the region (2.9%). Therefore, it is considered that time-shifted seismic activity can currently be implemented in this gas field.

[0007] Chinese patent application CN201010196389.3 discloses a method for well location deployment using time-shifted seismic data. The method includes the following steps: 1) Obtaining seismic data at two different time points according to steps a and b: a) Determining the basic formation parameters of the area to be measured; creating a reservoir profile of the area to be measured, and establishing a formation profile module based on the reservoir profile; obtaining three data volumes of P-wave velocity, S-wave velocity, and density based on the basic formation parameters and the formation profile module; b) Performing AVO forward modeling to obtain superimposed seismic data at various incident angles; 2) Processing the two seismic data sets to obtain the seismic data differences; 3) Inverting the seismic data differences to obtain the P-wave impedance difference, S-wave impedance difference, density difference, and P-wave / S-wave velocity ratio difference; 4) Predicting reservoir parameter changes; 5) Deploying well locations. This invention establishes a process for predicting reservoir parameter changes and determining well locations based on time-shifted seismic difference inversion, which cannot be achieved using conventional methods.

[0008] A comprehensive analysis of the above patents regarding time-lapse seismic monitoring of reservoirs reveals that current methods involve calculating seismic data volumes, attribute values, or attribute clustering values ​​within a certain time window along the reservoir's seismic reflection axis from the monitored earthquake and the base earthquake. The difference between these two data points is then calculated. This monitoring focuses on differences on the reservoir's horizontal plane; for single wells and between wells, it monitors the overall changes or most prominent changes in the reservoir. While time-lapse seismic techniques for horizontal reservoir monitoring are relatively mature, there is no corresponding method for vertical reservoir monitoring. Therefore, we have invented a novel dynamic monitoring method for vertical reservoir development based on time-lapse seismic data. Summary of the Invention

[0009] The purpose of this invention is to provide a dynamic monitoring method for the vertical development of oil reservoirs based on time-shifted seismic activity that can meet the requirements for improving the vertical monitoring capability of seismic oil reservoirs.

[0010] The objective of this invention can be achieved through the following technical measures: a dynamic monitoring method for vertical development of oil reservoirs based on time-shifted seismic data, comprising:

[0011] Step 1: Interpret the control horizons of stratigraphic slices for monitoring earthquakes and basic seismic oil layers, respectively;

[0012] Step 2: Calculate the amplitude difference between the monitoring earthquake and the base earthquake for the entire oil layer;

[0013] Step 3: Determine whether there is a positive proportional relationship between the overall amplitude difference of the oil reservoir and the dynamic data;

[0014] Step 4: Take appropriate and equal numbers of stratigraphic slices from both the monitored earthquake and the basic earthquake;

[0015] Step 5: Calculate the amplitude or attribute differences before and after time shift for each slice of the obtained earthquake and the basic earthquake, and select the slices with the most obvious differences in monitoring the vertical capacity of the oil layer.

[0016] Step 6: Compare the differences obtained from the stratigraphic slices, monitor the development differences in different parts of the oil layer in the vertical direction, and guide the adjustment of the development plan.

[0017] The objective of this invention can also be achieved through the following technical measures:

[0018] In step 1, the stratigraphic slices of the monitored seismic and basic seismic oil layers are controlled by the seismic reflection axis corresponding to the top and bottom interfaces of the oil layer, which is clearly defined and easy to trace, or the seismic reflection axis that is easy to trace and is adjacent to the top and bottom interfaces of the oil layer within the same sedimentary unit.

[0019] In step 1, during the interpretation process, the automatic tracking interpretation method is used to perform 1x1 grid interpretation of the peaks, troughs, or zero points of the seismic reflection axes corresponding to the control layer, ensuring the consistency of the control layer in the stratigraphic slices before and after the time shift.

[0020] In step 2, the top and bottom control layers of the oil layer stratigraphic slices of the basic earthquake and the monitoring earthquake explained in step 1 are used to extract the oil layer amplitude attributes or other time-shift sensitive attributes of the monitoring earthquake and the basic earthquake, respectively. Then, the difference between the amplitude attributes or other sensitive attributes is obtained by directly subtracting the overall oil layer amplitude attributes or other time-shift sensitive attributes of the monitoring earthquake from the overall oil layer amplitude attributes or other time-shift sensitive attributes of the basic earthquake.

[0021] In step 2, suitable sensitive attribute volumes for the basic earthquake and the monitoring earthquake are extracted separately. Then, the sensitive attributes of the overall oil layer segment of the basic earthquake and the monitoring earthquake are extracted using the top and bottom control layers of the oil layer stratigraphic slices of the basic earthquake and the monitoring earthquake explained in step 1. Finally, the difference in the overall oil layer segment sensitive attributes is obtained by directly subtracting the overall oil layer segment sensitive attributes of the monitoring earthquake from the overall oil layer segment sensitive attributes of the basic earthquake.

[0022] In step 3, the range of differences in the overall seismic amplitude attribute or other time-shifted seismic sensitive attributes of the oil-bearing section obtained in step 2 is compared with the dynamic data of the study well to determine and verify whether there is a positive proportional relationship between the range of differences and the dynamic data of a single well.

[0023] In step 4, stratigraphic slices are taken from the monitoring earthquake and the basic earthquake using the control horizon. The number of slices should be sufficient to reflect the seismic changes in different parts of the oil layer in all the study wells. For oil layers with strata, slices should be taken from each stratum, and the slices from the monitoring earthquake and the basic earthquake should correspond one-to-one.

[0024] In step 4, given the significant differences in oil layer distribution among the wells, it is necessary to extract an appropriate number of time-shifted and pre-shifted formation slices for each well area.

[0025] In step 5, amplitude attributes or other time-shift sensitive attributes are obtained for all stratigraphic slices along both the base earthquake and the monitored earthquake oil layer. Then, the amplitude attributes or other time-shift sensitive attributes of the monitored earthquake in each stratigraphic slice are directly subtracted from the differences or other time-shift sensitive attributes of the base earthquake to obtain the differences in amplitude attributes or other time-shift sensitive attributes of each stratigraphic slice. The most significant amplitude difference or other time-shift sensitive attribute difference that can monitor the vertical situation of the oil layer is then selected. Alternatively, the stratigraphic slices before and after time shift that can monitor the vertical distribution of the oil layer in the target well area are selected first, and then the differences in earthquake amplitude or other time-shift sensitive attributes are extracted from the selected stratigraphic slices and subtracted to obtain the differences in earthquake amplitude attributes or other time-shift sensitive attributes.

[0026] In step 5, sensitive attributes are first extracted from the basic earthquake and the monitoring earthquake, and then appropriate and equal number of stratigraphic slices are cut from the sensitive attributes of the monitoring earthquake and the basic earthquake using the control horizon. Then, the sensitive attribute slices of the monitoring earthquake and the basic earthquake are directly subtracted to obtain the slice sensitive attribute difference. Finally, the slice sensitive attribute difference that can monitor the vertical situation of the oil layer is selected.

[0027] In step 6, based on the research in step 5, the results of comparative analysis of the differences in seismic amplitude or other time-shifted seismic sensitivity attributes of different stratigraphic slices are used and combined with the dynamic data of oil reservoir development to monitor the differences in development status of different parts of the oil reservoir in the vertical direction and guide the adjustment of development plans.

[0028] In step 6, based on the difference in amplitude and other time-shifted seismic sensitive attributes around the well point on different slices, the range and direction of oil and gas activation around the well point on different formation slices are inferred, the differences in vertical development of oil layers are clarified, and the single-well steam injection scheme is adjusted accordingly.

[0029] In step 6, the amplitude differences or other time-shifted seismic sensitive attributes around the well points on different slices are combined with other dynamic data to analyze the differences in the vertical distribution of inter-well interference in the oil layer, and based on this, the design of vertical plugging and water shut-off schemes in the oil layer between wells is guided.

[0030] The objective of this invention can also be achieved through the following technical measures: a time-shifted seismic-based dynamic monitoring system for longitudinal development of oil reservoirs, wherein the time-shifted seismic-based dynamic monitoring system for longitudinal development of oil reservoirs employs a time-shifted seismic-based dynamic monitoring method for longitudinal seismic monitoring of oil reservoirs.

[0031] The present invention provides a dynamic monitoring method for vertical oil reservoir development based on time-lapse seismic data. This method utilizes differences in seismic amplitude or other attributes of formation slices at different locations along the vertical direction of the oil reservoir in seismic data before and after time-lapse development to reflect changes in oil reservoir development at different locations along the vertical direction. This allows for targeted technical adjustments to development plans, improving the ability of time-lapse seismic data to monitor the vertical direction of the oil reservoir and further enhancing oil recovery. Compared with existing technologies, this invention has the following advantages:

[0032] The technology of this invention is mature and reliable, and the operation process is simple. It improves the ability of time-shifted seismic monitoring of oil reservoirs and guides developers to take targeted technical measures to adjust development plans. It helps to improve the development and utilization capacity of reservoirs in and between wells and can further improve the effect of tapping the potential of remaining oil. It has great application value for the mid-to-late stage development of reservoirs. Attached Figure Description

[0033] Figure 1 This is a flowchart of a specific embodiment of the oil reservoir vertical development dynamic monitoring method based on time-shifted seismic data of the present invention;

[0034] Figure 2 This is a schematic diagram of the control horizon of the monitoring earthquake and the basic seismic oil layer stratigraphic slice before and after time shift in Embodiment 1 of the present invention;

[0035] Figure 3 This is a schematic diagram of the sensitivity attributes (left and middle) of the overall oil-bearing segment and the differences in sensitivity attributes (right) in the earthquake and basic earthquake monitoring before and after time shift in Embodiment 1 of the present invention;

[0036] Figure 4 This is a graph showing the positive proportional relationship between the cumulative oil production of a single well and the difference in the sensitivity attributes of the overall oil-bearing section in the monitored earthquakes and basic earthquakes before and after time shift around the well point in Embodiment 1 of the present invention.

[0037] Figure 5 This is a schematic diagram of the stratigraphic slice locations of oil layers in the earthquake and basic earthquake monitoring before and after time shift in Embodiment 1 of the present invention;

[0038] Figure 6 This is a schematic diagram showing the differences in amplitude properties between the basic earthquake and the monitored earthquake along the oil-bearing sections above and below the diaphragm in Embodiment 1 of the present invention;

[0039] Figure 7 This is a schematic diagram illustrating the monitoring of the vertical movement of oil layers based on the difference in amplitude between earthquake and basic seismic stratigraphic slices in Embodiment 1 of the present invention.

[0040] Figure 8 This is a schematic diagram illustrating the monitoring of the longitudinal inter-well interference of the oil reservoir caused by the difference in amplitude between the monitoring earthquake and the basic seismic stratigraphic slice in Embodiment 2 of the present invention.

[0041] Figure 9 This is a schematic diagram comparing the results of obtaining the differences in the attributes of two types of monitored earthquakes and basic earthquake stratigraphic slices in Embodiment 3 of the present invention;

[0042] Figure 10 This is a schematic diagram illustrating the monitoring of the longitudinal movement of the oil layer and the longitudinal inter-well interference in Example 3 of the present invention, based on the difference in amplitude between the earthquake and the basic earthquake stratigraphic slice. Detailed Implementation

[0043] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0044] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, and / or combinations thereof.

[0045] The present invention provides a dynamic monitoring method for vertical oil reservoir development based on time-shifted seismic activity, comprising the following specific steps:

[0046] Step 1: Interpret the stratigraphic control horizons of the monitored earthquake and the basic seismic oil layer, respectively.

[0047] The stratigraphic control horizon for monitoring earthquakes and basic seismic oil layers before and after time shift can be a clearly defined and easily traceable seismic reflection axis corresponding to the top and bottom interfaces of the oil layer, or an easily traceable seismic reflection axis within the same sedimentary unit, adjacent to the top and bottom interfaces of the oil layer.

[0048] During the interpretation process, automatic tracking interpretation methods should be used as much as possible to perform 1x1 grid interpretation of the peaks, troughs or zero points of the seismic reflection axes corresponding to the control layers, so as to ensure the consistency of the control layers of the stratigraphic slices before and after time shift.

[0049] Step 2: Using the top and bottom control layers of the oil layer stratigraphic slices of the basic earthquake and the monitoring earthquake explained in Step 1, extract the oil layer amplitude attributes or other time-shift sensitive attributes of the monitoring earthquake and the basic earthquake respectively. Then, directly subtract the overall oil layer amplitude attributes or other time-shift sensitive attributes of the monitoring earthquake from the overall oil layer amplitude attributes or other time-shift sensitive attributes of the basic earthquake to obtain the difference in amplitude attributes or other sensitive attributes.

[0050] In this step, you can first extract the appropriate sensitive attribute volumes for the basic earthquake and the monitoring earthquake, and then use the top and bottom control layers of the oil layer stratigraphic slices of the basic earthquake and the monitoring earthquake explained in step 1 to extract the sensitive attributes of the overall oil layer segment of the basic earthquake and the monitoring earthquake. Finally, subtract the sensitive attribute of the overall oil layer segment of the monitoring earthquake from the sensitive attribute of the overall oil layer segment of the basic earthquake to obtain the difference in the sensitive attribute of the overall oil layer segment.

[0051] Step 3: Compare the range of differences in the overall seismic amplitude attributes (or other time-shifted seismic sensitive attributes) of the oil-bearing section obtained in Step 2 with the dynamic data of the study well (such as cumulative oil production or gas intake test data, etc.) to determine and verify whether there is a positive proportional relationship between the range of differences and the dynamic data of a single well (such as cumulative oil production or gas intake test data, etc.). This is the basis for judging whether the range and shape of the amplitude attribute differences around the well point can monitor the activity of the oil layer.

[0052] Step 4: Using the interpreted control horizons, extract appropriate and equal numbers of stratigraphic slices from both the monitored earthquake and the basic earthquake.

[0053] Using control horizons, stratigraphic slices are taken from both monitoring and basic seismic data. The number of slices should be sufficient to reflect the seismic changes in different parts of the oil layers in all study wells, especially for oil layers with strata. Slices should capture each stratum as much as possible, and the slices from monitoring and basic seismic data should correspond one-to-one.

[0054] When there are significant differences in the distribution of oil layers between wells, it is necessary to extract an appropriate number of formation slices before and after time shift for each well area.

[0055] Step 5: Calculate the amplitude attributes or other time-shift sensitive attributes for all stratigraphic slices along both the base earthquake and the monitored earthquake oil layer. Then, subtract the amplitude attributes or other time-shift sensitive attributes of the monitored earthquake from the differences in the base earthquake or other time-shift sensitive attributes for each stratigraphic slice to obtain the differences in amplitude attributes or other time-shift sensitive attributes for each stratigraphic slice. Select the most significant amplitude difference (or other time-shift sensitive attribute difference) that can monitor the vertical distribution of the oil layer. Alternatively, first select seismic stratigraphic slices before and after time shift that can monitor the vertical distribution of the oil layer in the target well area, then extract the seismic amplitude (or other time-shift sensitive attribute differences) from the selected stratigraphic slices, and subtract them to obtain the differences in seismic amplitude attributes (or other time-shift sensitive attribute differences).

[0056] In step 4 and this step, sensitive attributes can be extracted from the basic earthquake and the monitoring earthquake respectively. Then, using the control horizon, appropriate and equal number of stratigraphic slices can be cut from the sensitive attributes of the monitoring earthquake and the basic earthquake respectively. Then, the sensitive attribute slices of the monitoring earthquake and the basic earthquake are directly subtracted to obtain the slice sensitive attribute difference. Finally, the most obvious slice sensitive attribute difference that can monitor the vertical situation of the oil layer is selected.

[0057] Step 6: Based on the research in Step 5, use comparative analysis of the differences in seismic amplitude or other time-shifted seismic sensitivity attributes of different stratigraphic slices, and combine this with oil reservoir development dynamic data to monitor the differences in development status of different parts of the oil reservoir in the vertical direction, and guide the adjustment of development plans.

[0058] Based on the difference in amplitude (and other time-shifted seismic sensitive attributes) around well points on different slices, the range and direction of oil and gas activation around well points on different formation slices can be inferred, clarifying the differences in vertical development of oil layers, which can guide the adjustment of single-well steam injection schemes.

[0059] Furthermore, the connectivity relationship of amplitude differences around well points on different slices (other time-shifted seismic sensitive attributes) can be combined with other dynamic data (such as tracer data, inter-well interference data, etc.) to analyze the differences in the vertical distribution of inter-well interference in the oil layer, thereby guiding the design of vertical plugging and water shut-off schemes in the oil layer between wells.

[0060] The following are several specific embodiments of the application of the present invention.

[0061] Example 1

[0062] In a specific embodiment 1 of the present invention, such as Figure 1 As shown, the method for improving the monitoring capability of longitudinal dynamic changes of time-lapse seismic oil layers by utilizing stratigraphic slice differences is applied in this example. It clarifies the operational range of the oil layer segments above and below the oil layer interlayer and provides direction for the next step of adjusting the steam injection scheme, including the following steps:

[0063] Step 1: Automatically track and interpret the control horizons of oil-bearing stratigraphic slices from the monitored earthquakes before and after time shift, and the base earthquakes. The grid is 1×1. The top control horizon is the easily traceable trough corresponding to the top of the oil-bearing formation, and the lower control horizon is the easily traceable peak adjacent to the bottom interface of the oil-bearing formation. The producing section of this oil-bearing formation includes two oil-bearing sections and one diaphragm, such as... Figure 2 As shown.

[0064] Step 2: Using the top and bottom control horizons of the stratigraphic slices obtained in Step 1, determine the overall seismic amplitude properties of the oil layer before and after the time shift. Then, directly subtract the overall seismic amplitude properties of the oil layer before and after the time shift to obtain the amplitude property difference. Figure 3 As shown.

[0065] Step 3, as follows Figure 4 As shown, by comparing the cumulative oil production of the well point with the difference range of the overall amplitude attributes around the well point obtained from the top and bottom control layers of the formation slices before and after time shift, it can be seen that there is a clear positive proportional relationship between the two. Based on this, it is believed that the difference range and shape of the amplitude attributes around the well point can monitor the activation range and shape of the oil layer.

[0066] Step 4: Using the top and bottom control horizons of the stratigraphic slices obtained in Step 1, 12 stratigraphic slices are extracted from the monitored earthquakes and the basic earthquakes. These 12 sets of slices fully consider the issue of the intermediate strata in the production intervals before and after time shift. Slices 4 and 5 are extracted from the oil-bearing segments above the strata, and slices 8 and 9 are extracted from the oil-bearing segments below the strata. Figure 5 The image shows the locations of the 4th, 5th, 8th, and 9th strata slices before and after time shift on the cross-section.

[0067] Step 5: Directly subtract the seismic amplitude attributes of all 12 groups of stratigraphic slices before and after time shift obtained in Step 4 to obtain 12 amplitude attribute differences. The most significant differences are found in the amplitude attribute differences of the 4th, 5th, 8th, and 9th stratigraphic slices before and after time shift. Comparing these differences reveals that the amplitude attribute differences of the 4th and 5th stratigraphic slices before and after time shift both correspond to oil-bearing segments above the interlayer, with very similar differences in shape and extent. Similarly, the differences in the 8th and 9th stratigraphic slices both correspond to oil-bearing segments below the interlayer, with very similar differences in shape and extent. Finally, the amplitude attribute differences of the 5th and 8th stratigraphic slices are selected as the monitoring results for the attribute differences between the oil-bearing segments above and below the interlayer. Figure 6 As shown.

[0068] Step 6: Utilize the differences in amplitude attributes between the 5th and 8th formation slices obtained in Step 5 to conduct vertical dynamic monitoring of the reservoir. Taking the X450 well area as an example, for instance... Figure 7As shown, the range of differences near well points in slice 5 is generally larger than that in slice 8, indicating that the range of heavy oil movement in the upper oil-bearing section is generally larger than that in the lower oil-bearing section. However, near wells X439 and X459, the range of amplitude attribute differences in slice 8 is larger than that in slice 5, indicating that the range of movement in the upper oil-bearing section of these wells is small, suggesting poor gas absorption capacity in the upper oil-bearing section, requiring increased steam injection in the upper oil-bearing section of these two wells. The shape of the attribute differences near well points in the upper and lower layers of the 5th and 8th formation slices is basically NW-trending, indicating that the heavy oil movement is NW-SE-trending, which should be influenced by the depositional trend. In the next stage of development, the steam injection scheme needs to be adjusted to expand the influence range of NW-SE-trending steam injection.

[0069] Example 2

[0070] This embodiment uses the same first five steps as in Embodiment 1. In step 6, this embodiment conducts vertical inter-well interference monitoring of heavy oil reservoirs based on the time-shifted seismic dynamic monitoring method, and guides the adjustment of the development plan. For example... Figure 8 As shown, wells X450 and X458 are affected by steam injection interference. The X450 well area represents a common situation, where the interference from this well to surrounding wells is greater in the upper oil-bearing zone than in the lower oil-bearing zone. However, in the X458 well area, the interference from this well to surrounding wells is less in the upper oil-bearing zone than in the lower oil-bearing zone. Therefore, during development, generally, inter-well interference requires enhanced gas plugging in the upper oil-bearing zone, while for well X458, enhanced gas plugging in the lower oil-bearing zone is necessary.

[0071] Example 3

[0072] In this embodiment, the first three steps are exactly the same as in Embodiment 1. In steps 4, 5, and 6, this embodiment first extracts the sensitive attribute volumes of the monitored earthquake and the basic earthquake, then extracts formation slices from the sensitive attribute volumes of the monitored earthquake and the basic earthquake, and finally calculates the differences in the sensitive attributes of the formation slices. These differences are then used to monitor the oil reservoir activation range and inter-well interference. Figure 9 The image shows a comparison of two methods for determining the differences in sensitive attributes of stratigraphic slices. It can be seen that the result of Example 1 (left image), which first determines the stratigraphic slices and then the attribute differences, exhibits obvious wavy lines. The result of Example 3 (right image), which first determines the attributes and then the attribute differences of the stratigraphic slices, does not show wavy lines. Figure 10 The image shows the results of reservoir monitoring in step 6 of this embodiment. Near well X521, the range of the upper reservoir segment being activated is significantly smaller than that of the lower reservoir segment. Inter-well steam injection interference occurs in wells P527 and P523, and the steam injection interference in the upper reservoir segment is significantly weaker than that in the lower reservoir segment. These situations require targeted adjustment measures in the development plan.

[0073] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0074] Except for the technical features described in the specification, all other technologies are known to those skilled in the art.

Claims

1. A dynamic monitoring method for vertical development of oil reservoirs based on time-shifted seismic data, characterized in that, This time-shifted seismic-based method for dynamic monitoring of reservoir vertical development includes: Step 1: Interpret the control horizons of stratigraphic slices for monitoring earthquakes and basic seismic oil layers, respectively; Step 2: Calculate the amplitude difference between the monitoring earthquake and the base earthquake for the entire oil layer; Step 3: Determine whether there is a positive proportional relationship between the overall amplitude difference of the oil reservoir and the dynamic data; Step 4: Take appropriate and equal numbers of stratigraphic slices from both the monitored earthquake and the basic earthquake; Step 5: Calculate the amplitude or attribute differences before and after time shift for each slice of the obtained earthquake and the basic earthquake, and select the slices with the most obvious differences in monitoring the vertical capacity of the oil layer. Step 6: Compare the differences obtained from the stratigraphic slices, monitor the development differences in different parts of the oil layer in the vertical direction, and guide the adjustment of the development plan.

2. The method for dynamic monitoring of vertical oil reservoir development based on time-shifted seismic data according to claim 1, characterized in that, In step 1, the stratigraphic slices of the monitored seismic and basic seismic oil layers are controlled by the seismic reflection axis corresponding to the top and bottom interfaces of the oil layer, which is clearly defined and easy to trace, or the seismic reflection axis that is easy to trace and is adjacent to the top and bottom interfaces of the oil layer within the same sedimentary unit.

3. The method for dynamic monitoring of vertical oil reservoir development based on time-shifted seismic data according to claim 1, characterized in that, In step 1, during the interpretation process, the automatic tracking interpretation method is used to perform 1x1 grid interpretation of the peaks, troughs, or zero points of the seismic reflection axes corresponding to the control layer, ensuring the consistency of the control layer in the stratigraphic slices before and after the time shift.

4. The method for dynamic monitoring of vertical oil reservoir development based on time-shifted seismic data according to claim 1, characterized in that, In step 2, the top and bottom control layers of the stratigraphic slices of the monitored earthquake and the basic earthquake oil layer explained in step 1 are used to extract the amplitude attributes or other time-shift sensitive attributes of the monitored earthquake and the basic earthquake oil layer respectively. Then, the difference between the amplitude attributes or other sensitive attributes is obtained by directly subtracting the amplitude attributes or other time-shift sensitive attributes of the monitored earthquake and the overall oil layer amplitude attributes or other time-shift sensitive attributes of the basic earthquake.

5. The method for dynamic monitoring of vertical oil reservoir development based on time-shifted seismic data according to claim 1, characterized in that, In step 2, suitable sensitive attribute volumes for the basic earthquake and the monitoring earthquake are extracted separately. Then, the sensitive attributes of the overall oil layer segment of the basic earthquake and the monitoring earthquake are extracted using the top and bottom control layers of the oil layer stratigraphic slices of the basic earthquake and the monitoring earthquake explained in step 1. Finally, the difference in the overall oil layer segment sensitive attributes is obtained by directly subtracting the overall oil layer segment sensitive attributes of the monitoring earthquake from the overall oil layer segment sensitive attributes of the basic earthquake.

6. The method for dynamic monitoring of vertical oil reservoir development based on time-shifted seismic data according to claim 1, characterized in that, In step 3, the range of differences in the overall seismic amplitude attribute or other time-shifted seismic sensitive attributes of the oil-bearing section obtained in step 2 is compared with the dynamic data of the study well to determine and verify whether there is a positive proportional relationship between the range of differences and the dynamic data of a single well.

7. The method for dynamic monitoring of vertical oil reservoir development based on time-shifted seismic data according to claim 1, characterized in that, In step 4, stratigraphic slices are taken from the monitoring earthquake and the basic earthquake using the control horizon. The number of slices should be sufficient to reflect the seismic changes in different parts of the oil layer in all the study wells. For oil layers with strata, slices should be taken from each stratum, and the slices from the monitoring earthquake and the basic earthquake should correspond one-to-one.

8. The method for dynamic monitoring of vertical oil reservoir development based on time-shifted seismic data according to claim 7, characterized in that, In step 4, given the significant differences in oil layer distribution among the wells, it is necessary to extract an appropriate number of time-shifted and pre-shifted formation slices for each well area.

9. The method for dynamic monitoring of vertical oil reservoir development based on time-shifted seismic data according to claim 1, characterized in that, In step 5, amplitude attributes or other time-shift sensitive attributes are obtained for all stratigraphic slices along both the base earthquake and the monitored earthquake oil layer. Then, the amplitude attributes or other time-shift sensitive attributes of the monitored earthquake in each stratigraphic slice are directly subtracted from the differences or other time-shift sensitive attributes of the base earthquake to obtain the differences in amplitude attributes or other time-shift sensitive attributes of each stratigraphic slice. The most significant amplitude difference or other time-shift sensitive attribute difference that can monitor the vertical situation of the oil layer is then selected. Alternatively, the stratigraphic slices before and after time shift that can monitor the vertical distribution of the oil layer in the target well area are selected first, and then the differences in earthquake amplitude or other time-shift sensitive attributes are extracted from the selected stratigraphic slices and subtracted to obtain the differences in earthquake amplitude attributes or other time-shift sensitive attributes.

10. The method for dynamic monitoring of vertical oil reservoir development based on time-shifted seismic data according to claim 1, characterized in that, In step 5, sensitive attributes are first extracted from the basic earthquake and the monitoring earthquake, and then appropriate and equal number of stratigraphic slices are cut from the sensitive attributes of the monitoring earthquake and the basic earthquake using the control horizon. Then, the sensitive attribute slices of the monitoring earthquake and the basic earthquake are directly subtracted to obtain the slice sensitive attribute difference. Finally, the slice sensitive attribute difference that can monitor the vertical situation of the oil layer is selected.

11. The method for dynamic monitoring of vertical oil reservoir development based on time-shifted seismic data according to claim 1, characterized in that, In step 6, based on the research in step 5, the results of comparative analysis of the differences in seismic amplitude or other time-shifted seismic sensitivity attributes of different stratigraphic slices are used and combined with the dynamic data of oil reservoir development to monitor the differences in development status of different parts of the oil reservoir in the vertical direction and guide the adjustment of development plans.

12. The method for dynamic monitoring of oil reservoir vertical development based on time-shifted seismic data according to claim 11, characterized in that, In step 6, based on the difference in amplitude and other time-shifted seismic sensitive attributes around the well point on different slices, the range and direction of oil and gas activation around the well point on different formation slices are inferred, the differences in vertical development of oil layers are clarified, and the single-well steam injection scheme is adjusted accordingly.

13. The method for dynamic monitoring of vertical oil reservoir development based on time-shifted seismic data according to claim 11, characterized in that, In step 6, the amplitude differences or other time-shifted seismic sensitive attributes around the well points on different slices are combined with other dynamic data to analyze the differences in the vertical distribution of inter-well interference in the oil layer, and based on this, the design of vertical plugging and water shut-off schemes in the oil layer between wells is guided.

14. A dynamic monitoring system for vertical development of oil reservoirs based on time-shifted seismic data, characterized in that: The time-shifted seismic-based vertical development dynamic monitoring system for oil reservoirs uses the time-shifted seismic-based vertical development dynamic monitoring method for oil reservoirs as described in any one of claims 1-13 to perform seismic vertical monitoring of oil reservoirs.

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