A rapid evaluation method for the development effect of flow field conversion in water-flooding reservoirs

Abstract

The present invention belongs to the field of oil and gas field development, and relates to a method for rapid evaluation of the development effect of a water-drive oil reservoir transition field. The method comprises: collecting geological development data of a target oil reservoir, establishing a streamline simulation model for the development of a target oil reservoir transition field; carrying out streamline numerical simulation of the development of a target oil reservoir transition field, and obtaining the instantaneous flow field distribution of the streamline simulation model before and after the transition field; extracting the position data of each point on each streamline in the instantaneous flow field distribution before and after the transition field, as well as the fluid property data on each streamline; calculating a rapid evaluation index for the development effect of a water-drive oil reservoir transition field; and judging whether the water-drive oil reservoir transition field measures are effective. The evaluation method of the present invention is short in time and highly efficient, and can be directly used for the evaluation of the development effect of a water-drive oil reservoir transition field.

Description

Technical Field

[0001] The invention belongs to the field of oil and gas field development and relates to a method for quickly evaluating the development effect of a water-driven oil reservoir flow field. Background Art

[0002] Oilfield development practice shows that water-driven oilfield development can achieve a higher ultimate recovery rate. At present, most oil reservoirs have entered the development stage of ultra-high water cut, but the overall recovery rate is low. Therefore, some oil fields have improved the recovery rate by adjusting the flow field distribution of the reservoir, changing the streamline displacement direction and swept volume. However, how to quickly and accurately quantitatively evaluate the development effect of such adjusted reservoirs and realize the efficient development of the reservoirs is an important concern of oilfield managers and research topics for scholars.

[0003] Chinese invention patent CN104794361B discloses a comprehensive evaluation method for water-flooding reservoir development effects. The method groups a number of water-flooding development effect evaluation indicators from the perspective of fuzzy theory, conducts a multi-level evaluation layer by layer, and uses multiple fuzzy operators to conduct a comprehensive analysis of the evaluation results to obtain the final comprehensive evaluation results of water-flooding development effects.

[0004] Chinese patent application CN107038516A discloses a quantitative evaluation method for water flooding development effect of medium permeability complex fault block oil reservoir. The method selects factors affecting water flooding development of medium permeability complex fault block oil reservoir, determines evaluation factors with relative independence and operability, establishes an evaluation grade membership matrix, and realizes quantitative evaluation of water flooding development effect of medium permeability complex oil reservoir.

[0005] Chinese patent application CN110410046A discloses a method for evaluating the effect of water flooding development in fracture-cavity carbonate reservoirs. The method scores the evaluation parameters of the target reservoir and draws a radar chart, calculates the fan-shaped filling area and perimeter of each indicator in the radar chart, and obtains a comprehensive evaluation function value, thereby quantitatively evaluating the effect of water flooding development in the reservoir.

[0006] However, the existing evaluation methods have the following problems: ① Most of the current water drive development evaluation methods are based on the post-evaluation of the static and dynamic parameters of the reservoir, which are difficult to be directly used to evaluate the development effect of the water drive reservoir flow field transition; ② The current water drive oil field flow field development effect evaluation method based on reservoir numerical simulation cannot directly characterize the displacement change characteristics of the underground flow field, and the evaluation efficiency is too dependent on the length of the simulation evaluation time and the calculation efficiency of the reservoir numerical simulator. The evaluation time cost for actual problems in large-scale mines is extremely high, and it is difficult to meet the needs of rapid on-site design. Summary of the invention

[0007] In order to solve the above problems, the present invention provides a method for quickly evaluating the development effect of water-flooding oil reservoir flow field transition, and the method of the present invention can be directly used for evaluating the development effect of water-flooding oil reservoir flow field transition.

[0008] To achieve the above object, the present invention adopts the following technical solutions:

[0009] A method for quickly evaluating the development effect of a water-flooding reservoir flow field is provided, the method comprising the following steps:

[0010] Step 1: Collect geological development data of the target reservoir and establish a streamline simulation model for flow field development of the target reservoir;

[0011] Step 2, carry out streamline numerical simulation of target reservoir flow field development, and obtain the instantaneous flow field distribution of the streamline simulation model before and after the flow field is switched;

[0012] Step 3, extracting the position data of each point on each streamline in the instantaneous flow field distribution before and after the flow field is switched, as well as the fluid property data on each streamline;

[0013] Step 4, calculating the rapid evaluation index of the development effect of the water drive reservoir flow field;

[0014] Step 5: Determine whether the flow field conversion measures for water drive reservoirs are effective.

[0015] To achieve the above object, the present invention can also adopt the following technical solutions:

[0016] In step 1, the geological development data collected include: reservoir structure, permeability, porosity, effective thickness, saturation, pressure distribution, water phase density and viscosity, oil phase density and viscosity, relative permeability curve, injection well and production well trajectory, perforation location, well network form, production well monthly oil production, monthly water production, injection well monthly water injection, production time step, flow field transition timing, flow field transition method.

[0017] A data body file of a streamline simulation model for target reservoir flow field development is established using a streamline simulator. The streamline simulator includes but is not limited to the FrontSim streamline simulator.

[0018] In step 2, the instantaneous flow field distribution is obtained as a prediction within 1 simulation time step.

[0019] In step 3, the extracted fluid attribute data include: oil phase saturation attribute data flowing through each point on each streamline, water phase saturation attribute data flowing through each point on each streamline, oil phase flow rate attribute data flowing through each point on each streamline, and water phase flow rate attribute data flowing through each point on each streamline.

[0020] In step 4, the rapid evaluation index of the water drive reservoir flow field development effect is calculated using the following formula:

[0021]

[0022] Where: ΔF is the rapid evaluation index value of the water drive reservoir flow field development effect; S otn is the oil phase saturation attribute data at the nth point on the tth streamline; S wtn is the water phase saturation attribute data at the nth point on the tth streamline; ν otn is the oil phase flow rate attribute data at the nth point on the tth streamline; ν wtn is the water phase flow rate attribute data at the nth point on the tth streamline; j t is the total number of points on the tth streamline; L is the total number of streamlines; subscript a represents after adjustment, and subscript b represents before adjustment.

[0023] In step 5, the effectiveness of the flow field conversion measures for water drive reservoirs is determined based on the value calculated in step 4. If the value obtained is greater than 0, it indicates that the development effect after the flow field conversion is improved compared with that before the flow field conversion, and the flow field conversion measures are effective.

[0024] Compared with the prior art, the beneficial effect of the present invention is that based on the instantaneous streamline simulation results before and after the flow field of the water-drive oil reservoir is switched, the long-term development effect of the water-drive oil reservoir after the flow field is switched is quantitatively evaluated by calculating the changes in the rapid evaluation index of the development effect of the flow field of the water-drive oil reservoir. The evaluation method of the present invention is fast and efficient. It can evaluate the long-term development effect of the flow field of the water-drive oil reservoir by simply judging the change of ΔF within one simulation time step. The evaluation method of the present invention can be directly used for the evaluation of the development effect of the flow field of the water-drive oil reservoir, and has important guiding significance for the evaluation of the development effect of the water-drive oil reservoir and the design of the scheme for implementing the flow field adjustment measures. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0026] Figure 1 It is a technical route frame diagram of a method for rapid evaluation of the development effect of water drive reservoir flow field in a specific embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the injection and production well pattern before the flow field is transferred;

[0028] Figure 3 This is a schematic diagram of the injection-production well pattern after the flow field is changed;

[0029] Figure 4 A schematic diagram for reading streamline characterization parameters;

[0030] Figure 5 This is a graph showing the cumulative oil production changes before and after the flow field is changed. DETAILED DESCRIPTION

[0031] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0032] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations and / or combinations thereof.

[0033] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with specific embodiments.

[0034] Example

[0035] like Figure 1 As shown in the figure, the rapid evaluation method for the development effect of the water drive reservoir flow field includes the following steps:

[0036] Step S10, collecting geological development data of the target oil reservoir and establishing a streamline simulation model for flow field development of the target oil reservoir.

[0037] The geological development data collected include: reservoir structure, permeability, porosity, effective thickness, saturation, pressure distribution, water phase density and viscosity, oil phase density and viscosity, relative permeability curve, injection well and production well trajectory, perforation location, well pattern, monthly oil production of production well, monthly water production, monthly water injection of injection well, production time step, flow field transition timing, flow field transition method:

[0038] The streamline simulator is used to establish the data volume file of the streamline simulation model for the target reservoir flow field development.

[0039] Step S20, using a streamline simulator, conduct streamline numerical simulation of the target reservoir flow field transition development, and obtain the instantaneous flow field distribution of the streamline simulation model before and after the flow field transition.

[0040] The data body file of the streamline simulation model is used to call the streamline simulator to obtain the instantaneous flow field distribution of the streamline simulation model before and after the flow field is switched.

[0041] Get the instantaneous flow field distribution as a prediction within 1 simulation time step.

[0042] Step S30, extracting the position data of each point on each streamline in the instantaneous flow field distribution before and after the flow field is switched, as well as the fluid property data on each streamline:

[0043] The fluid property data on each streamline include oil phase saturation property data flowing through each point on each streamline, water phase saturation property data flowing through each point on each streamline, oil phase flow rate property data flowing through each point on each streamline, and water phase flow rate property data flowing through each point on each streamline.

[0044] Step S40, calculating the rapid evaluation index of the water drive reservoir flow field development effect, using the following formula:

[0045]

[0046] Where: ΔF is the rapid evaluation index value of the water drive reservoir flow field development effect; S otn is the oil phase saturation attribute data at the nth point on the tth streamline; S wtn is the water phase saturation attribute data at the nth point on the tth streamline; ν otn is the oil phase flow rate attribute data at the nth point on the tth streamline; ν wtn is the water phase flow rate attribute data at the nth point on the tth streamline; j t is the total number of points on the tth streamline; L is the total number of streamlines; subscript a represents after adjustment, and subscript b represents before adjustment.

[0047] Step S50, judging whether the water drive reservoir flow field conversion measures are effective:

[0048] If the rapid evaluation index value ΔF of the development effect of the flow field transition of the water-drive oil reservoir is greater than 0, it indicates that the development effect after the flow field transition is improved compared with that before the flow field transition, that is, the flow field transition measures of the water-drive oil reservoir are effective; if the rapid evaluation index value ΔF of the development effect of the flow field transition of the water-drive oil reservoir is less than or equal to 0, it indicates that the development effect after the flow field transition is not improved compared with that before the flow field transition, that is, the flow field transition measures of the water-drive oil reservoir are ineffective.

[0049] Application Examples

[0050] Using the method described in the embodiment of the present invention, as follows Figure 2 and Figure 3 The flow field is transformed as shown in the figure, and the streamline simulation model is established. Figure 2 When the injection-production well pattern before the diversion field is produced to a water cut of 98%, it is converted to Figure 3 The injection-production well pattern shown continues to produce after the flow field is switched.

[0051] Fluid property data such as Figure 4 As shown, it includes: the oil phase saturation attribute data S at the nth point on the tth streamline otn , the water phase saturation attribute data S at the nth point on the tth streamline wtn , the oil phase flow rate attribute data v at the nth point on the tth streamline otn, the water phase flow rate attribute data v at the nth point on the tth streamline wtn .

[0052] The final calculated ΔF value is 0.021, that is, ΔF>0, indicating that the development effect after the flow field is changed is better than that before the flow field is changed, and the flow field change measures are effective. Figure 5 It is known that Figure 2 The well pattern flow field is adjusted to Figure 3 The cumulative oil production after the nine-point well pattern is shown to be higher than the cumulative oil production without flow field adjustment for a long time, proving that the adjustment is effective. It can be concluded that the effect evaluation method of the present invention is accurate in prediction.

[0053] From the above analysis, it can be seen that the method described in the embodiment of the present invention can evaluate the long-term development effect of the water drive reservoir flow field by simply judging the change of ΔF within one simulation time step; this method is time-saving, efficient, and has high evaluation result accuracy.

[0054] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for rapid evaluation of flow field development effect of water drive reservoir, characterized in that: The method comprises the following steps: Step 1: Collect geological development data of the target reservoir and establish a streamline simulation model for flow field development of the target reservoir; Step 2, carry out streamline numerical simulation of target reservoir flow field development, and obtain the instantaneous flow field distribution of the streamline simulation model before and after the flow field is switched; Step 3, extracting the position data of each point on each streamline in the instantaneous flow field distribution before and after the flow field is switched, as well as the fluid property data on each streamline; Step 4, calculating the rapid evaluation index of the development effect of the water drive reservoir flow field; Step 5, determining whether the water drive reservoir flow field conversion measures are effective; In step 4, the rapid evaluation index of the water drive reservoir flow field development effect is calculated using the following formula: Where: ΔF is the rapid evaluation index value of the water drive reservoir flow field development effect; S otn is the oil phase saturation attribute data at the nth point on the tth streamline; S wtn is the water phase saturation attribute data at the nth point on the tth streamline; ν otn is the oil phase flow rate attribute data at the nth point on the tth streamline; ν wtn is the water phase flow rate attribute data at the nth point on the tth streamline; j t is the total number of points on the tth streamline; L is the total number of streamlines; subscript a represents after adjustment, and subscript b represents before adjustment.

2. The method for rapid evaluation of flow field development effect of water drive reservoir according to claim 1, characterized in that: The geological development data collected in step 1 include: reservoir structure, permeability, porosity, effective thickness, saturation, pressure distribution, water phase density and viscosity, oil phase density and viscosity, relative permeability curve, well trajectory of injection wells and production wells, perforation location, well network form, monthly oil production of production wells, monthly water production, monthly water injection of injection wells, production time step, flow field transition timing, and flow field transition method.

3. The method for rapid evaluation of flow field development effect of water drive reservoir according to claim 1, characterized in that: In step 1, a streamline simulator is used to establish a data volume file of a streamline simulation model for flow field development of a target reservoir.

4. The method for rapid evaluation of flow field development effect of water drive reservoir according to claim 1, characterized in that: In step 2, the instantaneous flow field distribution is obtained as a prediction within 1 simulation time step.

5. The method for rapid evaluation of flow field development effect of water drive reservoir according to claim 1, characterized in that: In step 3, the extracted fluid attribute data include: oil phase saturation attribute data flowing through each point on each streamline, water phase saturation attribute data flowing through each point on each streamline, oil phase flow rate attribute data flowing through each point on each streamline, and water phase flow rate attribute data flowing through each point on each streamline.

6. The method for rapid evaluation of flow field development effect of water drive reservoir according to claim 1, characterized in that: In step 5, the effectiveness of the flow field conversion measures for water drive reservoirs is determined based on the value calculated in step 4. If the value obtained is greater than 0, it indicates that the development effect after the flow field conversion is improved compared with that before the flow field conversion, and the flow field conversion measures are effective.

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