Method capable of improving layered flow measurement and regulation efficiency

Abstract

The invention relates to the technical field of flow measurement and regulation, and provides a method capable of improving layered flow measurement and regulation efficiency, which comprises the following steps of: 1, displaying a relation curve of injection pressure and injection amount under a stable flowing condition through a water injection well water absorption indication curve, and displaying a specific indication curve in each layer section under layered water injection, displaying a relation curve between the injection pressure of each layer section and the water injection rate of the layer section; and 2, on the premise that the daily water injection rate of each layer section is determined, a pressure point meeting injection allocation of each layer section is found through a water injection well water absorption indication curve algorithm, and the wellhead pressure with the maximum value is selected as a water distribution pressure point of the water injection well. Wellhead pressure is recorded when a water injection well reaches the injection allocation amount, the maximum value is selected as a water distribution pressure point of the wellhead pressure, the maximum wellhead pressure is kept unchanged, the water amount of each layer section meets the water amount required by injection allocation by adjusting the sizes of water nozzles in layers layer by layer, and then the effects of eliminating interlayer interference influence factors and achieving rapid measurement and adjustment are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of flow measurement and adjustment, and specifically to a method that can improve the efficiency of layered flow measurement and adjustment. Background Art

[0002] An injection well refers to an engineering facility. Injection wells are an important engineering technology in oil and gas extraction. Injection wells help to push oil or natural gas, making it move near the production well, improving the recovery rate. The injection of water can drive oil and gas, making it easier to flow to the collection equipment. By adjusting the bottom hole pressure, the oil production efficiency can be improved, the life of the oilfield can be extended, and it plays an environmental protection role in the abandonment stage. The layered flow measurement and adjustment of injection wells means that in oil extraction, in order to effectively inject water or other liquids to maintain the reservoir pressure or improve the oil production efficiency, different flow rates or pressure levels are injected into different formations or oil layers, which can achieve precise control of different formations and efficient water injection, thereby improving the recovery rate and production efficiency of the oilfield, helping to ensure the balanced exploitation of each layer of the reservoir, and improving the oil production efficiency.

[0003] However, during the layered flow measurement and adjustment of injection wells, there is an interlayer interference problem. Especially for layered wells with more layers, the debugging difficulty is more prominent. When adjusting the flow rate of a certain layer, the flow rates of other layers also change accordingly. For the layers that have been adjusted, they change again when adjusting other layers. The interlayer interference problem during the layered flow measurement and adjustment of injection wells will affect the efficiency of layered flow measurement and adjustment. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a method that can improve the efficiency of layered flow measurement and adjustment, and solves the problem that the interlayer interference problem during the layered flow measurement and adjustment of injection wells affects the efficiency of layered flow measurement and adjustment.

[0005] To achieve the above objectives, the present invention is realized through the following technical solutions: A method that can improve the efficiency of layered flow measurement and adjustment, including the following steps;

[0006] Step 1, through the water absorption indicator curve of the injection well, display the relationship curve between the injection pressure and the injection volume under the condition of stable flow. Under layered injection, there is a specific indicator curve for each layer section, showing the relationship curve between the injection pressure of each layer section and the layer section injection volume;

[0007] Step 2, on the premise that the daily injection volume of each layer section is determined, through the water absorption indicator curve algorithm of the injection well, find the pressure points that meet the injection allocation of each layer section, and select the wellhead pressure with the maximum value as the water distribution pressure point of the injection well;

[0008] Step 3, keep the wellhead pressure with the maximum value in Step 2 unchanged, and by adjusting the size of the water nozzle, make the intersection pressure value of the water absorption curve of each layer section and the injection allocation volume equal to the water distribution pressure point.

[0009] Preferably, the water absorption indicator curve equation of the water injection well is as follows

[0010] P 井口 = kQ + P 启 + ΔP

[0011] Wherein, P wellhead represents the wellhead pressure, P start represents the wellhead pressure when the layer starts to absorb water, the pressure ΔP represents the pressure loss of the water nozzle, and Q represents the daily water injection volume of the layer.

[0012] Preferably, the P 井口 and the daily water injection volume Q of the layer correspond one-to-one.

[0013] Preferably, the test water injection well has a total of five layers, which are respectively offset 1, offset 2, offset 3, offset 4 and offset 5.

[0014] Preferably, when the pressure loss of the water nozzle is not considered, that is, ΔP = 0, there is a corresponding wellhead pressure for the water injection volume allocation of the five layers, and the maximum value is selected as the water distribution pressure point of the water injection well.

[0015] Preferably, the water distribution pressure point is selected under the condition that the fracture pressure is not exceeded and the well pump pressure can be satisfied. The water distribution pressure point is P 分 .

[0016] Preferably, the water nozzle adjustment range in step three is 0% to 100%.

[0017] Preferably, the fracture pressure of the test water injection well is 13.5MP, and the well pump pressure of the test water injection well is 14.2MPa.

[0018] The present invention provides a method that can improve the efficiency of stratified flow measurement and adjustment. It has the following beneficial effects:

[0019] The present invention records the wellhead pressure when the water injection well reaches the injection volume allocation, selects the maximum value as the water distribution pressure point of the wellhead pressure, keeps the maximum wellhead pressure unchanged, and adjusts the size of the water nozzle in the stratified layer layer by layer to make the water volume of each layer meet the required water volume of the injection volume allocation, thereby achieving the effect of eliminating the influencing factors of interlayer interference and realizing rapid measurement and adjustment. Brief Description of the Drawings

[0020] Figure 1 is a schematic flow chart of the method of the present invention;

[0021] Figure 2 is a schematic diagram of the corresponding relationship of the water absorption indicator curve of the present invention;

[0022] Figure 3 is a schematic diagram of the curve change of the water absorption indicator curve of the present invention;

[0023] Figure 4 Schematic diagram of the water separation pressure point of the present invention;

[0024] Figure 5 Schematic diagram of the intersection points of the pressure values of the five intervals of the present invention. Specific embodiments

[0025] Next, in conjunction with the accompanying drawings of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0026] Embodiment:

[0027] Please refer to the attached Figure 1 , the embodiment of the present invention provides a method that can improve the efficiency of stratified flow measurement and adjustment, including the following steps;

[0028] Step 1, through the water absorption indicator curve of the injection well, the water absorption indicator curve equation of the injection well is P 井口 = kQ + P 启 + ΔP, where P wellhead represents the wellhead pressure, P start represents the wellhead pressure when the interval starts to absorb water, the pressure ΔP represents the pressure loss of the nozzle, Q represents the daily injection volume of the interval, and further shows the relationship curve between the injection pressure and the injection volume under the condition of stable flow. Please refer to the attached Figure 2 , under stratified injection, each interval has a specific indicator curve, showing the relationship curve between the injection pressure and the injection volume of each interval. P 井口 and the daily injection volume Q of the interval correspond one by one. The test injection well has a total of five intervals, and the five intervals are respectively partial 1, partial 2, partial 3, partial 4, and partial 5;

[0029] Step 2, on the premise that the daily injection volume of each interval is determined, through the water absorption indicator curve algorithm of the injection well, find the pressure points that meet the injection allocation of each interval. When not considering the pressure loss of the nozzle, that is, ΔP = 0, the injection allocation volumes of the five layers all have corresponding wellhead pressures. Select the wellhead pressure with the maximum value as the water separation pressure point of the injection well. The water separation pressure point is selected under the condition that it does not exceed the fracture pressure of 13.5 MP of the test injection well and the well pump pressure can meet. The water separation pressure point is P 分 , please refer to the attached Figure 4 ;

[0030] Step 3, keep the wellhead pressure with the maximum value in Step 2 unchanged, and by adjusting the nozzle sizes of partial 1, partial 2, partial 3, partial 4, and partial 5 respectively, the nozzle adjustment range is 0% to 100%. When the nozzle changes, the interval indicator curve will move up and down along the P axis. Please refer to the attachedFigure 3 such that the intersection pressure values between the water absorption curves of each layer section and the water injection volume are all equal to P 分 , refer to the attachment Figure 5 , by keeping the wellhead pressure constant and continuously adjusting the nozzle size, the interlayer interference influencing factors are eliminated, the measurement and adjustment difficulty is reduced, and the measurement and adjustment efficiency is greatly improved.

[0031] Application cases;

[0032] Well Bei 1-1-Ping 75, on-site test of intelligent separate water injection with preset cable, with a total of five layer sections and prominent interlayer contradictions. The constant pressure method was used for testing, and the testing time was only 0.5 hours. The specific measurement and adjustment process is as follows: The pump pressure of this well is 14.2 MPa, and the fracture pressure is 13.5 MPa.

[0033] First, punch the inspection and matching card. The wellhead pressure of the water injection well is 12.9 MPa. The nozzle sizes of the five separate layers are adjusted respectively. The nozzle size of partial layer 1 is 6%, the nozzle size of partial layer 2 is 15%, the nozzle size of partial layer 3 is 49%, the nozzle size of partial layer 4 is 100%, and the nozzle size of partial layer 5 is 45%.

[0034] Inspection and matching 1 (Wellhead pressure: 12.9 MPa)

[0035]

[0036]

[0037] Second step: Raise the wellhead pressure of the water injection well to 13.3 MPa and punch the inspection and matching card.

[0038] Inspection and matching 2 (Wellhead pressure: 13.3 MPa)

[0039]

[0040] At this time, the water volume of partial layer 1 has reached the upper limit and the nozzle opening is near the lower limit at 6%. The nozzle of partial layer 4 cannot complete the water injection allocation even when adjusted to the maximum, and the interlayer contradiction is prominent. It can be determined that the test is carried out with 13.3 MPa as the water distribution point, and the nozzle openings of partial layer 1 and partial layer 4 do not need to be adjusted anymore. Next, keep the wellhead pressure at 13.3 MPa constant and adjust to partial layer 2, partial layer 3, and partial layer 5 in sequence.

[0041] Third step: Enlarge the nozzle of partial layer 2 to adjust the nozzle size of partial layer 2 to 70%, keep the wellhead pressure of the water injection well at 13.3 MPa, and punch the inspection and matching card.

[0042] Inspection and matching 3 (Wellhead pressure: 13.3 MPa)

[0043]

[0044]

[0045] Step 4: Enlarge the nozzle of the offset 3 water nozzle to adjust the size of the offset 3 water nozzle to 100%, maintain the wellhead pressure of the injection well at 13.3 MPa, and punch the inspection and matching card

[0046] Inspection and matching 4 (Wellhead pressure: 13.3 MPa)

[0047]

[0048] Step 5: Reduce the nozzle of the offset 5 water nozzle to adjust the size of the offset 5 water nozzle to 40%, maintain the wellhead pressure of the injection well at 13.3 MPa, and punch the inspection and matching card

[0049] Inspection and matching 5 (Wellhead pressure: 13.3 MPa)

[0050]

[0051]

[0052] The offset 1 of this well is a strong water absorption layer, and the water absorption of the offset 3 and offset 4 is poor. By adjusting the opening of the water nozzle, the interlayer contradiction can be overcome, so that each layer injects water according to the plan, and the maximum wellhead pressure remains unchanged. By adjusting the size of the water nozzle in each layer step by step, the water volume in each layer section meets the water volume requirements of the injection allocation, so as to achieve the effect of eliminating the influencing factors of interlayer interference and realizing rapid measurement and adjustment.

[0053] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for improving the efficiency of hierarchical flow measurement and adjustment, characterized in that, Including the following steps; Step 1: Through the water absorption indicator curve of the injection well, under the condition of stable flow, the relationship curve between the injection pressure and the injection volume is shown. Under separate layer injection, there is a specific indicator curve for each layer section, showing the relationship curve between the injection pressure and the layer section injection volume of each layer section; Step 2: On the premise that the daily injection volume of each layer section is determined, through the water absorption indicator curve algorithm of the injection well, find the pressure points that meet the injection allocation of each layer section, and select the wellhead pressure with the maximum value as the water distribution pressure point of the injection well; Step 3: Keep the maximum wellhead pressure in Step 2 unchanged, and by adjusting the size of the nozzle, make the intersection pressure values of the water absorption curves of each layer section and the injection allocation volume all equal to the water distribution pressure point.

2. The method for improving the efficiency of hierarchical flow measurement and adjustment according to claim 1, characterized in that, The water absorption indicator curve equation of the injection well is as follows P 井口 = kQ + P 启 + ΔP Among them, P wellhead represents the wellhead pressure, P start represents the wellhead pressure when the layer section starts to absorb water, the pressure ΔP represents the nozzle loss pressure, and Q represents the daily injection volume of the layer section.

3. A method for improving the efficiency of hierarchical flow measurement and adjustment according to claim 1, characterized in that The said P 井口 corresponds one-to-one with the daily water injection volume Q of the layer section.

4. A method for improving the efficiency of hierarchical flow measurement and adjustment according to claim 1, characterized in that, The test injection well has a total of five layer sections, which are respectively partial 1, partial 2, partial 3, partial 4 and partial 5.

5. A method for improving the efficiency of hierarchical flow measurement and adjustment according to claim 1, characterized in that, When not considering the pressure loss of the nozzle, that is, ΔP = 0, there is a corresponding wellhead pressure for the injection allocation volume of the five layers, and the maximum value is selected as the water distribution pressure point of the injection well.

6. A method for improving the efficiency of hierarchical flow measurement and adjustment according to claim 3, characterized in that, The water diversion pressure point is selected under the condition that it does not exceed the fracture pressure and the well pump pressure can be satisfied, and the water diversion pressure point is P 分 .

7. A method for improving the efficiency of hierarchical flow measurement and adjustment according to claim 1, characterized in that, The nozzle adjustment range in Step 3 is 0% to 100%.

8. A method for improving the efficiency of hierarchical flow measurement and adjustment according to claim 1, characterized in that The fracture pressure of the test injection well is 13.5 MP, and the well pump pressure of the test injection well is 14.2 MPa.

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