A fine control method for water injection well based on three fixed cards

Abstract

The present application relates to the field of oilfield injection well production control, in particular to a kind of injection well fine control method based on three fixed card, real-time flow and oil pressure data of injection well are obtained by sensor, and uploaded to cloud database, the data of cloud database is called by host computer, based on the injection allocation scheme issued by cloud and injection well three fixed card, processor module passes through establishing injection well operation fine control model, the optimal instantaneous injection volume under current injection pressure is analyzed, and corresponding valve group is automatically adjusted to execute flow adjustment operation, to meet the injection qualified rate under the premise, injection error, fluctuation error all meet the set requirement, and combined with oil pressure data variation trend, the intelligent control to the flow of injection well is realized.The present application carries out fault handling in time through injection well working condition analysis, improves injection efficiency, reduces the interference between injection layers, and improves the oil production capacity of oil well.

Description

Technical Field

[0001] This invention relates to the field of production control of water injection wells in oilfields, specifically a method for fine control of water injection wells based on three-dimensional cards. Background Technology

[0002] Currently, a daily water injection rate within 20% of the geological injection volume of a single well can meet the water injection qualification requirements. However, as the production conditions of injection wells change, leading to variations in injection pressure, the actual daily water injection volume often fails to meet the qualification requirements. Traditional water injection techniques have several problems, such as poor injection effect and inaccurate control of injection layer position and thickness. Therefore, a refined control method for injection wells is needed to monitor the production dynamics of injection wells in real time, conduct timely judgment and analysis, and optimize and adjust injection parameters more promptly. Summary of the Invention

[0003] The purpose of this invention is to provide a fine control method for water injection wells based on three-dimensional cards. This method relies on cloud-based water injection plans and commissioning data (three-dimensional cards) to establish a fine control model for water injection well operation. It intelligently analyzes the optimal instantaneous water injection volume under the current injection pressure and automatically adjusts the execution accordingly. While ensuring the water injection qualification rate, it strives to meet the requirements for water injection error and fluctuation error, effectively improving both the water injection efficiency and the overall success rate. Early warnings and alarms are provided for expired or overdue commissioning data.

[0004] The technical solution adopted by this invention to achieve the above objectives is: a fine control method for water injection wells based on three-fixed cards. This method acquires real-time flow and oil pressure data of the water injection well through sensors and uploads it to a cloud database. The host computer retrieves data from the cloud database. Based on the injection allocation plan and the three-fixed cards for the water injection well issued by the cloud, the processor module establishes a fine control model for the operation of the water injection well. It analyzes the optimal instantaneous water injection volume under the current injection pressure and automatically adjusts the corresponding valve groups to perform flow adjustment operations. This ensures that, while meeting the water injection qualification rate, the water injection error and fluctuation error both meet the set requirements. Furthermore, by combining the oil pressure data change trend, the method achieves real-time monitoring of the water injection well's operating status and intelligent adjustment of the water injection volume.

[0005] The host computer establishes a fine-grained control model for the operation of the injection well, analyzes the optimal instantaneous water injection rate under the current injection pressure, and automatically adjusts the corresponding valve groups to perform flow adjustment operations, specifically:

[0006] Step 1: The host computer retrieves the real-time flow and oil pressure data of the injection well collected by the sensor from the cloud database to determine the range of water injection error Z, the range of fluctuation error B, and the range of water injection completion rate P;

[0007] Step 2: The host computer determines the current operating condition. If the current operating condition is any of the following: over- or under-filling, three-fixed card nearing expiration, or debugging data pressure exceeding the range, only an alarm signal is output; otherwise, proceed to step 3.

[0008] Step 3: The processor module determines the water injection error Z, fluctuation error B, and water injection completion rate P based on the collected injected oil pressure data and the three-dimensional card, and performs corresponding control on the water injection well based on the water injection error Z, fluctuation error B, and water injection completion rate P.

[0009] Step 4: Based on the fluctuation error B and the water injection completion rate P, obtain the instantaneous flow control range Q of the injection well. PB Based on the instantaneous flow control interval Q PB Appropriate control should be exercised over the water injection wells;

[0010] Step 5: Based on the water injection error Z, fluctuation error B, and water injection completion rate P, obtain the optimal water volume control range Q. opt And determine the instantaneous flow rate and the optimal water control range Q. opt The relationship between the data and the oil pressure data is used to control the water injection well accordingly.

[0011] Step 6: Adjust the control according to the priority control sequence to complete the intelligent control of the water injection well.

[0012] Step 1 specifically includes:

[0013] 1-1) Based on the collected oil pressure data, the host computer establishes a quantity-pressure-speed lookup table according to the three-fixed card standard to determine the water volume range Z = [Zmin, Zmax] that meets the water injection error.

[0014] 1-2) Determine the water volume range P that satisfies the water injection completion rate according to the injection plan, that is:

[0015] Obtain the water injection completion rate, the upper and lower limits of the water injection completion rate, and the error interval of the instantaneous water volume water injection completion rate P = [Pmin, Pmax];

[0016] 1-3) Determine the water volume range B = [Bmin, Bmax] that meets the fluctuation error based on yesterday's water injection volume.

[0017] The aforementioned operating conditions fall under the categories of under-injection and over-injection, including: under-injection during water injection and over-injection during water injection; wherein:

[0018] 2-1) Under-injection under water injection condition: Based on the water injection plan including the water injection amount and the cumulative water volume, calculate the cumulative water injection volume in 24 hours. When the cumulative water injection volume is less than the lower limit water injection volume, and it is a non-absorption well, it is diagnosed as under-injection under water injection condition.

[0019] Over-injection under water injection conditions is defined as follows: Based on the water injection scheme, including the water injection plan allocation and the cumulative water volume, calculate the cumulative water injection volume over 24 hours. When the cumulative water injection volume is greater than the upper limit water injection volume and the water injection plan allocation is not 0, it is diagnosed as over-injection under water injection conditions.

[0020] 2-2) The three-point card nearing expiration includes: overdue debugging data and near-expiration warning for debugging data; wherein:

[0021] The debugging data has expired: the number of days the debugging data is used is calculated based on the current date and the test date. If the number of days used exceeds M days, the water injection well debugging data has expired.

[0022] The early warning for debugging data is as follows: The early warning period is N days. The number of days the debugging data can be used is calculated based on the current date and the test date. If the number of days of use exceeds MN days;

[0023] 2-3) The pressure exceeding the range in the debugging data means that, according to the real-time oil pressure data, the oil pressure is greater than the constant pressure range given in the debugging data.

[0024] Step 3) specifically includes:

[0025] 3-1) Instantaneous water volume is calculated according to the error range P = [P] of the water injection qualification rate. min ,P max ] and fluctuation error range B = [B min B max Find the intersection to obtain the instantaneous flow control interval Q. PB =[Q PBmin Q PBmax ],Right now:

[0026] Q PB =P∩B=[P min ,P max ]∩[B min B max ] = [Q PBmin Q PBmax ]

[0027] 3-2) Based on real-time instantaneous flow data, when the real-time instantaneous flow is in Q... PB =[Q PBmin Q PBmax When the flow rate is within the specified range, maintain the existing state and do not control the instantaneous flow rate.

[0028] When the instantaneous flow rate is less than the lower limit value Q PBmin At that time, adjust the instantaneous flow rate to the lower limit value Q. PBmin When the instantaneous flow rate is greater than the upper limit value Q PBmax At that time, adjust the instantaneous flow rate to the upper limit value Q. PBmax .

[0029] Step 4) specifically includes:

[0030] 4-1) If P∩Z∩B≠empty set, then the optimal flow control range is:

[0031] Q OTP =P∩Z∩B=[Q OPTmin Q OPTmax ];

[0032] Based on the instantaneous flow rate and the optimal water volume control range Q OTP The relationship between them is executed through the following steps:

[0033] When the instantaneous flow rate is within the optimal water volume control range Q OTP During this period, maintain the existing state and do not control the instantaneous flow rate;

[0034] When the instantaneous flow rate exceeds the optimal water volume control range Q OTP When the oil pressure is rising, the optimal flow rate for the injection well valve group should be adjusted as follows: Q opt =Q OPTmin ;

[0035] When the instantaneous flow rate exceeds the optimal water volume control range Q OTP When the oil pressure is decreasing, the optimal flow rate for the injection well valve group should be adjusted as follows: Q opt =Q OPTmax ;

[0036] 4-2) If P∩Z∩B = empty set, then the optimal flow control range is:

[0037] Q opt =P∩Z=Q PZ =[Q PZmin Q PZmax ];

[0038] Based on the instantaneous flow rate and the optimal water volume control range Q opt The relationship between them is executed through the following steps:

[0039] When the instantaneous flow rate is within the optimal water volume control range Q opt During this period, maintain the existing state and do not control the instantaneous flow rate;

[0040] When the instantaneous flow rate exceeds the optimal water volume control range Q opt When the oil pressure is rising, the optimal flow rate for the injection well valve group should be adjusted as follows: Q opt =Q PZmin ;

[0041] When the instantaneous flow rate exceeds the optimal water volume control range Qopt When the oil pressure is decreasing, the optimal flow rate for the injection well valve group should be adjusted as follows: Q opt =Q PZmax .

[0042] Step 1-1) specifically includes:

[0043] 1-1-1) Based on the cumulative water volume, calculate the real-time cumulative water injection volume for today and the cumulative water injection volume for yesterday. If the cumulative water injection volume for today is less than the lower limit of the fluctuation error or higher than the upper limit of the fluctuation error, it is diagnosed as a water injection condition.

[0044] Water injection error is calculated based on three fixed cards, which include: detected water volume [Q1,Q2,Q3] and detected pressure [P1,P2,P3].

[0045] 1-1-2) Calculate the slope of the straight line corresponding to the current oil pressure segment:

[0046] k=(Q n -Q n-1 ) / (P n -P n-1 )

[0047] 1-1-3) Calculate the total well injection volume corresponding to the current injection oil pressure:

[0048] Q 计算 =k·(PP) n )+Q n

[0049] 1-1-4) Calculate the water injection error based on the real-time instantaneous water volume:

[0050] Water injection error = (Q 瞬时 ·24-Q 计算 ) / Q 计算 100%.

[0051] Steps 1-2) are specifically as follows:

[0052] The water injection completion rate mentioned in 1-2-1) is:

[0053] Water injection completion rate = 24-hour cumulative water injection volume / water injection plan allocation volume;

[0054] The cumulative water injection volume over 24 hours is as follows:

[0055] 24-hour cumulative water injection volume = Real-time cumulative water volume - Cumulative water volume 24 hours ago

[0056] 1-2-2) When the injection volume of the scheme is <50m 3At that time, the upper and lower limits of the injection volume are adjusted according to ±20% of the injection volume in the injection plan. When the injection volume in the plan is >50m³, 3 At that time, the upper and lower limits of water injection volume shall be adjusted according to ±15% of the water injection volume in the water injection plan;

[0057] 1-2-3) The error range for the water injection qualification rate of instantaneous water volume is:

[0058] P = [Pmin = lower limit water injection volume / 24, Pmax = upper limit water injection volume / 24].

[0059] Steps 1-3) are specifically as follows:

[0060] 1-3-1) Calculation of cumulative water injection volume in 24 hours:

[0061] The cumulative water injection volume over 24 hours is:

[0062] 24-hour cumulative water injection volume = Current real-time cumulative water volume - Cumulative water volume 24 hours ago

[0063] 1-3-2) When the cumulative water injection volume yesterday is less than 50m³ 3 At that time, the upper and lower limits of the injection volume will be adjusted according to ±20% of yesterday's cumulative water volume. When yesterday's cumulative water volume is >50m³, the injection volume will be adjusted accordingly. 3 At that time, the upper and lower limits of water injection volume will be adjusted according to ±15% of yesterday's cumulative water volume.

[0064] 1-3-3) The error range for instantaneous water volume fluctuation is:

[0065] B = [B min = Lower limit of water injection volume during fluctuation / 24,B max = Fluctuation limit water injection volume / 24].

[0066] The priority control order is as follows: the well flow rate is adjusted according to the order of water injection completion rate, water injection error, and fluctuation error.

[0067] The present invention has the following beneficial effects and advantages:

[0068] 1. The precision water injection control method in this invention can better adapt to the characteristics of the oil layer and the distribution of the reservoir, thus improving the water injection effect. Secondly, by analyzing the working conditions of the water injection well, timely fault handling can be carried out, which improves the water injection efficiency, reduces the interference between water injection layers, and improves the oil production capacity of the oil well.

[0069] 2. This invention has a simpler process and effectively extends the service life of the three-fixed card. Through real-time water injection well optimization control technology, water injection parameters are adjusted and optimized in real time, making the water injection process more stable and efficient, and achieving the best oilfield development effect.

[0070] 3. This invention, through the application of a precise control method for water injection wells, can effectively improve the development efficiency and economic benefits of oil fields, and contribute to the sustainable development of oil fields. Attached Figure Description

[0071] Figure 1 The three-dimensional card diagram of the water injection well of this invention;

[0072] Figure 2 The present invention provides a flowchart for the fine control of water injection wells. Detailed Implementation

[0073] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0074] This invention discloses a method for fine control of water injection wells based on three fixed cards. It acquires real-time flow and oil pressure data of the water injection well through sensors and uploads them to a cloud database. The method then analyzes the water injection well's operating conditions, calculates two rates (water injection qualification rate (water injection error, fluctuation error, water injection completion rate) and water injection compliance rate (output included in the model)), and establishes a fine control model based on water injection well commissioning data pushed from the cloud. This model enables real-time monitoring of the water injection well's operating status, intelligent adjustment of the water injection volume, and, while meeting the water injection qualification rate, strives to meet the requirements for water injection error and fluctuation error, effectively improving the two rates and meeting the requirements for fine water injection control of stratified wells. It also promptly reports expired or critical water injection data to the cloud.

[0075] like Figure 2 The diagram shown is a flowchart of the fine control process for the water injection well according to the present invention. The host computer establishes a fine control model for the operation of the water injection well, analyzes the optimal instantaneous water injection volume under the current injection pressure, and automatically adjusts the corresponding valve groups to perform flow adjustment operations. Specifically:

[0076] Step 1: The host computer retrieves the real-time flow and oil pressure data of the injection well collected by the sensor from the cloud database to determine the range of water injection error Z, the range of fluctuation error B, and the range of water injection completion rate P;

[0077] Based on the injected oil pressure, the water volume range Z = [Zmin, Zmax] that meets the water injection error is determined using the "Quantity-Pressure Quick Lookup Table" on the three-fixed card; the water volume range P = [Pmin, Pmax] that meets the scheme qualification rate is determined based on the injection scheme; and the water volume range B = [Bmin, Bmax] that meets the fluctuation error is determined based on yesterday's water injection volume.

[0078] Step 2: The host computer determines the current operating condition. If the current operating condition is any of the following: over- or under-filling, three-fixed card nearing expiration, or debugging data pressure exceeding the range, only an alarm signal is output; otherwise, proceed to step 3.

[0079] The system analyzes and judges the operating conditions of injection wells based on injection well data. When abnormal operating conditions occur, alarms are triggered via the cloud platform, while conditions requiring control are precisely controlled based on the three-fixed card system. Key operating conditions include scheme qualification rate (over- or under-injection), three-fixed card exceeding its expiration date, and pressure exceeding the range in commissioning data.

[0080] (1) Water injection completion rate (over-injection, under-injection)

[0081] According to relevant regulations on oilfield water injection, the scheme qualification rate (water injection completion rate), the upper limit of the qualification rate water injection volume, and the lower limit of the qualification rate water injection volume are calculated to obtain the error range P of the instantaneous water volume scheme qualification rate P = [P min ,P max ].

[0082] (2) The three-fixed card is overdue

[0083] ① In this embodiment, the validity period of the water injection well commissioning data is 135 days. The number of days of use of the commissioning data is calculated based on the current date and the test date. If the number of days of use exceeds 135 days, the water injection well commissioning data has expired. The diagnosis is water injection well condition: commissioning data expired. The commissioning data expired report is made, and the control strategy is not to control and to issue an alarm.

[0084] ② Pre-expiration warning: In this embodiment, after communication with the site, the advance warning period is 15 days, that is, the warning is issued when the debugging data has been used for 120 days. The number of days of debugging data use is calculated based on the current date and the test date. If the number of days of use exceeds 120 days, the debugging data of the water injection well is about to expire. The diagnosis is that the water injection well is in the condition of "the debugging data is about to expire". A pre-expiration warning for the debugging data is issued, and the control strategy is not to control and to issue an alarm.

[0085] (3) The pressure of the debugging data is out of range.

[0086] ① Based on real-time oil pressure data, when the oil pressure exceeds the set pressure range given in the commissioning data, it is diagnosed as a water injection condition: the pressure in the commissioning data is out of range. When the pressure in the commissioning data is out of range, the commissioning data has become invalid, and it is impossible to further refine the control of water injection error. The instantaneous flow rate is controlled according to the scheme qualification rate (water injection completion rate) and the fluctuation error range between today and yesterday.

[0087] ② Based on real-time oil pressure data, when the oil pressure is within the given pressure warning range (default is the second upper and lower limit critical value of the constant pressure range), it is diagnosed as a water injection condition: the pressure of the test data is about to exceed the range.

[0088] Step 3: The processor module, based on the collected injected oil pressure data, and according to... Figure 1 The three-point card shown determines the water injection error Z, fluctuation error B, and water injection completion rate P, and the water injection well is controlled accordingly based on the water injection error Z, fluctuation error B, and water injection completion rate P.

[0089] Step 3-1: The formula for calculating the water injection completion rate P is as follows:

[0090] Water injection completion rate P = 24-hour cumulative water injection volume / planned injection volume

[0091] The formula for calculating the cumulative water injection volume over 24 hours is as follows:

[0092] 24-hour cumulative water injection volume = Real-time cumulative water volume - Cumulative water volume 24 hours ago

[0093] When the injection volume of the scheme is <50m 3 When the planned injection volume is >50m³, the calculation is based on ±20% of the planned injection volume. 3 At that time, the calculation is based on ±15% of the allocated amount in the plan, and the calculation formula is as follows:

[0094] When the injection is <50m 3 hour:

[0095] Lower limit of water injection volume = injection allocation × (1-20%)

[0096] Maximum water injection volume = Allocation volume × (1 + 20%)

[0097] When the dosage is >50m 3 hour:

[0098] Lower limit of water injection volume = injection volume × (1-15%)

[0099] Maximum water injection volume = Allocation volume × (1 + 15%)

[0100] Error range of instantaneous water volume qualification rate scheme:

[0101] P min =Lower limit water injection volume / 24

[0102] P max =Maximum water injection volume / 24

[0103] ① Based on the water injection plan's allocated volume and cumulative water volume, calculate the 24-hour cumulative water injection volume. When the cumulative water injection volume is less than the lower limit water injection volume, and it is a non-absorbent well, the diagnosis is under-injection: the plan is under-injected. This may be due to reasons such as well shut-in or perforation, resulting in the incomplete water injection plan. The control strategy is to not control and issue an alarm.

[0104] ② Based on the water injection plan and the cumulative water volume, calculate the cumulative water injection volume over 24 hours. When the cumulative water injection volume is greater than the upper limit water injection volume and the planned water injection is not 0, it is diagnosed as water injection over-injection: the plan is over-injected, and the control strategy is not to control and to alarm.

[0105] Step 3-2: The calculation method for fluctuation error B is as follows:

[0106] Based on the cumulative water injection data, fluctuation error and water injection error are calculated and judged. According to relevant oilfield water injection regulations, the upper and lower limits of today's and yesterday's fluctuation error are calculated to obtain the instantaneous water volume fluctuation error range B = [B...]. min B max ].

[0107] The formula for calculating the cumulative water injection volume over 24 hours is as follows:

[0108] 24-hour cumulative water injection volume = Current real-time cumulative water volume - Cumulative water volume 24 hours ago

[0109] Taking today at 12:00 as an example, the real-time cumulative water injection volume for today and the real-time cumulative water injection volume for yesterday are calculated as follows:

[0110] Today's cumulative water injection = Cumulative water volume (today at 12:00) - Cumulative water volume (yesterday at 12:00)

[0111] Yesterday's cumulative water injection = Cumulative water volume (yesterday at 12:00) - Cumulative water volume (the day before yesterday at 12:00)

[0112] When the cumulative water injection volume yesterday was less than 50m 3 At that time, calculated based on ±20% of yesterday's cumulative water volume, when yesterday's cumulative water injection volume > 50m³ 3 At that time, the calculation is based on ±15% of yesterday's cumulative water volume, using the following formula:

[0113] When the cumulative water injection volume yesterday was less than 50m 3 hour:

[0114] Lower limit of water injection volume = yesterday's cumulative water injection volume × (1-20%)

[0115] Fluctuation limit water injection volume = yesterday's cumulative water injection volume × (1 + 20%)

[0116] When the cumulative water injection volume yesterday is greater than 50m 3 hour:

[0117] Lower limit of water injection volume = yesterday's cumulative water injection volume × (1-15%)

[0118] Fluctuation limit water injection volume = yesterday's cumulative water injection volume × (1 + 15%)

[0119] Instantaneous water volume fluctuation error range:

[0120] B min = Lower limit of water injection volume during fluctuation / 24

[0121] B max = Fluctuation limit water injection volume / 24

[0122] Calculate the real-time cumulative water injection volume today and the cumulative water injection volume yesterday based on the cumulative water volume. When the cumulative water injection volume today is less than the lower limit of the fluctuation error water injection volume or higher than the upper limit of the fluctuation error water injection volume, it is diagnosed as the water injection condition.

[0123] Step 3-3) The calculation method of the water injection error Z is as follows:

[0124] Calculate the water injection error based on the three-fixed card. The three-fixed card includes the detected water volume [Q1, Q2, Q3] and the detected pressure [P1, P2, P3]. When the number of detected pressure points is 3, it is divided into two pressure segments P < P2 and P > P2; when the number of detected pressure points is 4, it is divided into three pressure segments P < P2, P2 < P < P3, and P > P3; when the number of detected pressure points is greater than 4, and so on.

[0125] ① Calculate the slope of the straight line of the pressure segment to which the current oil pressure belongs:

[0126] k = (Q n - Q n-1 ) / (P n - P n-1 )

[0127] ② Calculate the total well injection volume corresponding to the current injection pressure (oil pressure):

[0128] Q 计算 = k·(P - P n ) + Q n

[0129] ③ Calculate the water injection error according to the real-time instantaneous water volume:

[0130] Water injection error = (Q 瞬时 ·24 - Q 计算 ) / Q 计算 ·100%

[0131] Step 4: Obtain the instantaneous flow control interval Q PB of the water injection well according to the fluctuation error B and the water injection completion rate P, and perform corresponding control on the water injection well according to the instantaneous flow control interval Q PB ;

[0132] Step 5: Then, obtain the optimal water volume control range interval Q opt according to the water injection error Z, the fluctuation error B, and the water injection completion rate P, and judge the relationship between the instantaneous flow rate and the optimal water volume control range interval Q opt , and the oil pressure data, and perform corresponding control on the water injection well;

[0133] Step 6: Finally, according to the priority control order of the qualification rate, the water injection error, the fluctuation error, and the pressure change trend, intelligently adjust the well flow rate for different working conditions to achieve the optimal fine control of the water injection well.

[0134] In this embodiment, in steps 3 to 5, when the diagnostic condition is not one of the three conditions of over- or under-injection, three-fixed card exceeding the expiration date, or debugging data pressure exceeding the range, the instantaneous flow rate is controlled according to the scheme qualification rate (water injection completion rate) and the fluctuation error range between today and yesterday.

[0135] In step 4, the instantaneous flow rate and the optimal water control range interval Q are determined. opt The relationship between the data and the oil pressure is used to control the water injection wells accordingly, specifically:

[0136] The error range of instantaneous water volume according to the pass rate scheme is P = [P min ,P max ] and fluctuation error range B = [B min B max Find the intersection to obtain the instantaneous flow control interval Q. PB =[Q PBmin Q PBmax ]:

[0137] Q PB =P∩B=[P min ,P max ]∩[B min B max ] = [Q PBmin Q PBmax ]

[0138] Based on real-time instantaneous traffic data, when the instantaneous traffic is in Q... PB =[Q PBmin Q PBmax When the flow rate is within the specified range, maintain the current state; when the instantaneous flow rate is less than the lower limit Q... PBmin At that time, adjust the instantaneous flow rate to the lower limit value Q. PBmin When the instantaneous flow rate is greater than the upper limit value Q PBmax At that time, adjust the instantaneous flow rate to the upper limit value Q. PBmax .

[0139] In step 5, the instantaneous flow rate and the optimal water control range Q are determined. opt The relationship between the data and the oil pressure is used to control the water injection wells accordingly, specifically:

[0140] like The optimal water control range interval Q OTP =P∩Z∩B=[Q OPTmin Q OPTmax ]:

[0141] ① When the instantaneous flow rate is within the optimal water control range, maintain the existing production status and do not make any adjustments;

[0142] ② When the instantaneous flow rate exceeds the optimal water volume control range and the oil pressure is rising, the optimal control flow rate Q of the injection well should be... opt =Q OPTmin ;

[0143] ③ When the instantaneous flow rate exceeds the optimal water volume control range and the oil pressure is decreasing, the optimal control flow rate Q of the injection well should be... opt =Q OPTmax .

[0144] (3) If The optimal water control range interval Q opt =P∩Z=Q PZ =[Q PZmin Q PZmax ];

[0145] ① When the instantaneous flow rate is within the optimal water control range, maintain the existing production status and do not make any adjustments;

[0146] ② When the instantaneous flow rate exceeds the optimal water volume control range and the oil pressure is rising, the optimal control flow rate Q of the injection well should be... opt =Q PZmin ;

[0147] ③ When the instantaneous flow rate exceeds the optimal water volume control range and the oil pressure is decreasing, the optimal control flow rate Q of the injection well should be... opt =Q PZmax .

[0148] The above description is merely an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, extensions, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A method for fine control of water injection wells based on three-dimensional cards, characterized in that, Real-time flow and oil pressure data of the injection well are acquired by sensors and uploaded to the cloud database. The host computer retrieves the data from the cloud database and, based on the injection scheme and the three-fixed card of the injection well issued by the cloud, the processor module establishes a fine control model for the operation of the injection well, analyzes the optimal instantaneous injection volume under the current injection pressure, and automatically adjusts the corresponding valve group to perform flow adjustment operations. This ensures that the injection error and fluctuation error meet the set requirements while meeting the water injection qualification rate. Combined with the trend of oil pressure data changes, the system realizes real-time monitoring of the operation status of the injection well and intelligent adjustment of the water injection volume. The host computer establishes a fine-grained control model for the operation of the injection well, analyzes the optimal instantaneous water injection rate under the current injection pressure, and automatically adjusts the corresponding valve groups to perform flow adjustment operations, specifically: Step 1: The host computer retrieves the real-time flow and oil pressure data of the injection well collected by the sensor from the cloud database to determine the range of water injection error Z, the range of fluctuation error B, and the range of water injection completion rate P; Step 2: The host computer determines the current operating condition. If the current operating condition is any of the following: over- or under-filling, three-fixed card nearing expiration, or debugging data pressure exceeding the range, only an alarm signal is output; otherwise, proceed to step 3. Step 3: The processor module determines the water injection error Z, fluctuation error B, and water injection completion rate P based on the collected injected oil pressure data and the three-dimensional card, and performs corresponding control on the water injection well based on the water injection error Z, fluctuation error B, and water injection completion rate P. Step 4: Based on the fluctuation error B and the water injection completion rate P, obtain the instantaneous flow control range Q of the injection well. PB Based on the instantaneous flow control interval Q PB Appropriate control should be exercised over the water injection wells; Step 5: Based on the water injection error Z, fluctuation error B, and water injection completion rate P, obtain the optimal water volume control range Q. opt And determine the instantaneous flow rate and the optimal water control range Q. opt The relationship between the data and the oil pressure data is used to control the water injection well accordingly. Step 6: Adjust the control according to the priority control sequence to complete the intelligent control of the water injection well.

2. The method for fine control of water injection wells based on three-point cards according to claim 1, characterized in that, Step 1 specifically includes: 1-1) Based on the collected oil pressure data, the host computer establishes a quantity-pressure-speed lookup table according to the three-fixed card standard to determine the water volume range Z=[Zmin,Zmax] that meets the water injection error. 1-2) Determine the water volume range P that satisfies the water injection completion rate according to the injection plan, that is: Obtain the water injection completion rate, the upper and lower limits of the water injection completion rate, and the error interval of the instantaneous water volume water injection completion rate P=[Pmin, Pmax]; 1-3) Determine the water volume range B = [Bmin, Bmax] that meets the fluctuation error based on yesterday's water injection volume.

3. The method for fine control of water injection wells based on three-point cards according to claim 1, characterized in that, The aforementioned operating conditions fall under the categories of under-injection and over-injection, including: under-injection during water injection and over-injection during water injection; wherein: 2-1) Under-injection under water injection condition: Based on the water injection plan including the water injection amount and the cumulative water volume, calculate the cumulative water injection volume in 24 hours. When the cumulative water injection volume is less than the lower limit water injection volume, and it is a non-absorption well, it is diagnosed as under-injection under water injection condition. Over-injection under water injection conditions is defined as follows: Based on the water injection scheme, including the water injection plan allocation and the cumulative water volume, calculate the cumulative water injection volume over 24 hours. When the cumulative water injection volume is greater than the upper limit water injection volume and the water injection plan allocation is not 0, it is diagnosed as over-injection under water injection conditions. 2-2) The three-point card nearing expiration includes: overdue debugging data and near-expiration warning for debugging data; wherein: The debugging data has expired: the number of days the debugging data is used is calculated based on the current date and the test date. If the number of days used exceeds M days, the water injection well debugging data has expired. The early warning for debugging data is as follows: The early warning period is N days. The number of days the debugging data can be used is calculated based on the current date and the test date. If the number of days of use exceeds MN days; 2-3) The pressure exceeding the range in the debugging data means that, according to the real-time oil pressure data, the oil pressure is greater than the constant pressure range given in the debugging data.

4. The method for fine control of water injection wells based on three-point cards according to claim 1, characterized in that, Step 4 specifically includes: 3-1) Instantaneous water volume is calculated according to the error range P = [P] of the water injection completion rate. min , P max ] and fluctuation error range B=[B min B max Find the intersection to obtain the instantaneous flow control interval Q. PB =[Q PBmin Q PBmax ],Right now: Q PB = P∩B=[P min , P max ]∩[B min , B max ]= [Q PBmin , Q PBmax ] 3-2) Based on real-time instantaneous flow data, when the real-time instantaneous flow is in Q... PB =[Q PBmin Q PBmax When the flow rate is within the specified range, maintain the existing state and do not control the instantaneous flow rate. When the instantaneous flow rate is less than the lower limit value Q PBmin At that time, adjust the instantaneous flow rate to the lower limit value Q. PBmin When the instantaneous flow rate is greater than the upper limit value Q PBmax At that time, adjust the instantaneous flow rate to the upper limit value Q. PBmax .

5. The method for fine control of water injection wells based on three-point cards according to claim 1, characterized in that, Step 5 specifically involves: 4-1) If P∩Z∩B≠empty set, then the optimal water control range is: Q OTP =P∩Z∩B= [Q OPTmin , Q OPTmax ]; Based on the instantaneous flow rate and the optimal water volume control range Q OTP The relationship between them is executed through the following steps: When the instantaneous flow rate is within the optimal water volume control range Q OTP During this period, maintain the existing state and do not control the instantaneous flow rate; When the instantaneous flow rate exceeds the optimal water volume control range Q OTP When the oil pressure is rising, the optimal flow rate for the injection well valve group should be adjusted as follows: Q opt = Q OPTmin ; When the instantaneous flow rate exceeds the optimal water volume control range Q OTP When the oil pressure is decreasing, the optimal flow rate for the injection well valve group should be adjusted as follows: Q opt = Q OPTmax ; 4-2) If P∩Z∩B = empty set, then the optimal water control range is: Q opt = P∩Z = Q PZ =[Q PZmin , Q PZmax ]; Based on the instantaneous flow rate and the optimal water volume control range Q opt The relationship between them is executed through the following steps: When the instantaneous flow rate is within the optimal water volume control range Q opt During this period, maintain the existing state and do not control the instantaneous flow rate; When the instantaneous flow rate exceeds the optimal water volume control range Q opt When the oil pressure is rising, the optimal flow rate for the injection well valve group should be adjusted as follows: Q opt = Q PZmin ; When the instantaneous flow rate exceeds the optimal water volume control range Q opt When the oil pressure is decreasing, the optimal flow rate for the injection well valve group should be adjusted as follows: Q opt = Q PZmax .

6. The method for fine control of water injection wells based on three-dimensional cards according to claim 2, characterized in that, Step 1-1) specifically involves: 1-1-1) Based on the cumulative water volume, calculate the real-time cumulative water injection volume for today and the cumulative water injection volume for yesterday. If the cumulative water injection volume for today is less than the lower limit of the fluctuation error or higher than the upper limit of the fluctuation error, it is diagnosed as a water injection condition. Water injection error is calculated based on three fixed cards, which include: detected water volume [Q1, Q2, Q3] and detected pressure [P1, P2, P3]. 1-1-2) Calculate the slope of the straight line corresponding to the current oil pressure: k=(Q n -Q n-1 ) / (P n -P n-1 ) 1-1-3) Calculate the total well injection volume corresponding to the current injection oil pressure: Q 计算 =k·(P-P n )+ Q n 1-1-4) Calculate the water injection error based on the real-time instantaneous water volume: Water injection error = (Q) 瞬时 ·24-Q 计算 ) / Q 计算 100%.

7. The method for fine control of water injection wells based on three-point cards according to claim 2, characterized in that, Steps 1-2) are specifically as follows: The water injection completion rate mentioned in 1-2-1) is: Water injection completion rate = 24-hour cumulative water injection volume / water injection volume allocated according to the water injection plan; The cumulative water injection volume over 24 hours is as follows: 24-hour cumulative water injection volume = Real-time cumulative water volume - Cumulative water volume 24 hours ago 1-2-2) When the planned injection volume is <50m 3 At that time, the upper and lower limits of the water injection volume are adjusted according to ±20% of the water injection volume in the injection plan. When the injection volume in the plan is >50m³, 3 At that time, the upper and lower limits of water injection volume shall be adjusted according to ±15% of the water injection volume in the water injection plan; 1-2-3) The error range for the water injection qualification rate of instantaneous water volume is: P = [Pmin = lower limit injection volume / 24, Pmax = upper limit injection volume / 24].

8. The method for fine control of water injection wells based on three-point cards according to claim 2, characterized in that, Steps 1-3 are specifically as follows: 1-3-1) Calculation of cumulative water injection volume in 24 hours: The cumulative water injection volume over 24 hours is: 24-hour cumulative water injection volume = Current real-time cumulative water volume - Cumulative water volume 24 hours ago 1-3-2) When the cumulative water injection volume yesterday is less than 50m³ 3 At that time, the upper and lower limits of the water injection volume will be adjusted according to ±20% of yesterday's cumulative water volume. When yesterday's cumulative water injection volume is >50m³, the upper and lower limits of the water injection volume will be adjusted accordingly. 3 At that time, the upper and lower limits of water injection volume will be adjusted according to ±15% of yesterday's cumulative water volume. 1-3-3) The error range for instantaneous water volume fluctuation is: B=[B min =Lower limit of water injection volume during fluctuation / 24,B max = Fluctuation upper limit water injection volume / 24].

9. The method for fine control of water injection wells based on three-point cards according to claim 1, characterized in that, The priority control order is as follows: the well flow rate is adjusted according to the order of water injection completion rate, water injection error, and fluctuation error.

Images