Method and system for quantitatively evaluating fracturing sand adding construction

Abstract

The method comprises the steps that evaluation factor parameters of a well to be evaluated are collected, and the evaluation factor parameters comprise the construction pressure, the pump stopping pressure, the sand adding strength, the liquid using strength, the comprehensive sand ratio and the construction displacement; according to the evaluation factor parameters, the actual influence degree of each factor parameter on the sand adding construction difficulty is quantitatively evaluated; and determining the sand adding construction difficulty of the to-be-evaluated well according to the actual influence degree of each evaluation factor parameter. According to the method, quantitative evaluation of the sand adding difficulty degree is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas fracturing, and in particular to a measurement system and method based on a distributed optical fiber acoustic wave sensor. Background Art

[0002] Hydraulic fracturing technology is an effective means of shale gas development. Field practice shows that the gas well production capacity has a certain positive correlation with the scale of fracturing and sand adding. However, due to the heterogeneity of the reservoir, the difficulty of sand adding in reservoirs of different qualities varies greatly. If a set of sand adding modes is still used in the design, it is often difficult to achieve high-intensity sand adding (sand adding intensity > 2.0m3 / m). Therefore, it is necessary to conduct post-fracture evaluation on wells that have been fractured in different areas in the early stage and quantitatively evaluate the difficulty of reservoir sand adding, so as to provide reference for the optimization of subsequent well process parameters.

[0003] There are few quantitative evaluation schemes for the difficulty of adding sand in the existing technology. Since the field construction mainly uses a single parameter for evaluation, it lacks accuracy, and the relevant research is mainly limited to qualitative analysis, that is, the main influencing factors that lead to the difficulty of adding sand to fracturing construction are clarified, but quantitative evaluation under the influence of multiple factors cannot be achieved. Therefore, it is very important to accurately evaluate the difficulty of adding sand to volume fracturing wells. Summary of the invention

[0004] The purpose of the present invention is to provide a post-fracture evaluation scheme for shale gas volume fracturing wells to achieve quantitative evaluation of the difficulty of adding sand, thereby providing important parameter basis for subsequent fracturing well parameter design.

[0005] In order to solve the above technical problems, an embodiment of the present invention provides a method for quantitatively evaluating fracturing sand addition construction, comprising: collecting evaluation factor parameters of the well to be evaluated, the evaluation factor parameters including construction pressure, pump stop pressure, sand addition intensity, liquid intensity, comprehensive sand ratio and construction displacement; according to the evaluation factor parameters, quantitatively evaluating the actual influence of each factor parameter on the difficulty of sand addition construction; according to the actual influence of each evaluation factor parameter, determining the difficulty of sand addition construction of the well to be evaluated.

[0006] Preferably, the step of collecting the evaluation factor parameters of the well to be evaluated includes: collecting the evaluation factor parameters of each well section in the well to be evaluated, wherein, according to the on-site construction record data, the construction pressure of each well section in the well to be evaluated is obtained; according to the on-site construction record data, the pump stop pressure of each well section in the well to be evaluated is obtained; according to the on-site construction record data, the sand addition amount and the section length of each well section in the well to be evaluated are obtained, so as to obtain the sand addition intensity of different well sections through the sand addition amount and the section length of the corresponding well section; according to the on-site construction record data, the liquid consumption amount and the section length of each well section in the well to be evaluated are obtained, so as to obtain the liquid consumption intensity of different well sections through the liquid consumption amount and the section length of the corresponding well section; according to the sand addition amount and the liquid consumption amount of each well section in the well to be evaluated, the comprehensive sand ratio of different well sections is obtained through the ratio of the sand addition amount and the liquid consumption amount of the corresponding well section; according to the on-site construction record data, the construction displacement of each well section in the well to be evaluated is obtained.

[0007] Preferably, in the step of quantitatively evaluating the actual influence of each parameter on the difficulty of sand addition construction according to the evaluation factor parameters, it includes: 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 through a normalization algorithm 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.

[0008] Preferably, the step of determining the difficulty of sand filling construction of the well to be evaluated according to the actual influence degree of each evaluation factor parameter includes: determining the weight of each evaluation factor parameter; calculating the reservoir comprehensive compressibility index representing the difficulty of sand filling construction 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 using the following expression:

[0009]

[0010] Where K represents the comprehensive compressibility index of the reservoir, K i Indicates the actual influence of the parameter of the i-th evaluation factor, ω i Represents the weight of the i-th evaluation factor parameter.

[0011] Preferably, the weight of each evaluation factor parameter is calculated using the grey correlation method based on the collected evaluation factor parameters of the well to be evaluated.

[0012] Preferably, the weights of the construction pressure, the pump stop pressure, the sand adding intensity, the liquid usage intensity, the comprehensive sand ratio and the construction displacement are 0.27, 0.14, 0.16, 0.1, 0.2 and 0.13 respectively.

[0013] Preferably, the method also includes: determining a corresponding construction difficulty level according to the difficulty of sand adding construction of the well to be evaluated, the construction difficulty level including a first level, a second level and a third level, wherein the first level is determined when the sand adding construction difficulty is greater than or equal to 0 and less than 0.4, the second level is determined when the sand adding construction difficulty is greater than or equal to 0.4 and less than 0.7, and the third level is determined when the sand adding 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.

[0014] Preferably, in the step of configuring the corresponding fracturing process design parameters according to the construction difficulty level, it includes: when the current construction difficulty level is the first level, the fracturing construction design parameters include: the liquid viscosity is low viscosity, the sand adding mode is a high sand ratio continuous long stage, the pre-gel volume is 200m 3 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 construction design parameters include: liquid viscosity is moderately viscous, sand adding mode is step-by-step slow sand lifting ratio, and the amount of pre-filled glue is 220m 3 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 construction design parameters include: liquid viscosity is medium-high viscosity, sand adding mode is slug sand adding, and the amount of pre-filled glue is 250m 3 and proppant 70 / 140:40 / 70:30 / 50 in a ratio of 2:5:3.

[0015] On the other hand, an embodiment of the present invention further provides a system for quantitatively evaluating fracturing and sanding construction, comprising: a data collection module, which is configured to collect evaluation factor parameters of the well to be evaluated, the evaluation factor parameters including construction pressure, pump stop pressure, sanding intensity, liquid intensity, comprehensive sand ratio and construction displacement; a parameter scoring module, which is configured to quantitatively evaluate the actual influence of each factor parameter on the difficulty of sanding construction based on the evaluation factor parameters; a construction evaluation module, which is configured to determine the difficulty of sanding construction of the well to be evaluated based on the actual influence of each evaluation factor parameter.

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

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

[0018] The present invention proposes a method and system for quantitatively evaluating fracturing and sanding construction. The method and system provide a quantitative evaluation of the difficulty of adding sand after shale gas volume fracturing through quantitative evaluation analysis under the influence of multiple factors, thereby providing an important parameter basis for the subsequent fracturing well parameter design.

[0019] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0021] Figure 1 This is a schematic diagram of the steps of a method for quantitatively evaluating fracturing and sanding construction according to an embodiment of the present application.

[0022] Figure 2 This is a module block diagram of a method system for quantitatively evaluating fracturing and sanding construction according to an embodiment of the present application. DETAILED DESCRIPTION

[0023] The following will describe the implementation methods of the present invention in detail with reference to the accompanying drawings and embodiments, so that the implementation process of how the present invention applies 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 of the present invention and the various features in the embodiments can be combined with each other, and the technical solutions formed are all within the protection scope of the present invention.

[0024] In addition, the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions. Also, although a logical sequence is shown in the flowchart, in some cases, the steps shown or described can be performed in a sequence different from that here.

[0025] The terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms "one", "one" and "item" used herein are also intended to include plural numbers. It should also be understood that the terms "include" and / or "comprise" used herein specify the existence of stated features, integers, steps, operations, units and / or components, without excluding the existence 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 the gas well production capacity has a certain positive correlation with the scale of fracturing and sand adding. However, due to the heterogeneity of the reservoir, the difficulty of sand adding in reservoirs of different qualities varies greatly. If a set of sand adding modes is still used in the design, it is often difficult to achieve high-intensity sand adding (sand adding intensity > 2.0m3 / m). Therefore, it is necessary to conduct post-fracture evaluation on wells that have been fractured in different areas in the early stage and quantitatively evaluate the difficulty of reservoir sand adding, so as to provide reference for the optimization of subsequent well process parameters.

[0027] There are few quantitative evaluation schemes for the difficulty of adding sand in the existing technology. Since the field construction mainly uses a single parameter for evaluation, it lacks accuracy, and the relevant research is mainly limited to qualitative analysis, that is, the main influencing factors that lead to the difficulty of adding sand to fracturing construction are clarified, but quantitative evaluation under the influence of multiple factors cannot be achieved. Therefore, it is very important to accurately evaluate the difficulty of adding sand to volume fracturing wells.

[0028] In order to solve the above technical problems, the embodiment of the present application proposes a method and system for quantitatively evaluating fracturing and sanding construction. The method and system are based on a total of 6 evaluation factors, including the construction pressure, pump stop pressure, sanding intensity, liquid intensity, comprehensive sand ratio and construction displacement of the well to be evaluated. The method and system first conducts a sanding difficulty evaluation under the influence of a single factor, and then calculates the comprehensive sanding difficulty evaluation index of the reservoir by combining the weights of each factor. This provides a basis for the differentiated process parameter design of subsequent fracturing well parameters.

[0029] Embodiment 1

[0030] Figure 1 The following is a schematic diagram of the steps of the method for quantitatively evaluating fracturing and sanding construction according to the embodiment of the present application. The specific steps of the method for quantitatively evaluating fracturing and sanding construction (also referred to as "quantitative evaluation method") according to the embodiment of the present invention are described below.

[0031] like Figure 1 As shown, step S110 collects evaluation factor parameters of the well to be evaluated, wherein the evaluation factor parameters include construction pressure, pump stop pressure, sand addition intensity, fluid intensity, comprehensive sand ratio and construction displacement.

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

[0033] Preferably, the (fracturing) construction pressure P of each well section in the well to be evaluated is obtained according to the field construction record data. s .

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

[0035] Preferably, the sand addition amount and the length of each well section in the well to be evaluated are obtained according to the field construction record data, so that the sand addition intensity ω of different well sections can be obtained through the sand addition amount and the length of the corresponding well section. s Specifically, after obtaining the sand addition amount and the length of each well section in the well to be evaluated, the sand addition amount is divided by the length data of the corresponding well section to obtain the sand addition intensity (in m) of different well sections in the well to be evaluated. 3 / m).

[0036] Preferably, the amount of liquid used in each well section and the length of each well section in the well to be evaluated are obtained according to the on-site construction record data, so that the liquid intensity ω of different well sections can be obtained through the liquid amount and the length of the corresponding well section. y Specifically, after obtaining the fluid volume and length of each well section in the well to be evaluated, the fluid volume is divided by the length data of the corresponding well section to obtain the fluid intensity of different well sections in the well to be evaluated (in m 3 / m).

[0037] Preferably, the sand addition amount and liquid consumption amount of each well section in the well to be evaluated are used to obtain the comprehensive sand ratio S of different well sections through the ratio of the sand addition amount to the liquid consumption amount of the corresponding well section. Specifically, the liquid consumption data and sand addition amount data of different well sections in the well to be evaluated are first obtained through the on-site construction record data, and then the sand addition amount at the same well section position is divided by the liquid consumption to obtain the comprehensive sand ratio data of different well sections in the well to be evaluated.

[0038] Preferably, the construction displacement U of each well section in the well to be evaluated is obtained according to the on-site construction record data. In the embodiment of the present invention, the construction displacement is the displacement data of each well section in the well to be evaluated during stable construction.

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

[0040] refer to Figure 1 In step S120, based on the evaluation factor parameters collected in step S110, the actual influence of each evaluation factor parameter on the difficulty of sand adding construction is quantitatively evaluated.

[0041] Specifically, first, according to each evaluation factor parameter of each section in the well to be evaluated, the weighted average value of each factor parameter is calculated. Then, according to 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, the actual influence degree of each factor parameter is calculated through the normalized calculation method.

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

[0043]

[0044] Among them, K1 represents the construction pressure P s The actual impact degree, in %; It represents the weighted average of the construction pressure of the well to be evaluated, in MPa; P smax , P smin They respectively represent the highest and lowest values ​​of the construction pressure in the area where the well to be evaluated is located, in MPa.

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

[0046]

[0047] Among them, K2 represents the pump stop pressure P t The actual impact degree, in %; It represents the weighted average of the pump-off pressure of the well to be evaluated, in MPa; P tmax , P tmin They respectively represent the highest and lowest values ​​of the pump-off pressure in the area where the well to be evaluated is located, in MPa.

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

[0049]

[0050] Among them, K3 represents the sand adding intensity ω s The actual impact degree, in %; Represents the weighted average value of the sand addition intensity of the well to be evaluated, in m 3 / m;ω smax ,ω smin Respectively represent the highest and lowest values ​​of sand injection strength in the area where the well to be evaluated is located, in m 3 / m.

[0051] In one embodiment, the weighted average of the strength of the liquid used The actual degree of influence (i.e., score) of the fluid strength on the difficulty of adding sand is calculated using the following expression:

[0052]

[0053] Among them, K4 represents the liquid intensity ω y The actual impact degree, in %; It represents the weighted average value of the fluid intensity of the well to be evaluated, in m 3 / m;ω ymax ,ω ymin Respectively represent the highest and lowest values ​​of the fluid intensity in the area where the well to be evaluated is located, in units of m 3 / m.

[0054] In one embodiment, the weighted average value of the comprehensive sand ratio is The actual degree of influence (i.e., score) of the comprehensive sand ratio on the difficulty of adding sand is calculated using the following expression:

[0055]

[0056] Among them, K5 represents the actual influence of the comprehensive sand ratio S, the unit is %; It represents the weighted average value of the comprehensive sand ratio of the well to be evaluated, in %; S max , S min They respectively represent the highest and lowest values ​​of the comprehensive sand ratio in the area where the well to be evaluated is located, in %.

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

[0058]

[0059] Among them, K6 represents the actual impact degree of construction displacement U, the unit is %; Represents the weighted average of the construction displacement of the well to be evaluated, in m 3 / min; U max , U min Respectively represent the highest and lowest values ​​of the construction displacement in the area where the well to be evaluated is located, in m 3 / min.

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

[0061] Continue to refer Figure 1 In step S130, the difficulty of sand adding construction in the well to be evaluated is quantitatively determined according to the actual influence degree of each evaluation factor parameter.

[0062] In step S130, first, the weight of each evaluation factor parameter is determined, and then, according to the actual influence degree and corresponding weight of each evaluation factor parameter of the current well to be evaluated, the reservoir comprehensive compressibility index representing the difficulty of sand filling construction of the well to be evaluated is calculated.

[0063] Further, according to the evaluation factor parameters of the well to be evaluated collected in step S110, the grey correlation method is used to calculate the weights of various evaluation factor parameters. In one embodiment, the weights of the construction pressure, pump stop pressure, sand addition intensity, liquid intensity, comprehensive sand ratio and construction displacement 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]

[0066] Where K represents the comprehensive compressibility index of the reservoir, K i Indicates the actual influence of the parameter of the i-th evaluation factor, ω i Represents the weight of the i-th evaluation factor parameter.

[0067] In addition, the embodiment of the present invention further configures corresponding fracturing process design parameters according to the current quantitatively calculated sand adding construction difficulty data.

[0068] Specifically, first, according to the difficulty of sand adding construction of the well to be evaluated, the construction difficulty level that matches the current sand adding construction difficulty is determined, and then, the corresponding fracturing process design parameters are configured according to the currently determined construction difficulty level. For specific examples, see Table 1.

[0069] Table 1 Optimal design of fracturing parameters for different sand adding difficulty levels

[0070]

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

[0072] In the first embodiment, when the difficulty of sand adding construction is greater than or equal to 0 and less than 0.4, it is determined to be the first level. When the current construction difficulty level is the first level, the fracturing construction design parameters include: the liquid viscosity is low viscosity, the sand adding mode is a high sand ratio continuous long stage, the amount of pre-filled glue is 200m 3 and proppant 70 / 140:40 / 70:30 / 50 in a ratio of 1:4:5.

[0073] In the second embodiment, when the difficulty of sand adding construction is greater than or equal to 0.4 and less than 0.7, it is determined to be the second level. When the current construction difficulty level is the second level, the fracturing construction design parameters include: liquid viscosity is moderately viscous, sand adding mode is step-by-step slow sand lifting ratio, and the amount of pre-filled glue is 220m 3 and proppant 70 / 140:40 / 70:30 / 50 in a ratio of 1:6:3.

[0074] In the third embodiment, when the difficulty of sand adding construction is greater than or equal to 0.7 and less than 1, it is determined to be the third level. When the current construction difficulty level is the third level, the fracturing construction design parameters include: liquid viscosity is medium-high viscosity, sand adding mode is slug sand adding, and the amount of pre-placement glue is 250m 3 and proppant 70 / 140:40 / 70:30 / 50 in a ratio of 2:5:3.

[0075] Embodiment 2

[0076] Based on the quantitative evaluation method described in Example 1, the embodiment of the present invention takes three wells in a deep shale gas block in the Sichuan Basin as an example to perform post-pressure evaluation, and compares the advantages and disadvantages of the quantitative evaluation method described in the present invention with the current on-site single parameter evaluation method.

[0077] Step A: Collect the evaluation parameters of each stage during the fracturing operation of the three wells to be evaluated, including the operation pressure P s , Pump stop pressure P t 、Sand addition strength ω s 、Liquid strength ω y , comprehensive sand ratio S and construction displacement U. The evaluation factor parameters of the three wells are shown in Tables 2 to 4 respectively; then the weighted average values ​​of various parameters are calculated, see Table 5.

[0078] Table 2 Collection and summary of evaluation factor parameters of WY26-2HF well

[0079]

[0080] Table 3 Collection and summary of evaluation factor parameters of WY23-7HF well

[0081]

[0082]

[0083] Table 4 Collection and summary of evaluation factor parameters of WY29-8HF well

[0084]

[0085] Table 5 Summary of the actual impact of each factor parameter of the three wells to be evaluated

[0086]

[0087] Compared with conventional methods: Based on Table 5, a single parameter is often used for evaluation on site, that is, the construction pressure or the sand adding intensity is used for evaluation. The lower the construction pressure, the easier it is to add sand, or the higher the sand adding intensity, the easier it is to add sand. This method has two disadvantages:

[0088] First, the evaluation is inaccurate. A single parameter cannot reflect the comprehensive characteristics of the well. Take WY26-2 and WY29-8 as examples. The construction pressure of WY29-8 is 6.3MPa higher than that of WY26-2. The sand adding intensity is similar. Therefore, it is concluded that it is more difficult to add sand to WY29-8. However, the fact that WY26-2 has higher fluid intensity and lower comprehensive sand ratio is ignored. Although WY26-2 has lower pressure, the reservoir is sensitive to sand adding and more liquid is needed to carry the same amount of sand. The single parameter evaluation is inaccurate.

[0089] Secondly, the evaluation results cannot be quantified. Single parameter evaluation can only be used for ranking, and the difficulty of adding sand between wells cannot be quantitatively reflected.

[0090] The calculation process and the calculation results obtained by the quantitative evaluation method according to the embodiment of the present invention are listed below:

[0091] Step B: 3 well fracturing pressure P s As shown in Table 5, the minimum construction pressure P smin , the highest value P smax The operating pressures P of the three wells are calculated according to formula (1). s The actual impact levels K1 are 1, 0, and 0.32 respectively.

[0092] Step C: 3 wells fracturing pump stop pressure P t As shown in Table 5, the minimum pump stop pressure P tmin , the highest value P tmaxThe pump stop pressures P of the three wells are calculated according to formula (2). t The actual impact levels K2 are 0, 0.87, and 1 respectively.

[0093] Step D: Sanding intensity of 3 wells ω s As shown in Table 5, the minimum value of sand addition strength ω smin , the highest value ω smax 1.3m respectively 3 / m, 2.1m 3 / m, and the sand adding intensity ω of the three wells is calculated according to formula (3) s The actual impact levels K3 are 1, 0, and 0.81 respectively.

[0094] Step E: Fluid strength ω for 3 wells y As shown in Table 5, the minimum liquid strength ω ymin , the highest value ω ymax 24.6m respectively 3 / m、31.1m 3 / m, and the sand adding intensity ω of the three wells is calculated according to formula (4) y The actual impact levels K4 are 0, 0.61, and 1 respectively.

[0095] Step F: The comprehensive sand ratio S of the three wells is shown in Table 5. The lowest comprehensive sand ratio S min , the highest value S max They are 4.6 and 8.1 respectively. According to formula (5), the actual influence degree K5 of the comprehensive sand ratio S of the three wells is 0.65, 0 and 1 respectively.

[0096] Step G: The construction displacement U of the three wells is shown in Table 5. The minimum construction displacement U min , the highest value U max They are 11.2 and 14.2 respectively. According to formula (6), the actual influence degree K6 of the construction displacement U of the three wells is 0.98, 0 and 1 respectively.

[0097] Step H: Based on the sand adding difficulty scores of the three wells obtained in steps A to G, as shown in Table 1, the weights corresponding to the six factors are 27%, 14%, 16%, 10%, 20%, and 13%, respectively. According to formula (7), the sand adding difficulty scores of the three wells are 0.69, 0.18, and 0.79, respectively. Combined with Table 1, based on the quantitative evaluation results, guidance can be provided for the design of subsequent well fracturing process parameters.

[0098] At present, the quantitative evaluation method provided by the embodiment of the present invention has been used in 13 well-times of field application evaluation in a deep shale gas block in the Sichuan Basin, with an accuracy rate of 92.3%.

[0099] Embodiment 3

[0100] Based on the quantitative evaluation method described in the first or second embodiment above, the present invention further provides a system for quantitatively evaluating fracturing and sanding operations (also referred to as a "quantitative evaluation system").

[0101] Figure 2 This is a module block diagram of the method system for quantitatively evaluating fracturing and sanding construction in an embodiment of the present application. Figure 2 As shown, the quantitative evaluation system described in the embodiment of the present invention includes: a data collection module 21, a parameter scoring module 22 and a construction evaluation module 23.

[0102] The data collection module 21 is implemented according to the method described in the above step S110, and is configured to collect evaluation factor parameters of the well to be evaluated, wherein the evaluation factor parameters include construction pressure, pump stop pressure, sand addition intensity, liquid intensity, comprehensive sand ratio and construction displacement; the parameter scoring module 22 is implemented according to the method described in the above step S120, and is configured to quantitatively evaluate the actual influence 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 the above step S130, and is configured to determine the difficulty of sand addition construction of the well to be evaluated based on the actual influence of each evaluation factor parameter.

[0103] In addition, the quantitative evaluation system described in the embodiment of the present invention further includes a process parameter configuration module (not numbered). The process parameter configuration module includes: a construction difficulty level determination unit and a process parameter generation unit.

[0104] The construction difficulty level determination unit is used to determine the corresponding construction difficulty level according to the sand adding construction difficulty of the well to be evaluated. The construction difficulty level includes the first level, the second level and the third level. Among them, when the sand adding construction difficulty is greater than or equal to 0 and less than 0.4, it is determined as the first level; when the sand adding construction difficulty is greater than or equal to 0.4 and less than 0.7, it is determined as the second level; when the sand adding construction difficulty is greater than or equal to 0.7 and less than 1, it is determined as the third level;

[0105] The process parameter generation unit is used to configure the corresponding fracturing process design parameters according to the current construction difficulty level according to the above Table 1.

[0106] The present invention discloses a method and system for quantitatively evaluating fracturing and sanding construction. The method and system provide a quantitative evaluation of the difficulty of sanding after shale gas volume fracturing wells through quantitative evaluation analysis under the influence of multiple factors, thereby providing an important parameter basis for subsequent fracturing well parameter design.

[0107] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any person familiar with the technology within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

[0108] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0109] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0110] It should be understood that the embodiments disclosed in the present invention are not limited to the specific structures, processing steps or materials disclosed herein, but should be extended to equivalent substitutions of these features understood by ordinary technicians in the relevant field. It should also be understood that the terms used herein are only used for the purpose of describing specific embodiments and are not meant to be limiting.

[0111] The "one embodiment" or "embodiment" mentioned in the specification means that the specific features, structures or characteristics described in conjunction with the embodiment are included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment" or "embodiment" appearing in various places throughout the specification do not necessarily refer to the same embodiment.

[0112] Although the embodiments disclosed in the present invention are as above, the contents described are only embodiments adopted for facilitating the understanding of the present invention and are not intended to limit the present invention. Any technician in the technical field to which the present invention belongs can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A method for quantitatively evaluating fracturing and sanding construction, characterized in that: include: Collecting evaluation factor parameters of the well to be evaluated, wherein the evaluation factor parameters include construction pressure, pump stop pressure, sand addition intensity, fluid intensity, comprehensive sand ratio and construction displacement; According to the evaluation factor parameters, quantitatively evaluate the actual influence of each factor parameter on the difficulty of sand adding construction; The difficulty of sand adding construction in the well to be evaluated is determined based on the actual influence of various evaluation factor parameters.

2. The method according to claim 1, characterized in that The step of collecting the evaluation factor parameters of the well to be evaluated includes: collecting the evaluation factor parameters of each well section in the well to be evaluated, wherein: According to the on-site construction record data, the construction pressure of each section in the well to be evaluated is obtained; According to the on-site construction record data, the pump stop pressure of each section in the well to be evaluated is obtained; According to the on-site construction record data, the sand addition amount and section length of each well section in the well to be evaluated are obtained, so that the sand addition intensity of different well sections can be obtained through the sand addition amount and the section length of the corresponding well section; According to the on-site construction record data, the liquid consumption and section length of each well section in the well to be evaluated are obtained, so that the liquid consumption intensity of different well sections can be obtained through the liquid consumption and the section length of the corresponding well section; According to the amount of sand added and the amount of liquid used in each section of the well to be evaluated, the comprehensive sand ratio of different sections can be obtained through the ratio of the amount of sand added to the amount of liquid used in the corresponding section; According to the on-site construction record data, the construction displacement of each section in the well to be evaluated is obtained.

3. The method according to claim 1 or 2, characterized in that: The step of quantitatively evaluating the actual influence of each parameter on the difficulty of sand adding construction according to the evaluation factor parameters includes: Calculate the weighted average value of each factor parameter according to the evaluation factor parameters of each well section in the well to be evaluated; According to 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, the actual influence degree of each factor parameter is calculated through a normalization algorithm.

4. The method according to any one of claims 1 to 3, characterized in that The step of determining the difficulty of sand filling construction of the well to be evaluated according to the actual influence degree of each evaluation factor parameter includes: Determine the weight of each evaluation factor parameter; According to the actual influence degree and corresponding weight of each evaluation factor parameter, the reservoir comprehensive compressibility index representing the difficulty of sand filling construction of the well to be evaluated is calculated, wherein the reservoir comprehensive compressibility index is calculated using the following expression: Where K represents the comprehensive compressibility index of the reservoir, K i Indicates the actual influence of the parameter of the i-th evaluation factor, ω i Represents the weight of the i-th evaluation factor parameter.

5. The method according to claim 4, characterized in that According to the collected evaluation factor parameters of the wells to be evaluated, the grey correlation method is used to calculate the weight of each evaluation factor parameter.

6. The method according to claim 5, characterized in that The weights of the construction pressure, the pump stop pressure, the sand adding intensity, the liquid usage intensity, the comprehensive sand ratio and the construction displacement are 0.27, 0.14, 0.16, 0.1, 0.2 and 0.13 respectively.

7. The method according to any one of claims 1 to 6, characterized in that: The method further comprises: According to the difficulty of sand adding construction of the well to be evaluated, a corresponding construction difficulty level is determined, and the construction difficulty level includes a first level, a second level and a third level, wherein the first level is determined when the sand adding construction difficulty is greater than or equal to 0 and less than 0.4, the second level is determined when the sand adding construction difficulty is greater than or equal to 0.4 and less than 0.7, and the third level is determined when the sand adding construction difficulty is greater than or equal to 0.7 and less than 1; Corresponding fracturing process design parameters are configured according to the construction difficulty level.

8. The method according to claim 7, characterized in that The step of configuring corresponding fracturing process design parameters according to the construction difficulty level includes: When the current construction difficulty level is the first level, the fracturing construction design parameters include: the liquid viscosity is low viscosity, the sand adding mode is a high sand ratio continuous long stage, the pre-filled glue volume is 200m 3 and proppant 70 / 140:40 / 70:30 / 50 in a ratio of 1:4:5; When the current construction difficulty level is the second level, the fracturing construction design parameters include: liquid viscosity is moderately viscous, sand adding mode is step-by-step slow sand ratio, and the amount of pre-filled glue is 220m 3 and proppant 70 / 140:40 / 70:30 / 50 in a ratio of 1:6:3; When the current construction difficulty level is the third level, the fracturing construction design parameters include: liquid viscosity is medium-high viscosity, sand adding mode is slug sand adding, and the amount of pre-filled glue is 250m 3 and proppant 70 / 140:40 / 70:30 / 50 in a ratio of 2:5:

3.

9. A system for quantitatively evaluating fracturing and sanding operations, characterized in that: include: A data collection module configured to collect evaluation factor parameters of the well to be evaluated, wherein the evaluation factor parameters include construction pressure, pump stop pressure, sand addition intensity, liquid intensity, comprehensive sand ratio and construction displacement; A parameter scoring module is configured to quantitatively evaluate the actual influence of each factor parameter on the difficulty of sand adding construction according to the evaluation factor parameters; The construction evaluation module is configured to determine the difficulty of sand adding construction of the well to be evaluated according to the actual influence degree of each evaluation factor parameter.

10. The system according to claim 9, characterized in that The system further comprises: 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 according to the sand adding 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 first level is determined when the sand adding construction difficulty is greater than or equal to 0 and less than 0.4, the second level is determined when the sand adding construction difficulty is greater than or equal to 0.4 and less than 0.7, and the third level is determined when the sand adding construction difficulty is greater than or equal to 0.7 and less than 1; A process parameter generating unit is configured to configure corresponding fracturing process design parameters according to the construction difficulty level.

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