Artificially-assisted packing method for sand control and water control in fractured reservoir, and packing effect evaluation method

Abstract

The present invention belongs to the technical field of oil and gas engineering. Disclosed are an artificially-assisted packing method for sand control and water control in a fractured reservoir, and a packing effect evaluation method. The artificially-assisted packing method for sand control and water control in a fractured reservoir comprises the following steps: S11, calculating a fracture occurrence evaluation index F for a fractured reservoir; S12, calculating an artificially-assisted packing process implementation feasibility index G; and S13, on the basis of the fracture occurrence evaluation index F obtained in step S11 and the artificially-assisted packing process implementation feasibility index G obtained in step S12, selecting one of a natural micro-saturated packing process, an artificially-assisted squeezing supersaturated packing process and an artificially-assisted fracturing strong-saturated packing process for packing. By means of the packing method in the present invention, an appropriate packing mode is correspondingly selected on the basis of the structure of a natural fracture in a reservoir, and the matching degree between the natural fracture and an available proppant, thereby "making the remedy suit the case" and effectively ensuring the effect of sand control and water control.

Description

Cracked reservoir sand control and water control artificial auxiliary filling method and filling effect evaluation method TECHNICAL FIELD

[0001] The present application belongs to the technical field of oil and gas engineering, and particularly relates to a cracked reservoir sand control and water control artificial auxiliary filling method and a filling effect evaluation method. BACKGROUND

[0002] Cracked oil and gas reservoirs have huge reserves, such as deep cracked carbonate rock oil and gas reservoirs and cracked tight sandstone gas reservoirs in the Tarim Basin of China, which are the main target reservoirs for deep oil and gas development at present and in the future. As shown in FIG. 1, there are natural fractures 2 of different widths, angles and lengths in the cracked reservoir 1, which are interconnected or not interconnected. The natural fractures 2 are the main oil and gas reservoir space and permeation channel. In the process of exploitation, the filled material in the fractures slips and breaks under the action of ground stress and production pressure difference, and the reservoir sand particles 4 formed by the slip and break are discharged from the wellbore 3 along with the fluid, and the arrow direction in FIG. 1 is the discharge direction of the reservoir sand particles 4. At the same time, if the reservoir has edge and bottom water 5 which is relatively close, the edge and bottom water 5 is easy to break through along the fractures with large width and good flow-through property, resulting in early water breakthrough. The problems of sand production and water breakthrough are one of the key problems restricting the efficient development of cracked oil and gas reservoirs, and efficient sand control and water control are major technical requirements for the efficient exploitation of such oil and gas reservoirs.

[0003] The patent document with the publication number CN106372377A discloses a fine powder sand oil layer filling sand control method. According to the characteristics of the fine powder sand oil layer, the sand control measure layer and the construction pressure limit are scientifically set, the elastic deformation of the interlayer rock is restored, the degree of fracture extension to the water layer after extrusion filling is reduced, and thus the effectiveness of sand control is ensured and the sand control period is prolonged. The filling method of the patent document is suitable for water-wet sandstone sand production wells, and there are great differences between the leakage mechanism, filling mechanism and filling mode of the natural fractures of the cracked reservoir and the water-wet sandstone sand production wells. Therefore, the filling method disclosed in the patent document is not suitable for the cracked reservoir.

[0004] At present, there are still key problems in the sand control and water control process technology of cracked carbonate rock and sandstone reservoirs, including:

[0005] (1) The completion method of the cracked carbonate rock and sandstone reservoirs is mainly open hole completion at present, which does not have sand control function, and is easy to cause wellbore instability collapse and mud sand production in the production process, bury the wellbore with sand, and seriously affect the normal production and increase the maintenance operation cost. In recent years, attempts have been made to lower a punching pipe, a slotted pipe or other sand control screen pipe into the wellbore for sand control and anti-collapse completion, but the effect is still difficult to meet the production demand.

[0006] (2) Water control technology for fractured reservoirs is still in its infancy. A small number of experimental water control technologies mainly use conventional ICD (Inflow Control Device) screening to control water flow, which can only regulate the flow of oil and water within the wellbore, and has a limited scope and effect.

[0007] (3) Currently, sand control and water control are carried out separately for the sand and water production problems of fractured reservoirs, and are mostly achieved in the wellbore through tubing, which is difficult to penetrate into the reservoir. There is a lack of integrated sand and water control technology for fractured oil and gas reservoirs, which seriously restricts the sand control and water control effect of fractured oil and gas reservoirs. Summary of the Invention

[0008] To address the shortcomings of the existing technologies, this invention discloses an artificial assisted backfilling method for sand control and water control in fractured reservoirs, as well as a method for evaluating the backfilling effect, employing the following technical solution:

[0009] To facilitate understanding of the technical solution of this invention, the principle of the filling method of this invention will first be introduced with reference to Figure 2. The principle of the artificial assisted filling sand and water control technology for fractured reservoirs described in this invention is as follows: a proppant with waterproof and sand-preventing functions is carried by a proppant-carrying fluid and filled into a wide natural fracture near the wellbore or into a wide natural fracture that has been artificially opened. The proppant achieves a dense filling state in the fracture, which can not only block the formation sand production, but also delay the water breakthrough time, thereby achieving the purpose of sand and water synergistic control.

[0010] Different natural fractures have varying structures and different compatibility with waterproofing and sand-controlling proppants. To select the optimal filling scheme for different natural fractures, this invention refines the artificial assisted filling sand-water synergistic control technology for fractured reservoirs into three filling processes. The applicability of each filling process is as follows:

[0011] I. Natural Micro-Saturation Filling Technology: This technology is suitable for reservoirs with large natural fracture widths, high density, and easy natural filling. In their natural state, these natural fractures do not require high-intensity pumping conditions, and their width can accommodate proppant, achieving micro-saturation filling. See Figures 3a and 3b. Figure 3a shows the state of a large natural fracture before filling, and Figure 3b is a schematic diagram of Figure 3a after filling using the natural micro-saturation filling technology. In Figure 3b, 6 represents the natural fracture after filling using the natural micro-saturation filling technology. After filling, the width of the natural fracture increases by 1-1.2 times. From the natural fracture 6 after filling and the annulus 9 after filling, it can be seen that the particle size of the proppant in the natural fracture is smaller than that of the proppant filled in the annulus 8. The natural micro-saturation filling technology can achieve the expected filling strength without causing excessive fracture opening and extension.

[0012] II. Artificial auxiliary extrusion supersaturation filling process, which is suitable for reservoirs with small natural fracture width that is difficult to absorb solid particles. A reasonable higher pump pressure, displacement and sand ratio are needed to perform supersaturation (supersaturation refers to exceeding the volume of the fracture itself) extrusion filling, so that the fracture is appropriately opened to a certain extent, so that it can absorb a certain amount of filling particles. As shown in Figures 4a and 4b. Figure 4a is the state of the natural fracture with small width before filling, and Figure 4b is a schematic diagram of the natural fracture after filling by using the artificial auxiliary extrusion supersaturation filling process. In Figure 4b, 7 is the natural fracture after filling by using the artificial auxiliary extrusion supersaturation filling process. After filling, the fracture width of the natural fracture is expanded by 1.2-1.8 times. Similarly, the particle size of the proppant in the natural fracture is smaller than that of the proppant filled in the wellbore annulus part 8. The artificial auxiliary extrusion supersaturation filling process can appropriately widen the natural fracture that does not meet the filling conditions, and achieve the expected scale of filling strength, but does not make the fracture excessively open and extend.

[0013] III. Artificial auxiliary fracturing strong saturation filling process, which is suitable for reservoirs with extremely low natural fracture width and short fracture length. Higher strength filling construction parameters are needed to make the reservoir appear pressure cracking fractures, so as to achieve the expected scale of filling strength and achieve the purpose of water control and sand prevention. However, the fracturing scale should be strictly controlled to avoid the negative effect of inducing water breakthrough along the fracture due to the generation of large fractures. As shown in Figures 5a and 5b, Figure 5a is the state of the natural fracture with extremely small width before filling, and Figure 5b is a schematic diagram of the natural fracture after filling by using the artificial auxiliary fracturing strong saturation filling process. In Figure 5b, 10 is the natural fracture after filling by using the artificial auxiliary fracturing strong saturation filling process. After filling, the fracture width of the natural fracture is expanded by more than 1.8 times. Similarly, the particle size of the proppant in the natural fracture is smaller than that of the proppant filled in the wellbore annulus part 8. The artificial auxiliary fracturing strong saturation filling process can greatly widen the natural fracture that does not meet the filling conditions, and achieve the expected scale of filling strength, but does not make the fracture excessively open and extend.

[0014] Therefore, how to determine which filling method is suitable for the natural fracture in the reservoir becomes the key to artificial auxiliary filling of fractured reservoirs. On this basis, the present application discloses a kind of artificial auxiliary filling method for sand prevention and water control of fractured reservoirs, comprising the following steps:

[0015] S11, calculate the fracture occurrence evaluation index of the fractured reservoir:

[0016] The present application evaluates the fracture occurrence according to the fracture width range, fracture length range, fracture dip angle range, fracture flatness and fracture density of the natural fracture of the fractured reservoir:

[0017] The fracture width uses w fmax , w fa And wf The characteristic represents the maximum length, average length and characteristic length of the fracture respectively, and the unit is mm. The longer the average length and characteristic length are, the more favorable it is to obtain larger packing strength.

[0018] The fracture length uses L fmax , L fa and L f The characteristic represents the maximum length, average length and characteristic length of the fracture respectively, and the unit is mm. The longer the average length and characteristic length are, the more favorable it is to obtain larger packing strength.

[0019] The fracture dip angle uses β f , which means the normal projection of the wellbore on the fracture surface, and the unit is degree. The wellbore is regarded as a line, the fracture is a surface, and the normal projection is 0-90°. The more the angle approaches to 90 degrees, the easier it is to pack the proppant from the wellbore radius direction into the reservoir fracture.

[0020] The fracture flatness uses γ f , which means the degree of fracture flatness, and the unit is dimensionless. The flatness of a completely flat fracture is defined as 1.0, and the flatness of a fracture with a bending degree of 90 degrees or more is defined as 0. The higher the flatness is, the more favorable it is to fracture packing operation.

[0021] The fracture density uses P f , which means the number of fractures per unit length, and the unit is piece / m 3 . The larger the fracture density is, the easier it is to pack and the higher the packing strength is.

[0022] Based on this, the fracture occurrence evaluation index for evaluating the fracture occurrence is provided.

[0023] In formula (I), F is the fracture occurrence evaluation index, and the unit is dimensionless. The value of 1 indicates the best occurrence, and the smaller the value is, the worse the occurrence is.

[0024] w f is the characteristic fracture width of the fracture, mm; w f0 is the characteristic contrast solid phase particle size, mm. Preferably, w f0 is the average particle size of the lowest grade product of the packable solid phase particles in the to-be-packed land;

[0025] L f is the characteristic length of the fracture, mm; L f0 is the characteristic contrast fracture length, mm. Preferably, L f0 is 5*10 4 mm, or is the average value of the fracture length in the to-be-packed land;

[0026] β f is the fracture dip angle, degree; γf is the non-dimensional fracture flatness; p f is the fracture density, strip / m 3 ; p f0 is the characteristic contrast fracture density, strip / m 3 , preferably, p f0 is 10 strip / m 3 ;

[0027] w1, w2, w3, w4, w5 are weight coefficients of the five factors of seam width, seam length, inclination, flatness and density, respectively, and the recommended values are 0.25, 0.25, 0.15, 0.15 and 0.2, respectively, which are non-dimensional.

[0028] Preferably, the fracture occurrence can be determined based on the obtained occurrence evaluation index F: F>0.75, the fracture occurrence is evaluated as "ultra-high abundance fracture development"; 0.75≥F>0.5, the fracture occurrence is evaluated as "high abundance fracture development"; 0.5≥F>0.25, the fracture occurrence is evaluated as "medium abundance fracture development"; 0.25≥F>0.05, the fracture occurrence is evaluated as "weak fracture development"; F≤0.05, the fracture occurrence is evaluated as "no fracture development". The determination result is used to represent the development degree of the fracture.

[0029] S12, calculate the artificial assisted filling process implementation feasibility index:

[0030] Based on the fracture occurrence evaluation index of natural fractures, the present application further considers the reservoir strength and the particle size range of the proppant, and proposes an artificial assisted filling process implementation feasibility index:

[0031] In formula (II), G is the artificial assisted filling process implementation feasibility index, which is non-dimensional and is used to represent the matching degree of the fracture occurrence and the proppant; S b is the reservoir matrix strength, MPa; S f is the cementation strength of the fractured reservoir proppant, MPa; P f0 is the reservoir large fracture breakdown pressure, specifically the pressure required to open the formation without fractures in the conventional fracturing operation, MPa; P f is the reservoir natural fracture opening pressure, specifically the pressure used to open the fracture by overcoming the ground stress when the formation already has a fracture, MPa; w6, w7 and w8 are weight coefficients, and the recommended values are 0.25, 0.25 and 0.5, respectively;

[0032] S13, based on the fracture occurrence evaluation index F obtained in step S11 and the artificial assisted filling process implementation feasibility index G obtained in step S12, one of the artificial assisted filling sand-water synergistic control technologies for the fractured reservoir is selected for filling, and the recommended filling process and the recommended reason are shown in Table 1:

[0033] Table 1 selection of crack reservoir packing process

[0034] Further, in step S13, the specific operation steps of the packing are:

[0035] S131, open the casing gate, and circulate the flushing fluid to wash the well, the bottom hole pump pressure used for washing the well is Pta, and the displacement is Qa, the bottom hole pump pressure Pta and the displacement Qa are set according to experience, which are generally lower than the bottom hole pump pressure Pw and the displacement Q;

[0036] S132, close the casing gate, and squeeze pack the solid particles with a particle size of d a0 in the natural fracture, the bottom hole pump pressure used for the squeeze packing is Pw, the displacement is Q, and the sand ratio is Rs;

[0037] S133, open the casing gate, and use solid particles with a particle size greater than d a0 to perform wellbore circulation packing, in order to reduce the flow resistance in the wellbore, the particle size of the solid particles packed in the wellbore needs to be increased by one particle size than that of the fracture packing, the bottom hole pump pressure for wellbore circulation packing is Pw, and the displacement is Q.

[0038] The differences in the specific operation of the natural micro-saturation packing process, the artificial auxiliary squeeze supersaturation packing process and the artificial auxiliary fracturing strong saturation packing process are that the particle size d a0 of the solid phase particles used for squeeze packing, the bottom hole pump pressure Pw, the displacement Q and the sand ratio Rs in step S132 are different.

[0039] Further, the preferred packing parameter design of the three packing processes is shown in Table 2.

[0040] Table 2 packing technical parameter design of three packing processes in crack reservoir

[0041] Further, the preferred construction parameter design of the three packing processes is shown in Table 3, wherein the Pw is the bottom hole pump pressure, and the Pc is the fracture closure stress. The fracture closure stress Pc refers to the average pressure of the fluid in the existing fracture opening acting on the fracture surface, therefore, for natural fractures, controlling the opening requires controlling the bottom hole pump pressure Pw to be greater than the fracture closure stress Pc.

[0042] Table 3 construction parameter design of three packing processes in crack reservoir

[0043] The application further discloses a method for evaluating the filling effect of a fractured reservoir, which can be used for evaluating the fractured reservoir filled by the filling method or the fractured reservoir filled by an existing filling method, and comprises the following steps.

[0044] S21, calculating the fracture filling rate, the water content of production fluid, the daily average oil production, the water breakthrough time of oil well, the sand content of output fluid,

[0045] In the formula (V), alpha is the fracture filling rate, which is dimensionless; V c is the amount of gravel pumped into the fracture during construction, m 3 ; V s is the total volume of the fracture, m 3 ; V c = V a -V b (Ⅵ);

[0046] In the formula (VI), V a is the total amount of gravel pumped into the formation during construction, m 3 ; V b is the annular volume of the wellbore of the horizontal well, m 3 ;

[0047] In the formula (VII), beta is the water content of production fluid, which is dimensionless; n is the number of non-construction wells, which is dimensionless; R a is the water content of output fluid of the construction well, which is dimensionless; R bi is the water content of output fluid of the i-th non-construction well, i=1, 2, 3,..., n;

[0048] In the formula (VIII), gamma is the daily average oil production, which is dimensionless; Q a is the daily oil production of the construction well, ton; Q bi is the daily oil production of the i-th non-construction well, ton;

[0049] In the formula (IX), zeta is the water breakthrough time of oil well, which is dimensionless; T bi is the water breakthrough time of the i-th non-construction well, day; T a is the water breakthrough time of the construction well, day;

[0050] In the formula (X), eta is the sand content of output fluid, which is dimensionless; eta bi is the average sand content of output fluid of the i-th non-construction well, which is dimensionless; eta a is the sand content of output fluid of the construction well, which is dimensionless;

[0051] Among the above parameters, the total volume V of the fracture is calculated s The other parameters are obtained from logging or seismic inversion, and are common data used in oil well production.

[0052] S22, calculate the sand control and water control filling comprehensive evaluation index: N=aα+bβ+cγ+dζ+fη (XI);

[0053] In formula (XI), N is the sand control and water control filling comprehensive evaluation index, which is dimensionless; a, b, c, d and f are weight coefficients, and the values are 0.4, 0.2, 0.15, 0.15 and 0.1 respectively.

[0054] S23, based on the sand control and water control filling comprehensive evaluation index N obtained in step S22, the filling effect of the fractured reservoir is evaluated.

[0055] When 0.2>=N>0, it is loose filling, and the filling effect is poor; when 0.5>=N>0.2, it is general dense filling, and the filling effect is general; when 0.7>=N>0.5, it is dense filling, and the filling effect is better; and when 1.0>=N>0.7, it is extremely dense filling, and the filling effect is excellent.

[0056] By adopting the above technical scheme, the present application has the following beneficial effects:

[0057] The present application provides a reservoir natural fracture filling method, which can select natural micro-saturation filling process, artificial auxiliary extrusion over-saturation filling process or artificial auxiliary fracturing strong-saturation filling process according to the width distribution range of the natural fracture of the reservoir, the fracture length, the fracture inclination, the fracture density and the matching degree of the natural fracture and the available precipitation sand control proppant, so that the treatment is suitable for the disease, and the sand and water control effect is effectively ensured.

[0058] The present application also provides the filling technical parameters and the construction parameter range of the relatively optimal natural micro-saturation filling process, the artificial auxiliary extrusion over-saturation filling process and the artificial auxiliary fracturing strong-saturation filling process, thereby providing a set of systematic implementation scheme covering fracture occurrence evaluation, process implementation feasibility evaluation, process type selection and process parameter optimization for the sand control and water control of the fractured oil and gas reservoir.

[0059] The fractured reservoir filling effect evaluation method provided by the present application comprehensively and integrally evaluates the artificial auxiliary filling process of the fractured reservoir from the filling rate, the daily average oil production, the production fluid water content, the oil well water breakthrough time, the output fluid sand content and other parameters, the result is good in representativeness, the method is simple, fast and convenient, and is strong in practicability. BRIEF DESCRIPTION OF DRAWINGS

[0060] Fig. 1 is a schematic view of sand production and water production in the process of exploiting the fractured reservoir;

[0061] Fig. 2 is a schematic diagram of the principle of the sand prevention and water control artificial auxiliary filling sand water coordination control technology for a fractured reservoir;

[0062] Fig. 3a is a schematic diagram of the state before filling of a natural fracture with a large width;

[0063] Fig. 3b is a schematic diagram of the state after filling of the natural fracture in Fig. 3a using a natural micro-saturation filling process;

[0064] Fig. 4a is a schematic diagram of the state before filling of a natural fracture with a small width;

[0065] Fig. 4b is a schematic diagram of the state after filling of the natural fracture in Fig. 4a using an artificial auxiliary extrusion supersaturation filling process;

[0066] Fig. 5a is a schematic diagram of the state before filling of a natural fracture with an extremely low width;

[0067] Fig. 5b is a schematic diagram of the state after filling of the natural fracture in Fig. 5a using an artificial auxiliary fracturing strong saturation filling process.

[0068] In the figure, 1 is a fractured reservoir, 2 is a natural fracture, 3 is a wellbore, 4 is a reservoir sand particle, 5 is edge and bottom water, 6 is a natural fracture after a natural micro-saturation filling process, 7 is a natural fracture after an artificial auxiliary extrusion supersaturation filling process, 8 is a wellbore annulus part, 9 is a filled wellbore annulus part, and 10 is a natural fracture after an artificial auxiliary fracturing strong saturation filling process. DETAILED DESCRIPTION

[0069] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0070] Embodiment 1

[0071] The present embodiment discloses a sand prevention and water control artificial auxiliary filling method for a fractured reservoir. The basic information of the fractured reservoir in the present embodiment is as follows:

[0072] The structural features of a certain block in the Bohai Sea in China as a whole are fault-controlled half-anticlines, which are inclined downward to the northeast, and the high positions are in the shape of a saddle. The reservoir characteristics are Archean metamorphic granite, which has double-porosity medium characteristics. The main reservoir space is fractures, and the heterogeneity is strong. From top to bottom, there are weathering zones and inner buried hills.

[0073] The basic data of the oil well are shown in Table 4.

[0074] Table 4 Basic data of the oil well Table 4 Basic data of the oil well

[0075] The weathering zone is mainly of the crack-pore type or the pore-crack type under the weathering leaching effect, the reservoir development is good, and is the main production section; according to statistics, the crack opening degree around the well is distributed in 100-300 μm, the maximum is 500 μm, considering the characteristics of the dissolution pore and the corrosion pore, and combining with the rock sample observation, it is considered that the maximum crack size of the target layer section in the well area is about 800-1000 μm.

[0076] The fracture occurrence evaluation index F and the artificial auxiliary filling process implementation feasibility index G of the fractured reservoir in the embodiment are calculated by using formula (I) to formula (II), and the basic data used for calculation is shown in table 5 and table 6:

[0077] Table 5 basic data used for calculating F

[0078] Table 6 basic data used for calculating G

[0079] F=0.661 and G=0.535 are calculated, the recommended process type is the artificial auxiliary extrusion supersaturation filling process by selecting from table 1, and the specific operation steps are:

[0080] 1. Open the casing gate, and wash the well with the flushing liquid, the pump pressure used for washing the well is 12.5 Mpa, and the displacement is 0.8 m 3 / min;

[0081] 2. Parameter design: the expected filling radial depth is 28 m, the expected filling strength is 0.25 m 3 / m, and the expected filling amount is 14.5 m 3 ;

[0082] 3. Close the casing gate, and perform the auxiliary extrusion supersaturation filling, the liquid is replaced into the sand-carrying liquid, the median value of the proppant particle size is 0.64 mm according to the crack size, the filling displacement is 1.8 m 3 / min, the construction sand ratio is 120%, and the design construction pump pressure Pw-Pc=1.8 MPa;

[0083] 4. Open the casing gate, start the annular filling, the median value of the solid phase particle size is 0.72 mm, the displacement and the sand ratio in step 2 are kept unchanged to perform the cyclic filling, the pump is stopped after the pressure is suddenly increased, and the construction is completed.

[0084] Actual filling parameters: the filling radial depth is 24 m, the filling strength is 0.22 m 3 / m, and the filling amount is 13.25 m 3 .

[0085] Example 2

[0086] The embodiment discloses a method for evaluating the filling effect of a fractured reservoir, and particularly a method for evaluating the filling effect three months after the end of the construction of the embodiment 1.

[0087] The comprehensive evaluation index N of sand control and water control filling is calculated by using the formula (V) to formula (X) of the present application, and the basic data used for calculation is shown in Table 7.

[0088] Table 7 basic data used for calculating N

[0089] N is calculated to be 0.61, and the filling effect of the fractured reservoir is evaluated to be dense filling, and the filling effect is good.

[0090] The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the above embodiments, the ordinary skilled in the art can still modify the technical solutions recorded in the above embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the description of the present application.

Claims

1. A method of artificial assisted sand control and water control in a fractured reservoir, characterized in that, Comprising the following steps: S11. Calculate the fracture-occurrence-evaluation index of the fractured reservoir: In formula (I), F is a fracture occurrence evaluation index, dimensionless; w f is a characteristic fracture width of the fracture, mm; w f0 is a characteristic proppant particle size, mm; L f is a characteristic length of the fracture, mm; L f0 is a characteristic fracture length, mm; β f is a fracture dip angle, degrees; γ f is a fracture flatness, dimensionless; ρ f is a fracture density, pieces / m 3 ; ρ f0 Feature contrast crack density, strip / m 3 ; w1, w2, w3, w4, w5 are weight coefficients, the values are respectively 0.25, 0.25, 0.15, 0.15, 0.2, dimensionless; S12, calculate the artificial assisted filling process implementation feasibility index: In formula (II), G is an artificial assisted filling process feasibility index, dimensionless; S b is the reservoir matrix strength, MPa; S f For proppant cementing strength, MPa; P f0 For reservoir large fracture breakdown pressure, MPa; P f For reservoir natural fracture opening pressure, MPa; w6, w7, w8 are weight coefficients, the values are 0.25, 0.25, 0.5 respectively; S13, based on the fracture occurrence evaluation index F obtained in step S11 and the artificial assisted filling process implementation feasibility index G obtained in step S12, one of the artificial assisted filling sand water synergistic control technologies in the fractured reservoir is selected for filling: When F>0.75 and G>0.35, the natural micro-saturation filling process is selected for filling; when F>0.75 and G≤0.35, the artificial assisted extrusion supersaturation filling process is selected for filling; When 0.75≥F>0.5 and G>0.5, the artificial assisted extrusion supersaturation filling process is selected for filling; when 0.75≥F>0.5 and G≤0.5, the artificial assisted fracturing strong saturation filling process is selected for filling; When 0.5≥F>0.25 and G>0.75, the artificial assisted extrusion supersaturation filling process is selected for filling; when 0.5≥F>0.25 and G≤0.75, the artificial assisted fracturing strong saturation filling process is selected for filling; When 0.25≥F>0.05, the artificial assisted fracturing strong saturation filling process is selected for filling; when F≤0.05, no filling is performed or the artificial assisted fracturing strong saturation filling process is selected for filling.

2. The method according to claim 1, wherein, The w f The calculation method is: w f = 0.5(w fa +w fmax )(III). In formula (III), w fa is the average crack width, mm; w fmax is the widest crack width, mm.

3. The method of claim 1, wherein, The L f The calculation method is: L f = 0.5(L fa + L fmax )(IV). In formula (IV), L fa is the average length of the cracks, mm; L fmax is the maximum length of the cracks, mm.

4. The method of claim 1, wherein, The w f0 is the average particle size of the lowest particle size product of the proppant to be filled.

5. The method of claim 1, wherein, The L f0 5*10 4 mm, or the average length of the fissure to be filled; the p f0 10 pieces / m 3 .

6. The method of claim 1, wherein, In step S13, the specific operation steps of the filling are: S131, open the casing gate, and wash the well with a flushing fluid, the bottom hole pump pressure used for washing the well is Pta, and the displacement is Qa; S132, closing the sleeve gate, and squeezing the solid-phase particles with a particle size of d into the natural fracture, the pump pressure used for squeezing is Pw, the displacement is Q, and the sand ratio is Rs; a0 S132, closing the sleeve gate, and squeezing the solid-phase particles with a particle size of d into the natural fracture, the pump pressure used for squeezing is Pw, the displacement is Q, and the sand ratio is Rs; S133, opening the sleeve gate, using solid phase particles with particle size greater than d a0 to fill the wellbore, the pump pressure at the bottom of the wellbore is Pw, and the displacement is Q; The natural micro-saturation filling process, the artificial auxiliary extrusion super-saturation filling process and the artificial auxiliary fracturing strong-saturation filling process are different in the particle size d of the proppant used in the step S132 a0 , the pump pressure Pw at the well bottom, the displacement Q and the sand ratio Rs.

7. The method of claim 1, wherein, The filling technical parameters of the natural micro-saturation filling process are: support agent particle size d a0 > 0.12 mm, the expected filling radial depth is 10-15 m, the expected filling intensity is 0.02-0.25 m 3 / m, and the expected filling amount is 12-20 m 3 ; The filling technical parameters of the artificial auxiliary extrusion supersaturation filling process are: 0.045mm < d a0 <0.12mm, the expected filling radial depth is 10-30m, the expected filling strength is 0.05-0.3m 3 / m, and the expected filling amount is 10-15m 3 ; The filling technical parameters of the artificial assisted fracturing strong saturation filling process are: 0 mm < d a0 <0.045 mm, the expected filling radial depth is 20-40 m, the expected filling intensity is 0.2-0.5 m 3 / m, and the expected filling amount is 8-15 m 3 .

8. The method of claim 1, wherein, The construction parameters of the natural micro-saturation filling process are: 0 MPa < Pw-Pc < 1 MPa, sand ratio Rs is 80-120%, and discharge Q is 1-1.5 m 3 / min. The construction parameters of the artificial auxiliary extrusion supersaturation filling process are: 1 < Pw-Pc < 2 MPa, sand ratio Rs is 60-140%, and discharge Q is 1.5-2.5 m 3 / min. The construction parameters of the artificial assisted fracturing strong saturation filling process are: 2 < Pw-Pc < 4 MPa, sand ratio Rs is 40-160%, and discharge Q is 2-4 m 3 / min. The Pw is the bottom hole pump pressure, and the Pc is the fracture closure stress.

9. The method of claim 1, wherein, Step S11 further comprises fracture occurrence determination based on the calculated occurrence evaluation index F: F>0.75, the fracture occurrence is evaluated as "ultra-high abundance fracture development"; 0.75≥F>0.5, the fracture occurrence is evaluated as "high abundance fracture development"; 0.5≥F>0.25, the fracture occurrence is evaluated as "medium abundance fracture development"; 0.25≥F>0.05, the fracture occurrence is evaluated as "weak fracture development"; F≤0.05, the fracture occurrence is evaluated as "no fracture development".

10. A method for evaluating the filling effect of a fractured reservoir filled by the artificial assisted filling method for sand control and water control in a fractured reservoir according to any one of claims 1 to 9, characterized in that, Comprising the following steps: S21, calculating the post-construction crack filling rate, the production fluid water cut, the daily average oil production, the oil well water breakthrough time, the output fluid sand content, In formula (V), a is a fracture packing rate, dimensionless; V c is the amount of gravel pumped into the fracture for construction, m 3 ; V s is the total volume of the fracture, m 3 ; V c = V a - V b (VI); In formula (VI), V a is the total amount of gravel pumped into the formation, m 3 ; V b is the annular volume of the horizontal wellbore, m 3 ; In formula (VII), β is the water cut of the production fluid, dimensionless; n is the number of non- production wells, dimensionless; R a is the water cut of the production fluid of the production well, dimensionless; R bi is the water cut of the production fluid of the i-th non- production well, i = 1, 2, 3, ··· n; In formula (VIII), γ is the daily average oil production, dimensionless; Q a is the daily oil production of the construction well, tons; Q bi is the daily oil production of the i-th non-construction well, tons; In formula (IX), ζ is the water breakthrough time of the oil well, dimensionless; T bi The time of water breakthrough for the i-th non-construction well is in days; T a The time to water breakthrough at the well is in days; In formula (X), η is the sand content of the produced fluid, dimensionless; η bi Sf, i is the average sand concentration of the produced fluid from the ith non- producing well, dimensionless; η a Sf is the sand production fraction of the well stream, dimensionless; S22, calculating the sand control and water control filling comprehensive evaluation index: N=aα+bβ+cγ+dζ+fη (XI); In formula (XI), N is the sand control and water control filling comprehensive evaluation index, dimensionless; a, b, c, d, f are weight coefficients, and the values are 0.4, 0.2, 0.15, 0.15, and 0.1 respectively; S23, based on the sand control and water control filling comprehensive evaluation index N obtained in step S22, the filling effect of the fractured reservoir is evaluated: When 0.2≥N>0, it is loose filling, and the filling effect is poor; when 0.5≥N>0.2, it is general dense filling, and the filling effect is general; when 0.7≥N>0.5, it is dense filling, and the filling effect is better; when 1.0≥N>0.7, it is extremely dense filling, and the filling effect is excellent.

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