A method and system for quantitatively evaluating a fracturing and sanding operation

Abstract

The application discloses a method and system for quantitatively evaluating fracturing sanding construction, and comprises the following steps: collecting evaluation factor parameters of a well to be evaluated, wherein the evaluation factor parameters comprise construction pressure, pump-off pressure, sanding intensity, liquid intensity, comprehensive sand ratio and construction discharge; according to the evaluation factor parameters, quantitatively evaluating the actual influence degree of each factor parameter on the difficulty of sanding construction; and determining the sanding construction difficulty of the well to be evaluated according to the actual influence degree of each evaluation factor parameter.

Description

Technical Field

[0001] This invention relates to the field of oil and gas fracturing technology, and in particular to a method and system for quantitatively evaluating fracturing sand injection operations. Background Technology

[0002] Hydraulic fracturing technology is an effective means of shale gas development. Field practice shows that there is a certain positive correlation between gas well productivity and the scale of fracturing and sand addition. However, due to the heterogeneity of the reservoir, the ease of sand addition varies greatly among reservoirs of different qualities. If a single sand addition mode is still used in the design, it is often difficult to achieve high-intensity sand addition (sand addition intensity > 2.0 m3 / m). Therefore, it is necessary to conduct post-fracturing assessments on wells that have been fracturing in different areas in the early stage and to quantitatively evaluate the ease of sand addition in the reservoir in order to provide a reference for optimizing the process parameters of subsequent wells.

[0003] Existing technologies rarely address quantitative evaluation schemes for the ease of adding proppant. Because field operations primarily rely on single-parameter evaluations, accuracy is lacking. Furthermore, related research is mainly limited to qualitative analysis, identifying the main influencing factors leading to difficulties in proppant fracturing but failing to provide quantitative evaluation under multi-factor influence. Therefore, accurately evaluating the ease of adding proppant in volumetric fracturing wells is crucial. Summary of the Invention

[0004] The purpose of this invention is to provide a post-fracture evaluation scheme for shale gas volumetric fracturing wells, so as to achieve a quantitative evaluation of the ease of sand addition, thereby providing important parameter basis for subsequent fracturing well parameter design.

[0005] To address the aforementioned technical problems, this invention provides a method for quantitatively evaluating fracturing and sand injection operations, comprising: collecting evaluation factor parameters of the well to be evaluated, wherein the evaluation factor parameters include construction pressure, pump shutdown pressure, sand injection intensity, fluid intensity, comprehensive sand ratio, and construction discharge rate; quantitatively evaluating the actual impact of each factor parameter on the ease or difficulty of sand injection operations based on the evaluation factor parameters; and determining the sand injection difficulty of the well to be evaluated based on the actual impact of each evaluation factor parameter.

[0006] Preferably, the step of collecting evaluation factor parameters for the well to be evaluated includes: collecting the evaluation factor parameters for each well section in the well to be evaluated, wherein: based on field construction record data, the construction pressure of each well section in the well to be evaluated is obtained; based on field construction record data, the pump shutdown pressure of each well section in the well to be evaluated is obtained; based on field construction record data, the sand addition amount and section length of each well section in the well to be evaluated are obtained, thereby obtaining the sand addition intensity of different well sections by comparing the sand addition amount with the corresponding section length; based on field construction record data, the fluid consumption amount and section length of each well section in the well to be evaluated are obtained, thereby obtaining the fluid consumption intensity of different well sections by comparing the fluid consumption amount with the corresponding section length; based on the sand addition amount and fluid consumption amount of each well section in the well to be evaluated, the comprehensive sand ratio of different well sections is obtained by comparing the sand addition amount with the corresponding fluid consumption amount; and based on field construction record data, the construction discharge rate of each well section in the well to be evaluated is obtained.

[0007] Preferably, the step of quantitatively evaluating the actual impact of each parameter on the difficulty of sand addition construction based on the evaluation factor parameters includes: calculating the weighted average value of each factor parameter based on the evaluation factor parameters of each well section in the well to be evaluated; and calculating the actual impact of each factor parameter based on the weighted average value of each factor parameter, combined with the maximum and minimum values ​​of each factor parameter in the area where the well to be evaluated is located, using a normalization algorithm.

[0008] Preferably, the step of determining the difficulty of sand addition construction of the well to be evaluated based on the actual influence of each evaluation factor parameter includes: determining the weight of each evaluation factor parameter; and calculating the reservoir comprehensive compressibility index, which represents the difficulty of sand addition construction of the well to be evaluated, based on the actual influence of each evaluation factor parameter and its corresponding weight. The reservoir comprehensive compressibility index is calculated using the following expression:

[0009]

[0010] Where K represents the reservoir's overall compressibility index, This indicates the actual degree of influence of the i-th evaluation factor parameter. This represents the weight of the i-th evaluation factor parameter.

[0011] Preferably, based on the collected evaluation factor parameters of the wells to be evaluated, the grey relational analysis method is used to calculate the weight of each evaluation factor parameter.

[0012] Preferably, the weights of the construction pressure, the pump shutdown pressure, the sand addition intensity, the liquid usage intensity, the comprehensive sand ratio, and the construction discharge rate are 0.27, 0.14, 0.16, 0.1, 0.2, and 0.13, respectively.

[0013] Preferably, the method further includes: determining a corresponding construction difficulty level based on the sand addition construction difficulty of the well to be evaluated, wherein the construction difficulty level includes a first level, a second level, and a third level, wherein the sand addition construction difficulty is determined to be greater than or equal to 0 and less than 0.4 as the first level, the sand addition construction difficulty is determined to be greater than or equal to 0.4 and less than 0.7 as the second level, and the sand addition construction difficulty is determined to be greater than or equal to 0.7 and less than 1 as the third level; and configuring corresponding fracturing process design parameters according to the construction difficulty level.

[0014] Preferably, the step of configuring the corresponding fracturing process design parameters according to the construction difficulty level includes: when the current construction difficulty level is level one, the fracturing construction design parameters include: low liquid viscosity, high sand ratio continuous long stage sand addition mode, and 200m³ of pre-filled adhesive. 3 The ratio of proppant 70 / 140:40 / 70:30 / 50 is 1:4:5; when the current construction difficulty level is level two, the fracturing construction design parameters include: appropriate medium viscosity liquid viscosity, step-wise slow-lift proppant ratio proppant addition mode, and 220m³ of pre-prepared adhesive. 3 The ratio of proppant 70 / 140:40 / 70:30 / 50 is 1:6:3; when the current construction difficulty level is level three, the fracturing construction design parameters include: medium to high viscosity liquid, slug proppant proppant method, and pre-positioned gel volume of 250m³. 3 The ratio of proppant 70 / 140:40 / 70:30 / 50 is 2:5:3.

[0015] On the other hand, embodiments of the present invention also provide a system for quantitatively evaluating fracturing and sand injection operations, comprising: a data collection module configured to collect evaluation factor parameters of the well to be evaluated, the evaluation factor parameters including construction pressure, pump shutdown pressure, sand injection intensity, fluid intensity, comprehensive sand ratio, and construction discharge rate; a parameter scoring module configured to quantitatively evaluate the actual influence of each factor parameter on the difficulty of sand injection operations based on the evaluation factor parameters; and a construction evaluation module configured to determine the difficulty of sand injection operations of the well to be evaluated based on the actual influence of each evaluation factor parameter.

[0016] Preferably, the system further includes: a process parameter configuration module, wherein the process parameter configuration module comprises: a construction difficulty level determination unit, configured to determine a corresponding construction difficulty level based on the sand addition construction difficulty of the well to be evaluated, wherein the construction difficulty level includes a first level, a second level, and a third level, wherein the sand addition construction difficulty is determined to be the first level when it is greater than or equal to 0 and less than 0.4, the sand addition construction difficulty is determined to be the second level when it is greater than or equal to 0.4 and less than 0.7, and the sand addition construction difficulty is determined to be the third level when it is greater than or equal to 0.7 and less than 1; and a process parameter generation unit, configured to configure corresponding fracturing process design parameters based on the construction difficulty level.

[0017] Compared with the prior art, one or more embodiments of the above solutions may have the following advantages or beneficial effects:

[0018] This invention proposes a method and system for quantitatively evaluating fracturing and proppant injection operations. This method and system provide a quantitative assessment of the ease of proppant injection after fracturing in shale gas wells by analyzing multiple influencing factors, thus providing important parameter basis for subsequent fracturing well parameter design.

[0019] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0020] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0021] Figure 1 This is a schematic diagram of the steps in a method for quantitatively evaluating fracturing and sand-addition construction according to an embodiment of this application.

[0022] Figure 2 This is a block diagram of a method system for quantitatively evaluating fracturing and sand-addition operations, as described in an embodiment of this application. Detailed Implementation

[0023] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings and examples, so that the process of how the present invention uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. It should be noted that, as long as there is no conflict, the various embodiments and features in the various embodiments of the present invention can be combined with each other, and the resulting technical solutions are all within the protection scope of the present invention.

[0024] Furthermore, the steps illustrated in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Also, although a logical order is shown in the flowcharts, in some cases the steps shown or described may be performed in a different order than that shown here.

[0025] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms “a” and “an” as used herein are also intended to include the plural. It should also be understood that the terms “comprising” and / or “including” as used herein specify the presence of the stated features, integers, steps, operations, units, and / or components, without excluding the presence or addition of one or more other features, integers, steps, operations, units, components, and / or combinations thereof.

[0026] Hydraulic fracturing technology is an effective means of shale gas development. Field practice shows that there is a certain positive correlation between gas well productivity and the scale of fracturing and sand addition. However, due to the heterogeneity of the reservoir, the ease of sand addition varies greatly among reservoirs of different qualities. If a single sand addition mode is still used in the design, it is often difficult to achieve high-intensity sand addition (sand addition intensity > 2.0 m3 / m). Therefore, it is necessary to conduct post-fracturing assessments on wells that have been fracturing in different areas in the early stage and to quantitatively evaluate the ease of sand addition in the reservoir in order to provide a reference for optimizing the process parameters of subsequent wells.

[0027] Existing technologies rarely address quantitative evaluation schemes for the ease of adding proppant. Because field operations primarily rely on single-parameter evaluations, accuracy is lacking. Furthermore, related research is mainly limited to qualitative analysis, identifying the main influencing factors leading to difficulties in proppant fracturing but failing to provide quantitative evaluation under multi-factor influence. Therefore, accurately evaluating the ease of adding proppant in volumetric fracturing wells is crucial.

[0028] To address the aforementioned technical problems, this application proposes a method and system for quantitatively evaluating fracturing and proppant injection operations. This method and system are based on six evaluation factors: the well's operating pressure, pump shutdown pressure, proppant injection intensity, fluid usage intensity, overall proppant ratio, and operating displacement. First, the ease of proppant injection is evaluated based on the influence of each factor individually. Then, the overall ease of proppant injection for the reservoir is calculated by combining the weights of each factor. This provides a basis for designing differentiated process parameters for subsequent fracturing well operations.

[0029] Example 1

[0030] Figure 1 This is a schematic diagram illustrating the steps of a method for quantitatively evaluating fracturing and sand-addition operations according to an embodiment of this application. The specific steps of the method for quantitatively evaluating fracturing and sand-addition operations (also referred to as the "quantitative evaluation method") described in this embodiment of the invention will be explained below.

[0031] like Figure 1 As shown, step S110 collects the evaluation factor parameters of the well to be evaluated. These evaluation factor parameters include construction pressure, pump shutdown pressure, sand addition intensity, fluid usage intensity, overall sand ratio, and construction discharge rate.

[0032] In step S110, in the step of collecting evaluation factor parameters of the well to be evaluated, this embodiment of the invention collects each evaluation factor parameter of each well section in the well to be evaluated.

[0033] Preferably, the fracturing pressure of each section in the well to be evaluated is obtained based on the on-site construction record data. .

[0034] Preferably, the pump shutdown pressure of each section in the well to be evaluated is obtained based on the on-site construction record data. .

[0035] Preferably, based on on-site construction record data, the amount of sand added and the length of each well section in the well to be evaluated are obtained, thereby obtaining the sand addition intensity of different well sections by comparing the amount of sand added with the corresponding well section length. Specifically, after obtaining the amount of sand added and the length of each section in the well to be evaluated, the amount of sand added is divided by the length of the corresponding section to obtain the sand addition intensity (in meters) for different sections in the well to be evaluated. 3 / m).

[0036] Preferably, based on on-site construction record data, the fluid consumption and section length of each well segment in the well to be evaluated are obtained, thereby obtaining the fluid intensity of different well segments by comparing the fluid consumption with the corresponding section length. Specifically, after obtaining the fluid consumption and section length of each well segment in the well to be evaluated, the fluid consumption is divided by the corresponding section length data to obtain the fluid intensity (in meters) for different well segments in the well to be evaluated. 3 / m).

[0037] Preferably, based on the amount of sand added and the amount of fluid used in each section of the well to be evaluated, the comprehensive sand ratio of different sections is obtained by the ratio of the amount of sand added to the amount of fluid used in the corresponding section. Specifically, the fluid consumption and sand addition data for different well sections in the well to be evaluated are first obtained through on-site construction records. Then, the comprehensive sand ratio data for different well sections in the well to be evaluated is obtained by dividing the sand addition at the same well section location by the fluid consumption.

[0038] Preferably, the construction discharge rate for each section of the well to be evaluated is obtained based on on-site construction record data. In this embodiment of the invention, the construction discharge rate is the discharge rate data of each well section in the well to be evaluated during stable construction.

[0039] Therefore, after the data collection is completed, the process proceeds to step S120.

[0040] refer to Figure 1 Step S120, based on the various evaluation factor parameters collected in step S110, quantitatively evaluates the actual impact of each evaluation factor parameter on the ease or difficulty of sand addition construction.

[0041] Specifically, firstly, based on the parameters of each evaluation factor in each well section of the well to be evaluated, the weighted average value of each parameter is calculated. Then, based on the weighted average value of each parameter, combined with the maximum and minimum values ​​of each parameter in the area where the well to be evaluated is located, the actual influence of each parameter is calculated using a normalization method.

[0042] In one embodiment, based on the weighted average of the fracturing construction pressures. The actual degree of influence (i.e., score) of the impact of construction pressure on the ease of sand addition is calculated using the following expression:

[0043] (1)

[0044] in, Indicates construction pressure The actual degree of impact, expressed in % . This represents the weighted average of the construction pressures of the wells to be evaluated, in MPa. , These represent the highest and lowest construction pressure values ​​in the area where the well to be evaluated is located, respectively, in MPa.

[0045] In one embodiment, based on the weighted average of the pump shutdown pressure. The actual degree of influence (i.e., score) of the impact of pump shutdown pressure on the ease of sand addition is calculated using the following expression:

[0046] (2)

[0047] in, Indicates pump stop pressure The actual degree of impact, expressed in % . This represents the weighted average of the pump shutdown pressures of the wells to be evaluated, in MPa. , These represent the highest and lowest values ​​of the pump shutdown pressure within the area where the well to be evaluated is located, respectively, in MPa.

[0048] In one embodiment, based on the weighted average of sand addition intensity The actual degree of influence (i.e., score) of the sand addition strength on the ease of sand addition is calculated using the following expression:

[0049] (3)

[0050] in, Indicates sand strength The actual degree of impact, expressed in % . This represents the weighted average of the sand addition intensity of the well to be evaluated, in meters. 3 / m; , These represent the highest and lowest values ​​of sand addition intensity in the area where the well to be evaluated is located, respectively, in meters. 3 / m.

[0051] In one embodiment, based on a weighted average of the liquid strength. The actual degree of influence (i.e., score) of the effect of liquid strength on the ease of sand addition is calculated using the following expression:

[0052] (4)

[0053] in, Indicates the strength of the liquid The actual degree of impact, expressed in % . This represents the weighted average of the fluid intensity used in the wells to be evaluated, in units of m. 3 / m; , These represent the highest and lowest values ​​of fluid intensity in the area where the well to be evaluated is located, respectively, in cubic meters (m³). 3 / m.

[0054] In one embodiment, based on the weighted average of the overall sand ratio The actual degree of influence (i.e., score) of the overall sand ratio on the ease of sand addition is calculated using the following expression:

[0055] (5)

[0056] in, Indicates the overall sand ratio The actual degree of impact, expressed in % . This represents the weighted average of the overall sand ratio of the wells to be evaluated, expressed in % (%). , These represent the highest and lowest values ​​of the composite sand ratio within the area where the well to be evaluated is located, respectively, in units of %.

[0057] In one embodiment, based on the weighted average of construction displacement... The actual degree of influence (i.e., score) of the construction discharge rate on the ease of sand addition is calculated using the following expression:

[0058] (6)

[0059] in, Indicates construction displacement The actual degree of impact, expressed in % . This represents the weighted average of the construction discharge rates of the wells to be evaluated, in m³. 3 / min; , These represent the highest and lowest values ​​of the construction discharge rate within the area where the well to be evaluated is located, in m³. 3 / min.

[0060] After obtaining the actual impact data of each evaluation factor parameter, proceed to step S130.

[0061] Continue to refer to Figure 1 Step S130: Based on the actual influence of each evaluation factor parameter, quantitatively determine the difficulty of sand addition construction in the well to be evaluated.

[0062] In step S130, firstly, the weights of each evaluation factor parameter are determined. Then, based on the actual influence of each evaluation factor parameter of the current well to be evaluated and its corresponding weight, the reservoir comprehensive compressibility index, which represents the difficulty of sand addition construction of the well to be evaluated, is calculated.

[0063] Furthermore, based on the evaluation factor parameters of the well to be evaluated collected in step S110, the weight of each evaluation factor parameter is calculated using the grey relational analysis method. In one embodiment, the weights of construction pressure, pump shutdown pressure, sand addition intensity, fluid usage intensity, comprehensive sand ratio, and construction discharge rate are 0.27, 0.14, 0.16, 0.1, 0.2, and 0.13, respectively.

[0064] Furthermore, the reservoir comprehensive compressibility index is calculated using the following expression:

[0065] (7)

[0066] Where K represents the reservoir's overall compressibility index, This indicates the actual degree of influence of the i-th evaluation factor parameter. This represents the weight of the i-th evaluation factor parameter.

[0067] In addition, the embodiments of the present invention further configure appropriate fracturing process design parameters based on the currently quantitatively calculated data on the difficulty of sand addition construction.

[0068] Specifically, firstly, based on the current difficulty of sand addition construction in the well to be evaluated, a construction difficulty level matching the current difficulty of sand addition construction is determined. Then, based on the currently determined construction difficulty level, the corresponding fracturing process design parameters are configured. For specific examples, see Table 1.

[0069] Table 1 Optimal Design of Fracturing Parameters for Different Difficulties of Sand Addition

[0070]

[0071] In this embodiment of the invention, the construction difficulty level includes three levels, namely the first level, the second level, and the third level.

[0072] In the first embodiment, a sand-addition construction difficulty level greater than or equal to 0 and less than 0.4 is defined as Level 1. When the current construction difficulty level is Level 1, the fracturing construction design parameters include: low liquid viscosity, high sand ratio continuous long-stage sand-addition mode, and a pre-filled gel volume of 200m³. 3 The ratio of proppant 70 / 140:40 / 70:30 / 50 is 1:4:5.

[0073] In the second embodiment, when the sand addition difficulty is greater than or equal to 0.4 and less than 0.7, it is determined to be at the second level. When the current construction difficulty level is at the second level, the fracturing construction design parameters include: appropriate medium viscosity liquid viscosity, step-slow sand addition mode, and pre-filled gel volume of 220m³. 3 The ratio of proppant 70 / 140:40 / 70:30 / 50 is 1:6:3.

[0074] In the third embodiment, when the sand addition difficulty is greater than or equal to 0.7 and less than 1, it is determined to be at level three. When the current difficulty level is level three, the fracturing design parameters include: medium-high viscosity liquid, slug sand addition mode, and pre-filled gel volume of 250m³. 3 The ratio of proppant 70 / 140:40 / 70:30 / 50 is 2:5:3.

[0075] Example 2

[0076] Based on the quantitative evaluation method described in Example 1, this embodiment of the invention takes three wells in a deep shale gas block in the Sichuan Basin as examples for post-compression evaluation, and compares the advantages and disadvantages of the quantitative evaluation method described in this invention with the current field single-parameter evaluation method.

[0077] Step A: Collect evaluation factor parameters for each stage of the fracturing process of the three wells to be evaluated, including the fracturing pressure. Pump shutdown pressure Sand strength Liquid strength Comprehensive sand ratio and construction displacement The evaluation factors for the three wells are shown in Tables 2 to 4; then the weighted average of each parameter is calculated, as shown in Table 5.

[0078] Table 2 Summary of Evaluation Factors for Well WY26-2HF

[0079]

[0080] Table 3 Summary of Evaluation Factors for Well WY23-7HF

[0081]

[0082] Table 4 Summary of Evaluation Factors for Well WY29-8HF

[0083]

[0084] Table 5. Summary of the actual impact of each factor parameter on the three wells to be evaluated.

[0085]

[0086] Compared to conventional methods: Based on Table 5, on-site evaluation often uses a single parameter, namely the level of construction pressure or the level of sand addition strength. Lower construction pressure generally means easier sand addition, or higher sand addition strength means easier sand addition. This method has two drawbacks:

[0087] Firstly, the evaluation is inaccurate. A single parameter cannot reflect the comprehensive characteristics of the well. Taking WY26-2 and WY29-8 as examples, the construction pressure of WY29-8 is 6.3 MPa higher than that of WY26-2, and the sand addition intensity is similar. Therefore, it is concluded that sand addition is more difficult for WY29-8. However, the fact that WY26-2 has a higher fluid intensity and a lower overall sand ratio is ignored. Although the pressure of WY26-2 is lower, the reservoir is sensitive to sand addition and more fluid is needed to carry the same amount of sand. The evaluation based on a single parameter is inaccurate.

[0088] Secondly, the evaluation results cannot be quantified. Single-parameter evaluation can only be used for ranking, and the ease or difficulty of sand addition between wells cannot be quantitatively reflected.

[0089] The calculation process and results obtained by the quantitative evaluation method according to the embodiments of the present invention are listed below:

[0090] Step B: Fracturing pressure for 3 wells As shown in Table 5, the minimum construction pressure Maximum value The pressures are 72.6 MPa and 81.9 MPa respectively. The construction pressures of the three wells are calculated according to formula (1). The actual degree of impact The values ​​are 1, 0, and 0.32 respectively.

[0091] Step C: Fracturing and pump shutdown pressure of 3 wells As shown in Table 5, the minimum pump shutdown pressure Maximum value The pressures are 59.2 MPa and 60.1 MPa respectively. The pump shut-off pressures of the three wells are calculated according to formula (2). The actual degree of impact The values ​​are 0, 0.87, and 1, respectively.

[0092] Step D: Sand addition strength in 3 wells As shown in Table 5, the minimum strength value after sand addition. Maximum value 1.3m respectively 3 / m, 2.1m 3 / m, calculate the sand addition intensity of the three wells according to formula (3). The actual degree of impact The values ​​are 1, 0, and 0.81, respectively.

[0093] Step E: Fluid strength for 3 wells As shown in Table 5, the minimum liquid strength is... Maximum value 24.6m respectively 3 / m, 31.1m 3 / m, calculate the sand addition intensity of the three wells according to formula (4). The actual degree of impact The values ​​are 0, 0.61, and 1, respectively.

[0094] Step F: Overall sand ratio of 3 wells As shown in Table 5, the minimum value of the comprehensive sand ratio Maximum value The values ​​are 4.6 and 8.1 respectively. The comprehensive sand ratio of the three wells is calculated according to formula (5). The actual degree of impact The values ​​are 0.65, 0, and 1, respectively.

[0095] Step G: Discharge rate during well construction As shown in Table 5, the minimum construction displacement value Maximum value The values ​​are 11.2 and 14.2 respectively. The discharge capacity of the three wells is calculated according to formula (6). The actual degree of impact The values ​​are 0.98, 0, and 1, respectively.

[0096] Step H: Based on the sand addition difficulty scores of the three wells obtained from steps A to G, as shown in Table 1, the weights of the six factors are 27%, 14%, 16%, 10%, 20%, and 13% respectively. According to formula (7), the sand addition difficulty scores of the three wells are 0.69, 0.18, and 0.79 respectively. Based on the quantitative evaluation results in Table 1, guidance can be provided for the design of subsequent well fracturing process parameters.

[0097] Currently, the quantitative evaluation method provided in this invention has been applied in 13 wells in a deep shale gas block in the Sichuan Basin, with an accuracy rate of 92.3%.

[0098] Example 3

[0099] Based on the quantitative evaluation method described in Embodiment 1 or Embodiment 2 above, the present invention also provides a system for quantitatively evaluating fracturing and sand-addition operations (also referred to as a "quantitative evaluation system").

[0100] Figure 2 This is a block diagram of a method system for quantitatively evaluating fracturing and sand-addition operations, as described in an embodiment of this application. Figure 2 As shown, the quantitative evaluation system described in this embodiment of the invention includes: a data collection module 21, a parameter scoring module 22, and a construction evaluation module 23.

[0101] The data collection module 21 is implemented according to the method described in step S110 above, and is configured to collect evaluation factor parameters of the well to be evaluated, wherein the evaluation factor parameters include construction pressure, pump shutdown pressure, sand addition intensity, fluid intensity, comprehensive sand ratio and construction discharge rate; the parameter scoring module 22 is implemented according to the method described in step S120 above, and is configured to quantitatively evaluate the actual impact of each factor parameter on the difficulty of sand addition construction based on the evaluation factor parameters; the construction evaluation module 23 is implemented according to the method described in step S130 above, and is configured to determine the difficulty of sand addition construction of the well to be evaluated based on the actual impact of each evaluation factor parameter.

[0102] In addition, the quantitative evaluation system described in this embodiment of the invention also includes a process parameter configuration module (unnumbered). The process parameter configuration module comprises: a construction difficulty level determination unit and a process parameter generation unit.

[0103] The construction difficulty level determination unit is used to determine the corresponding construction difficulty level based on the difficulty of sand addition construction in the well to be evaluated. The construction difficulty levels include Level 1, Level 2, and Level 3. Specifically, Level 1 is defined as a sand addition construction difficulty greater than or equal to 0 and less than 0.4; Level 2 is defined as a sand addition construction difficulty greater than or equal to 0.4 and less than 0.7; and Level 3 is defined as a sand addition construction difficulty greater than or equal to 0.7 and less than 1.

[0104] The process parameter generation unit is used to configure the corresponding fracturing process design parameters according to the current construction difficulty level and Table 1 above.

[0105] This invention discloses a method and system for quantitatively evaluating fracturing and proppant injection operations. This method and system provide a quantitative assessment of the ease of proppant injection after fracturing in shale gas wells by analyzing multiple influencing factors, thereby providing important parameter basis for subsequent fracturing well parameter design.

[0106] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

[0107] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0108] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0109] It should be understood that the embodiments disclosed herein are not limited to the specific structures, processing steps, or materials disclosed herein, but should be extended to equivalent substitutions of these features as understood by those skilled in the art. It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

[0110] The phrase "an embodiment" or "an embodiment" used in this specification means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Therefore, the phrase "an embodiment" or "an embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0111] While the embodiments disclosed in this invention are as described above, the content is merely for the purpose of facilitating understanding of the invention and is not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and changes in form and detail of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection of this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A method for quantitatively evaluating a fracturing and sanding operation, characterized in that, The method comprises the following steps: collecting evaluation factor parameters of a well to be evaluated, the evaluation factor parameters comprising construction pressure, pump-off pressure, sanding intensity, fluid intensity, comprehensive sand ratio and construction discharge rate; quantitatively evaluating the actual influence degree of each factor parameter on the difficulty of sanding construction according to the evaluation factor parameters; determining the sanding construction difficulty of the well to be evaluated according to the actual influence degree of each evaluation factor parameter; wherein the method further comprises the following steps: determining a corresponding construction difficulty level according to the sanding construction difficulty of the well to be evaluated, the construction difficulty level comprising a first level, a second level and a third level, wherein the first level is determined when the sanding construction difficulty is greater than or equal to 0 and less than 0.4, the second level is determined when the sanding construction difficulty is greater than or equal to 0.4 and less than 0.7, and the third level is determined when the sanding construction difficulty is greater than or equal to 0.7 and less than 1; configuring corresponding fracturing process design parameters according to the construction difficulty level; in the step of configuring corresponding fracturing process design parameters according to the construction difficulty level, the following steps are included: When the current construction difficulty level is the first level, the fracturing process design parameters include: liquid viscosity is low viscosity, sanding mode is high sand ratio continuous long stage, pre-gel liquid volume is 200 m 3 and the ratio of proppant 70 / 140:40 / 70:30 / 50 is 1:4:5; When the current construction difficulty level is the second level, the fracturing process design parameters include: liquid viscosity is appropriate medium viscosity, sand adding mode is ladder slow sand ratio, pre-gel liquid volume is 220 m 3 and the ratio of proppant 70 / 140:40 / 70:30 / 50 is 1:6:3; When the current construction difficulty level is the third level, the fracturing process design parameters include: liquid viscosity is medium-high viscosity, sanding mode is slug sanding, pre-gel liquid volume is 250 m 3 and the ratio of proppant 70 / 140:40 / 70:30 / 50 is 2:5:

3.

2. The method of claim 1, wherein, in the step of collecting evaluation factor parameters of a well to be evaluated, the following step is included: collecting the evaluation factor parameters of each well section in the well to be evaluated, wherein obtaining the construction pressure of each well section in the well to be evaluated according to field construction record data; obtaining the pump-off pressure of each well section in the well to be evaluated according to field construction record data; obtaining the sanding amount of each well section in the well to be evaluated and the length of each well section according to field construction record data, so as to obtain the sanding intensity of different well sections by the sanding amount and the length of the corresponding well section; obtaining the fluid amount of each well section in the well to be evaluated and the length of each well section according to field construction record data, so as to obtain the fluid intensity of different well sections by the fluid amount and the length of the corresponding well section; obtaining the sanding amount and the fluid amount of each well section in the well to be evaluated, so as to obtain the comprehensive sand ratio of different well sections by the ratio of the sanding amount to the fluid amount of the corresponding well section; obtaining the construction discharge rate of each well section in the well to be evaluated according to field construction record data.

3. The method according to claim 1 or 2, characterized in that, in the step of quantitatively evaluating the actual influence degree of each factor parameter on the difficulty of sanding construction according to the evaluation factor parameters, the following steps are included: calculating the weighted average value of each factor parameter according to the evaluation factor parameters of each well section in the well to be evaluated; calculating the actual influence degree of each factor parameter by a normalization algorithm, in combination with the maximum value and the minimum value of each factor parameter in the area where the well to be evaluated is located, according to the weighted average value of each factor parameter.

4. The method according to claim 1 or 2, characterized in that, in the step of determining the sanding construction difficulty of the well to be evaluated according to the actual influence degree of each evaluation factor parameter, the following steps are included: determining the weight of each evaluation factor parameter; calculating a reservoir comprehensive compressibility index representing the sanding construction difficulty of the well to be evaluated according to the actual influence degree of each evaluation factor parameter and the corresponding weight, wherein the reservoir comprehensive compressibility index is calculated by using the following expression: ； wherein, K represents a reservoir comprehensive compressibility index, represents the first i evaluation factor parameter, represents the first i evaluation factor parameter.

5. The method of claim 4, wherein, calculating the weight of each evaluation factor parameter by using the grey correlation method according to the collected evaluation factor parameters of the well to be evaluated.

6. The method of claim 5, wherein, The weights of the construction pressure, the pump-off pressure, the sanding intensity, the fluid intensity, the comprehensive sand ratio and the construction discharge rate are respectively 0.27, 0.14, 0.16, 0.1, 0.2 and 0.

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7. A system for quantitative evaluation of a fracturing and sanding operation, characterized in that, Comprise: a data collection module configured to collect evaluation factor parameters of a well to be evaluated, the evaluation factor parameters comprising a construction pressure, a pump-off pressure, a sanding intensity, a fluid intensity, a comprehensive sand ratio and a construction discharge rate; a parameter scoring module configured to quantitatively evaluate an actual influence degree of each factor parameter on the difficulty of sanding construction according to the evaluation factor parameters; a construction evaluation module configured to determine the sanding construction difficulty of the well to be evaluated according to the actual influence degree of each evaluation factor parameter; The system further comprises a process parameter configuration module, wherein the process parameter configuration module has: a construction difficulty level determination unit configured to determine a corresponding construction difficulty level according to the sanding construction difficulty of the well to be evaluated, the construction difficulty level comprising a first level, a second level and a third level, wherein the first level is determined when the sanding construction difficulty is greater than or equal to 0 and less than 0.4, the second level is determined when the sanding construction difficulty is greater than or equal to 0.4 and less than 0.7, and the third level is determined when the sanding construction difficulty is greater than or equal to 0.7 and less than 1. a process parameter generating unit, configured to configure corresponding fracturing process design parameters according to the construction difficulty level configuration, wherein: when the current construction difficulty level is the first level, the fracturing process design parameters include: the liquid viscosity is low viscosity, the sand adding mode is high sand ratio continuous long stage, the pre-gel liquid volume is 200m 3 and the ratio of proppant 70 / 140:40 / 70:30 / 50 is 1:4:5; when the current construction difficulty level is the second level, the fracturing process design parameters include: the liquid viscosity is moderate viscosity, the sand adding mode is ladder slow sand ratio, the pre-gel liquid volume is 220m 3 and the ratio of proppant 70 / 140:40 / 70:30 / 50 is 1:6:3; when the current construction difficulty level is the third level, the fracturing process design parameters include: the liquid viscosity is medium-high viscosity, the sand adding mode is slug sand, and the pre-gel liquid volume is 250m 3 and the ratio of proppant 70 / 140:40 / 70:30 / 50 is 2:5:3.

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