Shale oil pressure orderly replacement production regulation and control method and system
By optimizing parameters based on fracturing simulation, predicting the number of days of stuffy wells, and implementing stuffy wells to promote absorption, liquid control and sand control, rapid drainage and precipitation, and pressure maintenance and stable production, the problem of the lack of full life cycle shale oil production control methods in the existing technology has been solved. problems, achieving reasonable production control and efficient shale oil development.
Patent Information
- Application Number
- CN202310902169.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-07-21
- Publication Date
- 2025-01-21
AI Technical Summary
The existing technology lacks a full-life cycle shale oil production regulation method based on orderly pressure replacement, resulting in poor universality and poor guidance in different regions. The geological conditions and pressure characteristics of shale oil have a great impact, and the silence of wells There are huge differences in time and control methods.
By numerically simulating and optimizing parameters based on fracturing simulation, we can predict the number of days of stuffy wells, promote suction, liquid control and sand control, rapid drainage and precipitation, maintain pressure and stabilize production, and achieve orderly pressure replacement and production control.
It achieves reasonable optimization under different geological characteristics and pressure construction conditions, makes full use of formation energy and artificial energy, increases single well productivity, extends stable production period, and improves elastic productivity.
Smart Images
Figure CN119333089A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of oil and gas exploitation, and in particular to a method and system for regulating and controlling shale oil pressure orderly succession production. Background Art
[0002] Shale oil and gas reservoirs are currently a hot spot for oil and gas exploration and development. Rich shale oil resources have been discovered in multiple strata in multiple basins in China. At present, shale oil is mainly developed by elastic development after volume fracturing. Elastic energy is the basis for elastic development of shale oil after fracturing. Reducing stress-sensitive losses and improving imbibition are conducive to making full use of formation energy combined with fracturing fluid energy, improving shale oil utilization and single-well EUR. Different working systems have an important impact on the production capacity of a single well, and the rational optimization of production control methods is the key to improving economic benefits. Although different oilfields have developed a variety of different working systems such as advanced energy replenishment and well control and drainage, there is still a lack of a full-life cycle production control method for continental shale oil based on orderly pressure succession.
[0003] It is preliminarily believed that the elastic development method of well blocking and controlled drainage can achieve better development results. Affected by key parameters such as shale oil geological conditions, pressure characteristics, fluid physical properties, and compressibility, there are huge differences in well blocking time and controlled drainage methods in different regions. Due to the lack of relatively clear parameter indicators, the working system in different regions has poor universality and weak guidance. There is still a lot of room for optimization of the reasonable working system for elastic development of shale oil. Summary of the invention
[0004] In view of the above problems, the present invention is proposed to provide a shale oil pressure orderly succession production control method and system that overcomes the above problems or at least partially solves the above problems.
[0005] According to one aspect of the present invention, a method for regulating and controlling shale oil pressure orderly succession production is provided, the method comprising:
[0006] Based on the fracturing simulation, the parameters are optimized by numerical simulation;
[0007] Predict the number of days of well blockage;
[0008] Stuffing the well promotes suction. Stuffing the well after fracturing promotes the spread of pressure to the far well area.
[0009] Control fluid and prevent sand, calculate critical sand production velocity;
[0010] Rapid drainage and water reduction, enlarging the oil nozzle to activate each fracturing stage, and rapid drainage to reduce the water content of daily production fluid;
[0011] Maintain pressure and stabilize production, and fine pressure control to reduce the speed of crack closure.
[0012] Optionally, based on the fracturing simulation, the numerical simulation optimization parameters specifically include:
[0013] Based on the fracturing simulation fitting microseismic results, the stress sensitivity and capillary force were considered to simulate the process of fracturing fluid injection into the wellbore. When the bottom hole pressure tends to be stable, the wellbore is terminated.
[0014] Optionally, the numerical simulation optimization parameters specifically include: the number of days of well blocking, and the liquid production rate at different stages.
[0015] Optionally, the numerical simulation optimization of the liquid production rate at different stages specifically includes: optimizing the liquid production rate at different stages after the well is blocked by numerical simulation, and optimizing the nozzle control method.
[0016] Optionally, the predicted number of days of well blocking specifically includes: referring to key data of production performance of old wells and fracturing construction parameters of the current well.
[0017] Optionally, the predicted number of days of well blocking specifically includes:
[0018] The effects of fracturing parameters and well blocking time on production performance of different horizontal wells in the same depression were compared, and the number of well blocking days was preliminarily predicted.
[0019] Optionally, the method of sealing the well to promote absorption and sealing the well after fracturing to promote the propagation of pressure to the far wellbore area specifically includes:
[0020] During the well sealing stage, the bottom hole pressure is calculated every 12 hours. When the bottom hole descent rate is less than 0.05MPa / day for four consecutive times, the well sealing is stopped.
[0021] Optionally, the fluid control and sand prevention specifically include:
[0022] During the liquid control and sand prevention stage, under the condition of sand production rate lower than the critical rate, spray through a 2-3mm oil nozzle for 5-10 days or until the water content drops significantly.
[0023] Optionally, the calculating critical sand production speed specifically includes:
[0024] Calculation of critical sand production speed:
[0025]
[0026] Where Q is the flowback velocity, m 3 / h; v is the critical flow velocity, m / s; ρ, ρ s is the density of fracturing fluid and proppant, kg / m 3 ; h is the reservoir thickness, m; w is the fracture width, mm; B is the porosity of the supporting section, %; o is the volume coefficient; g is the acceleration due to gravity, m / s 2 ; d is the proppant particle size, mm.
[0027] Optionally, the rapid drainage and water reduction, enlarging the oil nozzle to activate each fracturing stage specifically includes: gradually enlarging the oil nozzle by 4-8 mm, and rapidly draining liquid to reduce the water content of daily produced liquid.
[0028] Optionally, maintaining pressure and stabilizing production and finely controlling pressure to reduce the crack closing speed specifically include:
[0029] Fine pressure control reduces the crack closing speed, and gradually reduces the nozzle size to control the oil pressure drop rate to less than 0.2MPa / day, extending the stable production cycle and improving the elastic yield.
[0030] Optionally, the calculation of the elastic yield includes:
[0031]
[0032] The present invention also provides a shale oil pressure orderly succession production control system, which is applied to the above-mentioned shale oil pressure orderly succession production control method, and the control system includes:
[0033] Numerical simulation optimization module, used for numerical simulation optimization parameters based on fracturing simulation;
[0034] Prediction module, used to predict the number of days of well blockage;
[0035] The well-blocking and absorption-promoting module is used to block the well and promote absorption. After fracturing, the well is blocked to promote the spread of pressure to the far well area.
[0036] Liquid control and sand prevention module, used for liquid control and sand prevention, and calculation of critical sand production velocity;
[0037] The quick drainage module is used for quick drainage, enlarging the oil nozzle to activate each fracturing stage, and quickly draining the liquid to reduce the water content of the daily produced liquid;
[0038] The pressure-maintaining and production-stabilizing module is used to maintain pressure and stabilize production, and finely control pressure to reduce the speed of crack closure.
[0039] The present invention provides a shale oil pressure orderly succession production control method and system, the control method includes: based on fracturing simulation, numerical simulation optimization parameters; predicting the number of days of well blocking; well blocking to promote suction, after fracturing, well blocking promotes pressure to spread to the far well area; liquid control to prevent sand, calculate the critical sand production rate; fast drainage and water reduction, enlarge the oil nozzle to activate each fracturing stage, fast drainage to reduce the water content of daily production liquid; maintain pressure and stabilize production, fine pressure control to reduce the crack closure speed. With the goal of making full use of formation energy and artificial energy and improving the single well production capacity, a full life cycle shale oil pressure orderly succession production control method is proposed.
[0040] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS
[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.
[0042] Figure 1 A flow chart of a shale oil pressure orderly succession production control method provided by an embodiment of the present invention;
[0043] Figure 2 It is a conceptual model of pressure orderly succession production control in a specific embodiment of the present invention;
[0044] Figure 3 It is a typical well pressure orderly succession production regulation production dynamics in a specific embodiment of the present invention;
[0045] Figure 4 It is a typical well elastic yield change curve in a specific embodiment of the present invention. DETAILED DESCRIPTION
[0046] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.
[0047] The terms "comprises" and "having" and any variations thereof in the description embodiments, claims and drawings of the present invention are intended to cover non-exclusive inclusions, for example, including a series of steps or units.
[0048] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.
[0049] The present invention provides a shale oil pressure orderly succession production control method based on the whole life cycle, which realizes or improves: (1) reasonable optimization of the well blocking time under different geological characteristics and pressure construction conditions, promoting the imbibition effect to make full use of artificial energy; (2) using a small oil nozzle to release fluid to control sand, improve the fracturing transformation effect and avoid sand blockage; (3) fully activate different fracturing sections to achieve balanced utilization of the whole well, and quickly reduce the water content to improve the development efficiency; (4) fine pressure control effectively reduces the influence of stress sensitivity, prolongs the stable production period, and improves the elastic yield.
[0050] The present invention provides a shale oil pressure orderly succession production control method based on the whole life cycle, which specifically includes the following steps:
[0051] Step 1) Based on the fracturing simulation, numerical simulation is performed to optimize parameters such as the number of days of well blocking and the fluid production rate at different stages;
[0052] Step 2) Preliminarily predict the number of days the well will be blocked by referring to the key data such as the production performance of the old well and the fracturing operation parameters of the current well;
[0053] Step 3) Stuffing the well to promote absorption: Stuffing the well after fracturing promotes the spread of pressure to the far well area and improves the absorption efficiency;
[0054] Step 4) controlling fluid and preventing sand, calculating the critical sand production velocity, and spraying with a small nozzle to prevent sand production and improve the fracturing effect;
[0055] Step 5) Rapid drainage and water reduction, enlarging the oil nozzle to activate each fracturing stage, and rapidly draining the fluid to reduce the water content of the daily produced fluid;
[0056] Step 6) Maintain pressure and stabilize production. Fine pressure control reduces the speed of crack closure, improves elastic yield, and extends the stable production period.
[0057] The purpose of the present invention can also be achieved by the following technical measures:
[0058] In step 1, based on the fracturing simulation fitting microseismic results, the stress sensitivity and capillary force are considered to simulate the process of injecting fracturing fluid into the well. When the bottom hole pressure tends to be stable, the well is blocked.
[0059] In step 1, the fluid production rate at different stages after the well is blocked is optimized through numerical simulation, and the nozzle control method is optimized;
[0060] In step 2, the effects of fracturing parameters and well-clogging time on production performance of different horizontal wells in the same depression are compared, and the number of well-clogging days is preliminarily predicted. Under the condition of high fracturing fluid usage, the number of well-clogging days is appropriately increased.
[0061] In step 3, during the well blocking stage, the bottom hole pressure is calculated once every 12 hours. When the bottom hole descent rate is less than 0.05 MPa / day for four consecutive times, the well blocking is stopped.
[0062] In step 4, during the liquid control and sand prevention stage, the fluid is sprayed through a 2-3 mm nozzle for 5-10 days or until the water content drops significantly, at a rate lower than the critical sand production rate.
[0063] Calculation of critical sand production speed:
[0064]
[0065] Where, Q is the flowback velocity, m 3 / h; v——critical flow velocity, m / s; ρ, ρ s ——Fracturing fluid density, proppant density, kg / m 3 ; h——reservoir thickness, m; w——fracture width, mm; ——support section porosity, %; B o ——volume coefficient; g——gravitational acceleration, m / s 2 ; d——proppant particle size, mm.
[0066] In step 5, in order to quickly reduce the water content and activate each fracturing stage to achieve balanced utilization, it is necessary to increase the production pressure difference and the flowback rate, so the oil nozzle is gradually enlarged by 4-8mm to quickly discharge the liquid to reduce the water content of the daily production liquid.
[0067] In step 6, shale oil reservoirs are highly sensitive to stress, and precise pressure control is used to reduce the speed of fracture closure. The nozzle size is gradually reduced to control the oil pressure drop rate to less than 0.2 MPa / day, thereby extending the stable production period and improving the elastic yield.
[0068] Elastic yield calculation:
[0069]
[0070] Example 1
[0071] In one embodiment 1 of the present invention, the following steps are specifically included:
[0072] Step 1) Based on the fracturing simulation, considering the influence of imbibition, numerical simulation optimizes the well-clogging days to 15-25 days, controls the liquid production to 200-400 t / d in the initial stage, controls the liquid production to 50-100 t / d in the middle stage, and controls the liquid production rate to more than 10 t / d in the late stage;
[0073] Step 2) referring to the key data such as the production performance of the old well and the fracturing operation parameters of the current well, it is preliminarily predicted that the target well A will be blocked for 15-20 days;
[0074] Step 3) Stifling the well to promote absorption: after the target well A was fractured and sealed for 20 days, the wellhead oil pressure tended to be stable, and the well was opened after being sealed for 20 days;
[0075] Step 4) Control liquid and prevent sand. The critical sand production rate is calculated to be about 500t / d. A 2-3mm small oil nozzle is used to control the liquid production rate to be less than 250t / d. Oil is seen in 4 days, and no sand is seen in 10 days of spraying. The water content is significantly reduced.
[0076] Step 5) Rapid drainage and dewatering, 4mm-6mm oil nozzles quickly release and spray, the maximum liquid production rate is 400t / d, the water content drops rapidly, averaging 1.7% per day, the cycle is about 30 days, the tracer shows that each section contributes to the water production and oil production, and the error is small, and each fracturing stage is activated;
[0077] Step 6) Maintain pressure and stabilize production. After the water content stabilizes, gradually reduce the nozzle by 4-2mm to stabilize production. When the oil pressure drop rate exceeds 0.2MPa / day, reduce the nozzle size to increase the elastic yield in turn and extend the stable production period.
[0078] Beneficial effects: The present invention provides a shale oil pressure orderly succession production control method based on the whole life cycle, which solves the problems of (1) lack of reasonable production control key parameters such as well-clogging days; (2) insufficient utilization of formation energy and artificial energy; and (3) sand production from fractures and large stress sensitivity losses.
[0079] The above specific implementation methods further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific implementation methods of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A method for regulating and controlling shale oil production by orderly succession of pressure, characterized in that: The control method comprises: Based on the fracturing simulation, the parameters are optimized by numerical simulation; Predict the number of days of well blockage; Stuffing the well promotes suction. Stuffing the well after fracturing promotes the spread of pressure to the far well area. Control fluid and prevent sand, calculate critical sand production velocity; Rapid drainage and water reduction, enlarging the oil nozzle to activate each fracturing stage, and rapid drainage to reduce the water content of daily production fluid; Maintain pressure and stabilize production, and fine pressure control to reduce the speed of crack closure.
2. A shale oil pressure orderly succession production control method according to claim 1, characterized in that: Based on the fracturing simulation, the numerical simulation optimization parameters specifically include: Based on the fracturing simulation fitting microseismic results, the stress sensitivity and capillary force were considered to simulate the process of fracturing fluid injection into the wellbore. When the bottom hole pressure tends to be stable, the wellbore is terminated.
3. The method for regulating and controlling shale oil pressure orderly succession production according to claim 1, characterized in that: The numerical simulation optimization parameters specifically include: the number of days of well blocking and the liquid production rate at different stages.
4. A shale oil pressure orderly succession production control method according to claim 3, characterized in that: The numerical simulation optimization of the liquid production rate at different stages specifically includes: optimizing the liquid production rate at different stages after the well is blocked by numerical simulation, and optimizing the nozzle control method.
5. The method for regulating and controlling shale oil pressure orderly succession production according to claim 1, characterized in that: The predicted number of days of well blockage specifically includes: referring to the key data of the production performance of the old well and the fracturing construction parameters of the current well.
6. A shale oil pressure orderly succession production control method according to claim 1, characterized in that: The predicted number of days of well blocking specifically includes: The effects of fracturing parameters and well blocking time on production performance of different horizontal wells in the same depression were compared, and the number of well blocking days was preliminarily predicted.
7. The method for regulating and controlling shale oil pressure orderly succession production according to claim 1, characterized in that: The method of blocking the well to promote absorption and blocking the well after fracturing to promote the spread of pressure to the far wellbore area specifically includes: During the well sealing stage, the bottom hole pressure is calculated every 12 hours. When the bottom hole descent rate is less than 0.05MPa / day for four consecutive times, the well sealing is stopped.
8. The method for regulating and controlling shale oil pressure orderly succession production according to claim 1, characterized in that: The fluid control and sand prevention specifically include: During the liquid control and sand prevention stage, under the condition of sand production rate lower than the critical rate, spray through a 2-3mm oil nozzle for 5-10 days or until the water content drops significantly.
9. The method for controlling shale oil pressure orderly succession production according to claim 1, characterized in that: The calculation of the critical sand production speed specifically includes: Calculation of critical sand production speed: Where Q is the flowback velocity, m 3 / h; v is the critical flow velocity, m / s; ρ, ρ s is the density of fracturing fluid and proppant, kg / m 3 ; h is the reservoir thickness, m; w is the fracture width, mm; B is the porosity of the supporting section, %; o is the volume coefficient; g is the acceleration due to gravity, m / s 2 ; d is the proppant particle size, mm.
10. The method for regulating and controlling shale oil pressure orderly succession production according to claim 1, characterized in that: The rapid drainage and water reduction and enlarging the oil nozzle to activate each fracturing stage specifically include: gradually enlarging the oil nozzle by 4-8mm and rapidly draining the liquid to reduce the water content of the daily produced liquid.
11. A shale oil pressure orderly succession production control method according to claim 1, characterized in that: The said maintaining pressure and stabilizing production and finely controlling pressure to reduce the crack closing speed specifically include: Fine pressure control reduces the crack closing speed, and gradually reduces the nozzle size to control the oil pressure drop rate to less than 0.2MPa / day, extending the stable production cycle and improving the elastic yield.
12. A shale oil pressure orderly succession production control method according to claim 11, characterized in that: The calculation of the elastic yield includes:
13. A shale oil pressure orderly succession production control system, applied to a shale oil pressure orderly succession production control method as described in any one of claims 1 to 12, characterized in that: The control system comprises: Numerical simulation optimization module, used for numerical simulation optimization parameters based on fracturing simulation; Prediction module, used to predict the number of days of well blocking; The well-blocking and absorption-promoting module is used to block the well and promote absorption. After fracturing, the well is blocked to promote the spread of pressure to the far well area. Liquid control and sand prevention module, used for liquid control and sand prevention, and calculation of critical sand production velocity; The quick drainage module is used for quick drainage, enlarging the oil nozzle to activate each fracturing stage, and quickly draining the liquid to reduce the water content of the daily produced liquid; The pressure-maintaining and production-stabilizing module is used to maintain pressure and stabilize production, and finely control pressure to reduce the speed of crack closure.