Description method and device for VSP well-seismic combined 4D development well sidetrack coring remaining oil

Abstract

The invention discloses a VSP well-seismic combination 4D development well sidetrack drilling coring remaining oil description method and device, and relates to the technical field of oilfield development. The concept of earthquake-geology-engineering-development integration is used as guidance, the 4D time delay monitoring technology based on well-seismic combination and the development well through casing sidetrack drilling coring technology are applied, and the method and device for describing the remaining oil of the VSP well-seismic combination 4D development well sidetrack drilling coring are achieved. Potential of information such as earthquakes, logging, development data and rock core information is fully excavated, and a development area anisotropic earthquake migration imaging result with higher fidelity and resolution can be obtained to serve as development basic data for supporting fine potential tapping of remaining oil; 4D well-seismic combined residual oil dynamic monitoring with better consistency and stability is realized; on the basis of the lowest engineering cost and the lowest operation risk, important data-exploitation well side tracking coring real objects and data for comprehensively analyzing the remaining oil distribution rule are obtained, the remaining oil fine description and potential tapping success rate of a complex research object in a developed block are greatly improved, and then the old oil field development efficiency is improved, and the recovery efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of oilfield development, and in particular to a method and device for describing remaining oil by side-tracking coring of a VSP well-seismic combined 4D development well. Background Art

[0002] The remaining oil in high water cut old oilfields is highly dispersed. The means of oilfield development have changed from large-area drilling to precise tapping of local remaining oil. Among them, side-tracking of development wells is one of the important means for targeted tapping of locally enriched remaining oil. Clearly understanding the remaining oil changes at different scales from sub-layers to individual sand bodies in the developed reservoir is an important basis for accurately designing and implementing measures for tapping potential and further improving the recovery rate. At present, the means for analyzing the distribution characteristics of remaining oil mainly include numerical simulation of reservoir models, dynamic comprehensive analysis, saturation testing through casings, etc. However, due to the influence of simulation efficiency, accuracy of dynamic data, testing costs, etc., the accuracy of quantitative evaluation of remaining oil is difficult to meet the design requirements for targeted tapping of locally enriched remaining oil (such as side-tracking horizontal wells, etc.).

[0003] 4D seismic serving development research is an effective means for evaluating the changes in long-term developed reservoirs, but it has a high cost. At present, the geophones used in China can only maintain good consistency within a 5-year cycle. After that, as time increases, the consistency and stability of the geophones are greatly reduced. Even if the same processing process as in the initial production period is adopted, objective comparison results cannot be obtained. However, VSP (Vertical Seismic Profile) has great advantages. Before the new well is put into production, VSP construction and acquisition can be carried out in both open-hole wells and cased wells. At the same time, the VSP received data in the well can be separated into three different types of wave field data through three-component rotation. The resolution and fidelity of the processing results are higher than those of surface seismic. Therefore, it is very appropriate to use 3D VSP as the seismic prediction means for describing remaining oil by 4D well-seismic combination in the present invention.

[0004] Side-tracking of development wells is the whole process of opening a window on one side of the casing at a predetermined well section of an oil production or injection well, drilling a new wellbore through the window, and setting a liner in the new wellbore to fix the well (such as Figure 1)。The sidetracking technology is to fix a whipstock at a specific depth in oil and water wells. Utilizing its inclined surface for deflecting and guiding, a milling cone is used to open a window on the side of the casing. A new wellbore is drilled from the window, and then a liner is run in and cemented in place, which is a complete set of technology. Sidetracking construction mainly includes: wellbore preparation before sidetracking, fixing the whipstock, casing windowing, open-hole drilling, coring and other processes. The selection of the windowing position should be as deep as possible on the basis of meeting the requirements of geological design, logging and coring. That is to say, it should be as close as possible to the target layer depth, but the casing damage situation should be mastered in advance, and the collar should be avoided by more than 3 meters. After accurately positioning the target layer through the combination of well logging and seismic data, it is necessary to calculate at what position above the target layer to start the sidetracking with windowing. This distance is very crucial. Since logging and coring will be carried out after horizontal well drilling in the target layer, taking a vertical well as an example, it is necessary to calculate the accurate position of sidetracking with windowing according to factors such as the required build-up rate, the radius of the technical casing, the casing damage situation, the difficulty of windowing and the cement sheath bonding quality. However, the most important of the above factors is the rationality, timeliness and economy of the build-up rate design. On the basis of supporting accurate target hitting, the length of the build-up section should be shortened to the greatest extent. At the same time, the optimal combination plan of the drill string for each build-up section should be considered. Build-up is not only the interaction between the selected drill string and the formation, but also a solution process for optimizing the drill string combination to save costs. Generally speaking, the curvature of the wellbore trajectory formed after windowing on the casing wall of a development well is the build-up rate of the drill string. In the actual process of sidetracking with windowing, if the designed build-up rate of a short-radius well is too high, the designed build-up rate ≥ 25° / 30 m, and once the build-up rate is too low or other situations affecting the trajectory occur during the actual drilling process, it is necessary to pull out the drill string and replace the screw with a larger degree. More seriously, it will cause the construction well to be backfilled. The build-up rate design must be cautious, and even a certain space can be reserved in advance for accurate target hitting. Through the above analysis, it can be seen that there are actually many parameter settings in the design of the windowing position and the build-up plan that are contradictory to each other. In order to improve efficiency and reduce costs, the sidetracking with windowing should be carried out as close as possible to the target layer; but if the distance is too close, it will not only increase the risk of build-up, but also greatly increase the difficulty of accurate target hitting of geological steering. Moreover, the too-close distance does not leave room for adjustment after the target is exited in the horizontal section. Generally speaking, these several important designs are a process of finding the optimal solution for the engineering cycle, cost, risk and steering error tolerance rate, and there is often no standard answer. It is necessary to make a good design in combination with the actual situation and make a solution plan for possible problems such as windowing failure, build-up failure or target exit in the horizontal section.

[0005] When the design is well done and the window is opened and the well is deviated smoothly, and the geosteering is completed under the support of anisotropic depth migration and seismic-geological integrated modeling, and the drilling accurately enters the target, the coring operation of the developed reservoir should be carried out. The coring tool usually consists of components such as an upper stabilizer, a water distribution joint, a hole plugging steel ball, an external return nozzle, a suspension assembly, an inner core barrel group, an outer core barrel group, a lower stabilizer, a combined inner barrel shoe, a core catcher, and a coring bit. The length of the core barrel is selected according to different well depth conditions: generally, a short barrel is selected for shallow wells and a medium-long barrel for deep wells; the pressure type of the coring tool should also be determined according to the formation hardness of the coring object: in loose and soft formations, a pressurized coring tool is usually selected, while in medium-hard to hard formations and soft formations with good core column formation, a self-locking coring tool should be selected - that is, coring with pressure preservation as much as possible. Pressure-preserving and sealed coring refers to, in the later stage of the development of a sandstone oilfield, in order to accurately obtain data such as reservoir fluid saturation, reservoir pressure, relative humidity, and reservoir conditions under the bottom-hole conditions at that time, in order to formulate a reasonable development adjustment plan and improve the ultimate recovery rate of the oilfield, a pressure-preserving and sealed coring tool and a sealing fluid are used to drill cores that maintain the integrity of the reservoir fluid under the condition of water-based drilling fluid, that is, drill cores that are not contaminated by the free water of the drilling fluid and maintain the reservoir pressure under the bottom-hole conditions at that time. This coring equipment and technology are relatively complex and costly, and are applicable to soft, medium-hard, and hard formations with diagenesis.

[0006] After obtaining all the cores according to the geological design of the remaining oil in the development well, a series of studies such as 4D seismic dynamic data, logging data, test data, development data, laboratory measurement data, comparison of the seven properties of new and old cores, forward modeling of physical models, and numerical simulation should be combined to finally realize the dynamic monitoring of the reservoir in the developed area and the accurate description of the remaining oil. Summary of the Invention

[0007] The purpose of the present invention is to provide a method and device for describing remaining oil by coring while sidetracking 4D development wells with VSP well-seismic combination. The present invention serves the fine geological research of development, guided by the concept of "seismic-geological-engineering-development integration", and supported by the 4D time-lapse monitoring technology based on well-seismic combination and the technology of coring while sidetracking through casing in development wells, fully exploring the potential of information such as seismic, logging, development data, and core data. To achieve the above purpose, the present invention provides the following technical solutions:

[0008] The present invention provides a method for describing remaining oil by coring while sidetracking 4D development wells with VSP well-seismic combination, and the method includes the following steps:

[0009] Step S1, collect well and seismic basic data, and re-collect three-dimensional VSP data;

[0010] Step S2: Process the VSP data obtained during the initial development stage and the new well drilling stage using the same process. Through attribute comparison analysis and pre-stack and post-stack inversion analysis, achieve 4D monitoring of the remaining oil field and determine the areas where the remaining oil has changed;

[0011] Step S3: Define the target layer of the coring well where the remaining oil is enriched. Select the calibration wells around the coring well to update the anisotropic parameter field, complete the anisotropic depth quality control around the coring well, and achieve iterative integrated anisotropic depth migration;

[0012] Step S4: Based on the anisotropic depth migration results, determine the sidetracking azimuth of the coring well, conduct casing deformation and cementing quality control on the area 500 meters above the target layer, and record the depth areas of the sections that pass the quality control;

[0013] Step S5: Based on the quality control results within the depth areas of the sections that pass the quality control, complete the design of the sidetracking window location, build-up, and horizontal well trajectory plan for the development well;

[0014] Step S6: Based on the above plan, complete the sidetracking window construction. Comprehensively utilize the anisotropic depth migration results and the geological model for real-time tracking while drilling to complete integrated collaborative geological steering and achieve the horizontal section of the target layer to enter the target;

[0015] Step S7: After entering the target, according to the actual well conditions, complete the design of the small-hole coring plan;

[0016] Step S8: Based on the coring plan, combined with the geological design requirements for the development of the remaining oil, complete the small-hole pressure-maintaining coring operation;

[0017] Step S9: Based on the indoor remaining oil analysis and numerical simulation of the cores from the sidetracked small holes, guide the fine development geological research and the implementation of remaining oil potential tapping.

[0018] Furthermore, the specific steps of Step S1 are as follows:

[0019] S101: Determine the study area for the fine description and precise tapping of the remaining oil. Determine the four-point coordinates and collect various basic data of the study area, including 3D seismic data, velocity field interpretation results, anisotropic field interpretation results, development well logging data, and development data;

[0020] S102: Determine the sidetracked coring well Well T , requiring that VSP construction has been completed during the initial development stage of this well, and collect VSP data, VSP processing results, and calibration results;

[0021] S103: Deploy and implement 3D VSP construction in the determined sidetracked coring well Well T to re-collect a new round of 3D VSP data.

[0022] Further, the specific steps of step S2 are as follows:

[0023] S104. Perform casing wave suppression processing and resonance suppression processing on the newly collected three-dimensional VSP data;

[0024] S105. Successively perform VSP first arrival picking, static correction, wavefield separation, amplitude compensation, velocity analysis, residual static correction, and target line migration on the processed three-dimensional VSP data;

[0025] S106. Perform amplitude calibration on the target line migration results obtained from the processing of three-dimensional seismic data and the first VSP processing results at the same location, and calculate the amplitude correction amount of the new processing results;

[0026] S107. Apply the obtained amplitude correction amount to the pre-migration VSP gather data to complete the three-dimensional VSP migration processing of the entire study area;

[0027] S108. Through the first VSP processing results collected by S102 and the most recently collected and amplitude-corrected VSP processing results obtained in S107, determine the remaining oil change area through attribute contrast analysis and pre-stack and post-stack inversion analysis;

[0028] S109. Use the area with the most significant remaining oil change delimited by S108 to screen and determine the coring well Well T The remaining oil enrichment layer is used as the target layer for the lateral drilling horizontal section, and it is required that the structure is relatively flat and the well conditions are good for lateral drilling coring construction.

[0029] Further, the specific steps of step S3 are as follows:

[0030] S110. Extend one well spacing in each of the four mutually perpendicular directions around the coring well Well T determined by S109, and select the calibration wells Well R1 to Well R4 ;

[0031] S111. Use the calibration wells Well R1 -Well R4 found by S110 to update the anisotropic parameter field, and re-perform anisotropic depth migration in the well area around the coring well Well T ;

[0032] S112. Quality control the well-to-well structural error of the anisotropic depth migration results. If the target well Well T and the calibration wells Well R1 to Well R4For well structures with an error of more than 3000 meters, if the error is less than one-thousandth, it passes quality control; if the buried depth is between 2000 meters and 3000 meters and the structural error is less than 2 meters, it passes quality control; if the target layer depth is between 1000 meters and 2000 meters and the structural error is less than 1 meter, it passes quality control; if the structural error is greater than the above standards, depth domain update under well control is required. By iteratively improving the results of anisotropic depth migration, the structural error of the well is continuously reduced until the quality control requirements for the structural error are met and the quality control of this step is passed, completely eliminating the coring well Well T Anisotropy problems in the well area.

[0033] Further, the specific steps of step S4 are as follows:

[0034] S113. Using the anisotropic depth migration results obtained in S112, combined with the research needs of remaining oil development in the target layer, determine the accurate sidetracking position of the coring well Well T and complete a 40-arm caliper measurement in the area 500 meters above the target layer;

[0035] S114. Use the 40-arm caliper measurement results obtained in S113 to determine the casing damage situation. If the maximum casing deformation radius is less than or equal to 10% and the length of the casing deformation accounts for 5% of the measured length, it passes quality control. If it does not pass quality control, the casing needs to be repaired and the casing deformation degree needs to be re-measured;

[0036] S115. Collect the CBL and VDL data and interpretation results after the cementing construction of the coring well Well T and quality control the cementing quality in the area 500 meters above the target layer. If the cement bond quality reaches more than 99%, it passes quality control, and record the depth area of the layer segment that passes quality control.

[0037] Further, the specific steps of step S5 are as follows:

[0038] S116. Within the depth range of the layer segment that meets the construction quality control in S114 and S115, complete the window cutting position design. Determine the window cutting position according to the casing damage and cementing quality, generally not higher than 200 meters above the target layer. To prevent inaccurate target entry in the horizontal section, refer to the seismic anisotropic imaging results and geological understanding, and reserve a thickness of one oil layer group in advance as an alternative horizontal coring plan;

[0039] S117. Based on the optimal sidetracking window cutting depth obtained in S116, complete the build-up plan design, formulate a three-stage specific plan and drill string assembly, and complete the horizontal well trajectory design plan.

[0040] The present invention also provides a VSP well-seismic combined 4D development well sidetracking coring remaining oil description device, which includes:

[0041] An acquisition unit, configured to collect well and seismic basic data and re-collect 3D VSP data;

[0042] A determination unit, configured to perform the same process on the VSP data obtained during the initial development stage and the new well drilling stage, and realize 4D monitoring of the remaining oil field and determine the remaining oil change area through attribute comparison analysis and pre-stack and post-stack inversion analysis;

[0043] A quality control unit, configured to delimit the target layer of the coring well with rich remaining oil, select the calibration wells around the coring well to update the anisotropic parameter field, complete the anisotropic depth quality control around the coring well, and realize iterative integrated anisotropic depth migration;

[0044] A recording unit, configured to determine the side-drilling azimuth of the coring well based on the anisotropic depth migration results, perform casing deformation and cementing quality control on the area 500 meters above the target layer, and record the depth area of the layer segments passing the quality control;

[0045] A first design unit, configured to complete the design of the side-drilling window position, build-up angle, and horizontal well trajectory plan for the development well based on the quality control results within the depth area of the quality-controlled layer segments;

[0046] A geological steering unit, configured to complete the side-drilling window construction based on the plan, and comprehensively utilize the anisotropic depth migration results and the geological model for tracking while drilling to complete integrated collaborative geological steering and realize the side-drilling into the target of the horizontal section of the target layer;

[0047] A second design unit, configured to complete the design of the small-hole coring plan according to the actual well conditions after entering the target;

[0048] An operation unit, configured to complete the small-hole pressure-maintaining coring operation based on the coring plan and in combination with the geological design requirements for the development of the remaining oil;

[0049] An implementation unit, configured to guide the implementation of fine development geological research and remaining oil potential tapping based on the indoor remaining oil analysis and numerical simulation of the side-drilled small-hole core;

[0050] The present invention also provides an electronic device, including:

[0051] One or more processors;

[0052] A storage device, configured to store one or more programs;

[0053] When the one or more programs are executed by the one or more processors, the one or more processors implement the above-mentioned method for describing remaining oil in a side-drilled coring of a VSP well-seismic combined 4D development well.

[0054] The present invention also provides a storage medium containing computer-executable instructions, which are used to execute the above-described method for describing remaining oil by side-drilling and coring in a 4D development well combining VSP well and seismic data when executed by a computer processor.

[0055] Technical effects and advantages of the present invention:

[0056] First, the present invention obtains anisotropic seismic migration imaging results with higher fidelity and resolution in the development area as basic development data to support the fine tapping of remaining oil.

[0057] Second, the present invention realizes better consistency and stability in the dynamic monitoring of remaining oil by combining 4D well and seismic data;

[0058] Third, on the basis of the lowest engineering cost and the lowest operation risk, the present invention obtains important materials for comprehensively analyzing the distribution law of remaining oil - physical objects and data of side-drilling and coring in development wells, greatly improving the success rate of fine description and potential tapping of remaining oil in complex research objects in developed blocks, and further improving the development efficiency and recovery rate of old oilfields, and having good application and promotion prospects.

[0059] Other features and advantages of the present invention will be described in the following specification, and part of them will become obvious from the specification or be understood by implementing the present invention. The objectives and other advantages of the present invention can be realized and obtained through the structures pointed out in the specification, claims and drawings. Description of the Drawings

[0060] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0061] Figure 1 Schematic diagram of side-drilling in a development well for the prior art;

[0062] Figure 2 Flowchart of a method for describing remaining oil by side-drilling and coring in a 4D development well combining VSP well and seismic data according to an embodiment of the present invention;

[0063] Figure 3 Schematic diagram of a device for describing remaining oil by side-drilling and coring in a 4D development well combining VSP well and seismic data according to an embodiment of the present invention;

[0064] Figure 4 Schematic diagram of an electronic device of the present invention. Detailed Embodiments

[0065] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0066] Embodiment

[0067] Taking a certain area in the northern part of Daqing Oilfield as an example, the study area belongs to the Sixth Oil Production Plant. After the drilling construction or cementing construction of multiple key wells in the study area is completed during the exploration stage, VSP acquisition construction has been carried out. The most recent seismic results are the multi-wave and multi-classification 3D seismic data collected in Area L in 2009. A certain research block in the area has experienced 40 years of development, with a relatively high comprehensive water cut, and the distribution of remaining oil is unknown, making it impossible to accurately describe the precise spatial distribution of remaining oil, resulting in the inability to formulate an effective remaining oil tapping plan, the inability to continue improving the recovery rate of the block, and the continuous decline in production capacity year by year.

[0068] Figure 2 It is a flow chart of a method for describing remaining oil by side-tracking coring of a VSP well-seismic combination 4D development well according to an embodiment of the present invention. As Figure 2 shown, it includes the following steps:

[0069] Step S1: Collect well and seismic basic data, and re-collect 3D VSP data, specifically including steps S101 - 103:

[0070] S101: Determine the study area for fine description and precise tapping of remaining oil, determine the four-point coordinates, and collect various basic data of the study area, including 3D seismic data, velocity field interpretation results, anisotropy field interpretation results, logging data of development wells, and development data, etc.

[0071] S102: Determine the side-tracking coring well Well T , and it is required that VSP construction has been completed during the initial development of this well, and collect VSP data, VSP processing results, and calibration results.

[0072] S103: Deploy and implement 3D VSP construction in the determined side-tracking coring well Well T to re-collect a new round of 3D VSP data.

[0073] Step S2: Perform the same process on the VSP data obtained during the initial development and the new well drilling period to achieve 4D monitoring of the remaining oil field and determine the remaining oil change area, specifically including steps S104 - 109:

[0074] S104: Perform casing wave suppression processing and resonance suppression processing on the newly collected round of 3D VSP data.

[0075] S105. Sequentially perform VSP first arrival picking, static correction, wavefield separation, amplitude compensation, velocity analysis, residual static correction, and target line migration on the processed three-dimensional VSP data.

[0076] S106. Perform amplitude calibration on the target line migration results obtained from the processing of the three-dimensional seismic data (the results collected in the early stage in S101) and the first VSP processing results (the results in S105) at the same location, and calculate the amplitude correction amount for the newly processed results.

[0077] S107. Apply the obtained amplitude correction amount to the pre-migration VSP gather data to complete the three-dimensional VSP migration processing of the entire study area.

[0078] S108. Through the first VSP processing results collected in S102 and the most recently acquired and amplitude-corrected VSP processing results obtained in S107, determine the remaining oil change area through attribute contrast analysis and pre-stack and post-stack inversion analysis.

[0079] S109. Use the area with the most significant change in remaining oil delimited in S108 to screen and determine the coring well Well T The remaining oil enrichment layer as the target layer for the horizontal section of sidetracking, requiring relatively gentle structure and good well conditions suitable for sidetracking coring construction.

[0080] Step S3. Delimit the target layer of the coring well with remaining oil enrichment, select the calibration wells around the coring well to update the anisotropic parameter field, and complete the anisotropic depth quality control around the coring well, specifically including steps S110 - 112:

[0081] S110. Extend one well spacing in each of the four mutually perpendicular directions around the coring well Well T determined in S109 according to the well pattern density, and select the calibration wells Well R1 to Well R4 .

[0082] S111. Use the calibration wells Well R1 -Well R4 found in S110 to update the anisotropic parameter field, and re-perform anisotropic depth migration in the well area around the coring well Well T .

[0083] S112. Quality control the pair-well structural error of the anisotropic depth migration results. If the target well Well T and the calibration wells Well R1 to Well R4For well structures with an error of more than 3000 meters, if the error is less than one-thousandth, it passes quality control; if the buried depth is between 2000 and 3000 meters and the structural error is less than 2 meters, it passes quality control; if the target layer depth is between 1000 and 2000 meters and the structural error is less than 1 meter, it passes quality control; if the structural error is greater than the above standards, depth domain updates under well control are required. By iteratively improving the results of anisotropic depth migration, the structural error of the well is continuously reduced, guiding the quality control requirements for meeting the structural error to pass the quality control in this step, and completely eliminating the coring well Well T Anisotropy problems in the well area.

[0084] Step S4: Determine the sidetracking azimuth of the coring well, and conduct quality control on casing deformation and cementing quality in the 500-meter area above the target layer, specifically including steps S113 - 115:

[0085] S113: Using the anisotropic depth migration results obtained in S112, and combining with the research needs for the remaining oil development of the target layer, determine the accurate sidetracking position of the coring well Well T in the 500-meter area above the target layer and complete a 40-arm caliper log measurement.

[0086] S114: Use the 40-arm caliper log measurement results obtained in S113 to determine the casing damage situation. If the maximum casing deformation radius is less than or equal to 5% of the measurement length and accounts for 5% of the casing deformation length, it passes quality control. If it does not pass quality control, the casing needs to be repaired and the casing deformation degree needs to be re-measured.

[0087] S115: Collect the CBL (cement bond logging) and VDL (variable density log) data and interpretation results after the cementing operation of the coring well Well T and conduct quality control on the cementing quality in the 500-meter area above the target layer. If the cement bond quality reaches more than 99%, it passes quality control, and record the depth area of the layer section that passes quality control.

[0088] Step S5: Design the sidetracking window position, build-up plan, and horizontal well trajectory for the development well, specifically including steps S116 - 117:

[0089] S116: Within the depth range of the layer section that meets the construction quality control requirements in S114 and S115, complete the design of the sidetracking window position. Determine the sidetracking window position based on casing damage and cementing quality, generally not higher than 200 meters above the target layer. To prevent inaccurate target entry in the horizontal section, refer to the seismic anisotropic imaging results and geological understanding, and an oil reservoir group thickness can be reserved in advance as an alternative horizontal coring plan.

[0090] S117. Based on the optimal sidetracking window-opening depth obtained in S116, complete the build-up plan design, formulate a specific three-stage plan and drill string assembly, and complete the horizontal well trajectory design plan.

[0091] Step S6. Integrate the anisotropic depth migration results with the geological model for geosteering, specifically including step S118:

[0092] S118. Utilize the optimal window-opening position calculated in S115, the build-up plan and horizontal well trajectory design plan set in S116 to complete the sidetracking window-opening construction, monitor the cuttings in logging, and apply the anisotropic depth migration results after passing through the cement sheath to complete geosteering, and achieve that the coring well Well T The development well sidetracks through the casing and enters the target formation into the pay zone.

[0093] Step S7. Conduct a wellbore condition analysis and design a small-hole coring plan after the horizontal section enters the target, specifically including step S119:

[0094] S119. Complete the coring plan design according to the actual wellbore condition after entering the target.

[0095] Step S8. Combine the geological design requirements for remaining oil development and complete the small-hole pressure-maintaining coring operation, specifically including step S120:

[0096] S120. Complete the coring in the horizontal well section according to the coring plan design obtained in S119, and study that there are no less than 5 samples per coring barrel in the pay zone.

[0097] Step S9. Based on the indoor remaining oil analysis and simulation of the core from the sidetracked small hole, guide the fine development geological research and the implementation of remaining oil tapping, specifically including step S121:

[0098] S121. Use the core obtained in S120 to conduct indoor remaining oil analysis and simulation, complete all research work, and use it to guide the fine development geological research and remaining oil tapping in a certain development area of Oilfield L.

[0099] Based on the same concept, the present invention also provides a VSP well-seismic combined 4D development well sidetracking coring remaining oil description device. Figure 3 It is a schematic diagram of a VSP well-seismic combined 4D development well sidetracking coring remaining oil description device according to an embodiment of the present invention, as Figure 3As shown in the figure, the device includes: a collection unit 201, which is used to collect well and seismic basic data and re-collect three-dimensional VSP data; a determination unit 202, which is used to perform the same process on the VSP data obtained during the initial development stage and the new well drilling stage, and through attribute comparison analysis and pre-stack and post-stack inversion analysis, realize 4D monitoring of the remaining oil field and determine the remaining oil change area; a quality control unit 203, which is used to delimit the target layer of the coring well with rich remaining oil, select the calibration wells around the coring well to update the anisotropic parameter field, complete the anisotropic depth quality control around the coring well, and realize iterative integrated anisotropic depth migration; a recording unit 204, which is used to determine the side-drilling azimuth of the coring well based on the anisotropic depth migration results, perform casing deformation and cementing quality control on the area 500 meters above the target layer, and record the depth area of the layer section that passes the quality control; a first design unit 205, which is used to complete the design of the side-drilling window position, build-up angle, and horizontal well trajectory plan of the development well based on the quality control results within the depth area of the quality-controlled layer section; a geological steering unit 206, which is used to complete the side-drilling window construction based on the plan, comprehensively utilize the anisotropic depth migration results, and cooperate with the geological model during drilling to complete integrated collaborative geological steering and realize the side-drilling into the target of the horizontal section of the target layer; a second design unit 207, which is used to complete the design of the small-hole coring plan according to the actual well conditions after entering the target; an operation unit 208, which is used to complete the small-hole pressure-maintaining coring operation based on the coring plan and in combination with the geological design requirements for the development of the remaining oil; an implementation unit 209, which is used to guide the implementation of fine development geological research and remaining oil potential tapping based on the indoor remaining oil analysis and numerical simulation of the core of the side-drilled small hole.

[0100] Based on the same inventive concept, the present invention also provides an electronic device. Figure 4 As shown in the figure, it is a schematic diagram of an electronic device provided by the present invention. Figure 4 As shown in the figure, the electronic device includes at least one processor 301, at least one communication interface 302, at least one memory 303, and at least one communication bus 304; wherein, the processor 301, the communication interface 302, and the memory 303 complete communication with each other through the communication bus 304;

[0101] The memory 303 stores a computer program.

[0102] When the processor 301 is used to execute the program stored in the memory 303, it realizes the VSP well-seismic combined 4D development well side-drilling coring remaining oil description method.

[0103] Optionally, the communication interface may be an interface of a communication module, such as an interface of a GSM module; the processor may be a processor CPU, or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present invention. The memory may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk memory. Among them, the memory stores a program, and the processor calls the program stored in the memory to execute some or all of the above method embodiments.

[0104] Based on the same inventive concept, the present invention also provides a computer-readable storage medium storing a computer program, which when run, implements some or all of the above method embodiments. Optionally, the storage medium may be a non-transitory computer-readable storage medium. For example, the non-transitory computer-readable storage medium may be ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc.

[0105] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacement of some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for describing remaining oil by side-tracking coring of a VSP well-seismic combined 4D development well, characterized in that, The method includes the following steps: Step S1: Collect well and seismic basic data, and re-collect 3D VSP data; Step S2: Perform the same process on the VSP data obtained during the initial development stage and the new well drilling stage. Through attribute contrast analysis and pre-stack and post-stack inversion analysis, realize 4D monitoring of the remaining oil field and determine the remaining oil change area; Step S3: Define the target layer of the coring well with rich remaining oil, select the calibration wells around the coring well to update the anisotropic parameter field, complete the anisotropic depth quality control around the coring well, and realize iterative integrated anisotropic depth migration; Step S4: Based on the anisotropic depth migration results, determine the sidetracking azimuth of the coring well, perform casing deformation and cementing quality control on the area 500 meters above the target layer, and record the depth area of the sections passing the quality control; Step S5: Based on the quality control results within the depth area of the quality-controlled sections, complete the design of the sidetracking window position, build-up, and horizontal well trajectory plan for the development well; Step S6: Based on the plan, complete the sidetracking window construction. By comprehensively using the anisotropic depth migration results and the geological model for real-time tracking while drilling, complete the integrated collaborative geological steering to realize the horizontal section of the target layer to enter the target; Step S7: After entering the target, complete the design of the small-hole coring plan according to the actual well conditions; Step S8: Based on the coring plan, combined with the geological design requirements for the development of remaining oil, complete the small-hole pressure-maintaining coring operation; Step S9: Based on the indoor remaining oil analysis and numerical simulation of the cores from the sidetracked small holes, guide the fine development geological research and the implementation of remaining oil tapping potential.

2. A method for describing the remaining oil in side-tracking coring of a VSP well-seismic combined 4D development well according to claim 1, characterized in that, The specific steps of step S1 include the following steps: S101: Determine the fine description of remaining oil and the precise tapping potential development research area, determine the four-point coordinates, and collect various basic data of the research area, including 3D seismic data, velocity field interpretation results, anisotropic field interpretation results, development well logging data, and development data; S102. Determine the sidetracking coring well Well in the development and research area, T requiring that VSP construction be completed during the initial stage of the well development, and collecting VSP data, VSP processing results and calibration results; S103. Deploy and implement 3D VSP construction in the determined sidetracking coring well Well T and re - collect a new round of 3D VSP data.

3. A method for describing the remaining oil in side-tracking coring of a VSP well-seismic combined 4D development well according to claim 2, characterized in that, The specific steps of step S2 include the following steps: S104: Perform casing wave suppression processing and resonance suppression processing on the newly collected 3D VSP data; S105: Perform VSP first arrival picking, static correction, wave field separation, amplitude compensation, velocity analysis, residual static correction, and target line migration on the processed 3D VSP data in sequence; S106: Make amplitude calibration on the target line migration results obtained from the processing of 3D seismic data and the first processing results of VSP at the same position, and calculate the amplitude correction amount of the new processing results; S107: Apply the obtained amplitude correction amount to the pre-migration VSP gather data to complete the 3D VSP migration processing of the entire research area; S108: Through the first VSP processing results collected in S102 and the VSP processing results of the most recently collected and amplitude-corrected in S107, determine the remaining oil change area through attribute contrast analysis and pre-stack and post-stack inversion analysis; S109. Screen and determine the coring well Well using the area with the most significant change in remaining oil delineated by S108. T Use the remaining oil enrichment layer as the target layer for the horizontal sidetrack section, requiring relatively gentle structure and good well conditions suitable for sidetrack coring operation.

4. A method for describing remaining oil in side-tracking coring of a VSP well-seismic combined 4D development well according to claim 3, characterized in that, The specific steps of step S3 include the following steps: S110. Use the core hole Well determined in S109 T and extend one well spacing in each of the four mutually perpendicular directions according to the well pattern density around it to select the calibration well Well R1 to Well R4 ; S111. Use the calibration well Well found in S110 R1 -Well R4 Update the anisotropic parameter field and re-perform anisotropic depth migration in the well area around the core well Well T ; complete anisotropic depth migration in the surrounding well area S112. Check the structural error of the well pairs for the results of quality-controlled anisotropic depth migration. If the target well Well T and the calibration well Well R1 to Well R4 have a structural error of less than one-thousandth for a well pair with a depth difference of more than 3000 meters, it passes the quality control; if the structural error is less than 2 meters for a depth range of 2000 - 3000 meters, it passes the quality control; if the structural error is less than 1 meter for the target layer depth in the range of 1000 - 2000 meters, it passes the quality control; if the structural error is greater than the above standards, depth domain update under well control is required. By iteratively improving the results of anisotropic depth migration, the structural error of the well pair is continuously reduced to meet the quality control requirements for the structural error and pass the quality control in this step, completely eliminating the anisotropy problem in the well area of the coring well Well T .

5. A method for describing remaining oil in side-tracking coring of a VSP well-seismic combined 4D development well according to claim 4, characterized in that, The specific steps of step S4 include the following steps: S113. Using the anisotropic depth migration results obtained in S112, and in combination with the research needs for the development of remaining oil in the target layer, determine the accurate sidetracking position of the coring well Well T and complete a 40-arm caliper log in the area 500 meters above the target layer; S114: Use the 40-arm caliper measurement results obtained in S113 to determine the casing damage situation of the wellbore. If the maximum casing deformation radius If the length of casing deformation less than or equal to 10% accounts for 5% of the measured length, it passes the quality control. If it fails the quality control, the wellbore needs to be repaired and the casing deformation degree should be measured again. S115. Collect the coring well Well T After the cementing operation, collect the CBL and VDL data and the interpretation results, and quality control the cementing quality in the upper 500-meter area of the target layer. If the cement bond quality reaches more than 99%, it passes the quality control, and record the depth area of the layer section that passes the quality control.

6. A method for describing remaining oil in side-tracking coring of a VSP well-seismic combined 4D development well according to claim 5, characterized in that, The specific steps of step S5 are as follows: S116. Within the depth range of the section that meets the construction quality control in S114 and S115, complete the design of the window-opening position. Determine the window-opening position according to casing damage and cementing quality. Generally, it should not be higher than 200 meters from the target layer. To prevent inaccurate target entry in the horizontal section, refer to the seismic anisotropic imaging results and geological understanding, and reserve a thickness of an oil reservoir group in advance as an alternative horizontal coring plan. S117. Based on the optimal sidetracking window-opening depth obtained in S116, complete the design of the deviation control plan, formulate a specific three-stage plan and drill string assembly, and complete the horizontal well trajectory design plan.

7. A device for describing remaining oil by side-tracking coring of a VSP well-seismic combined 4D development well, characterized in that, The device includes: An acquisition unit, which is used to collect well and seismic basic data and re-acquire 3D VSP data. A determination unit, which is used to perform the same process on the VSP data obtained during the initial development stage and the new drilling stage. Through attribute contrast analysis and pre-stack and post-stack inversion analysis, realize 4D monitoring of the remaining oil field and determine the remaining oil change area. A quality control unit, which is used to demarcate the target layer of the coring well with rich remaining oil, select the calibration wells around the coring well to update the anisotropic parameter field, complete the anisotropic depth quality control around the coring well, and realize iterative integrated anisotropic depth migration. A recording unit, which is used to determine the sidetracking azimuth of the coring well based on the anisotropic depth migration results, perform quality control on the casing deformation and cementing quality in the area 500 meters above the target layer, and record the depth area of the section that passes the quality control. A first design unit, which is used to complete the design of the sidetracking window-opening position, deviation control, and horizontal well trajectory plan of the development well based on the quality control results within the depth area of the quality control. A geological steering unit, which is used to complete the sidetracking window-opening construction based on the plan, and comprehensively utilize the anisotropic depth migration results and the geological model during drilling to complete integrated collaborative geological steering and realize the lateral entry of the horizontal section of the target layer into the target. A second design unit, which is used to complete the design of the small-hole coring plan according to the actual well conditions after entering the target. An operation unit, which is used to complete the small-hole pressure-maintaining coring operation based on the coring plan and in combination with the geological design requirements for the development of remaining oil. An implementation unit, which is used to guide the implementation of fine development geological research and remaining oil potential tapping based on the indoor remaining oil analysis and numerical simulation of the core taken from the sidetracked small hole.

8. An electronic device, characterized in that, It includes: One or more processors; A storage device, which is used to store one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement a method for describing remaining oil in a 4D development well with sidetracking and coring by combining VSP and well seismic as described in any one of claims 1-6.

9. A storage medium containing computer-executable instructions, characterized in that, The computer-executable instructions are used to execute a method for describing remaining oil in a 4D development well with sidetracking and coring by combining VSP and well seismic as described in any one of claims 1-6 when executed by a computer processor.

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