Characterization and calculation method of energy consumption in whole cycle of oil reservoir fracturing

Abstract

The present application provides a kind of oil reservoir fracturing reconstruction whole cycle injection energy consumption characterization and calculation method, which includes: step 1, the technical index of energy consumption under the unit benefit of fracturing flow system is constructed, and the energy consumption characterization mode is established;Step 2, use the fracturing reservoir parameters of target oil field, carry out geological modeling;Step 3, fracture propagation simulation is carried out, and the parameters such as fracture volume and conductivity are obtained;Step 4, productivity prediction is carried out;Step 5, calculate the fracture pressure drop parameter;Step 6, calculate the energy consumption index after fracturing reconstruction.The oil reservoir fracturing reconstruction whole cycle injection energy consumption characterization and calculation method constructs the technical index of energy consumption under the unit benefit of fracturing flow system, which is used for overall energy consumption evaluation;It can be feasible to characterize the energy consumption of fracturing reconstruction system, which can provide reference for oil field construction, process optimization, improve energy efficiency and guide energy saving.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil field energy saving, in particular to a method for characterizing and calculating injection-production energy consumption in the whole cycle of oil reservoir fracturing reconstruction. BACKGROUND

[0002] Under the background of the "double carbon" goal, for many oilfields that have entered the high water-cut development stage, reducing energy consumption has become a key issue. In order to better improve production measures, improve production efficiency, and reduce oilfield costs, it is necessary to have a clear understanding of the development state of the oilfield. It is necessary to refer to the production energy consumption indicators of each system of the oilfield in this process.

[0003] At present, the evaluation of oilfield development energy consumption mainly focuses on injection-production systems and gathering systems. For example, the unit pressure water injection power consumption, pumping system efficiency for injection-production systems, and the self-consumption gas per ton of oil and the power consumption per ton of oil for gathering systems are proposed as energy consumption indicators, and have been applied in many domestic oilfields.

[0004] Research shows that the pressure loss (energy consumption) of the near-well reservoir- wellbore inflow system accounts for more than 85% of the reservoir flow energy consumption, and the near-well reservoir- wellbore inflow system is the main node of energy saving and consumption reduction. However, there is currently a lack of research on the energy consumption evaluation of underground fracturing and other reconstruction measures, and there is no method for quantitatively characterizing the energy consumption of underground fracturing. It is difficult for oilfields to better optimize production measures from the aspect of energy consumption.

[0005] In the Chinese patent application with application number CN201911085801.1, a method for overall optimization of injection-production system energy consumption in a water injection development oilfield is disclosed. The method includes the following steps: step 1, determining the decision variables of the optimization model; step 2, determining the objective function of the optimization model; step 3, determining the constraint conditions of the optimization model; and step 4, solving the optimization model by using a particle swarm algorithm combined with numerical simulation. The method takes the reservoir system as the hub, comprehensively considers the energy consumption of water injection, reservoir, and lifting systems, obtains relevant parameters by means of numerical simulation, establishes an overall optimization model of the injection-production system, optimizes the injection-production scheme of the reservoir, and optimizes the total energy consumption of the injection-production system under the condition of meeting the reservoir scheme, thereby achieving further energy saving and consumption reduction under the condition of meeting the reservoir scheme, and providing a new method for oilfield energy saving and consumption reduction.

[0006] In the Chinese patent application with the application number CN201310331316.4, a model-free gradient optimization control method and simulation device for offshore platform injection-production are involved. The method comprises: calculating real-time system efficiency; updating the highest efficiency point based on the calculated real-time system efficiency; calculating the efficiency change gradient based on the efficiency of the current period and the previous period; determining the next period working point based on the efficiency change gradient and the highest efficiency point, and performing production control. The simulation device comprises: a computer control center, a control cabinet, a relay, a frequency converter, a 24V power supply, an intelligent I / O acquisition module, a transformer, a voltage transmitter, a current transmitter, a simulation device running platform, a water injection module, and an oil production module. The invention can collect the required data in real time, find the corresponding optimal working point through optimization, and realize online optimization of the efficiency and yield of the injection-production system production process. The invention collects the operation data of the offshore oil platform injection-production system, establishes a mathematical model, improves the overall efficiency of the water injection pump, and reduces energy consumption.

[0007] In the Chinese patent application with the application number CN201910370372.6, a water drive reservoir energy-consumption-yield-benefit integrated characterization method is involved. The water drive reservoir energy-consumption-yield-benefit integrated characterization method comprises: step 1, performing oil and gas production system process analysis and node division; step 2, calculating the energy efficiency of the water injection system; step 3, calculating the energy efficiency of the oil production system; step 4, calculating the energy efficiency of the treatment and circulation system; step 5, calculating the water-oil conversion efficiency of the reservoir system; step 6, calculating the total system yield; and step 7, calculating the total system benefit. The water drive reservoir energy-consumption-yield-benefit integrated characterization method can predict the yield and benefit under given energy and cost input conditions. By comparing the difference between the theoretical model yield and the actual yield, the working condition of the oil and gas production system can be accurately grasped, and the problem link can be analyzed to provide improvement suggestions to guide oilfield production.

[0008] The above prior art has great differences from the present application and cannot solve the technical problems we want to solve. Therefore, we have invented a new oil reservoir fracturing reconstruction full-cycle injection-production energy consumption characterization and calculation method. SUMMARY

[0009] The purpose of the present application is to provide an oil reservoir fracturing reconstruction full-cycle injection-production energy consumption characterization and calculation method for constructing the energy consumption of the fracturing flow system under unit benefit, which is used for overall energy consumption evaluation.

[0010] The purpose of the present application can be achieved by the following technical measures: an oil reservoir fracturing reconstruction full-cycle injection-production energy consumption characterization and calculation method, which comprises:

[0011] Step 1, construct the technical index of energy consumption under the unit benefit of the fracturing flow system, and establish the energy consumption characterization mode;

[0012] Step 2, using the fracturing reservoir parameters of the target oilfield, geological modeling is carried out;

[0013] Step 3, fracture propagation simulation is carried out to obtain parameters such as fracture volume and conductivity;

[0014] Step 4, productivity prediction is carried out;

[0015] Step 5, the fracture pressure drop parameter is calculated;

[0016] Step 6, the energy consumption index after fracturing reconstruction is calculated.

[0017] The purpose of the application can also be achieved by the following technical measures:

[0018] In step 1, the actual energy consumption of fluid flow in the fracture area is obtained based on the law of conservation of energy, and the energy consumption per unit time is further obtained, the energy consumption index is defined, the technical index of energy consumption under the unit benefit of the fracturing flow system is constructed, and the energy consumption characterization mode is established.

[0019] Step 1 includes:

[0020] Step 1a, calculate the actual energy consumption of fluid flow in the fracturing reconstruction area within a certain time;

[0021] Step 1b, propose the equivalent energy consumption index, i.e. energy consumption per unit time;

[0022] Step 1c, for single-phase flow, ignoring the difference in flow rate and density, calculate the equivalent energy consumption index ΔEd;

[0023] Step 1d, construct the technical index of energy consumption under the unit benefit of the fracturing flow system according to the equivalent energy consumption index.

[0024] In step 1a, the actual energy consumption of fluid flow in the fracturing reconstruction area within a certain time is:

[0025]

[0026] In formula (1), ΔE represents the energy consumption of fluid flow, J; P0 represents the inlet pressure of fracturing reconstruction, Pa; V0 represents the fluid volume flowing into the fracturing reconstruction area within a certain time, m 3 : P1 represents the bottom hole pressure of the production well, Pa; V1 represents the fluid volume flowing into the bottom hole of the production well within a certain time, m 3 : m is the mass of fluid passing through the fracturing reconstruction area per unit time, kg; v0 is the flow rate of fluid at the inlet end of the fracturing reconstruction, m / s; v1 is the flow rate of fluid at the bottom hole of the production well, m / s; q mis the fluid mass flow rate, kg / s; p0 is the fluid density at the inlet end of the fracturing reconstruction, kg / m 3 ; p1 is the fluid density at the bottom of the oil production well, kg / m 3 ; Δt is the time, s.

[0027] In step 1b, the equivalent energy consumption index is proposed, i.e., the energy consumption per unit time is:

[0028]

[0029] In formula (2), ΔE d1 represents the equivalent energy consumption, J / s; t represents the time, s; q m represents the fluid mass flow rate, kg / s; p0 represents the fluid density at the inlet end of the fracturing reconstruction, kg / m 3 ; p1 represents the fluid density at the bottom of the oil production well, kg / m; P1 represents the pressure at the bottom of the oil production well, Pa; P0 represents the reservoir pressure, Pa.

[0030] In step 1c, for single-phase flow, if the flow rate and density difference are ignored, the equivalent energy consumption index ΔE d is:

[0031] ΔE d = Q v · (P0-P1) = Q v · ΔP (3)

[0032] In formula (3), ΔE d represents the equivalent energy consumption index, J / s; Q v represents the oil well production, m 3 / s; ΔP represents the pressure drop in the reconstruction area, Pa.

[0033] In step 1d, the technical index of energy consumption under the unit benefit of the fracturing flow system is constructed according to the equivalent energy consumption index:

[0034] The energy consumption gradient K L :

[0035] K L = ΔE d / L (4)

[0036] In formula (4), ΔE d represents the equivalent energy consumption, J / (m·s); L represents the average fracture half-length, m;

[0037] The energy consumption density K v :

[0038] K v = ΔE d / V (5)

[0039] In formula (5), K v represents energy consumption density, J / (s·m 3 ); V represents the volume of the reformation, m 3 .

[0040] In step 3, according to the parameters of the pump injection, fracture propagation simulation is carried out by using the fracture simulation software, and parameters such as fracture volume and flow conductivity are obtained.

[0041] In step 4, considering the time effectiveness of the fracture flow conductivity, the Intersect module of the Kinetix platform is used to carry out the productivity prediction.

[0042] In step 4, the calculation of the time effectiveness of the fracture flow conductivity includes:

[0043] Based on the fracture flow conductivity instrument, long-term fracture flow conductivity experimental tests are carried out on different types of reservoir cores.

[0044] According to the experimental results, a mathematical model of the change of the fracture flow conductivity with time is constructed.

[0045] In step 4, long-term fracture flow conductivity experimental tests are carried out on different types of reservoir cores, which means that long-term fracture flow conductivity experimental tests are carried out on the parameters of lithology, proppant type and particle size, sanding concentration and closure pressure, and in-slit pressure drop data are obtained.

[0046] In step 5, for a planar double-wing fracture, the reformation area pressure drop is calculated by using the pressure drop calculation formula; for a complex fracture, an equivalent pressure drop calculation model is constructed based on sufficient numerical simulation, and the fracture pressure drop parameters are obtained.

[0047] In step 5, the steps of constructing the equivalent pressure drop model by using the numerical simulation method are as follows:

[0048] Step 1: calculate the corresponding productivity Q1 under the conditions of different reformation volumes V and matrix permeability k1 by using the Intersect module of the Kinetix platform;

[0049] Step 2: fit the relationship between the different matrix permeability k2 and the productivity Q2 of the unfractured well when other conditions are the same;

[0050] Step 3: calculate the equivalent unfractured well production pressure drop ΔP of the complex fracture reservoir under the condition of equal productivity;

[0051] Step 4: fit the relationship between the complex fracture pressure drop ΔP and the parameters V and k1 to obtain the pressure drop model.

[0052] The purpose of the present application can also be achieved by the following technical measures: an oil reservoir fracturing reconstruction full-cycle injection-production energy consumption characterization and calculation method system, which adopts an oil reservoir fracturing reconstruction full-cycle injection-production energy consumption characterization and calculation method to construct technical indexes of energy consumption under unit benefit of a fracturing flow system, and is used for overall energy consumption evaluation.

[0053] The oil reservoir fracturing reconstruction full-cycle injection-production energy consumption characterization and calculation method in the present application can be used for research on energy consumption efficiency of underground fracturing and other reconstruction measures, provides reference for oil field optimization of injection-production technology and improvement of energy consumption efficiency, and provides support for realizing green, low-carbon and high-quality development of oil fields. BRIEF DESCRIPTION OF DRAWINGS

[0054] Figure 1 It is a fracturing system flow schematic diagram in a specific embodiment of the present application;

[0055] Figure 2 It is a schematic diagram of a formation and oil well model in a specific embodiment of the present application;

[0056] Figure 3 It is a schematic diagram of a fracture propagation graph in a specific embodiment of the present application;

[0057] Figure 4 It is a schematic diagram of fracture feature data in a specific embodiment of the present application;

[0058] Figure 5 It is a productivity prediction graph in a specific embodiment of the present application;

[0059] Figure 6 It is a graph of change of fracture conductivity with time in a specific embodiment of the present application;

[0060] Figure 7 It is a schematic diagram of pressure drop in a reconstruction area in a specific embodiment of the present application;

[0061] Figure 8 It is a schematic diagram of energy consumption index results in a specific embodiment of the present application;

[0062] Figure 9 It is a schematic diagram of a fracture propagation graph in a specific embodiment of the present application;

[0063] Figure 10A fracture feature data diagram in a specific embodiment of the present application;

[0064] Figure 11 A productivity prediction diagram in a specific embodiment of the present application;

[0065] Figure 12 A fracture conductivity change over time diagram in a specific embodiment of the present application;

[0066] Figure 13 A modified region pressure drop diagram in a specific embodiment of the present application;

[0067] Figure 14 An energy consumption index result diagram in a specific embodiment of the present application;

[0068] Figure 15 A fracture propagation diagram in a specific embodiment of the present application;

[0069] Figure 16 A fracture feature data diagram in a specific embodiment of the present application;

[0070] Figure 17 A productivity prediction diagram in a specific embodiment of the present application;

[0071] Figure 18 A fracture conductivity change over time diagram in a specific embodiment of the present application;

[0072] Figure 19 A modified region pressure drop diagram in a specific embodiment of the present application;

[0073] Figure 20 An energy consumption index result diagram in a specific embodiment of the present application;

[0074] Figure 21 A flow chart of a specific embodiment of the oil reservoir fracturing modification full cycle injection-production energy consumption representation and calculation method of the present application. DETAILED DESCRIPTION

[0075] It should be noted that the following detailed description is exemplary in nature and is intended to provide further description of the present application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0076] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0077] As shown in Figure 9 The oil reservoir fracturing reconstruction full-cycle injection-production energy consumption characterization and calculation method of the present application includes:

[0078] Step (101) obtains the actual energy consumption of fluid flow in the fracture area based on the law of conservation of energy, and further obtains the energy consumption per unit time, defines an energy consumption index, constructs a technical index of energy consumption under unit benefit of the fracturing flow system, and establishes an energy consumption characterization method.

[0079] Step (102) uses the fracturing reservoir parameters of the target oilfield to perform geological modeling.

[0080] Step (103) performs fracture propagation simulation by using fracturing simulation software according to pump injection parameters to obtain parameters such as fracture volume and conductivity.

[0081] Step (104) uses the Intersect module of the Kinetix platform to perform productivity prediction in consideration of the time effectiveness of the fracture conductivity.

[0082] Step (105) uses a pressure drop calculation formula to calculate the pressure drop in the reconstruction area for a planar double-wing fracture, and uses an equivalent pressure drop calculation model based on sufficient numerical simulation to obtain fracture pressure drop parameters for a complex fracture.

[0083] Step (106) calculates the energy consumption index after fracturing reconstruction.

[0084] Further, the specific process of establishing the oil reservoir fracturing reconstruction energy consumption characterization method in step (101) is as follows:

[0085] Step 1 The actual energy consumption of fluid flow in the fracturing reconstruction area within a certain time is:

[0086]

[0087] In formula (1), ΔE represents the energy consumption of fluid flow, J; P0 represents the inlet pressure of fracturing reconstruction, Pa; V0 represents the fluid volume flowing into the fracturing reconstruction area within a certain time, m 3 P1 represents the bottom hole pressure of the production well, Pa; V1 represents the fluid volume flowing into the bottom hole of the production well within a certain time, m 3m is the mass of fluid passing through the fracturing region per unit time, kg; v0 is the fluid flow rate at the inlet end of the fracturing region, m / s; v1 is the fluid flow rate at the bottom of the oil production well, m / s; q m is the fluid mass flow rate, kg / s; p0 is the fluid density at the inlet end of the fracturing region, kg / m 3 ; p1 is the fluid density at the bottom of the oil production well, kg / m 3 ; Δt is time, s.

[0088] Step 2: Propose the equivalent energy consumption index, which is the energy consumption per unit time:

[0089]

[0090] In formula (2), ΔE d1 is the energy consumption per unit time, J / s; t is time, s; q m is the fluid mass flow rate, kg / s; p0 is the fluid density at the inlet end of the fracturing region, kg / m 3 ; p1 is the fluid density at the bottom of the oil production well, kg; P1 represents the pressure at the bottom of the oil production well, Pa; P0 represents the reservoir pressure, Pa;

[0091] Step 3: For single-phase flow, if the flow rate and density difference are ignored, the equivalent energy consumption index ΔE d is:

[0092] ΔE d = Q v · (P0-P1) = Q v · ΔP (3)

[0093] In formula (3), ΔE d represents the equivalent energy consumption index, J / s; Q v represents the oil well production, m 3 / s; ΔP represents the pressure drop in the fracturing region, Pa.

[0094] Step 4: According to the equivalent energy consumption index, construct the technical index of energy consumption under the unit benefit of the fracturing flow system:

[0095] Energy consumption gradient K L :

[0096] K L = ΔE d / L (4)

[0097] In formula (4), ΔE d represents the equivalent energy consumption, J / (m·s); L represents the average fracture half-length, m.

[0098] Energy density K v :

[0099] K v = ΔE d / V(5)

[0100] In formula (5), K v represents energy consumption density, J / (s·m 3 ); V represents the volume of the transformation, m 3 .

[0101] Further, the step (104) considering the time-dependent calculation of the fracture conductivity includes:

[0102] Based on the fracture conductivity instrument, fracture long-term conductivity experimental tests are carried out on different types of reservoir cores.

[0103] According to the experimental results, a mathematical model of the change of fracture conductivity with time is constructed.

[0104] Further, the fracture long-term conductivity experimental tests on different types of reservoir cores refer to the long-term conductivity experimental tests on the proppant-filled fractures for parameters such as lithology, proppant type and particle size, sanding concentration and closure pressure, and the pressure drop data in the fractures are obtained.

[0105] Further, the step (105) of constructing the equivalent pressure drop model by using the numerical simulation method includes:

[0106] Step 1: Calculate the corresponding productivity Q1 under different transformation volumes V and matrix permeability k1 based on the Intersect module of the Kinetix platform.

[0107] Step 2: Fit the relationship between different matrix permeability k2 and productivity Q2 of the unfractured well when other conditions are the same.

[0108] Step 3: Calculate the equivalent unfractured well (matrix permeability k2) production pressure drop ΔP of the complex fracture reservoir under the condition of equal productivity.

[0109] Step 4: Fit the relationship between complex fracture pressure drop ΔP and parameters such as V and k1 to obtain the pressure drop model.

[0110] The method of the present application is based on the numerical simulation method, combined with the time-dependent test experiment of fracture conductivity, by modeling the formation in the fracturing area and the production well, simulating the fracturing process and the production result after fracturing, obtaining the fracture characteristics and productivity after fracturing under different construction parameters, using the pressure drop calculation model to obtain the pressure drop in the transformation area, using the proposed simple energy consumption characterization formula to calculate the energy consumption index under the construction condition, providing a reference for the evaluation of the underground energy consumption of the fractured well reservoir and the optimization of the construction process parameters, which helps to optimize the injection and production technology of the oilfield, improve the energy efficiency, and realize the green, low-carbon and high-quality development of the oilfield.

[0111] The following are several specific embodiments of the application

[0112] Example 1

[0113] The implementation of the present example is based on a vertical well in Yong 1 block of Shengli Oilfield, the well depth is 2300m, the vertical well is fractured, the fracturing section is 1990-2017m, the reconstruction span is 32m, the minimum principal stress of the oil layer is 26-30MPa, the stress between the layers is between 32-36MPa, the stress difference between the reservoir and the layer is between 4-6MPa, the average porosity of the reservoir is 11.4%, and the average permeability is 29MD.

[0114] According to the present application, step (1) is performed, the fluid energy at the inlet and outlet of the fracturing reconstruction system is calculated based on the energy conservation, the actual energy consumption of the fracturing reconstruction area is obtained, and the equivalent energy consumption characterization mode is obtained.

[0115] As shown in Figure 1 , the actual energy consumption in the flow area within a certain time is:

[0116]

[0117] In formula (1), ΔE represents the energy consumption of fluid flow, J; P0 represents the pressure at the inlet end of the fracturing reconstruction, Pa; V0 represents the fluid volume flowing into the fracturing reconstruction area within a certain time, m 3 ; P1 represents the bottom hole pressure of the oil production well, Pa; V1 represents the fluid volume flowing into the bottom hole of the oil production well within a certain time, m 3 ; m is the fluid mass passing through the fracturing reconstruction area per unit time, kg; v0 is the fluid flow rate at the inlet end of the fracturing reconstruction, m / s; v1 is the fluid flow rate at the bottom hole of the oil production well, m / s; q m is the fluid mass flow rate, kg / s; p0 is the fluid density at the inlet end of the fracturing reconstruction, kg / m 3 ; p1 is the fluid density at the bottom hole of the oil production well, kg / m 3 ; Δt is the time, s.

[0118] The equivalent energy consumption index is proposed, that is, the energy consumption per unit time:

[0119]

[0120] In formula (2), ΔE d1 is the energy consumption per unit time, J / s; t is the time, s; q m is the fluid mass flow rate, kg / s; p0 is the fluid density at the inlet end of the fracturing reconstruction, kg / m 3 ; p1 is the fluid density at the bottom hole of the oil production well, kg / m; P1 represents the bottom hole pressure of the oil production well, Pa; P0 represents the reservoir pressure, Pa;

[0121] If the differences in flow velocity and density are ignored, then the equivalent energy consumption index ΔE d for:

[0122] ΔE d =Q v ·(P0-P1)=Q v ·ΔP (3)

[0123] In equation (3), ΔE d Q represents the equivalent energy consumption index, in J / s; v Indicates oil well production, m 3 / s; ΔP represents the pressure drop in the modified area, in Pa.

[0124] Technical indicators of energy consumption per unit revenue for fracturing flow systems are constructed based on equivalent energy consumption indicators.

[0125] Energy consumption gradient K L :

[0126] K L =ΔE d / L (4)

[0127] In equation (4), K L L represents the energy consumption gradient, J / (s·m); L represents the average crack half-length, m.

[0128] Energy density K v :

[0129] K v =ΔE d / V (5)

[0130] In equation (5), K v Energy density, expressed in J / (s·m 3 V represents the volume of the modification, in meters. 3 .

[0131] According to the present invention, step (2) is performed to conduct geological modeling and obtain oil well and formation models, such as... Figure 2 As shown.

[0132] According to the present invention, step (3) is performed to conduct a fracturing simulation. The perforation thickness is 8m, the perforation density is selected as 14 / 16 / 18 / 20 holes / meter, and the pumping flow rate is 7m³ / min. 3 / min, pumping volume 125m³ 3 The amount of sand pumped in is 12.5m³. 3 Fracturing pattern as follows Figure 3 As shown, the fracture length, fracture height, and fracture conductivity parameters were obtained, as follows: Figure 4 As shown.

[0133] According to the present application, step (4) is performed, the productivity prediction under different injection parameters is performed using the Intersect module of the Kinetix platform, correction is performed using the constructed fracture conductivity change model over time, production is performed under a constant bottom hole flowing pressure, a production time of 3 years is set, and the cumulative oil production is obtained, as shown in Figure 5 .

[0134] In step (4), the method for considering the time effectiveness of the fracture conductivity is as follows:

[0135] (1) The fracture conductivity instrument is used to select the target reservoir rock plate, 20 / 40 mesh ceramic proppant used in the field, sand laying concentration of 10 kg / m 2 , and the closure pressure under 40 MPa, the long-term fracture conductivity experiment test of the proppant packing is carried out, the influence of the proppant embedding and crushing on the overall conductivity of the fractured fracture is measured, and the pressure drop data in the fracture are obtained.

[0136] (2) The experimental data are used to construct a mathematical model of the change of the fracture conductivity over time by fitting, and the result is as shown in Figure 6 .

[0137] According to the present application, step (5) is performed, and the pressure drop of the transformed region is calculated according to the case of the straight well fracturing planar double-wing fracture of the present example, combined with the formation parameters and the fracturing production parameters, as shown in Figure 7 .

[0138] In step (5), the calculation formula of the straight well planar double-wing fracture pressure drop is:

[0139]

[0140] According to the present application, step (6) is performed. For the ordinary double-wing fracture straight well of single-phase fluid flow, formula (3) and (4) are selected to calculate the equivalent energy consumption and the energy consumption gradient. The energy consumption parameters under different perforation densities are obtained, as shown in Figure 8 .

[0141] Example 2

[0142] The implementation of the present example takes a straight well in Yong 1 block of Shengli Oilfield as an example. The well depth is 2300 m, the well is fractured, the fracturing section is 2001.5-2066.5 m, the fracturing target layer spans 65 m, the minimum principal stress of the oil layer is between 28-34 MPa, the interlayer stress is between 36-41 MPa, the stress difference between the reservoir and the interlayer is between 4-9 MPa, the average porosity of the reservoir is 13%, and the average permeability is 32 MD.

[0143] According to the present application, step (1) is performed, the fluid energy at the outlet / inlet of the fracturing transformation system is calculated based on the energy conservation, the actual energy consumption of the fracturing transformation region is obtained, and the equivalent energy consumption representation method is obtained. As shown in Example 1.

[0144] According to the present application, step (2) is performed to carry out geological modeling to obtain the oil well and formation model.

[0145] According to the present application, step (3) is performed to carry out fracture simulation. The perforation thickness is 8 m, the perforation density is selected to be 16 holes / m, the pump injection displacement is 7 m 3 / min, the pump-in fluid volume is 500 m 3 , the pump-in sand volume is 50 m 3 , the fracture pattern is shown in Figure 9 , and the fracture length, fracture height and fracture conductivity parameters are obtained, as shown in Figure 10 .

[0146] According to the present application, step (4) is performed to use the Intersect module of the Kinetix platform to carry out productivity prediction under different pump injection parameters, to use the built fracture conductivity model to carry out correction with time, to adopt constant bottom hole pressure production, to set the production time to be 3 years, and to obtain the cumulative oil production, as shown in Figure 11 .

[0147] In step (4), the method for considering the time effectiveness of the fracture conductivity is as follows:

[0148] (1) The fracture conductivity instrument is used to select the target reservoir rock plate, the 40 / 70 mesh ceramic used in the field, the sand laying concentration of 5 kg / m 2 , and the closure pressure under 40 MPa, to carry out long-term fracture conductivity test of the proppant packed fracture, to measure the influence of the proppant embedding and crushing on the overall fracture conductivity of the fracture, and to obtain the fracture pressure drop data.

[0149] (2) The experimental data are used to build a mathematical model of the fracture conductivity changing with time by fitting, and the result is shown in Figure 12 .

[0150] According to the present application, step (5) is performed to calculate the pressure drop of the reformed region according to the case of the straight well fracture planar double-wing fracture of the present example, in combination with the formation parameters and the fracture production parameters, as shown in Figure 13 .

[0151] In step (5), the calculation formula of the straight well planar double-wing fracture pressure drop is:

[0152]

[0153] According to the present application, step (6) is performed. For the ordinary double-wing fracture straight well of single-phase fluid flow, the equivalent energy consumption and energy consumption gradient are calculated by using formula (3) and (4). The energy consumption parameters under different fluid volumes are obtained, as shown in Figure 14 .

[0154] Example 3

[0155] The implementation of the present example takes a straight well in Yong 1 block of Shengli Oilfield as an example, the well depth is 2700m, the well is fractured, the fracturing section is 2511.5-2066.5m, the fracturing target layer spans 55m, the minimum principal stress of the oil layer is between 30-35MPa, the stress of the barrier layer is between 38-43MPa, the stress difference between the reservoir and the barrier layer is between 4-7MPa, the average porosity of the reservoir is 7%, and the average permeability is 11MD.

[0156] According to the present application, step (1) is performed, the fluid energy at the outlet / inlet of the fracturing reconstruction system is calculated based on energy conservation, the actual energy consumption of the fracturing reconstruction area is obtained, and the equivalent energy consumption representation method is obtained. As shown in Example 1.

[0157] According to the present application, step (2) is performed, and geological modeling is performed to obtain an oil well and formation model.

[0158] According to the present application, step (3) is performed, and fracturing simulation is performed. The perforation thickness is 8m, the perforation density is selected to be 16 holes / m, the pump displacement is 6 / 7 / 8 / 9m 3 / min, the pumped liquid volume is 500m 3 , the pumped sand volume is 50m 3 , the fracturing pattern is as shown in Figure 9 , and the fracture length, fracture height and fracture conductivity parameters are obtained, as shown in Figure 15 .

[0159] According to the present application, step (4) is performed, the Intersect module of the Kinetix platform is used to perform productivity prediction under different pump parameters, the constructed fracture conductivity change-over-time model is used for correction, fixed bottom-hole flowing pressure production is adopted, the production time is set to be 3 years, and the cumulative oil production is obtained, as shown in Figure 16 .

[0160] In step (4), the method for considering the time effectiveness of the fracture conductivity is as follows:

[0161] (1) The fracture conductivity instrument is used, the target reservoir rock plate, 40 / 70 mesh quartz sand used in the field, sand laying concentration of 5kg / m 2 and closure pressure under 40MPa are selected, long-term fracture conductivity experiment test of the proppant filling is carried out, the influence of proppant embedding and crushing on the overall fracture conductivity of the fracturing fracture is measured, and the pressure drop data in the fracture are obtained.

[0162] (2) The experimental data are used to construct a mathematical model of the change-over-time of the fracture conductivity, and the result is as shown in Figure 17 .

[0163] According to the present application, step (5) is performed, and the pressure drop of the reformed region is calculated according to the case of the straight well fracturing planar double-wing slot of the present example, combined with the formation parameters and fracturing production parameters, as shown in the following table. Figure 18

[0164] In step (5), the calculation formula of the pressure drop of the straight well planar double-wing slot is as follows:

[0165]

[0166] According to the present application, step (6) is performed. For the ordinary double-wing slot straight well of single-phase fluid flow, formula (3) and (4) are selected to calculate the equivalent energy consumption and energy consumption gradient. The energy consumption parameters under different liquid conditions are obtained, as shown in the following table. Figure 19

[0167] Finally, it should be noted that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or make equivalent replacements to some technical features. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

[0168] In addition to the technical features described in the specification, they are known to those skilled in the art.​​

Claims

1. A method for characterizing and calculating injection-production energy consumption in the whole cycle of oil reservoir fracturing reconstruction, characterized in that, The oil reservoir fracturing reconstruction full-cycle injection-production energy consumption characterization and calculation method comprises: Step 1, constructing the technical index of energy consumption under the unit benefit of the fracturing flow system, and establishing the energy consumption characterization method; Step 2, using the fracturing reservoir parameters of the target oilfield to carry out geological modeling; Step 3, carrying out fracture propagation simulation to obtain parameters such as fracture volume and conductivity; Step 4, carrying out productivity prediction; Step 5, calculating fracture pressure drop parameters; Step 6, calculating the energy consumption index after fracturing reconstruction; In step 1, the actual energy consumption of fluid flow in the fracture area is obtained based on the law of conservation of energy, and the energy consumption per unit time is further obtained, the energy consumption index is defined, the technical index of energy consumption under the unit benefit of the fracturing flow system is constructed, and the energy consumption characterization method is established; Step 1 includes: Step 1a, calculating the actual energy consumption of fluid flow in the fracturing reconstruction area within a certain time; Step 1b, proposing the equivalent energy consumption index, i.e. energy consumption per unit time; Step 1c, for single-phase flow, ignoring the differences in flow rate and density, calculating the equivalent energy consumption index ΔEd; Step 1d, constructing the technical index of energy consumption under the unit benefit of the fracturing flow system according to the equivalent energy consumption index; At step 1c, for single phase flow, if the flow rate and density differences are ignored, the equivalent energy consumption indicator DE d is: ΔE d = Q v • (P0 - P1) = Q v • ΔP (3) In formula (3), ΔE d represents equivalent energy consumption index, J / s; Q v represents oil well production, m 3 / s; P0represents fracturing inlet end pressure, Pa; P1represents oil production well bottom hole pressure, Pa; ΔP represents the transformation region pressure drop, Pa; In step 1d, the technical index of energy consumption under the unit benefit of the fracturing flow system is constructed according to the equivalent energy consumption index: Energy consumption gradient K L : K L = ΔE d / L (4) In formula (4), ΔE d represents the equivalent energy consumption, J / (m-s); L represents the average crack half-length, m; Energy density K v : K v = ΔE d / V (5) In formula (5), K v represents energy consumption density, J / (s·m 3 ); V represents the volume of the modification, m 3 ; In step 4, considering the time effectiveness of the fracture conductivity, the Intersect module of the Kinetix platform is used to carry out productivity prediction; The calculation considering the time effectiveness of the fracture conductivity includes: Based on the fracture conductivity instrument, long-term fracture conductivity experimental tests are carried out for different types of reservoir cores; According to the experimental results, a mathematical model of the change of fracture conductivity with time is constructed; In step 5, for a planar double-wing fracture, the pressure drop in the reconstruction area is calculated using the pressure drop calculation formula; for a complex fracture, an equivalent pressure drop calculation model is constructed based on sufficient numerical simulation to obtain the fracture pressure drop parameters.

2. The method of claim 1, wherein, In step 1a, the actual energy consumption of fluid flow in the fracturing reconstruction area within a certain time is: In formula (1), ΔE represents fluid flow energy consumption, J; V0 represents fluid volume flowing into the fracturing reconstruction region in a certain time, m 3 ; V1 represents fluid volume flowing into the bottom of the production well in a certain time, m 3 ; m is fluid mass passing through the fracturing reconstruction region per unit time, kg; v0 is fluid flow rate at the inlet end of the fracturing reconstruction, m / s; v1 is fluid flow rate at the bottom of the production well, m / s; q m is fluid mass flow rate, kg / s; p0 is fluid density at the inlet end of the fracturing reconstruction, kg / m 3 ; p1 is fluid density at the bottom of the production well, kg / m 3 ; Δt is time, s.

3. The method of claim 1, wherein, In step 1b, the equivalent energy consumption index, i.e. energy consumption per unit time, is proposed: In formula (2), ΔE d1 is the energy consumption per unit time, J / s; t is the time, s; q m is the fluid mass flow rate, kg / s; p0 is the fluid density at the inlet end of the fracturing reconstruction, kg / m 3 ; p1 is the fluid density at the bottom of the oil production well, k; P1 represents the bottom hole pressure of the oil production well, Pa; P0 represents the reservoir pressure, Pa.

4. The method of claim 1, wherein, In step 3, according to the pump injection parameters, fracture propagation simulation is carried out through fracturing simulation software to obtain parameters such as fracture volume and conductivity.

5. The method of claim 1, wherein, In step 4, long-term fracture conductivity experimental tests are carried out for different types of reservoir cores, which means that long-term fracture conductivity experimental tests are carried out for parameters such as lithology, proppant type and particle size, sanding concentration and closure pressure, and fracture pressure drop data are obtained.

6. The method of claim 1, wherein, In step 5, the steps for constructing the equivalent pressure drop model using numerical simulation method are: Step ① Calculate the corresponding productivity Q1 under different reconstruction volumes V and matrix permeability k1 using the Intersect module of the Kinetix platform; Step ② Fit the relationship between different matrix permeability k2 and productivity Q2 of the unfractured well when other conditions are the same; Step ③ Calculate the equivalent production pressure drop ΔP of the complex fracture reservoir unfractured well under the condition of equal productivity; Step ④ Fit the relationship between complex fracture pressure drop ΔP and parameters V and k1 to obtain the pressure drop model.

7. A system for characterizing and calculating energy consumption of injection and production in the whole cycle of oil reservoir fracturing reconstruction, characterized in that, The oil reservoir fracturing reconstruction whole cycle injection and production energy consumption characterization and calculation method system adopts the technical index of energy consumption under the unit benefit of the fracturing flow system constructed by the oil reservoir fracturing reconstruction whole cycle injection and production energy consumption characterization and calculation method in any one of claims 1 to 6, and is used for overall energy consumption evaluation.

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