An electric driven fracturing unit, system and control method

Abstract

The present invention relates to an electric-driven fracturing unit, system and control method; the electric-driven fracturing unit comprises: a fracturing skid assembly and a frequency conversion system, the fracturing skid assembly comprises at least a frequency conversion fracturing skid and a fixed frequency fracturing skid; the fixed frequency fracturing skid is connected to a power supply bus; one end of the frequency conversion system is connected to the power supply bus, and the other end is connected to the frequency conversion fracturing skid to adjust the current frequency of the frequency conversion fracturing skid. In this way, the fixed frequency fracturing skid is replaced, thereby reducing the floor space and price cost corresponding to the replacement part, thereby generally solving the problem that the existing electric-driven fracturing equipment occupies too large an area and is too costly.

Description

Technical Field

[0001] The present invention relates to the technical field of electric-driven fracturing, and in particular to an electric-driven fracturing unit, system and control method. Background Art

[0002] At oil and gas field operation sites around the world, electric fracturing drives fracturing skids to work in places with relatively complete power equipment. Existing electric fracturing equipment, in order to adjust the speed and displacement of the fracturing skid, is driven by setting a variable frequency motor, and the speed and displacement of the fracturing skid are controlled by controlling the change of frequency.

[0003] However, although this variable frequency control method can flexibly adjust the speed and displacement of the fracturing skid, in terms of hardware, each fracturing skid needs to be equipped with a frequency converter, and each existing frequency converter occupies at least 15 square meters and costs more than 3 million yuan. This occupies too much space and is too expensive for existing electric fracturing equipment. Summary of the invention

[0004] In order to solve at least one aspect of the above technical problems to a certain extent, the present invention provides an electric-driven fracturing unit, which includes: a fracturing skid assembly and a frequency conversion system, wherein the fracturing skid assembly includes at least a variable frequency fracturing skid and a fixed frequency fracturing skid; the fixed frequency fracturing skid is connected to a power supply bus; one end of the frequency conversion system is connected to the power supply bus, and the other end is connected to the variable frequency fracturing skid to adjust the current frequency of the variable frequency fracturing skid.

[0005] In this way, the fixed-frequency fracturing skid is used for replacement, thereby reducing the floor space and price cost of the replacement part, thereby generally solving the problem of the existing electric-driven fracturing equipment occupying too much floor space and being too costly.

[0006] Optionally, the total rated power of the fixed-frequency fracturing skid in the fracturing skid assembly is 1 / 3-2 / 3 of the total rated power of the fracturing skid assembly, or

[0007] The number of the fixed-frequency fracturing skids in the fracturing skid assembly is 0.5-2 times the number of the variable-frequency fracturing skids.

[0008] In this way, the floor space and price cost of the frequency converter can be saved, thereby further solving the problem of floor space and price cost.

[0009] Optionally, the total rated power of the fixed-frequency fracturing skid in the fracturing skid assembly is 1 / 2 of the total rated power of the fracturing skid assembly, or

[0010] The number of the fixed-frequency fracturing skids in the fracturing skid assembly is the same as the number of the variable-frequency fracturing skids.

[0011] In this way, the occupation ratio of the variable frequency fracturing skid can be minimized while ensuring the total power range of the fracturing skid assembly, thereby saving floor space and price costs to the maximum extent, thereby further solving the problem of floor space and price costs.

[0012] Optionally, the rated power of the fixed-frequency fracturing skid in the fracturing skid assembly falls within the total power range of the variable-frequency fracturing skid.

[0013] In this way, the total power range of the fracturing skid assembly can cover all powers, thereby avoiding omissions due to incomplete coverage.

[0014] Optionally, the number of the fixed-frequency fracturing skids in the fracturing skid assembly is multiple, the number of the variable-frequency fracturing skids is one or two, and the rated power of at least one of the fixed-frequency fracturing skids falls within the total power range of the variable-frequency fracturing skids.

[0015] In this way, only one or two variable frequency fracturing skids are used, thereby greatly reducing the number of frequency converters used while ensuring the coverage of the total power range of the fracturing skid assembly, thereby greatly reducing the floor space and price cost.

[0016] Optionally, the variable frequency fracturing skid / the fixed frequency fracturing skid includes a driving motor and a fracturing pump, and the driving motor drives the fracturing pump.

[0017] In this way, the driving motor provides driving force to drive the fracturing pump to work, thereby completing the fracturing work.

[0018] Optionally, there are multiple fracturing pumps, and the variable frequency fracturing skid / the fixed frequency fracturing skid further includes a transfer case, and the drive motor is connected to the multiple fracturing pumps via the transfer case, and the transfer case distributes the power of the drive motor to the multiple fracturing pumps.

[0019] In this way, a plurality of connected fracturing pumps can be driven to work through a transfer case by one driving motor; the transfer case distributes the power of the driving motor to each connected fracturing pump, thereby driving the fracturing pump to work normally.

[0020] Optionally, in the variable frequency fracturing skid / the fixed frequency fracturing skid, the number of the driving motor is one.

[0021] Optionally, the frequency conversion system includes a frequency converter, and the frequency converter is connected to the frequency conversion fracturing skid.

[0022] In this way, the frequency converter in the frequency conversion system is directly connected to the drive motor in the frequency conversion fracturing skid, and the frequency of the alternating current flowing into the drive motor is adjusted, thereby adjusting the operating power of the drive motor.

[0023] Optionally, one frequency converter is connected to two or three frequency conversion fracturing skids.

[0024] In this way, the frequency converters of two or three frequency converter fracturing skids can be integrated together, thereby reducing the occupied area and price cost of the frequency converter.

[0025] Another object of the present invention is to provide an electric-driven fracturing system, which comprises the electric-driven fracturing unit and the generator set as described above, wherein the generator set is connected to the electric-driven fracturing unit through the power supply bus.

[0026] In this way, the fixed-frequency fracturing skid is used for replacement, thereby reducing the floor space and price cost of the replacement part, thereby generally solving the problem of the existing electric-driven fracturing equipment occupying too much floor space and being too costly.

[0027] Another object of the present invention is to provide a method for controlling an electric-driven fracturing unit, which comprises:

[0028] After the electric-driven fracturing unit is powered on, the predicted working power, the rated power of each of the fixed-frequency fracturing skids, and the power range of each of the variable-frequency fracturing skids are obtained;

[0029] According to the predicted working power and the rated power of the fixed-frequency fracturing skid, determining the fixed-frequency fracturing skid to be started and starting it;

[0030] Obtaining operating parameters of the electric-driven fracturing unit;

[0031] According to the operating parameters and the power range of the variable frequency fracturing skid, the operating power of the variable frequency fracturing skid is increased one by one until the operating parameters meet the construction requirements;

[0032] The operating power of each of the variable frequency fracturing pries is counted, and the total operating power of the variable frequency fracturing pries is distributed in equal proportion according to the maximum power within the power range of each of the variable frequency fracturing pries.

[0033] In this way, the fixed-frequency fracturing skid can be started first and then the variable-frequency fracturing skid can be started; on the one hand, the operating parameters can finally meet the construction requirements, and on the other hand, the current shock effect between the fixed-frequency start-up and the variable-frequency start-up can be avoided.

[0034] Optionally, the counting of the operating powers of the variable frequency fracturing plies and the proportional distribution of the total operating powers of the variable frequency fracturing plies according to the maximum powers of the power ranges of the variable frequency fracturing plies include:

[0035] Counting the operating power of each variable frequency fracturing skid;

[0036] Calculating the total operating power of the variable frequency fracturing skid according to the operating power of each variable frequency fracturing skid;

[0037] Determining a ratio of the maximum powers of the variable frequency fracturing skids according to the maximum powers of the power ranges of the variable frequency fracturing skids;

[0038] The total operating power of the variable frequency fracturing skid is redistributed according to the ratio of the maximum power of each variable frequency fracturing skid.

[0039] In this way, after redistribution, any one of the variable frequency fracturing skids operates at the same proportion of its maximum power (, thereby greatly reducing the damage to the service life of the running variable frequency fracturing skid. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a structural diagram of an electric-driven fracturing unit according to an embodiment of the present invention;

[0041] Figure 2 This is a schematic structural diagram of an electric-driven fracturing unit according to an embodiment of the present invention;

[0042] Figure 3 This is a schematic diagram of the structure of an electric-driven fracturing system according to an embodiment of the present invention;

[0043] Figure 4 This is a flow chart of a method for controlling an electric-driven fracturing unit according to an embodiment of the present invention;

[0044] Figure 5 Flow chart of step 500 of the method for controlling an electric-driven fracturing unit according to an embodiment of the present invention.

[0045] Description of reference numerals:

[0046] 1- fracturing skid assembly; 11- variable frequency fracturing skid 11; 12- fixed frequency fracturing skid; 13- driving motor; 14- fracturing pump; 15- transfer case; 2- variable frequency system; 21- inverter; 3- power supply bus; 4- generator set. DETAILED DESCRIPTION

[0047] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0048] If there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features.

[0049] It should be noted here that, for the fracturing skid assembly and even the entire electric-driven fracturing unit, to describe its specific working capacity, it is generally judged by the displacement or power of the fracturing skid assembly or the electric-driven fracturing unit, wherein the power is obtained by dividing the product of the displacement and the corresponding pressure by a coefficient. In the present application, in order to facilitate description and definition, the working capacity of the fracturing skid assembly or the entire electric-driven fracturing unit is uniformly defined by power. However, this does not mean that the present application abandons the method of defining or describing the working capacity by displacement or other operating parameters. Whether the working capacity is described by power or by the corresponding converted displacement or other operating parameters such as operating pressure, it falls within the protection scope of the present invention.

[0050] like Figure 1 As shown, it is a structural diagram of the electric-driven fracturing unit according to an embodiment of the present invention; Figure 2 The electric-driven fracturing unit comprises: a fracturing skid assembly 1 and a frequency conversion system 2, wherein the fracturing skid assembly 1 comprises at least a frequency conversion fracturing skid 11 and a fixed frequency fracturing skid 12; the fixed frequency fracturing skid 12 is connected to a power supply bus 3; one end of the frequency conversion system 2 is connected to the power supply bus 3, and the other end is connected to the frequency conversion fracturing skid 11 to adjust the current frequency of the frequency conversion fracturing skid 11.

[0051] In this way, alternating current is provided through the power supply bus 3, and fracturing work is completed through the fracturing skid assembly 1; for the fixed-frequency fracturing skid 12 in the fracturing skid assembly 1, fixed-frequency alternating current is directly provided through the power supply bus 3, and for the variable-frequency fracturing skid 11, the alternating current provided by the power supply bus 3 is adjusted in current frequency after passing through the frequency conversion system 2, and then provided to the variable-frequency fracturing skid 11, so that the variable-frequency fracturing skid 11 can work.

[0052] In this way, in this electric-driven fracturing unit, a part of the fracturing work is completed by replacing the variable-frequency fracturing pry 11 with the fixed-frequency fracturing pry 12, and the corresponding variable-frequency system 2 of this part can be omitted, thereby reducing the corresponding floor space and price cost of this part; in this way, the fixed-frequency fracturing pry 12 is used for replacement, thereby reducing the corresponding floor space and price cost of the replaced part, thereby generally solving the problem of the existing electric-driven fracturing equipment occupying too large an area and being too costly.

[0053] In addition, by replacing the variable frequency fracturing skid 11 with the fixed frequency fracturing skid 12, the number of intermediate links and wiring connections is also reduced.

[0054] Optionally, the total rated power of the fixed-frequency fracturing skid 12 in the fracturing skid assembly 1 is 1 / 3-2 / 3 of the total rated power of the fracturing skid assembly 1 .

[0055] Among them, the fracturing skid assembly 1 includes multiple fixed-frequency fracturing skids 12 and multiple variable-frequency fracturing skids 11; wherein each fixed-frequency fracturing skid 12 has its rated power, and each variable-frequency fracturing skid 11 has its adjustable power range; the maximum power in the adjustable power range of the variable-frequency fracturing skid 11 is considered to be the rated power of the variable-frequency fracturing skid 11 in this application.

[0056] Among them, the total rated power of the fixed-frequency fracturing pry 12 is the sum of the rated powers of all fixed-frequency fracturing pry 12; the total rated power of the variable-frequency fracturing pry 11 is the sum of the rated powers (maximum power within the adjustable power range) of all variable-frequency fracturing pry 11; the total rated power of the fracturing pry assembly 1 is the sum of the total rated power of the fixed-frequency fracturing pry 12 and the total rated power of the variable-frequency fracturing pry 11 in the fracturing pry assembly 1.

[0057] In this way, compared with the variable frequency fracturing pry 11, the fixed frequency fracturing pry 12 can save the floor space and price cost occupied by the frequency converter 21; therefore, setting the total rated power of the fixed frequency fracturing pry 12 to 1 / 3-2 / 3 of the total rated power of the fracturing pry assembly 1 means that 1 / 3-2 / 3 of the floor space and price cost of the frequency converter 21 can be saved, thereby further solving the problem of floor space and price cost.

[0058] Here, it is necessary to explain the total rated power of the fixed frequency fracturing skid 12 and the total rated power of the fracturing skid assembly 1. The fracturing skid assembly 1 includes a fixed frequency fracturing skid 12 and a variable frequency fracturing skid 11, wherein the fixed frequency fracturing skid 12 works according to the rated power, and the variable frequency fracturing skid 11 is adjusted to work within the range of 0-rated power. Here, when analyzing the selectable power of the entire fracturing skid assembly 1, we need to consider the fixed frequency fracturing skid 12 and the variable frequency fracturing skid 11:

[0059] First, considering the floor space and price cost, the larger the share of the total rated power of the fixed-frequency fracturing skid 12 is, the more variable-frequency fracturing skids 11 are replaced, and the more floor space and price cost can be saved; therefore, considering the floor space and price cost, the larger the share of the total rated power of the fixed-frequency fracturing skid 12 is, the better.

[0060] Secondly, consider the selectable power of the entire fracturing skid assembly 1 based on the number of fixed-frequency fracturing skids 12 activated: For the sake of illustration, we assume that the rated power of all fixed-frequency fracturing skids 12 is the same (rated power is E), the number of fixed-frequency fracturing skids 12 is n, the adjustable power range of all variable-frequency fracturing skids 11 is the same (the maximum value of the adjustable range is F), and the number of variable-frequency fracturing skids 11 is m: then the number of fixed-frequency fracturing skids 12 activated is different, and the total power range of the entire fracturing skid assembly 1 is also different. In order to facilitate further analysis, we calculated and counted the total power range of the fracturing skid assembly 1 when different numbers of fixed-frequency fracturing skids 12 were activated, as shown in the following table:

[0061]

[0062] From the above table, we can find that if the total power range of the fracturing skid assembly 1 is to cover 0-(nE+mF), E≤mF must be satisfied; that is, the rated power of the fixed-frequency fracturing skid 12 falls within the total power range of the variable-frequency fracturing skid 11.

[0063] Finally, the above conclusions are analyzed based on the premise that all variable frequency fracturing skids 11 are started at the same time and the rated powers of the fixed frequency fracturing skids 12 are the same. In the case where the rated powers of the fixed frequency fracturing skids 12 are different, the actual situation will be adjusted.

[0064] Optionally, the rated power of the fixed-frequency fracturing skid 12 in the fracturing skid assembly 1 falls within the total power range of the variable-frequency fracturing skid 11 .

[0065] In this way, the total power range of the fracturing skid assembly 1 can cover all powers (the power is less than the maximum value in the total power range), thereby avoiding omissions due to incomplete coverage (omissions mean that the fracturing skid assembly 1 cannot be adjusted to the omitted power).

[0066] Optionally, the number of the fixed-frequency fracturing pries 12 in the fracturing pry assembly 1 is 0.5-2 times the number of the variable-frequency fracturing pries 11 .

[0067] In this way, the quantitative relationship between the fixed-frequency fracturing skids 12 and the variable-frequency fracturing skids 11 in the fracturing skid assembly 1 is limited from the perspective of the number of fracturing skids, so that part of the variable-frequency fracturing skids 11 can be replaced by fixed-frequency fracturing skids 12, thereby saving floor space and price costs.

[0068] Optionally, the total rated power of the fixed-frequency fracturing skid 12 in the fracturing skid assembly 1 is 1 / 2 of the total rated power of the fracturing skid assembly 1 .

[0069] In this way, the occupancy ratio of the variable frequency fracturing skid 11 can be reduced to the maximum extent (considering the existence of a variable frequency fracturing skid 11 and a fixed frequency fracturing skid 12) while ensuring the total power range of the fracturing skid assembly 1, thereby saving floor space and price costs to the maximum extent, thereby further solving the problem of floor space and price costs.

[0070] Optionally, the number of the fixed-frequency fracturing skids 12 in the fracturing skid assembly 1 is the same as the number of the variable-frequency fracturing skids 11 .

[0071] In this way, the quantitative relationship between the fixed-frequency fracturing pry 12 and the variable-frequency fracturing pry 11 in the fracturing pry assembly 1 is limited from the perspective of the number of fracturing prys, so as to replace the variable-frequency fracturing pry 11 with the fixed-frequency fracturing pry 12 to the maximum extent (considering the existence of one variable-frequency fracturing pry 11 and one fixed-frequency fracturing pry 12), thereby saving floor space and price costs.

[0072] Optionally, the number of the fixed-frequency fracturing pry 12 in the fracturing pry assembly 1 is multiple, the number of the variable-frequency fracturing pry 11 is one, and the rated power of at least one of the fixed-frequency fracturing pry 12 falls within the total power range of the variable-frequency fracturing pry 11 .

[0073] In this way, only one variable frequency fracturing skid 11 is used, thereby greatly reducing the number of frequency converters 21 used while ensuring the coverage of the total power range of the fracturing skid assembly 1, thereby greatly reducing the floor space and price cost.

[0074] Optionally, the number of the fixed-frequency fracturing prys 12 in the fracturing pry assembly 1 is multiple, the number of the variable-frequency fracturing prys 11 is two, and the rated power of at least one of the fixed-frequency fracturing prys 12 falls within the total power range of the variable-frequency fracturing pry 11 .

[0075] The above-mentioned use of only one variable frequency fracturing pry 11 means that only one variable frequency fracturing pry 11 can be adjusted to achieve the preset power of the entire fracturing pry assembly 1; this means that the requirements for adjustment are relatively strict and demanding, which is very disadvantageous for the staff and can easily cause misoperation by the staff; on this basis, the number of the variable frequency fracturing pry 11 is set to two, thereby greatly increasing the margin and fault tolerance of the variable frequency fracturing unit during control, and maximizing the number of fixed frequency fracturing pry 12, thereby greatly reducing the floor space and price cost.

[0076] Optional, such as Figure 2 As shown, the variable frequency fracturing skid 11 / the fixed frequency fracturing skid 12 includes a driving motor 13 and a fracturing pump 14 , and the driving motor 13 drives the fracturing pump 14 .

[0077] In this way, the driving motor 13 provides driving force to drive the fracturing pump 14 to work, thereby completing the fracturing work.

[0078] It should be noted here that the structures of the variable frequency fracturing pry 11 and the fixed frequency fracturing pry 12 are the same, and the only difference is that the drive motor 13 in the variable frequency fracturing pry 11 is a variable frequency drive motor 13; the drive motor 13 in the fixed frequency fracturing pry 12 is a fixed frequency drive motor 13.

[0079] Optional, such as Figure 2 As shown, there are multiple fracturing pumps 14, and the variable frequency fracturing skid 11 / the fixed frequency fracturing skid 12 also includes a transfer case 15. The drive motor 13 is connected to the multiple fracturing pumps 14 through the transfer case 15, and the transfer case 15 distributes the power of the drive motor 13 to the multiple fracturing pumps 14.

[0080] In this way, a plurality of connected fracturing pumps 14 can be driven to work through a transfer case 15 by a driving motor 13; the transfer case 15 distributes the power of the driving motor 13 to each connected fracturing pump 14, and drives the fracturing pump 14 to work normally.

[0081] Optional, such as Figure 2 As shown, in the variable frequency fracturing skid 11 / the fixed frequency fracturing skid 12, the number of the driving motor 13 is one.

[0082] Optional, such as Figure 2 As shown, the frequency conversion system 2 includes a frequency converter 21 , and the frequency converter 21 is connected to the frequency conversion fracturing skid 11 .

[0083] In this way, the frequency converter 21 in the frequency conversion system 2 is directly connected to the drive motor 13 in the variable frequency fracturing skid 11 , and the frequency of the alternating current flowing into the drive motor 13 is adjusted, thereby adjusting the operating power of the drive motor 13 .

[0084] Optionally, one frequency converter 21 is connected to two or three variable frequency fracturing skids 11 .

[0085] In this way, the frequency converters 21 of two or three frequency conversion fracturing skids 11 can be integrated together in an integrated manner, thereby reducing the occupied area and price cost of the frequency converter 21.

[0086] like Figure 3 As shown, it is a structural schematic diagram of the electric-driven fracturing system of an embodiment of the present invention; wherein, the electric-driven fracturing system includes the electric-driven fracturing unit and the generator set 4 as described above, and the generator set 4 is connected to the electric-driven fracturing unit through the power supply bus 3.

[0087] In this way, the fixed-frequency fracturing skid 12 is used for replacement, thereby reducing the floor space and price cost corresponding to the replacement part, thereby generally solving the problem of the existing electric-driven fracturing equipment occupying too much floor space and being too costly.

[0088] like Figure 4 As shown, it is a flow chart of the electric-driven fracturing unit control method of an embodiment of the present invention; wherein the electric-driven fracturing unit control method is the electric-driven fracturing unit control method described above, comprising:

[0089] Step 100, after the electric-driven fracturing unit is powered on, the predicted working power, the rated power of each of the fixed-frequency fracturing skids 12 and the power range of each of the variable-frequency fracturing skids 11 are obtained;

[0090] The predicted working power is the prediction of the possible working power during fracturing by the design institute before the oil and gas field fracturing operation. The predicted working power is close to the actual working power of the electric-driven fracturing unit during fracturing, but will not be exactly the same due to the influence of the actual situation.

[0091] Step 200, determining the fixed-frequency fracturing skid 12 to be started and starting it according to the predicted working power and the rated power of the fixed-frequency fracturing skid 12;

[0092] In this step, the method for determining the fixed-frequency fracturing pry 12 to be started is: the sum of the rated powers of the screened fixed-frequency fracturing pry 12 to be started is as large as possible under the premise of being less than the predicted working power.

[0093] The specific screening process can be determined according to the actual situation: for example, screening from top to bottom according to rated power, or screening from bottom to top, or screening according to a preset order.

[0094] If when a fixed-frequency fracturing pry 12 is screened, the sum of the rated powers of all the screened fixed-frequency fracturing pry 12 is greater than the predicted working power; but in the previous screening of the fixed-frequency fracturing pry 12, the sum of the rated powers of all the screened fixed-frequency fracturing pry 12 is less than the predicted working power; then the screening can be stopped at this time and the fixed-frequency fracturing pry 12 can be abandoned.

[0095] The starting process of the fixed-frequency fracturing skid 12 to be started is a soft start; in this way, the impact current generated by the fixed-frequency drive motor 13 during startup can be reduced, protecting the equipment from damage caused by the impact current.

[0096] The specific process of the soft start is easily implemented by those skilled in the art and will not be described in detail again.

[0097] Step 300, obtaining the operating parameters of the electric-driven fracturing unit;

[0098] Among them, the operating parameters of the electric-driven fracturing unit are parameters that reflect whether the operation of the electric-driven fracturing unit meets the operating requirements (construction requirements). It can be a single parameter such as the pressure in the pipe or the current displacement, etc.; it can also be a comprehensive reflection of multiple parameters, as long as it can reflect whether the operation of the electric-driven fracturing unit meets the operating requirements.

[0099] Based on the operating parameters, we can determine whether the electric-driven fracturing unit meets the operating requirements, and we can also determine the approximate gap between the operating requirements and the operating requirements when the operating requirements are not met.

[0100] Step 400, increasing the operating power of the variable frequency fracturing pry 11 one by one according to the operating parameters and the power range of the variable frequency fracturing pry 11, until the operating parameters meet the construction requirements;

[0101] In this step, the operating parameters are used to determine whether the construction requirements are met; the power range of the variable frequency fracturing skid 11 is used to constrain the maximum operating power of the variable frequency fracturing skid 11 to avoid exceeding the power range.

[0102] The step of increasing the operating power of the variable frequency fracturing skids 11 one by one can be achieved in a variety of ways, such as:

[0103] Implementation method 1: select one of the variable frequency fracturing prys 11 and gradually increase its operating power until it reaches the maximum value within the power range; then select one from the remaining variable frequency fracturing prys 11 and repeat the operation until the operating parameters meet the construction requirements or the variable frequency fracturing prys 11 are completely traversed.

[0104] Implementation method 2: Setting the adjustment amplitude of the variable frequency fracturing pry 11, increasing the adjustment amplitude of each variable frequency fracturing pry 11 by one according to a set order (the set order can be randomly selected or sorted from the maximum value of the power range and then selected from large to small or selected from small to large or pre-set); then re-circulating each variable frequency fracturing pry 11 to increase the adjustment amplitude by one until the operating parameters meet the construction requirements or the variable frequency fracturing pry 11 are all increased to the maximum value within the power range.

[0105] Implementation method three: setting the optimal operating power for the variable frequency fracturing pry 11 within the power range, referring to implementation method one, each variable frequency fracturing pry 11 gradually increases the operating power to the optimal operating power (no longer increases to the maximum value within the power range); until the operating parameters meet the construction requirements or the variable frequency fracturing pry 11 is completely traversed; if the variable frequency fracturing pry 11 still does not meet the construction requirements after the complete traversal, reselect the variable frequency fracturing pry 11, gradually increase the optimal operating power to the maximum value within the power range, and then select one from the remaining variable frequency fracturing pry 11 to repeat the operation until the operating parameters meet the construction requirements or the variable frequency fracturing pry 11 is completely traversed.

[0106] Other improvements may also be made on the basis of the above implementations or the above implementations may be combined.

[0107] Step 500 , counting the operating power of each of the variable frequency fracturing pry 11 , and distributing the total operating power of the variable frequency fracturing pry 11 in equal proportion according to the maximum power within the power range of each of the variable frequency fracturing pry 11 .

[0108] In this way, the fixed-frequency fracturing skid 12 can be started first and then the variable-frequency fracturing skid 11 can be started; on the one hand, the operating parameters can finally meet the construction requirements, and on the other hand, the current impact between the fixed-frequency start-up and the variable-frequency start-up can be avoided.

[0109] Optional, such as Figure 5 As shown, the step 500 counts the operating power of each of the variable frequency fracturing pry 11, and distributes the total operating power of the variable frequency fracturing pry 11 in equal proportion according to the maximum power of the power range of each of the variable frequency fracturing pry 11, including:

[0110] Step 510, counting the operating power of each variable frequency fracturing skid 11;

[0111] The operating powers of the variable frequency fracturing skids 11 are different, and some of them may even be in a non-operating state, so it is necessary to count the current operating powers of the variable frequency fracturing skids 11 respectively.

[0112] Step 520, calculating the total operating power of the variable frequency fracturing skid 11 according to the operating power of each variable frequency fracturing skid 11;

[0113] The total operating power of the variable frequency fracturing skid 11 is the sum of the operating powers of the various variable frequency fracturing skids 11 .

[0114] Step 530, determining a ratio of the maximum powers of the variable frequency fracturing skids 11 according to the maximum powers of the power ranges of the variable frequency fracturing skids 11;

[0115] Each of the variable frequency fracturing skids 11 has its own power range, and the maximum power within the power range represents the maximum allowable power of the variable frequency fracturing skid 11 .

[0116] Step 540 : reallocate the total operating power of the variable frequency fracturing skids 11 according to the ratio of the maximum power of each variable frequency fracturing skid 11 .

[0117] In this step, all the variable frequency fracturing skids 11 are operated at the same percentage of the corresponding maximum power. That is to say, after redistribution, any of the variable frequency fracturing skids 11 is operated at the same proportion of its maximum power (for example, all the variable frequency fracturing skids 11 are operated at half of their respective maximum powers). This can greatly reduce the damage to the service life of the running variable frequency fracturing skids 11.

[0118] Although the disclosure is disclosed as above, the protection scope of the disclosure is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the disclosure, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A control method for an electric-driven fracturing unit, applied to an electric-driven fracturing unit, characterized in that: The electric-driven fracturing unit comprises: a fracturing skid assembly (1) and a frequency conversion system (2); the fracturing skid assembly (1) comprises at least a frequency conversion fracturing skid (11) and a fixed frequency fracturing skid (12); the fixed frequency fracturing skid (12) is connected to a power supply bus (3); one end of the frequency conversion system (2) is connected to the power supply bus (3), and the other end is connected to the frequency conversion fracturing skid (11), so as to adjust the current frequency of the frequency conversion fracturing skid (11); the rated power of the fixed frequency fracturing skid (12) in the fracturing skid assembly (1) falls within the total power range of the frequency conversion fracturing skid (11); The electric drive fracturing unit control method comprises: Step 100, after the electric-driven fracturing unit is powered on, the predicted working power, the rated power of each of the fixed-frequency fracturing skids, and the power range of each of the variable-frequency fracturing skids are obtained; Step 200, determining the fixed-frequency fracturing skid to be started and starting it according to the predicted working power and the rated power of the fixed-frequency fracturing skid; Step 300, obtaining the operating parameters of the electric-driven fracturing unit; Step 400, increasing the operating power of the variable frequency fracturing skid one by one according to the operating parameters and the power range of the variable frequency fracturing skid until the operating parameters meet the construction requirements; Step 500: Count the operating powers of the various variable frequency fracturing plies, and distribute the total operating powers of the variable frequency fracturing plies in equal proportion according to the maximum powers within the power ranges of the various variable frequency fracturing plies.

2. The electric drive fracturing unit control method according to claim 1, characterized in that: The total rated power of the fixed-frequency fracturing skid (12) in the fracturing skid assembly (1) is 1 / 3-2 / 3 of the total rated power of the fracturing skid assembly (1), or The number of the fixed-frequency fracturing skids (12) in the fracturing skid assembly (1) is 0.5-2 times the number of the variable-frequency fracturing skids (11).

3. The electric-driven fracturing unit control method according to claim 1, characterized in that: The total rated power of the fixed-frequency fracturing skid (12) in the fracturing skid assembly (1) is 1 / 2 of the total rated power of the fracturing skid assembly (1), or The number of the fixed-frequency fracturing skids (12) in the fracturing skid assembly (1) is the same as the number of the variable-frequency fracturing skids (11).

4. The electric drive fracturing unit control method according to claim 1, characterized in that: The number of the fixed-frequency fracturing skids (12) in the fracturing skid assembly (1) is multiple, the number of the variable-frequency fracturing skids (11) is one or two, and the rated power of at least one of the fixed-frequency fracturing skids (12) falls within the total power range of the variable-frequency fracturing skid (11).

5. The control method of an electric-driven fracturing unit according to any one of claims 1 to 3, characterized in that: The variable frequency fracturing skid (11) / the fixed frequency fracturing skid (12) comprises a drive motor (13) and a fracturing pump (14); the drive motor (13) drives the fracturing pump (14).

6. The electric-driven fracturing unit control method according to claim 5, characterized in that: There are a plurality of the fracturing pumps (14); the variable frequency fracturing skid (11) / the fixed frequency fracturing skid (12) further comprises a transfer case (15); the drive motor (13) is connected to the plurality of the fracturing pumps (14) via the transfer case (15); and the transfer case (15) distributes the power of the drive motor (13) to the plurality of the fracturing pumps (14).

7. The control method of the electric-driven fracturing unit according to claim 5, characterized in that: In the variable frequency fracturing skid (11) / the fixed frequency fracturing skid (12), the number of the driving motor (13) is one.

8. The control method of an electric-driven fracturing unit according to any one of claims 1 to 3, characterized in that: The frequency conversion system (2) comprises a frequency converter (21), and the frequency converter (21) is connected to the frequency conversion fracturing skid (11).

9. The control method of the electric-driven fracturing unit according to claim 8, characterized in that: One frequency converter (21) is connected to two or three frequency conversion fracturing skids (11).

10. The method for controlling an electric-driven fracturing unit according to claim 1, characterized in that: The step 500, counting the operating power of each of the variable frequency fracturing prys, and distributing the total operating power of the variable frequency fracturing prys in equal proportion according to the maximum power of the power range of each of the variable frequency fracturing prys, includes: Step 510, counting the operating power of each variable frequency fracturing skid; Step 520, calculating the total operating power of the variable frequency fracturing skid according to the operating power of each variable frequency fracturing skid; Step 530, determining a ratio of the maximum powers of the variable frequency fracturing skids according to the maximum powers of the power ranges of the variable frequency fracturing skids; Step 540: reallocate the total operating power of the variable frequency fracturing skids according to the ratio of the maximum power of each variable frequency fracturing skid.

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