A method, device, medium and equipment for predicting the top depth of an oil layer
Through forward simulation and -90° phase shift attribute analysis, the impact of the partition layer on the depth of the oil layer is predicted, which solves the problem of predicting the top depth of the oil layer in the prior art, and improves the prediction accuracy and drilling efficiency.
Patent Information
- Application Number
- CN202510092098.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-21
- Publication Date
- 2025-04-08
AI Technical Summary
In the prior art, when predicting the top depth of the oil layer, especially in longitudinal strong heterogeneous reservoirs, it is difficult to accurately predict due to the influence of the interlayer, resulting in a deviation in the drilling landing depth and affecting oil field production.
Through forward simulation, different geological models were designed, the -90° phase shift attribute was extracted, the effect of the partition layer on the depth of the oil layer was analyzed, and the plane distribution characteristics of the partition layer were predicted, and the drilling landing position and depth were adjusted.
It improves the accuracy of the depth prediction at the top of the oil layer, reduces the loss of oil columns caused by depth deviation during drilling, and improves the development efficiency of the oil field.
Smart Images
Figure CN119777840A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of oil and gas exploration, and in particular relates to a method for predicting the top depth of an oil layer during a drilling phase. Background Art
[0002] With the continuous deepening of offshore development, horizontal well technology has become an effective means to improve the utilization of reserves, increase recovery rate and single well production capacity. Horizontal wells achieve the purpose of increasing single well production and development benefits by expanding the oil leakage area of the reservoir. To expand the oil leakage area, the key is to increase the oil layer drilling rate of horizontal well development.
[0003] There are two key stages in the drilling process of horizontal wells: landing of the horizontal well and tracking while drilling of the horizontal section. The success or failure of landing directly determines whether the horizontal section can be smoothly implemented. To do a good job of landing, we must first have an accurate prediction of the depth of the top of the oil layer. The most commonly used prediction method is the small layer comparison method, that is, selecting adjacent wells that are close and in the same sedimentary phase belt, and predicting the depth of the oil layer in this well by comparing layer by layer and using the formation velocity calibrated by the seismic calibration of the adjacent wells. For bottom water reservoirs, in order to prevent the bottom water cone from flooding the oil layer, the landing position is best at the top of the oil layer, and the vertical depth error is required to be less than 5m. If the actual drilling depth of the oil layer is deeper than the predicted oil layer depth, the oil column height will be lost, affecting the oil field production. For lateral strong heterogeneity formations, the lateral velocity changes in the work area will cause a deviation between the depth prediction and the actual landing depth. Velocity is the main reason for the depth prediction error. However, the main frequency of seismic data is often 15-35Hz. Depending on the depth of the formation, the seismic velocity is often 2000-5000m / s. The thickness of the formation that can be effectively resolved is often around 15m to 80m, which is much greater than the 5m vertical depth error requirement. Due to the limited seismic resolution, the reasons for the error between the predicted depth and the actual depth cannot be fully analyzed by only the lateral change of velocity.
[0004] For vertically highly heterogeneous reservoirs, due to the development of mudstone interlayers and physical interlayers, the oil content of the oil layer is uneven, and the presence of interlayers may also cause a deviation between the depth prediction and the actual depth of the top of the oil layer. Overall, there is little research in the industry on the impact of interlayers on the prediction of the top depth of the oil layer, and there is no mature geophysical method to analyze the impact of interlayers on the top depth of the oil layer, and then predict the top depth of the oil layer. Summary of the invention
[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a method for predicting the top depth of an oil layer, which aims to analyze the predicted depth of the top of the oil layer through forward simulation, solve the problem of predicting the top depth of the oil layer in the prior art, and provide technical support for drilling implementation.
[0006] To achieve the above object, the present invention adopts the following technical solutions:
[0007] In a first aspect, the present invention provides a method for predicting the top depth of an oil layer, comprising the following steps:
[0008] According to the geological characteristics of the study area, different geological models are designed for forward simulation, synthetic records are made, and -90° phase shift attributes are extracted from the synthetic records. The amplitude strength characteristics under the influence of interlayers and the numerical characteristics of the oil layer in the -90° phase shift attribute corresponding to the amplitude strength characteristics are analyzed. The time corresponding to the middle value of the synthetic record trough is compared with the time corresponding to the top of the thick oil layer in the forward simulation. The positional relationship between the actual oil layer depth and the predicted oil layer depth is preliminarily analyzed to determine the influence of interlayers on the actual oil layer depth.
[0009] Predict the interlayer plane distribution characteristics through -90° phase shift properties;
[0010] By using the planar distribution characteristics of interlayers and the influence of interlayers on the actual oil layer depth, the landing position is adjusted and the landing depth is predicted during the implementation of drilling landing.
[0011] As a preferred embodiment, the aforementioned “according to the geological characteristics of the study area, different geological models are designed for forward simulation, synthetic records are made, and -90° phase shift attributes are extracted from the synthetic records, the amplitude strength characteristics under the influence of the interlayer and the numerical characteristics of the oil layer in the -90° phase shift attribute corresponding to the amplitude strength characteristics are analyzed, the time corresponding to the middle value of the synthetic record trough is compared with the time corresponding to the top of the thick oil layer in the forward simulation, the positional relationship between the actual oil layer depth and the predicted oil layer depth is preliminarily analyzed, and the influence of the interlayer on the actual oil layer depth is determined” is specifically:
[0012] According to the geological characteristics of the study area, the following six geological models are designed: the first geological model - no interlayer; the second geological model - there are thin interlayers below the top interface of the forward design formation; the third geological model - there are poor oil layers and interlayers above the top interface of the forward design formation; the fourth geological model - there are interlayers above the top interface of the forward design formation and poor oil layers below; the fifth geological model - there are a small amount of interlayers below the top interface of the forward design formation; the sixth geological model - there is a positive cycle below the top interface of the forward design formation;
[0013] The time-depth relationship of the exploration well was used to perform forward simulation on the above six geological models, produce synthetic records, and extract -90° phase shift attributes. The time corresponding to the middle value of the trough of the synthetic record, the time corresponding to the top of the thick oil layer in the first to sixth geological models, and the seismic response characteristics under the influence of interlayers were compared, and the following results were obtained: ① The amplitude was the strongest when there was no interlayer, and the value of the oil layer in the -90° phase shift attribute was the lowest. The time corresponding to the top of the thick oil layer in the forward simulation was consistent with the time position corresponding to the middle value of the trough; ② There were thin interlayers and interlayers below the top interface of the forward-designed formation, the amplitude weakened, and the value of the oil layer in the -90° phase shift attribute was higher than that of the first geological model, the trough was pulled down, and the time corresponding to the top of the thick oil layer in the forward simulation was deeper than the time position corresponding to the middle value of the trough. In this case, the actual oil layer depth was deeper than the predicted oil layer depth; ③ There were poor oil layers and interlayers above the top of the oil layer, the amplitude weakened, and the oil layer in the -90° phase shift attribute was ④ There are interlayers above the top of the oil layer and poor oil layers below it, the amplitude becomes weaker, the value of the oil layer in the -90° phase shift attribute is higher than that in the first geological model, the trough is pulled down, and the time corresponding to the top of the thick oil layer in the forward simulation is deeper than the time position corresponding to the middle value of the trough; ⑤ There are a small number of interlayers below the top of the oil layer, the amplitude is weakened, the value of the oil layer in the -90° phase shift attribute is higher than that in the first geological model, the trough is pulled down, and the time corresponding to the top of the thick oil layer in the forward simulation is deeper than the time position corresponding to the middle value of the trough; ⑥ There is a positive cycle below the top of the oil layer, the amplitude is weakened, the value of the oil layer in the -90° phase shift attribute is higher than that in the first geological model, the trough is pulled down, and the time corresponding to the top of the thick oil layer in the forward simulation is deeper than the time position corresponding to the middle value of the trough; ⑥ There is a positive cycle below the top of the oil layer, the amplitude is weakened, the value of the oil layer in the -90° phase shift attribute is higher than that in the first geological model, the trough position is consistent with the position when a thick oil layer is developed below the top of the oil layer, and the time corresponding to the top of the thick oil layer in the forward simulation is consistent with the time position corresponding to the middle value of the trough.
[0014] Based on the forward simulation results above, we further conclude that the interlayers affect the actual oil layer depth: the development of interlayers will lead to a weakened amplitude, and the value of the oil layer in the -90° phase shift attribute is higher than when there are no interlayers. Therefore, the value of the oil layer in the -90° phase shift attribute can be used to predict the interlayer development area, and then predict the area where the actual oil layer depth may be deeper than the predicted oil layer depth.
[0015] As a preferred embodiment, the “prediction of interlayer plane distribution characteristics through -90° phase shift properties” is specifically:
[0016] Based on the influence of interlayers on the actual reservoir depth, the minimum attribute of the -90° phase shift attribute within the 10ms time window from the reservoir top to the reservoir top below the reservoir top is further extracted, which is the planar distribution feature of the interlayers.
[0017] As a preferred embodiment, the “application of the interlayer plane distribution characteristics and the influence of the interlayer on the actual oil layer depth to adjust the landing position and predict the landing depth during the drilling landing process” is specifically:
[0018] Conduct detailed well seismic calibration analysis of exploration wells to determine the time-depth relationship of exploration wells;
[0019] Use the time-depth relationship of the exploration well to predict the depth of the top surface of the oil layer in the development well;
[0020] Select a low value of the -90° phase shift attribute, and the amplitude is relatively stronger, that is, the horizontal well is landed at a plane position where interlayers are not developed, to ensure that good reservoirs are encountered first. Compare the relationship between the amplitude of the development well to be landed and the exploration well. If the amplitude is not much different, ignoring the lateral change of velocity, it is inferred that the actual oil layer depth is not much different from the predicted depth of the top surface of the oil layer of the development well;
[0021] Compare the relationship between the amplitude of the development well to be landed and the exploration well. If the amplitude of the development well is weak, then the well may have a positive cycle or may have interlayers: if a positive cycle is drilled during the drilling process, that is, the natural gamma curve and the resistivity curve are bell-shaped, it is speculated that the actual oil layer depth is not much different from the predicted oil layer depth; if the development well to be landed does not develop a positive cycle, the natural gamma curve and the resistivity curve show that interlayers are drilled, and it is speculated that the actual oil layer depth is deeper than the predicted oil layer depth. The weaker the amplitude, the more obvious the depth deepening.
[0022] As a preferred embodiment, the “applying the time-depth relationship of the exploration well to predict the depth of the top surface of the oil layer of the development well” is specifically:
[0023] When the lateral velocity in the study area is constant, the exploration well and the development well have the same time-depth relationship;
[0024] According to the seismic interpretation results, find the time corresponding to the middle value of the trough of the top of the oil layer;
[0025] By applying the time-depth relationship of the exploration well, the depth corresponding to the time corresponding to the middle value of the trough at the top of the oil layer is obtained, which is the depth of the top surface of the oil layer in the development well.
[0026] In a second aspect, the present invention provides a device for predicting the top depth of an oil layer, comprising:
[0027] The first processing unit is used to design different geological models for forward simulation according to the geological characteristics of the study area, produce synthetic records, and extract -90° phase shift attributes from the synthetic records, analyze the amplitude strength characteristics under the influence of interlayers and the numerical characteristics of the oil layer in the -90° phase shift attribute corresponding to the amplitude strength characteristics, compare the time corresponding to the middle value of the synthetic record trough with the time corresponding to the top of the thick oil layer in the forward simulation, preliminarily analyze the positional relationship between the actual oil layer depth and the predicted oil layer depth, and determine the influence of interlayers on the actual oil layer depth;
[0028] The second processing unit is used to predict the interlayer plane distribution characteristics through the -90° phase shift attribute;
[0029] The third processing unit is used to adjust the landing position and predict the landing depth during the drilling landing implementation process by applying the planar distribution characteristics of the interlayer and the influence of the interlayer on the actual oil layer depth.
[0030] In a third aspect, the present invention provides a computer-readable storage medium, characterized in that a computer program is stored therein, and the computer program is executed by a processor to control the device where the processor is located to implement the steps of the method for predicting the top depth of the oil layer described in the first aspect of the present invention.
[0031] In a fourth aspect, the present invention provides a computer device, characterized in that it comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the method for predicting the top depth of the oil layer described in the first aspect of the present invention are implemented.
[0032] The present invention adopts the above technical solution, which has the following advantages:
[0033] 1. The method for predicting the depth of the top of the oil layer provided by the present invention can apply forward simulation analysis to obtain the influence of the interlayer on the predicted depth of the top of the oil layer, and use the planar distribution characteristics of the interlayer predicted by the -90° phase shift attribute to adjust the landing position and predict the landing depth during the implementation of drilling landing, thereby solving the problem of predicting the depth of the top of the oil layer in the prior art.
[0034] 2. The present invention can provide effective technical support for the implementation of horizontal well landing in the development stage through fine characterization. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Throughout the accompanying drawings, the same reference numerals are used to represent the same components. In the accompanying drawings:
[0036] Figure 1 A flow chart of a method for predicting the top depth of an oil layer provided by an embodiment of the present invention;
[0037] Figure 2 Forward simulation and -90° phase shift diagram for different geological models. DETAILED DESCRIPTION
[0038] In order to make the purpose, technical scheme and advantages of the present invention clearer, the specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.
[0039] The method for predicting the top depth of the oil layer provided by the present invention includes: designing different geological models for forward simulation according to the geological characteristics of the study area, making synthetic records, and extracting -90° phase shift attributes from the synthetic records, analyzing the amplitude strength characteristics under the influence of interlayers and the corresponding numerical characteristics of the oil layer in the -90° phase shift attributes, comparing the time corresponding to the middle value of the synthetic record trough with the time corresponding to the top of the thick oil layer in the forward simulation, preliminarily analyzing the positional relationship between the actual oil layer depth and the predicted oil layer depth, and determining the influence of the interlayer on the actual oil layer depth; predicting the planar distribution characteristics of the interlayer through the -90° phase shift attributes; using the planar distribution characteristics of the interlayer and the influence of the interlayer on the actual oil layer depth, adjusting the landing position and predicting the landing depth during the implementation of drilling landing. The present invention can solve the problem of predicting the top depth of the oil layer in the prior art and provide technical support for drilling implementation.
[0040] A method and device for predicting the top depth of an oil layer provided by an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.
[0041] Embodiment 1:
[0042] See also Figure 1 The present embodiment provides a method for predicting the top depth of an oil layer, comprising the following steps:
[0043] S100. According to the geological characteristics of the study area, different geological models are designed for forward simulation, synthetic records are made, and -90° phase shift attributes are extracted from the synthetic records. The amplitude strength characteristics under the influence of interlayers and the numerical characteristics of the oil layer in the -90° phase shift attribute corresponding to the amplitude strength characteristics are analyzed. The time corresponding to the middle value of the synthetic record trough (i.e. Figure 2 The predicted oil layer depth in the forward modeling) corresponds to the time corresponding to the top of the thick oil layer (i.e. Figure 2 The actual oil layer depth in the prediction is compared with the actual oil layer depth in the prediction, and the positional relationship between the actual oil layer depth and the predicted oil layer depth is preliminarily analyzed to determine the influence of the interlayer on the actual oil layer depth, specifically:
[0044] S101.Please refer to Figure 2According to the geological characteristics of the study area, the following six geological models are designed: ① No interlayer; ② There are thin interlayers below the top interface of the forward design formation; ③ There are poor oil layers and interlayers above the top interface of the forward design formation; ④ There are interlayers above the top interface of the forward design formation and poor oil layers below; ⑤ There are a small amount of interlayers below the top interface of the forward design formation; ⑥ There is a positive cycle below the top interface of the forward design formation (i.e., sandstone with good physical properties at the bottom and poor physical properties at the top). The sandstone velocity in this example is 2000m / s and the density is 2.4g / cm 3 , mudstone velocity 2200m / s, density 2.8g / cm 3 .
[0045] S102. Using the time-depth relationship of the exploration well, the six geological models mentioned above were forward simulated, synthetic records were made, and -90° phase shift attribute extraction was carried out. The time corresponding to the middle value of the synthetic record trough, the time corresponding to the top of the thick oil layer in the ①-⑥ geological models, and the seismic response characteristics under the influence of interlayers were compared, and the following results were obtained: ① The amplitude of the non-interlayer was the strongest, and the value of the oil layer in the -90° phase shift attribute was the lowest. The time corresponding to the top of the thick oil layer in the forward simulation was consistent with the time position corresponding to the middle value of the trough. In this case, the predicted oil layer depth was consistent with the actual oil layer depth; ② There was a thin interlayer below the top interface of the formation designed by the forward modeling. Interlayer, the amplitude becomes weaker, the value of the oil layer in the -90° phase shift attribute is higher than that in the first geological model, the trough is pulled down, the time corresponding to the top of the thick oil layer in the forward simulation is deeper than the time position corresponding to the middle value of the trough, and the depth of this embodiment is 3-4ms. After the time-to-depth conversion is performed according to the formation velocity of 2000m / s, the time of 3-4ms corresponds to the depth of 3-4m. In this case, the actual oil layer depth will be 3-4m deeper than the predicted oil layer depth; ③ There are poor oil layers and interlayers above the top of the oil layer, the amplitude becomes weaker, the value of the oil layer in the -90° phase shift attribute is higher than that in the first geological model, the trough is moved up, and the time corresponding to the top of the thick oil layer in the forward simulation is deeper than the trough. The time position corresponding to the middle value is deep, and in this embodiment it is 1-2ms deep, corresponding to a depth of 1-2m. In this case, the actual oil layer depth will be 1-2m deeper than the predicted oil layer depth; ④ There are interlayers above the top of the oil layer and poor oil layers below, the amplitude becomes weaker, and the value of the oil layer in the -90° phase shift attribute is higher than that of the ① geological model, the trough is pulled down, and the time corresponding to the top of the thick oil layer in the forward simulation is deeper than the time position corresponding to the middle value of the trough, and in this embodiment it is 2-3ms deep, corresponding to a depth of 2-3m. In this case, the actual oil layer depth will be 2-3m deeper than the predicted oil layer depth; ⑤ There are a small amount of interlayers below the top of the oil layer, the amplitude is weakened, and the -90° phase The value of the oil layer in the phase shift attribute is higher than that in the first geological model, the trough is pulled down (not obvious), the time corresponding to the top of the thick oil layer in the forward simulation is deeper than the time position corresponding to the middle value of the trough, and in this embodiment it is 2-3ms deep. In this case, the actual oil layer depth will be 2-3m deeper than the predicted oil layer depth; ⑥ There is a positive cycle below the top of the oil layer, and the amplitude is weakened. The value of the oil layer in the -90° phase shift attribute is higher than that in the first geological model, the trough position is consistent with the position when a thick oil layer is developed below the top of the oil layer, the time corresponding to the top of the thick oil layer in the forward simulation is consistent with the time position corresponding to the middle value of the trough, and in this case the predicted oil layer depth is consistent with the actual oil layer depth.
[0046] S103. Based on the forward simulation results in step S102, the influence of interlayers on the actual oil layer depth can be further derived: (1) When the lateral velocity remains unchanged, interlayers will cause the actual oil layer depth to be deeper than the predicted oil layer depth, especially when interlayers are developed in the lower part of the oil layer top, the influence is greater; (2) The development of interlayers will cause the amplitude to weaken, and the value of the oil layer in the -90° phase shift attribute is higher than when there is no interlayer. Therefore, the value of the oil layer in the -90° phase shift attribute can be used to predict the interlayer development area, and then predict the area where the actual oil layer depth may be deeper than the predicted oil layer depth; (3) The development of interlayers will not cause the actual oil layer depth to be shallower than the predicted oil layer depth. The situation where the actual oil layer depth is shallower than the predicted oil layer depth often requires adjustment of the time-depth relationship, which is caused by the change in regional lateral velocity.
[0047] S200. Predict the interlayer plane distribution characteristics through the -90° phase shift attribute, specifically:
[0048] Based on the influence of interlayers on the actual oil layer depth obtained in step S103 (2), the minimum attribute of the -90° phase shift attribute within the time window range of 10ms from the oil layer top to the oil layer top is further extracted, which is the interlayer plane distribution feature. The lower the value, the lower the development degree of the interlayer; otherwise, the development degree of the interlayer is high.
[0049] S300. Using the planar distribution characteristics of interlayers and the influence of interlayers on the actual oil layer depth, during the implementation of drilling landing, the landing position is adjusted and the landing depth is predicted, specifically:
[0050] S301. Carry out detailed well seismic calibration analysis of the exploration well to determine the time-depth relationship of the exploration well;
[0051] S302. Use the time-depth relationship of the exploration well to predict the depth of the top surface of the oil layer in the development well, specifically:
[0052] S3021. When the lateral velocity in the study area remains constant, the exploration well and the development well have the same time-depth relationship;
[0053] S3022. According to the seismic interpretation results, find the time corresponding to the middle value of the trough of the top surface of the oil layer;
[0054] S3023. Apply the time-depth relationship of the exploration well to obtain the depth corresponding to the time corresponding to the middle value of the trough at the top of the oil layer, which is the depth of the top surface of the oil layer of the development well.
[0055] S303. Prioritize the low value of the -90° phase shift attribute, where the amplitude is relatively stronger, i.e., the plane position where the interlayer is not developed, to implement the horizontal well landing, to ensure that the good reservoir is drilled first, and compare the relationship between the amplitude of the development well to be landed and the exploration well. If the amplitude is not much different, ignoring the lateral change of the velocity, it is inferred that the actual oil layer depth is not much different from the depth of the top surface of the oil layer of the development well predicted in step S302;
[0056] S304. Compare the relationship between the amplitude of the development well to be landed and the exploration well. If the amplitude of the development well is weak, then the well may be a positive cycle or may have interlayers: if a positive cycle is drilled during the drilling process, that is, the GR (natural gamma curve) and the resistivity curve are bell-shaped, it is speculated that the actual oil layer depth is not much different from the predicted oil layer depth; if the development well to be landed does not develop a positive cycle, the GR and resistivity curves show that interlayers are encountered, and it is speculated that the actual oil layer depth is deeper than the predicted oil layer depth. The weaker the amplitude, the more obvious the deepening of the depth. In this case, the inclination should be reduced first, and the inclination should be increased rapidly after drilling to the oil layer to avoid the loss of horizontal distance in stabilizing the inclination and finding the layer, which will affect the oil field production.
[0057] Embodiment 2:
[0058] The above-mentioned embodiment 1 provides a method for predicting the depth of the top of an oil layer. Correspondingly, this embodiment provides a device for predicting the depth of the top of an oil layer. The prediction device provided in this embodiment can implement the prediction method of embodiment 1, and the prediction device can be implemented by software, hardware, or a combination of software and hardware. For example, the prediction device may include integrated or separate functional modules or functional units to execute the corresponding steps in each method of embodiment 1. Since the prediction device of this embodiment is basically similar to the method embodiment, the description process of this embodiment is relatively simple. For the relevant parts, please refer to the partial description of embodiment 1. The prediction device of this embodiment is only schematic.
[0059] The device for predicting the top depth of an oil layer provided in this embodiment includes:
[0060] The first processing unit is used to design different geological models for forward simulation according to the geological characteristics of the study area, produce synthetic records, and extract -90° phase shift attributes from the synthetic records, analyze the amplitude strength characteristics under the influence of interlayers and the numerical characteristics of the oil layer in the -90° phase shift attribute corresponding to the amplitude strength characteristics, compare the time corresponding to the middle value of the synthetic record trough with the time corresponding to the top of the thick oil layer in the forward simulation, preliminarily analyze the positional relationship between the actual oil layer depth and the predicted oil layer depth, and determine the influence of interlayers on the actual oil layer depth;
[0061] The second processing unit is used to predict the interlayer plane distribution characteristics through the -90° phase shift attribute;
[0062] The third processing unit is used to adjust the landing position and predict the landing depth during the drilling landing implementation process by applying the planar distribution characteristics of the interlayer and the influence of the interlayer on the actual oil layer depth.
[0063] Embodiment 3:
[0064] This embodiment provides a processing device for implementing the method for predicting the top depth of the oil layer provided in this embodiment 1. The processing device can be a processing device for a client, such as a mobile phone, a laptop computer, a tablet computer, a desktop computer, etc., to execute the method of embodiment 1.
[0065] The processing device includes a processor, a memory, a communication interface and a bus, and the processor, the memory and the communication interface are connected through the bus to complete mutual communication. The memory stores a computer program that can be run on the processor, and the processor executes the method for predicting the top depth of the oil layer provided in this embodiment 1 when running the computer program.
[0066] Preferably, the memory may be a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk memory.
[0067] Preferably, the processor may be a central processing unit (CPU), a digital signal processor (DSP) or other general-purpose processors of various types, which are not limited here.
[0068] Embodiment 4:
[0069] The method for predicting the oil layer top depth of the present embodiment 1 can be specifically implemented as a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for executing the method described in the present embodiment 1.
[0070] Computer readable storage media can be tangible devices that hold and store instructions used by instruction execution devices. Computer readable storage media can be, for example, but not limited to, electronic storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any combination thereof.
[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.
Claims
1. A method for predicting the depth of the top of an oil layer, characterized in that: The following steps are involved: According to the geological characteristics of the study area, different geological models are designed for forward simulation, synthetic records are made, and -90° phase shift attributes are extracted from the synthetic records. The amplitude strength characteristics under the influence of interlayers and the numerical characteristics of the oil layer in the -90° phase shift attribute corresponding to the amplitude strength characteristics are analyzed. The time corresponding to the middle value of the synthetic record trough is compared with the time corresponding to the top of the thick oil layer in the forward simulation. The positional relationship between the actual oil layer depth and the predicted oil layer depth is preliminarily analyzed to determine the influence of interlayers on the actual oil layer depth. Predict the interlayer plane distribution characteristics through -90° phase shift properties; By using the planar distribution characteristics of interlayers and the influence of interlayers on the actual oil layer depth, the landing position is adjusted and the landing depth is predicted during the implementation of drilling landing.
2. The prediction method according to claim 1, characterized in that: The "design of different geological models for forward simulation according to the geological characteristics of the study area, making synthetic records, extracting -90° phase shift attributes from the synthetic records, analyzing the amplitude strength characteristics under the influence of interlayers and the numerical characteristics of the oil layer in the -90° phase shift attributes corresponding to the amplitude strength characteristics, comparing the time corresponding to the middle value of the synthetic record trough with the time corresponding to the top of the thick oil layer in the forward simulation, preliminarily analyzing the positional relationship between the actual oil layer depth and the predicted oil layer depth, and determining the influence of interlayers on the actual oil layer depth" is specifically: According to the geological characteristics of the study area, the following six geological models are designed: the first geological model - no interlayer; the second geological model - there are thin interlayers below the top interface of the forward design formation; the third geological model - there are poor oil layers and interlayers above the top interface of the forward design formation; the fourth geological model - there are interlayers above the top interface of the forward design formation and poor oil layers below; the fifth geological model - there are a small amount of interlayers below the top interface of the forward design formation; the sixth geological model - there is a positive cycle below the top interface of the forward design formation; The time-depth relationship of the exploration well was used to perform forward simulation on the above six geological models, produce synthetic records, and extract -90° phase shift attributes. The time corresponding to the middle value of the trough of the synthetic record, the time corresponding to the top of the thick oil layer in the first to sixth geological models, and the seismic response characteristics under the influence of interlayers were compared, and the following results were obtained: ① The amplitude was the strongest when there was no interlayer, and the value of the oil layer in the -90° phase shift attribute was the lowest. The time corresponding to the top of the thick oil layer in the forward simulation was consistent with the time position corresponding to the middle value of the trough; ② There were thin interlayers and interlayers below the top interface of the forward-designed formation, the amplitude weakened, and the value of the oil layer in the -90° phase shift attribute was higher than that of the first geological model, the trough was pulled down, and the time corresponding to the top of the thick oil layer in the forward simulation was deeper than the time position corresponding to the middle value of the trough. In this case, the actual oil layer depth was deeper than the predicted oil layer depth; ③ There were poor oil layers and interlayers above the top of the oil layer, the amplitude weakened, and the oil layer in the -90° phase shift attribute was ④ There are interlayers above the top of the oil layer and poor oil layers below it, the amplitude becomes weaker, the value of the oil layer in the -90° phase shift attribute is higher than that in the first geological model, the trough is pulled down, and the time corresponding to the top of the thick oil layer in the forward simulation is deeper than the time position corresponding to the middle value of the trough; ⑤ There are a small number of interlayers below the top of the oil layer, the amplitude is weakened, the value of the oil layer in the -90° phase shift attribute is higher than that in the first geological model, the trough is pulled down, and the time corresponding to the top of the thick oil layer in the forward simulation is deeper than the time position corresponding to the middle value of the trough; ⑥ There is a positive cycle below the top of the oil layer, the amplitude is weakened, the value of the oil layer in the -90° phase shift attribute is higher than that in the first geological model, the trough is pulled down, and the time corresponding to the top of the thick oil layer in the forward simulation is deeper than the time position corresponding to the middle value of the trough; Based on the forward simulation results above, we further conclude that the interlayers affect the actual oil layer depth: the development of interlayers will lead to a weakened amplitude, and the value of the oil layer in the -90° phase shift attribute is higher than when there are no interlayers. Therefore, the value of the oil layer in the -90° phase shift attribute can be used to predict the interlayer development area, and then predict the area where the actual oil layer depth may be deeper than the predicted oil layer depth.
3. The prediction method according to claim 2, characterized in that: The “prediction of interlayer plane distribution characteristics through -90° phase shift properties” is specifically: Based on the influence of interlayers on the actual reservoir depth, the minimum attribute of the -90° phase shift attribute within the 10ms time window from the reservoir top to the reservoir top below the reservoir top is further extracted, which is the planar distribution feature of the interlayers.
4. The prediction method according to claim 3, characterized in that: The aforementioned "using the planar distribution characteristics of interlayers and the influence of interlayers on the actual oil layer depth to adjust the landing position and predict the landing depth during the implementation of drilling landing" is specifically: Conduct detailed well seismic calibration analysis of exploration wells to determine the time-depth relationship of exploration wells; Use the time-depth relationship of the exploration well to predict the depth of the top surface of the oil layer in the development well; Select a low value of the -90° phase shift attribute, and the amplitude is relatively stronger, that is, the horizontal well is landed at a plane position where interlayers are not developed, to ensure that good reservoirs are encountered first. Compare the relationship between the amplitude of the development well to be landed and the exploration well. If the amplitude is not much different, ignoring the lateral change of velocity, it is inferred that the actual oil layer depth is not much different from the predicted depth of the top surface of the oil layer of the development well; Compare the relationship between the amplitude of the development well to be landed and the exploration well. If the amplitude of the development well is weak, then the well may have a positive cycle or may have interlayers: if a positive cycle is drilled during the drilling process, that is, the natural gamma curve and the resistivity curve are bell-shaped, it is speculated that the actual oil layer depth is not much different from the predicted oil layer depth; if the development well to be landed does not develop a positive cycle, the natural gamma curve and the resistivity curve show that interlayers are drilled, and it is speculated that the actual oil layer depth is deeper than the predicted oil layer depth. The weaker the amplitude, the more obvious the depth deepening.
5. The prediction method according to claim 4, characterized in that: The aforementioned "using the time-depth relationship of the exploration well to predict the depth of the top surface of the oil layer of the development well" is specifically: When the lateral velocity in the study area is constant, the exploration well and the development well have the same time-depth relationship; According to the seismic interpretation results, find the time corresponding to the middle value of the trough of the top of the oil layer; By applying the time-depth relationship of the exploration well, the depth corresponding to the time corresponding to the middle value of the trough at the top of the oil layer is obtained, which is the depth of the top surface of the oil layer in the development well.
6. A device for predicting the top depth of an oil layer, characterized in that: include: The first processing unit is used to design different geological models for forward simulation according to the geological characteristics of the study area, produce synthetic records, and extract -90° phase shift attributes from the synthetic records, analyze the amplitude strength characteristics under the influence of interlayers and the numerical characteristics of the oil layer in the -90° phase shift attribute corresponding to the amplitude strength characteristics, compare the time corresponding to the middle value of the synthetic record trough with the time corresponding to the top of the thick oil layer in the forward simulation, preliminarily analyze the positional relationship between the actual oil layer depth and the predicted oil layer depth, and determine the influence of interlayers on the actual oil layer depth; The second processing unit is used to predict the interlayer plane distribution characteristics through the -90° phase shift attribute; The third processing unit is used to adjust the landing position and predict the landing depth during the drilling landing implementation process by applying the planar distribution characteristics of the interlayer and the influence of the interlayer on the actual oil layer depth.
7. A computer-readable storage medium, characterized in that: A computer program is stored, and the computer program is executed by a processor to control the device where the processor is located to implement the steps of the method for predicting the top depth of the oil layer as described in any one of claims 1 to 5.
8. A computer device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method for predicting the top depth of an oil layer as claimed in any one of claims 1 to 5 when executing the computer program.