Method for reducing interference of fracturing on production well

Abstract

According to the method for reducing the interference of fracturing on the production well, the influence on production of the production well is controlled by quantitatively optimizing the fracturing parameters of the new well from the control of the energy injection mode of the high-seepage channel according to the geologically-recognized mutual relation between the high-seepage channel such as fractures and natural fractures of different grades and the track of the new well, and the production of the production well is controlled. The targeted fracturing scheme design of the risk section is guided, and the overall development effect of the block is improved. By means of the technical method, the effectiveness of fracturing interference control measures can be improved, clear guidance is provided for on-site fracturing scheme optimization, and the overall development effect of an oil field can be improved; according to the technical thought of the invention, the formulation of fracturing interference control measures can be conveniently and quickly realized.

Description

Technical Field

[0001] The invention relates to a fracturing interference control technology in the field of petroleum development, and in particular to a method for reducing the interference of fracturing on production wells. Background Art

[0002] The main body of unconventional oil and gas reservoirs is developed by horizontal well volume fracturing. As the development of the block progresses, the newly deployed wells interfere with the normal production of the production wells during the fracturing process, causing the pressure and water content to rise, destroying the original seepage state, and affecting the output and recovery rate of the production wells.

[0003] At present, the reasons why fracturing interferes with production wells are basically clear, mainly due to the artificial fractures of new well fracturing connecting to high-conductivity channels such as fractures and natural fractures or the original fractures of the production well. For the artificial fractures of new well fracturing connecting to old fractures in the production well, it is mainly caused by the small well spacing or the large scale of fracturing in the new well, which can be predicted and targeted measures can be taken in advance. However, for the types of high-conductivity channels such as artificial fractures connecting fractures and natural fractures in new well fracturing, it is difficult to predict the interference risk and the control measures are unclear due to the current accuracy of identifying the location of high-seepage channels. Summary of the invention

[0004] In order to overcome the defects of the prior art, the present invention provides a method for reducing the interference of fracturing on production wells. In view of the interference of fracturing caused by high-seepage channels such as faults and natural fractures, the impact on the production of production wells is controlled by quantitatively optimizing the fracturing parameters of new wells, guiding the design of targeted fracturing schemes for risk sections, and improving the overall development effect of the block.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for reducing the interference of fracturing on a production well, comprising:

[0007] S1, obtaining the main fracturing parameters of the target area, evaluating the location and degree of fractures or natural fractures in the target area according to the main fracturing parameters, and dividing the target area into a determined area and a potential area according to the evaluation results;

[0008] S2, determine the fracturing interference control index;

[0009] S3, based on the three-dimensional geological model of the target area, simulate the influence of different intersection angles between the fracture or natural fracture and the new well trajectory on the pressure distribution in the fracture or natural fracture, and determine the angle between the fracture or natural fracture and the new well trajectory corresponding to the highest risk working condition;

[0010] S4, for the determined area, based on the three-dimensional geological model of the target area, the angle between the fracture or natural fracture corresponding to the highest risk working condition and the trajectory of the new well is used to simulate the pressure distribution and diffusion distance in the fracture or natural fracture under different avoidance fracturing distances of the new well, and the avoidance fracturing distance is selected according to the fracturing interference control index;

[0011] S5. For potential areas, based on the three-dimensional geological model of the target area, the pressure distribution and diffusion distance in the fractures or natural fractures corresponding to the highest risk working condition and the new well trajectory are simulated under different fracturing parameters of the new well, and the fracturing parameters of the new well are comprehensively designed according to the fracturing interference control index;

[0012] S6, based on the avoidance distance of fracturing obtained in S4 and the fracturing parameters of the new well obtained in S5, compile measures to reduce the impact of fracturing interference in the target area.

[0013] Preferably, in S1, the main fracturing parameters of the target area are obtained based on one or more of the seismic data, drilling data, logging data, well logging data and development history data of the target area.

[0014] Preferably, in S1, the area of ​​the target region where open fractures or semi-open fractures exist is divided into a determined area, and the area where closed fractures exist is divided into a potential area.

[0015] Preferably, in S2, the fracturing interference control index is determined based on the historical development data of the target area.

[0016] Preferably, in S2, the fracturing interference control index is the pressure increase amplitude of the production well after the interference.

[0017] Preferably, in S3, the average leakage coefficient is used as an evaluation parameter for the impact on the pressure distribution in the fracture or natural fracture, and the angle between the fracture or natural fracture and the new well trajectory corresponding to the highest risk working condition is determined.

[0018] Furthermore, in S3, the angle between the fracture or natural fracture and the new well trajectory corresponding to 90% of the maximum value of the average leakage coefficient is taken as the angle between the fracture or natural fracture and the new well trajectory corresponding to the highest risk condition.

[0019] Preferably, in S4, based on the three-dimensional geological model of the target area, a three-dimensional fracture extension numerical simulation technology is used for simulation.

[0020] Preferably, in S5, based on the three-dimensional geological model of the target area, a three-dimensional fracture extension numerical simulation technology is used for simulation.

[0021] Preferably, in S5, the fracturing parameters include fracturing displacement, scale, stage cluster design and temporary plugging technology.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The method of reducing the interference of fracturing on production wells of the present invention is based on the relationship between high-seepage channels such as fractures and natural fractures of different levels identified geologically and the trajectory of new wells, and starts from the way of controlling the injection energy of high-seepage channels to reduce the impact on the production of production wells. The method of the present invention is completed on the basis of a large amount of theoretical research, numerical simulation research and field application, and has been verified by the Jimusar shale oil in the Xinjiang Oilfield, and the results are reliable; the technical method of the present invention can improve the effectiveness of the measures for controlling the interference of fracturing, provide clear guidance for the optimization of the on-site fracturing scheme, and improve the overall development effect of the oilfield; according to the technical ideas of the present invention, the formulation of measures for controlling the interference of fracturing can be realized conveniently and quickly. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The present invention is a flow chart of a method for reducing the interference of hydraulic fracturing on production wells. DETAILED DESCRIPTION

[0025] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0026] It should be noted that the process equipment or devices not specifically specified in the following embodiments are all conventional equipment or devices in the art.

[0027] In addition, it should be understood that one or more method steps mentioned in the present invention do not exclude the existence of other method steps before or after the combination step or the insertion of other method steps between these explicitly mentioned steps, unless otherwise specified; and, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to define the scope of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the present invention without substantially changing the technical content.

[0028] The present invention provides a method for controlling the impact on production of production wells by quantitatively optimizing new well fracturing parameters in response to the situation where high-permeability channels such as faults and natural fractures cause fracturing interference.

[0029] The technical process of the method includes the following steps:

[0030] (1) Based on the target area's seismic, drilling, logging, mud logging, development history data and other information, clarify the main fracturing parameters of the target area, evaluate the location and degree of fractures and natural fractures in the target area, and divide the target area into a confirmed area and a potential area based on the evaluation results.

[0031] (2) Based on the historical development data of the target area, the pressure increase amplitude of the production well after the disturbance is determined as the fracturing interference control index.

[0032] (3) Based on the three-dimensional geological model of the target area, the three-dimensional fracture extension numerical simulation technology is used to simulate the impact of different intersection angles between the fracture or natural fracture and the new well trajectory on the pressure distribution in the fracture or natural fracture, and determine the angle corresponding to the highest risk condition.

[0033] (4) For the determined area, based on the three-dimensional geological model of the target area, the three-dimensional fracture extension numerical simulation technology is used to simulate the pressure distribution and diffusion distance in the fracture or natural fracture of the new well at different avoidance fracturing distances at the angle corresponding to the highest risk condition determined in step (3), and the avoidance fracturing distance is selected according to the fracturing interference control index determined in step (2).

[0034] (5) For the potential area, based on the three-dimensional geological model of the target area, the three-dimensional fracture extension numerical simulation technology is used to simulate the pressure distribution and diffusion distance in the fault or natural fracture under different fracturing parameters (fracturing displacement, scale, stage cluster design, temporary plugging process) of the new well at the angle corresponding to the highest risk condition determined in step (3). The fracturing parameters (fracturing displacement, scale, stage cluster design, temporary plugging process) of the new well are comprehensively designed based on the fracturing interference control index determined in step (2).

[0035] (6) Based on the results of steps (4) and (5), prepare measures to reduce the impact of fracturing interference in the target area, including the avoidance distance of the fracturing area and the fracturing parameters of the potential area.

[0036] Example

[0037] The reservoir of this embodiment is located in the shale oil of Lucaogou Formation in Jimusar Sag, Junggar Basin.

[0038] The method of reducing the interference of hydraulic fracturing on production wells in this embodiment includes:

[0039] Step 1: Based on the target area’s seismic, drilling, logging, mud logging, development history data and other data, the main fracturing parameters of the target area are collected: bridge plug cluster perforation fracturing technology, construction displacement of 15-18m 3 / min, sand adding strength 3.0m 3 / m, cluster spacing of 8m, 6 clusters in a single segment, and 1 temporary plugging in a single segment; the development characteristics of the target layer faults, among which the areas where open faults and semi-open faults are located are defined as confirmed areas, and the areas where closed faults are located are defined as potential areas.

[0040] Step 2: Based on the historical development data of the target area, collect the pressure increase amplitude and the impact on the production of the production wells after the new well fracturing interference, and determine that controlling the pressure increase of the production wells at 5MPa is the fracturing interference control indicator.

[0041] Step 3, based on the three-dimensional geological model of the target area, simulate the pressure distribution inside the fracture at different angles between the fracture and the new well trajectory. In this example, the angle corresponding to 90% of the maximum value of the average leakage coefficient is used as the angle between the fracture and the new well trajectory corresponding to the highest risk condition, and the angle corresponding to the highest risk condition is determined to be 75°.

[0042] Step 4. For the determined area, based on the three-dimensional geological model of the target area, use the three-dimensional fracture extension numerical simulation technology to simulate the pressure changes in the fracture at different new well fracturing positions and fracture distances at the angle corresponding to the highest risk condition determined in step 3. According to the fracturing interference control index determined in step 2, determine that the avoidance distance for fracturing is 20 to 40 meters.

[0043] Step 5: For the potential area, based on the 3D geological model of the target area, the 3D fracture extension numerical simulation technology is used to simulate the pressure changes in the fracture under different new well fracturing parameters. According to the fracturing interference control index determined in step 2, the construction displacement of 10-12m 3 / min, sand adding strength 2.0~2.5m 3 / m, cluster spacing 8m, 6 clusters in a single section, and temporary blockage of a single section twice.

[0044] In step 6, according to the results of steps 4 and 5, the hydraulic fracturing in the determined area is conducted away from the fracture by 20 to 40 m, and the construction displacement is 10 to 12 m in the potential area. 3 / min, sand adding strength 2.0~2.5m 3 / m, cluster spacing 8m, 6 clusters in a single section, and temporary blocking of a single section twice.

[0045] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A method for reducing the interference of fracturing on production wells, characterized in that: include: S1, obtaining the main fracturing parameters of the target area, evaluating the location and degree of fractures or natural fractures in the target area according to the main fracturing parameters, and dividing the target area into a determined area and a potential area according to the evaluation results; S2, determine the fracturing interference control index; S3, based on the three-dimensional geological model of the target area, simulate the influence of different intersection angles between the fracture or natural fracture and the new well trajectory on the pressure distribution in the fracture or natural fracture, and determine the angle between the fracture or natural fracture and the new well trajectory corresponding to the highest risk working condition; S4, for the determined area, based on the three-dimensional geological model of the target area, the angle between the fracture or natural fracture corresponding to the highest risk working condition and the trajectory of the new well is used to simulate the pressure distribution and diffusion distance in the fracture or natural fracture under different avoidance fracturing distances of the new well, and the avoidance fracturing distance is selected according to the fracturing interference control index; S5. For potential areas, based on the three-dimensional geological model of the target area, the pressure distribution and diffusion distance in the fractures or natural fractures corresponding to the highest risk working condition and the new well trajectory are simulated under different fracturing parameters of the new well, and the fracturing parameters of the new well are comprehensively designed according to the fracturing interference control index; S6, based on the avoidance distance of fracturing obtained in S4 and the fracturing parameters of the new well obtained in S5, compile measures to reduce the impact of fracturing interference in the target area.

2. The method for reducing the interference of hydraulic fracturing on production wells according to claim 1, characterized in that: In S1, main fracturing parameters of the target area are obtained based on one or more of seismic data, drilling data, well logging data, mud logging data and development history data of the target area.

3. The method for reducing the interference of hydraulic fracturing on production wells according to claim 1, characterized in that: In S1, the target area where open faults or semi-open faults exist is divided into a confirmed area, and the area where closed faults exist is divided into a potential area.

4. The method for reducing the interference of fracturing on production wells according to claim 1, characterized in that: In S2, the fracturing interference control index is determined based on the historical development data of the target area.

5. The method for reducing the interference of hydraulic fracturing on production wells according to claim 1, characterized in that: In S2, the fracturing interference control index is the pressure increase amplitude of the production well after the interference.

6. The method for reducing the interference of hydraulic fracturing on production wells according to claim 1, characterized in that: In S3, the average leakage coefficient is used as an evaluation parameter for the impact on the pressure distribution in the fracture or natural fracture, and the angle between the fracture or natural fracture and the new well trajectory corresponding to the highest risk condition is determined.

7. The method for reducing the interference of hydraulic fracturing on production wells according to claim 6, characterized in that: In S3, the angle between the fault or natural fracture and the new well trajectory corresponding to 90% of the maximum value of the average leakage coefficient is taken as the angle between the fault or natural fracture and the new well trajectory corresponding to the highest risk working condition.

8. The method for reducing the interference of hydraulic fracturing on production wells according to claim 1, characterized in that: In S4, the simulation was performed using the three-dimensional fracture propagation numerical simulation technology based on the three-dimensional geological model of the target area.

9. The method for reducing the interference of hydraulic fracturing on production wells according to claim 1, characterized in that: In S5, the simulation is performed using the three-dimensional fracture propagation numerical simulation technology based on the three-dimensional geological model of the target area.

10. The method for reducing the interference of hydraulic fracturing on production wells according to claim 1, characterized in that: In S5, the fracturing parameters include fracturing displacement, scale, stage cluster design and temporary plugging technology.

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