A method, device, storage medium and electronic device for determining vertical well potential tapping technology

Abstract

The present invention relates to the technical field of unconventional oil and gas fracturing and transformation technology, and in particular to a method, device, storage medium and electronic device for determining a vertical well potential development technology. According to the geological characteristics of the target area of ​​the fractured oil and gas reservoir and the production status of the developed vertical wells, the target vertical wells with the potential for secondary transformation are screened out, and the vertical well potential development technology is determined; radial micro-wellbore drilling is used to communicate with the natural fracture body at the far end of the wellbore, and hydraulic fracturing is used to form partially supported fracturing cracks in the natural fracture body communicated by the radial micro-wellbore, so that the oil and gas in the natural fracture body flows through the reservoir to the fracturing cracks, and then flows from the fracturing cracks to the radial micro-wellbore drilling, and finally flows to the development wellbore, which can further communicate the fracture body storage space that has not been communicated after the initial fracturing transformation, and produce the remaining oil and gas in the reservoir at the far end of the wellbore, thereby improving the single well recovery rate and economic benefits.

Description

Technical Field

[0001] The present disclosure relates to the technical field of unconventional oil and gas fracturing and transformation technology, and in particular to a method, device, storage medium and electronic device for determining a vertical well potential tapping technology. Background Art

[0002] The storage space of tight oil and gas reservoirs is mainly fracture bodies. When the fractured fractures encounter natural fractures during the fracturing process, the transformation effect can be greatly improved. Newly developed unconventional oil and gas are mainly horizontal wells, but the unconventional oil and gas developed in the early stage are mainly vertical wells, and the number of vertical wells is large, that is, there are many vertical wells and old wells. Vertical wells and old wells are mainly developed by small-scale fracturing or open hole completion. Their production mainly comes from the fracture bodies connected by the fracturing fractures or the fracture bodies near the wellbore. Therefore, there may be a large amount of residual oil and gas around the vertical wells and old wells.

[0003] Regarding how to communicate the remaining oil and gas around vertical wells and old wells, a lot of process and technology research has been carried out at home and abroad. Various technologies have their advantages and disadvantages:

[0004] (1) Repeated fracturing transformation technology. Conventional repeated fracturing technology is the main means to tap the potential of old vertical wells. It is currently the most widely used technology. This technology mainly includes two types: plugging old fractures to press new fractures and expanding old fractures. In the technology of plugging old fractures to press new fractures, the original perforations are temporarily plugged or a new wellbore is rebuilt, and then perforation and fracturing are performed again. However, the morphology of the fracturing cracks transformed by this technology is affected by multiple factors such as natural fractures, original fracturing cracks, and ground stress near the wellbore. It is difficult to control the extension direction and fracture morphology of the fracturing cracks, which may result in the secondary fracturing transformation effect not being able to achieve the expected results. In the technology of expanding old fractures, secondary fracturing is mainly carried out on the basis of the original perforation holes, and the resulting fracturing cracks mainly extend along the initial fracturing cracks, which results in limited fracturing transformation effects.

[0005] (2) Side drilling technology. Side drilling technology is mainly used to drill sideways for the remaining oil distribution of old vertical wells, and to further communicate the remaining oil. Side drilling technology mainly uses small-diameter mechanical drill bits to drill sideways. However, in the case of side-drilling horizontal wells or directional wells formed by drilling with small-diameter mechanical drill bits, most side-drilling wells are directly used for oil or gas production without fracturing transformation, which results in the failure to achieve the expected increase in production of tight unconventional oil and gas.

[0006] The above technical solutions have the problem that the effect of fracturing transformation is limited. Therefore, this field urgently needs a solution to further communicate the remaining oil and gas around the old vertical wells and improve the recovery rate of the vertical wells. Summary of the invention

[0007] The present invention provides a method, device, storage medium and electronic device for determining a vertical well potential tapping process, which solves the technical problem of improving the recovery rate of a vertical well.

[0008] In a first aspect, the present disclosure provides a method for determining a vertical well potential tapping process, comprising:

[0009] According to the geological characteristics of the target area of ​​fractured oil and gas reservoirs and the production status of developed vertical wells, select the preferred target area with potential for secondary transformation and tapping potential;

[0010] Based on the single-well remaining oil and gas distribution results of each developed vertical well in the preferred target area and the unconnected natural fracture distribution characteristics around each developed vertical well in the preferred target area, each developed vertical well is screened to obtain target vertical wells with secondary reconstruction potential;

[0011] Based on the initial fracturing transformation crack morphology and ground stress analysis of the target vertical well, as well as the residual oil and gas distribution characteristics of the target vertical well, the vertical well potential tapping process is determined, and the vertical well potential tapping process includes the radial micro-wellbore drilling process and the fracturing transformation construction process.

[0012] In some technical solutions, the preferred target area with potential for secondary transformation and tapping is selected based on the geological characteristics of the target area of ​​the fractured oil and gas reservoir and the production status of the developed vertical wells, including:

[0013] Based on the geological characteristics of the target area of ​​fractured oil and gas reservoirs and the production status of developed vertical wells, preliminary target areas with potential for secondary transformation and tapping are selected;

[0014] Performing regional reservoir characteristic analysis on the preliminary target area to obtain the reservoir residual oil and gas distribution characteristics and water and oil saturation distribution characteristics of the preliminary target area;

[0015] Based on the remaining oil and gas distribution characteristics of the reservoir and the water-oil saturation distribution characteristics, preferred target areas with potential for secondary transformation and tapping are screened out from the preliminary target areas.

[0016] In some technical solutions, the method of selecting the preferred target area with the potential for secondary transformation and tapping potential based on the geological characteristics of the target area of ​​the fractured oil and gas reservoir and the production status of the developed vertical wells also includes:

[0017] The distribution characteristics of natural fractures in the preferred target area are analyzed to determine the distribution positions of natural fractures in the reservoir of the preferred target area.

[0018] In some technical solutions, the single-well remaining oil and gas distribution results of each developed vertical well in the preferred target area are obtained by performing a primary fracturing process analysis on the developed vertical wells in the preferred target area, and the primary fracturing process analysis on the developed vertical wells in the preferred target area includes:

[0019] Determine the distribution orientation and morphology of the primary fracturing fractures of each developed vertical well in the preferred target area in combination with geological characteristics, reservoir physical properties, reservoir thickness, natural fracture distribution characteristics and reservoir fracturability;

[0020] Determine the relationship between the initial fracturing process and the initial fracturing transformation effect of each developed vertical well in the preferred target area in combination with the initial fracturing fracture morphology and the communicating natural fracture conditions;

[0021] According to the initial fracturing transformation effect, the residual oil and gas distribution around each developed vertical well in the preferred target area is analyzed to obtain the single-well residual oil and gas distribution results of each developed vertical well in the preferred target area.

[0022] In some technical solutions, the crack morphology and ground stress analysis of the initial fracturing stimulation based on the target vertical well, as well as the analysis of the remaining oil and gas distribution characteristics of the target vertical well, determine the vertical well potential tapping process, including:

[0023] Performing an initial fracturing crack morphology and ground stress analysis on the target vertical well to obtain the initial fracturing crack morphology distribution characteristics and fracturing transformation effect;

[0024] Based on the initial fracturing crack morphology and distribution characteristics and fracturing transformation effect, determine the radial micro-wellbore drilling process, the radial micro-wellbore drilling process includes the number of drilling holes, length, drilling position and drilling orientation;

[0025] Based on the radial micro-borehole drilling process and the fracturing transformation process, the construction process of the fracturing transformation is determined.

[0026] In some technical solutions, the process of determining radial micro-wellbore drilling based on the initial fracturing crack morphology distribution characteristics and fracturing transformation effect includes:

[0027] According to the distribution positions of the unconnected natural fractures around the target vertical well and the remaining oil and gas distribution characteristics of the target vertical well, the number of radial micro-wellbore drilling holes is designed so that all radial micro-wellbores can connect the natural fractures;

[0028] The drilling position of radial micro-wellbore drilling is designed according to the reservoir thickness, the initial perforation position, the initial perforation section length and the initial fracturing fracture morphology;

[0029] Determine the drilling azimuth of the radial micro-wellbore according to the distribution characteristics of the unconnected natural fractures around the target vertical well, so that the drilling azimuth of the radial micro-wellbore penetrates the middle position of the natural fracture;

[0030] According to the distance between the unconnected natural fractures around the target vertical well and the wellbore of the target vertical well, the length of the radial micro-wellbore drilling is designed so that each radial micro-wellbore drilling corresponds to a different natural fracture and the length of the radial micro-wellbore drilling penetrates the corresponding natural fracture.

[0031] In some technical solutions, when designing the drilling position for radial micro-borehole drilling:

[0032] If the upper or lower end of the primary perforation section can be hydraulically jetted for radial micro-borehole drilling, the holes of the radial micro-borehole drilling are distributed at the upper and lower ends of the primary perforation section, and the difference in the number of holes at the two ends is as small as possible, and the number of radial micro-borehole drilling at the upper end of the primary perforation section is greater than the number of radial micro-borehole drilling at the lower end of the primary perforation section;

[0033] If hydraulic jet radial micro-borehole drilling is not possible at the upper or lower end of the primary perforation section, all radial micro-borehole drillings are distributed at the lower or upper end of the primary perforation section. When the radial micro-borehole drillings encounter natural fractures, the radial micro-boreholes are made perpendicular or approximately perpendicular to the distribution direction of the natural fractures.

[0034] In some technical solutions, based on the radial micro-wellbore drilling process and the fracturing transformation process, the construction process of the fracturing transformation is determined, including:

[0035] When all radial micro-wellbore holes are distributed at the lower end of the primary perforation section, the fracturing construction technology of packer setting and tubing injection is adopted;

[0036] When all radial micro-wellbore holes are located at the upper end of the primary perforation section, the bridge plug lower plugging and casing injection fracturing construction technology is adopted;

[0037] When the radial micro-boreholes are distributed at the upper and lower ends of the primary perforation hole, the radial micro-borehole drilling and fracturing construction is first carried out at the lower end, and then the radial micro-borehole drilling and fracturing construction is carried out at the upper end.

[0038] In a second aspect, the present disclosure provides a vertical well potential tapping construction method, comprising:

[0039] Determine the vertical well potential tapping process according to the method for determining the vertical well potential tapping process described in the first aspect, wherein the vertical well potential tapping process includes a radial micro-wellbore drilling process and a construction process for fracturing transformation;

[0040] Perform radial micro-borehole drilling construction according to the radial micro-borehole drilling process;

[0041] Fracturing transformation potential tapping construction is carried out according to the construction technology of fracturing transformation.

[0042] In a third aspect, the present disclosure provides a device for determining a vertical well potential tapping process, comprising:

[0043] The module for determining the optimal target area is used to select the optimal target area with the potential for secondary transformation and tapping potential according to the geological characteristics of the target area of ​​the fractured oil and gas reservoir and the production status of the developed vertical wells;

[0044] A target vertical well determination module is used to screen each developed vertical well based on the single well remaining oil and gas distribution results of each developed vertical well in the preferred target area and the unconnected natural fracture distribution characteristics around each developed vertical well in the preferred target area to obtain a target vertical well with secondary transformation potential;

[0045] The process determination module is used to determine the vertical well potential tapping process based on the initial fracturing transformation crack morphology and ground stress analysis of the target vertical well, as well as the residual oil and gas distribution characteristics of the target vertical well. The vertical well potential tapping process includes the radial micro-wellbore drilling process and the fracturing transformation construction process.

[0046] In a fourth aspect, the present disclosure provides a storage medium storing a plurality of instructions, wherein the plurality of instructions are used for a processor to load and execute the vertical well potential tapping process determination method as described in the first aspect.

[0047] In a fifth aspect, the present disclosure provides an electronic device, comprising: a processor, configured to execute a plurality of instructions;

[0048] A memory for storing a plurality of instructions;

[0049] Wherein, the plurality of instructions are stored by the memory, and loaded and executed by the processor as the method for determining the vertical well potential tapping process as described in the first aspect.

[0050] The technical scheme disclosed in the present invention selects target vertical wells with secondary transformation potential according to the geological characteristics of the target area of ​​the fractured oil and gas reservoir and the production status of the developed vertical wells, and determines the vertical well potential development process; uses radial micro-borehole drilling to communicate with the natural fracture body in the far end of the wellbore, and uses hydraulic fracturing to form partially supported fracturing cracks in the natural fracture body communicated by the radial micro-borehole, so that the oil and gas in the natural fracture body flows through the reservoir to the fracturing cracks, and from the fracturing cracks to the radial micro-boreholes, and finally flows to the development wellbore, which can further communicate the fracture body storage space that has not been communicated after the initial fracturing transformation, and produce the remaining oil and gas in the reservoir in the far end of the wellbore, thereby improving the single well recovery rate and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The present disclosure will be described in more detail below based on embodiments and with reference to the accompanying drawings:

[0052] Figure 1 A schematic diagram of a flow chart of a method for determining a vertical well potential tapping process provided by an embodiment of the present disclosure;

[0053] FIG2( a ) is a schematic diagram of radial micro-wellbore drilling provided by an embodiment of the present disclosure;

[0054] FIG2( b ) is a schematic diagram of a radial micro-wellbore fracturing transformation provided by an embodiment of the present disclosure;

[0055] FIG3( a ) is a schematic diagram of fracturing in the lower area of ​​the initial perforation provided in an embodiment of the present disclosure;

[0056] FIG3( b ) is a schematic diagram of fracturing in the upper area of ​​a primary perforation provided in an embodiment of the present disclosure (a bridge plug is placed at the upper end of the primary perforation section);

[0057] FIG3( c ) is a schematic diagram of fracturing in the upper area of ​​a primary perforation provided in an embodiment of the present disclosure (a bridge plug is placed at the lower end of the primary perforation section).

[0058] Description of reference numerals:

[0059] 6—target vertical well;

[0060] 7—initial perforation holes;

[0061] 8—initial fracturing crack;

[0062] 9—Natural fractures that were not connected by the initial fracturing;

[0063] 10—Radial micro-borehole drilling;

[0064] 11—Natural fractures connected by the initial fracturing fractures;

[0065] 12—Target reservoir, optimal target area;

[0066] 13—Fracturing and reforming cracks;

[0067] 14—Fracturing wellhead;

[0068] 15—Fracturing tubing;

[0069] 16—Fracturing casing;

[0070] 17—Fracturing reservoirs;

[0071] 18—initial fracturing crack;

[0072] 19—initial perforation hole;

[0073] 20—Packer;

[0074] 21—Radial micro-borehole drilling;

[0075] 22—Proppant;

[0076] 23—Fracturing wellhead;

[0077] 24—Fracturing wellbore;

[0078] 25—Fracturing reservoirs;

[0079] 26—initial fracturing crack;

[0080] 27—Radial micro-borehole drilling;

[0081] 28—Isolated bridge plug;

[0082] 29—initial perforation hole;

[0083] 30—Temporary plugging proppant.

[0084] In the drawings, the same reference numerals are used for the same components and the drawings are not drawn to scale. DETAILED DESCRIPTION

[0085] In order to enable those skilled in the art to better understand the scheme of the present disclosure, and to fully understand and implement how the present disclosure applies technical means to solve technical problems and achieve the corresponding technical effects, the technical scheme in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only embodiments of a part of the present disclosure, not all of the embodiments. The embodiments of the present disclosure and the various features in the embodiments can be combined with each other without conflict, and the technical schemes formed are all within the scope of protection of the present disclosure. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present disclosure.

[0086] It should be noted that the terms "first", "second", etc. in the specification and claims of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present disclosure described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products, or devices.

[0087] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0088] Unconventional oil and gas reservoirs often develop natural fractures to a certain extent, and natural fractures are the main oil and gas storage space. In the early stage of oil and gas development, vertical wells were mainly used. During the initial fracturing and transformation of vertical wells, due to the influence of the transformation process and reservoir characteristics, conventional fracturing transformation cannot completely communicate the natural fractures around the vertical wellbore, resulting in the inability to recover the oil and gas in the natural fractures that have not been communicated by the fracturing fractures of the initial fracturing transformation. Therefore, there is room for secondary transformation and potential tapping in the developed vertical wells. In this field, there are technical problems in the secondary transformation and potential tapping of old vertical wells in fractured tight oil and gas reservoirs in the late stage of development.

[0089] In response to the above technical problems, the present invention conducts targeted research on the potential tapping process and technology of vertical wells and old wells based on the characteristics of fractured tight oil and gas reservoirs. The present invention analyzes the characteristics of regional reservoirs, selects potential old wells, designs the potential tapping process and parameters, and then performs on-site construction of the potential tapping process and effect evaluation and analysis. The present invention can further improve the development stable production time, development stable production period and single well recovery rate of vertical wells and old wells in fractured oil and gas reservoirs, and further improve the development economic benefits of vertical wells and old wells.

[0090] In order to solve the problem of tapping the remaining oil and gas potential in old vertical wells of fractured oil and gas reservoirs, in the technical solution disclosed in the present invention, geology, radial micro-borehole drilling and hydraulic fracturing transformation are combined, radial micro-borehole drilling is used to form sufficiently long holes that communicate with natural fractures, and hydraulic fracturing technology is used to further communicate with natural fracture bodies and form supporting fracture fractures, forming seepage channels with high conductivity, thereby fully utilizing the advantages of the two process technologies of radial micro-borehole drilling and hydraulic fracturing transformation to maximize the production increase effect. The technical solution disclosed in the present invention uses radial micro-borehole drilling to accurately communicate the natural fracture bodies and fracture transformation fracture bodies of the reservoir, greatly improving the stable production time and recovery rate of fractured oil and gas reservoirs, realizing the precise tapping of potential and production increase development for potential old wells, improving the tapping effect, and realizing the maximum development effect of fractured oil and gas reservoirs. The potential tapping process disclosed in the present invention for developed vertical wells in fractured oil and gas reservoirs is better than the effect of secondary fracturing transformation of conventional developed vertical wells.

[0091] Embodiment 1

[0092] Figure 1 A flow chart of a method for determining a vertical well potential tapping process provided by an embodiment of the present disclosure. Figure 1 As shown, the method includes steps S1 to S3:

[0093] Step S1, selecting the preferred target area with potential for secondary transformation and tapping potential based on the geological characteristics of the target area of ​​the fractured oil and gas reservoir and the production status of the developed vertical wells;

[0094] Step S2, based on the single-well remaining oil and gas distribution results of each developed vertical well in the preferred target area and the unconnected natural fracture distribution characteristics around each developed vertical well in the preferred target area, each developed vertical well is screened to obtain a target vertical well with secondary transformation potential;

[0095] Step S3, based on the initial fracturing and reconstruction crack morphology and ground stress analysis of the target vertical well, as well as the residual oil and gas distribution characteristics of the target vertical well, determine the vertical well potential tapping process, which includes the radial micro-wellbore drilling process and the fracturing reconstruction construction process.

[0096] In this embodiment, the step S1 of regional reservoir characteristic analysis selects the preferred target area with the potential for secondary transformation and potential tapping according to the geological characteristics of the target area of ​​the fractured oil and gas reservoir and the production status of the developed vertical wells. The step S2 of potential old well selection selects the target vertical wells with the potential for secondary transformation from each of the developed vertical wells based on the single-well residual oil and gas distribution results of each developed vertical well in the preferred target area and the distribution characteristics of the uncommunicated natural fractures around each of the developed vertical wells in the preferred target area. The step S3 of potential tapping process and parameter design performs the initial fracturing transformation crack morphology and ground stress analysis on the target vertical wells, as well as the residual oil and gas distribution characteristics analysis of the target vertical wells, to determine the vertical well potential tapping. Process; the vertical well potential development process determined by the method includes both the process of radial micro-borehole drilling and the construction process of fracturing transformation. The determined radial micro-borehole drilling process can be used to communicate with the natural fracture body at the far end of the wellbore through radial micro-borehole drilling, and the determined construction process of fracturing transformation can be used to form partially supported fracturing cracks in the natural fracture body communicated by the radial micro-borehole by hydraulic fracturing, so that the oil and gas in the natural fracture body flows through the reservoir to the fracturing cracks, and from the fracturing cracks to the radial micro-boreholes, and finally to the development wellbore, which can further communicate the fracture body storage space that has not been communicated after the initial fracturing transformation, and produce the remaining oil and gas in the reservoir at the far end of the wellbore, thereby improving the single well recovery rate and economic benefits.

[0097] Embodiment 2

[0098] On the basis of the above embodiment, step S1 selects the preferred target area with the potential for secondary transformation and tapping potential according to the geological characteristics of the target area of ​​the fractured oil and gas reservoir and the production status of the developed vertical wells, and includes the following steps:

[0099] Step S11, preliminarily selecting a preliminary target area with potential for secondary transformation and tapping potential based on the geological characteristics of the target area of ​​the fractured oil and gas reservoir and the production status of the developed vertical wells;

[0100] In this embodiment, based on the overall geological characteristics, structural characteristics, geological conditions and reservoir characteristics of the target area of ​​the fractured oil and gas reservoir, combined with the production status of the developed vertical wells, the contribution of natural fracture bodies (including natural fractures 9 that are not connected by the initial fracturing fractures and natural fractures 11 that are connected by the initial fracturing fractures as shown in Figure 2(a)) to the development capacity is evaluated, and preliminary target areas with potential for secondary transformation and tapping are preliminarily selected.

[0101] Step S12, performing regional reservoir characteristic analysis on the preliminary target area to obtain the reservoir residual oil and gas distribution characteristics and water and oil saturation distribution characteristics of the preliminary target area;

[0102] In this embodiment, a refined regional reservoir characteristic analysis is performed on the preliminary target area in combination with reservoir geological characteristics, seismic interpretation, reservoir physical properties, development status and development technology, to obtain the reservoir remaining oil and gas distribution and water and oil saturation distribution characteristics of the preliminary target area.

[0103] Step S13, based on the distribution characteristics of the remaining oil and gas in the reservoir and the distribution characteristics of the water and oil saturation, selecting a preferred target area with potential for secondary transformation from the preliminary target area;

[0104] In this embodiment, based on the distribution of remaining oil and gas in the reservoir and the distribution characteristics of water and oil saturation, a preferred target area with potential for secondary transformation (for example, the preferred target area 12 shown in Figure 2(a)) is selected from the preliminary target area to provide support for subsequent potential development of old wells.

[0105] In some cases, the natural fracture distribution characteristics of the preferred target area are also analyzed to provide the most direct support basis for the selection of target vertical wells that need to be secondary reformed and tapped, so step S1 also includes:

[0106] Step S14, analyzing the distribution characteristics of natural fractures in the preferred target area to determine the distribution positions of natural fractures in the reservoir of the preferred target area;

[0107] In this embodiment, a refined analysis of the distribution characteristics of natural fractures is performed for the preferred target area 12. Specifically, based on geological data, seismic data, combined with data such as drilling, well logging, coring, and core observation, and in conjunction with FIG. 2, the distribution characteristics and distribution rules of natural fractures in the preferred target area 12 are analyzed to determine the distribution positions of the natural fracture bodies in the preferred target area 12, especially the distribution characteristics and distribution rules of the natural fractures around each developed vertical well, so as to provide the most direct support basis for the selection of the target vertical well 6 that needs to be reconstructed and tapped.

[0108] By analyzing the geological characteristics of the target area of ​​the fractured oil and gas reservoir and the production status of the developed vertical wells, this embodiment can screen out the preferred target area with the potential for secondary transformation and potential tapping, providing a more accurate range for the selection of target vertical wells and improving the efficiency of secondary transformation and potential tapping well selection.

[0109] Embodiment 3

[0110] On the basis of the above-mentioned embodiment, the single-well remaining oil and gas distribution results of each developed vertical well in the preferred target area are obtained by performing a primary fracturing process analysis on the developed vertical wells in the preferred target area. The primary fracturing process analysis on the developed vertical wells in the preferred target area includes steps S21 to S23:

[0111] Step S21, determining the distribution orientation and morphology of the primary fracturing fractures of each developed vertical well in the preferred target area in combination with geological characteristics, reservoir physical properties, reservoir thickness, natural fracture distribution characteristics and reservoir fracturing ability;

[0112] In this embodiment, the primary fracturing process analysis of the developed vertical wells is performed in the preferred target area 12. The distribution orientation and morphology of the primary fracturing cracks of the developed vertical wells are determined in combination with the geological characteristics, reservoir physical properties, reservoir thickness, natural fracture distribution characteristics and reservoir fracturability.

[0113] Step S22, combining the initial fracturing crack morphology and the communicating natural fracture conditions, determining the relationship between the initial fracturing process and the initial fracturing transformation effect of each developed vertical well in the preferred target area;

[0114] In this embodiment, combined with the morphology of the primary fracturing crack 8 in Figure 2(a) and the situation of the natural fracture 11 connected by the primary fracturing crack, the relationship between the primary fracturing process and the primary fracturing transformation effect of each developed vertical well in the preferred target area 12 can be determined by comprehensively considering the fracturing transformation process, the position of the initial perforation hole 7, the reservoir thickness, construction parameters, liquid type, reservoir characteristics, and especially the distribution characteristics of the natural fractures.

[0115] Step S23, according to the initial fracturing effect, performing residual oil and gas distribution analysis around each developed vertical well in the preferred target area, and obtaining single well residual oil and gas distribution results of each developed vertical well in the preferred target area;

[0116] In this embodiment, according to the initial fracturing transformation effect and the development history, the residual oil and gas distribution around each developed vertical well in the preferred target area is analyzed to obtain the single well residual oil and gas distribution results of each developed vertical well in the preferred target area 12. Further, based on the single well residual oil and gas distribution results and the distribution characteristics of the unconnected natural fractures 9 around each developed vertical well, each developed vertical well is optimized to obtain the target vertical well 6 with the potential for secondary transformation.

[0117] By determining the orientation and morphology of the primary fracturing cracks of each developed vertical well in the preferred target area, as well as the single-well residual oil and gas distribution results of each developed vertical well in the preferred target area, the scope of optimization for each developed vertical well can be reduced, and the efficiency of obtaining target vertical wells with secondary transformation potential can be improved.

[0118] Embodiment 4

[0119] On the basis of the above-mentioned embodiment, the vertical well potential tapping process is determined based on the initial fracturing and reconstruction crack morphology and ground stress analysis of the target vertical well, as well as the residual oil and gas distribution characteristics analysis of the target vertical well, including steps S31 to S33:

[0120] Step S31, performing an initial fracturing crack morphology and ground stress analysis on the target vertical well to obtain the initial fracturing crack morphology distribution characteristics and fracturing transformation effect;

[0121] In this embodiment, the primary fracturing crack morphology and ground stress analysis of the target vertical well 6 is performed. The primary fracturing crack morphology analysis is performed on the target vertical well 6 to clarify the morphological distribution characteristics of the primary fracturing crack 8 and the fracturing transformation effect, wherein the primary fracturing crack morphology analysis includes the following parts:

[0122] Step S311, natural fracture distribution characteristic analysis: Based on the geological characteristics of the target vertical well 6, three-dimensional seismic data, regional natural fracture distribution, drilling, well logging, drilling coring and fracturing construction curve analysis results, the distribution characteristics of the natural fractures around the target vertical well 6 (including the natural fractures 9 that are not connected by the initial fracturing fractures and the natural fractures 11 that are connected by the initial fracturing fractures) are analyzed to clarify the distribution position of the natural fractures 9 that are not connected by the initial fracturing fractures around the target vertical well 6, the distance from the wellbore and other parameters, and determine the distribution characteristics of the natural fractures 9 that are not connected by the initial fracturing fractures around the wellbore diameter (for example, within 100m).

[0123] Step S312, primary fracturing crack morphology analysis: Based on the target reservoir thickness, reservoir physical properties, reservoir-interlayer geostress distribution, the position of the initial perforation hole 7, the primary fracturing process and construction parameters, etc., perform morphological inversion of the primary fracturing crack 8 of the target vertical well 6, clarify the expansion orientation and transformation range of the primary fracturing cracks 8, 18, and 26, obtain the morphological distribution characteristics of the primary fracturing crack 8, and provide guidance for the distribution of radial micro-wellbore drilling during secondary transformation.

[0124] Step S313, geostress distribution characteristic analysis: According to the regional geostress distribution characteristics around the target vertical well 6, the distribution of natural fractures, the morphology of the primary fracturing fractures 8, and the production characteristics of the developed vertical wells are comprehensively considered to perform geostress analysis near the wellbore after the primary fracturing development, clarify the geostress distribution characteristics and principal stress orientation characteristics of the target vertical well 6 before the secondary transformation (i.e., at present), and provide a theoretical basis for the radial micro-borehole drilling hole distribution and secondary fracturing transformation during the secondary transformation.

[0125] Step S314, residual oil and gas distribution analysis: Combined with the distribution of natural fractures, the fractures transformed by the initial fracturing and the production characteristics after the initial fracturing, a numerical simulation study of the reservoir of the target vertical well 6 is conducted to clarify the residual oil and gas distribution characteristics around the target vertical well 6 and obtain the initial fracturing transformation effect.

[0126] Step S32, based on the initial fracturing crack morphology distribution characteristics and fracturing transformation effect, determine the radial micro-wellbore drilling process, the radial micro-wellbore drilling process includes at least one of the number of drilling holes, length, drilling position and drilling orientation;

[0127] In this embodiment, radial micro-wellbore drilling is designed. According to the initial fracturing crack morphology distribution characteristics and fracturing transformation effects, such as the natural fracture distribution of the target vertical well 6, the remaining oil and gas distribution characteristics, the reservoir thickness, the initial fracturing perforation position and the initial fracturing crack morphology distribution, the radial micro-wellbore drilling 10 is designed, including the number of holes, length, drilling position, and drilling orientation.

[0128] Step S33, determining a construction process for hydraulic fracturing based on the radial micro-wellbore drilling process and the hydraulic fracturing process;

[0129] In this embodiment, according to the drilling process of radial micro-wellbore and the drilling position and fracturing transformation process of radial micro-wellbore, the construction process of fracturing transformation is determined and the parameters of secondary transformation fracturing transformation process are optimized. As shown in FIG2(b), by using secondary fracturing transformation, fracturing transformation cracks 13 are formed around the natural cracks 9 that are not communicated by the primary fracturing cracks communicated by the radial micro-wellbore drilling 10. The morphology of the fracturing transformation cracks 13 is mainly affected by the distribution of the natural cracks 9 that are not communicated by the primary fracturing cracks. The fracturing transformation cracks 13 formed by the secondary fracturing transformation have an important influence on the effect of the secondary fracturing transformation. The fracturing transformation cracks 13 are made to communicate with the natural cracks 9 that are not communicated by the primary fracturing cracks around the radial micro-wellbore drilling 10 as much as possible. The secondary fracturing transformation design mainly includes the fracturing transformation construction displacement, construction fluid volume, temporary plugging process, proppant dosage, etc.

[0130] By determining the radial micro-borehole drilling process based on the primary fracturing crack morphology distribution characteristics and the fracturing transformation effect, the maximum transformation effect can be achieved with as few radial micro-borehole drilling as possible. The present invention changes the geostress distribution of the reservoir near the wellbore through radial micro-borehole drilling, reduces the influence of the geostress direction and crack expansion characteristics of the reservoir where the target vertical well is located, and ensures that the transformation range of the secondary transformation fracturing crack is within the fracture body communicated by the radial micro-borehole drilling holes.

[0131] Embodiment 5

[0132] On the basis of the above-mentioned embodiment, the process of determining radial micro-wellbore drilling based on the initial fracturing crack morphology distribution characteristics and fracturing transformation effect includes steps S321 to S324:

[0133] Step S321, designing the number of radial micro-wellbores to be drilled according to the distribution positions of unconnected natural fractures around the target vertical well and the single-well remaining oil and gas distribution results of the target vertical well, so as to make all radial micro-wellbores connect with natural fractures as much as possible;

[0134] In this embodiment, the number of radial micro-wellbore drilling holes 10 is designed. According to the number and distribution position of the unconnected natural fractures 9 around the target vertical well 6 and the single well residual oil and gas distribution result of the target vertical well before the secondary potential tapping, the number of radial micro-wellbore drilling holes 10 is designed so that all radial micro-wellbore drilling holes 10 can connect the natural fractures 9 that are not connected by the primary fracturing fractures. Among them, the number of radial micro-wellbore drilling holes at the same layer position is not greater than the preset number (for example, 6), so as to reduce the construction difficulty while obtaining a good transformation effect.

[0135] Step S322, designing the drilling position of radial micro-wellbore drilling according to the reservoir thickness, the initial perforation position, the initial perforation section length and the initial fracturing fracture morphology;

[0136] In this embodiment, the drilling position of the radial micro-borehole 10 is designed. The drilling position of the radial micro-borehole 10 is designed according to the reservoir thickness, the position of the initial perforation holes 7 and the length of the perforation section (i.e., the area including all the initial perforation holes 7), the shape of the primary fracturing cracks 8, etc.

[0137] Step S323, determining the drilling orientation of the radial micro-wellbore according to the distribution characteristics of the unconnected natural fractures around the target vertical well, so that the drilling orientation of the radial micro-wellbore penetrates the middle position of the natural fracture;

[0138] In this embodiment, the drilling orientation of the radial micro-borehole 10 is designed based on the distribution characteristics of the natural fractures 9 that are not connected by the initial fracturing fractures around the target vertical well. The drilling orientation of the radial micro-borehole 10 penetrates the middle position of the natural fractures 9 that are not connected by the initial fracturing fractures as much as possible, so that the radial micro-borehole 10 can control the natural fractures 9 that are not connected by the initial fracturing fractures as much as possible.

[0139] Step S324, designing the length of the radial micro-wellbore drilling according to the distance between the unconnected natural fractures around the target vertical well and the wellbore of the target vertical well, so that each radial micro-wellbore drilling corresponds to a different natural fracture, and the length of the radial micro-wellbore drilling penetrates the corresponding natural fracture;

[0140] In this embodiment, the length of the radial micro-wellbore borehole 10 is designed according to the distance between the natural fractures 9 that are not connected by the primary fracturing fractures around the target vertical well 6 and the wellbore of the target vertical well 6. Each radial micro-wellbore borehole 10 corresponds to a different natural fracture body 9 that is not connected by the primary fracturing fractures. The length of the radial micro-wellbore borehole 10 needs to penetrate the corresponding natural fracture body 9 that is not connected by the primary fracturing fractures as much as possible. According to the radial micro-wellbore drilling process, the length of a single radial micro-wellbore borehole 10 is not greater than a preset length, for example, 100 m, so as to reduce the secondary transformation cost while obtaining the best possible transformation effect.

[0141] By determining the radial micro-borehole drilling process based on the primary fracturing crack morphology distribution characteristics and fracturing transformation effects, the radial micro-borehole drilling can be targeted, thereby maximizing the utilization of radial micro-borehole drilling and reducing the secondary transformation cost.

[0142] Embodiment 6

[0143] On the basis of the above embodiment, when designing the drilling position of the radial micro-wellbore:

[0144] (1) If the upper or lower end of the primary perforation section can be hydraulically jetted for radial micro-wellbore drilling, the holes of the radial micro-wellbore drilling are distributed at the upper and lower ends of the primary perforation section, and the difference in the number of holes at the two ends is as small as possible. At the same time, the number of radial micro-wellbore drilling holes at the upper end of the primary perforation section is greater than the number of radial micro-wellbore drilling holes at the lower end of the primary perforation section;

[0145] In this embodiment, according to Figure 3(a) to Figure 3(c) It can be seen from the schematic diagram of the tapping process fracturing that the overall distribution design of the radial micro-wellbore drilling holes 21 and 27 is carried out according to the position of the initial perforation hole 7 of the target vertical well 6, the thickness of the fracturing reservoir 17, 25, the distance between the upper end of the primary perforation section formed by the primary perforation holes 19 and 29 and the upper part of the fracturing reservoir 17, 25, and the distance between the lower end of the primary perforation section formed by the primary perforation holes 19 and 29 and the lower part of the fracturing reservoir 17, 25. If the upper end or the lower end of the primary perforation section can be drilled with hydraulic jet radial micro-wellbore, the holes of the radial micro-wellbore drilling holes 21 and 27 are distributed at the upper and lower ends of the primary perforation section formed by the primary perforation holes 19 and 29, and the difference in the number of the two ends is as small as possible, and at the same time, the number of radial micro-wellbore drilling holes at the upper end of the primary perforation section formed by the primary perforation holes 19 and 29 is greater than the number of radial micro-wellbore drilling holes at the lower end of the primary perforation section.

[0146] (2) If hydraulic jetting radial micro-wellbore drilling is not possible at the upper or lower end of the primary perforation section, all radial micro-wellbore drillings are distributed at the lower or upper end of the primary perforation section. When the radial micro-wellbore drillings encounter natural fractures, the radial micro-wellbore is perpendicular or approximately perpendicular to the distribution direction of the natural fractures.

[0147] In this embodiment, if the upper or lower end of the initial perforation section cannot be hydraulically jetted for radial micro-borehole drilling, all radial micro-boreholes 10 can be designed at the lower or upper part of the initial perforation section. The vertical spacing of the radial micro-boreholes 10 must be greater than or equal to the preset spacing (e.g., 1.0 m), and the angle between adjacent radial micro-boreholes 10 must be greater than 60° as much as possible. At the same time, the vertical spacing of the radial micro-boreholes 10 from the position of the initial perforation hole must be greater than or equal to the preset spacing (e.g., 1.0 m). When the radial micro-boreholes 10 encounter a natural fracture body, the radial micro-boreholes 10 should be as vertical or close to the distribution direction of the natural fractures 9 as possible, so as to ensure that the transformation volume can be increased to the greatest extent during the fracturing process.

[0148] By judging whether the upper or lower end of the primary perforation section can be used for hydraulic jet radial micro-wellbore drilling, this embodiment provides different overall distribution designs of radial micro-wellbores 21 and 27, thereby improving the convenience of construction and reducing construction costs.

[0149] Embodiment 7

[0150] On the basis of the above embodiment, based on the radial micro-wellbore drilling process and the fracturing transformation process, the construction process of the fracturing transformation is determined, including:

[0151] (1) When all radial micro-wellbore holes are distributed at the lower end of the primary perforation section, a fracturing construction process of packer setting and tubing injection is adopted;

[0152] In this embodiment, according to Figure 3(a) to Figure 3(c) It can be seen from the schematic diagram of the potential tapping process fracturing that if all radial micro-wellbore holes 10 are distributed at the lower end of the primary perforation section, the process design of the secondary fracturing construction is carried out after the drilling is completed according to the radial micro-wellbore drilling plan. The process schematic diagram is shown in Figure 3 (a). The fracturing construction process adopts the fracturing construction process of the packer 20 setting and the fracturing oil pipe 15 injection. Among them, if there are other development layers under the fracturing reservoir 17, a certain amount of proppant 22 (such as artificial well bottom filling proppant) is lowered into the bottom of the well according to the position of the artificial well bottom to seal the perforations of the lower development layer, and then the packer 20 and the fracturing oil pipe 15 are lowered. After the packer 20 is set, the ground fracturing pump truck is used to perform fracturing construction through the fracturing wellhead 14 and the fracturing oil pipe 15. Among them, the fracturing parameters are mainly as follows:

[0153] Fracturing fluid type: For fractured oil and gas reservoirs, the amount of liquid filtration is large during the fracturing process, and it is difficult to create fractures with conventional low-viscosity fracturing fluids. Therefore, fracturing fluids of different viscosities can be used for composite fracturing in the early stage. The fracturing fluid uses a linear gel-slick water-guar gum composite fracturing liquid system;

[0154] Construction parameters: Construction displacement is 6-10m 3 / min, during the fracturing process, the construction displacement should be increased as much as possible. The construction fluid volume is determined based on the number of holes in the radial micro-wellbore drilling. The total fluid volume per hole is 400m 3 , total liquid volume = number of holes * 400m 3 The proportions of the liquids in each part are: 1 / 6 of the front linear glue, 1 / 2 of the slippery water, and 1 / 3 of the sand-carrying guanidine glue. For example, when the total number of holes in the lower part is 3, the total liquid volume of each hole is 400m 3 , total liquid volume is 1200m 3 The proportion of each part of the liquid is 200m 3 , Slippery Water 600m 3 , 400m3 of sand-carrying guanidine glue 3 If the number of holes in the radial micro-wellbore drilling 10 exceeds 4, the radial micro-wellbore can be temporarily plugged during the fracturing construction process, and the radial micro-wellbore drilling 10 can be temporarily plugged using a high sand ratio proppant and a soluble temporary plugging agent, wherein the high sand ratio proppant is accumulated in the radial micro-wellbore drilling 10, and then a soluble temporary plugging agent is used to temporarily plug part of the radial micro-wellbore.

[0155] Type and dosage of proppant. The type of proppant is selected comprehensively according to the minimum principal stress of the reservoir and the compressive strength of the proppant. For wells with a reservoir depth of less than 2500m, quartz sand proppant can be selected. If the reservoir depth exceeds 2500m, ceramsite proppant is used. The specific type of proppant can also be selected according to the reservoir closure stress. Regarding the amount of sand added to the proppant, the proppant volume of a single hole in a radial micro-wellbore drilling 10 is 20m 3 , total proppant volume = number of holes in radial micro-well drilling * 20m 3 .

[0156] (2) When all radial micro-wellbore holes are located at the upper end of the primary perforation section, the bridge plug lower plugging and casing injection fracturing construction technology is adopted;

[0157] In this embodiment, the fracturing transformation adopts the lower plugging of the bridge plug, and the fracturing casing 16 is injected into the fracturing process. The secondary transformation fracturing construction is shown in schematic diagram 3 (b) and / or Figure 3 (c).

[0158] If the upper part of the primary perforation section formed by the primary perforation holes 29 has enough depth to place the isolation bridge plug 28 and there is a reserved pocket of sufficient depth, the isolation bridge plug 28 is placed as shown in FIG3(b), and the isolation bridge plug 28 is placed at the upper end of the primary perforation section, and the isolation bridge plug 28 is lowered to the predetermined position and then pressurized and set. After the isolation bridge plug 28 is set, casing injection fracturing is adopted, and casing injection fracturing is performed through the fracturing wellhead 23 using the surface pump truck injection system.

[0159] If there is not enough space between the upper end of the primary perforation section and the position of the lowest radial micro-wellbore borehole 10 to place the isolation bridge plug 28 and the reserved pocket, the isolation bridge plug 28 is placed as shown in Figure 3(c). The isolation bridge plug 28 is placed at the lower part of the primary perforation section, and then a certain amount of temporary plugging proppant 30 is lowered into the fracturing wellbore 24 to form an artificial bottom of the well. The temporary plugging proppant 30 completely blocks the primary perforation hole 29, and then the fracturing construction is carried out. The fracturing parameters are basically the same as the above parameters of this embodiment. Due to the use of casing injection, the friction resistance of the liquid column is much lower than the friction resistance of the oil pipe injection. Therefore, during the construction process, the construction displacement is increased as much as possible according to the wellhead pressure limit value and the construction capacity, thereby improving the liquid's fracture-making ability and sand-carrying ability. At the same time, if the number of radial micro-wellbore boreholes 10 exceeds 4, the temporary plugging process is considered during the fracturing process.

[0160] (3) When the radial micro-wellbore drilling is distributed at the upper and lower ends of the primary perforation hole, the lower radial micro-wellbore drilling and fracturing construction are first carried out, and then the upper radial micro-wellbore drilling and fracturing construction are carried out;

[0161] In this embodiment, when the radial micro-wellbore drilling is distributed at the upper and lower ends of the primary perforation hole, the fracturing construction is carried out in two steps. First, the radial micro-wellbore drilling and fracturing construction of the lower part of the primary perforation hole is carried out, and then the radial micro-wellbore drilling and fracturing construction of the upper part of the primary perforation hole is carried out. The radial micro-wellbore drilling and fracturing construction of the lower part of the primary perforation hole can refer to the construction scheme of the first case of the present embodiment. The radial micro-wellbore drilling and fracturing construction of the upper part of the primary perforation hole can refer to the fracturing construction design of the construction scheme of the second case of the present embodiment.

[0162] According to the positional relationship between the radial micro-wellbore drilling and the primary perforation section, this embodiment designs different construction processes, which can improve the transformation effect in different situations and reduce the transformation cost. For radial micro-wellbore drilling at different positions, this disclosure adopts different fracturing construction processes to meet different reservoir thickness requirements. This disclosure adopts the temporary plugging of wellbore proppant to realize the secondary fracturing transformation of radial micro-wellbore drilling at reservoirs at different positions.

[0163] Embodiment 8

[0164] Based on the above embodiments, this embodiment discloses a vertical well potential tapping construction method, including:

[0165] Step S41, according to the vertical well potential tapping process determination method described in the above embodiment, determine the vertical well potential tapping process, that is, the vertical well potential tapping process, the vertical well potential tapping process includes the radial micro-wellbore drilling process and the construction process of fracturing transformation;

[0166] Step S42, performing radial micro-borehole drilling construction according to the radial micro-borehole drilling process;

[0167] In this embodiment, radial micro-borehole drilling construction is performed according to the process of radial micro-borehole drilling 10, such as the position, number of holes, drilling orientation, and hole length of radial micro-borehole drilling 10. The specific drilling construction plan can be constructed according to the construction operation process of the drilling tool. In the radial micro-borehole drilling process, the orientation of the radial micro-borehole 10 is controlled according to the hole design, so that there is a minimum drilling distance between the fracturing wellbore 24 and the natural fracture 9. At the same time, in the radial micro-borehole drilling process, the hole orientation and length of the radial micro-borehole 10 are adjusted in real time according to the reservoir conditions and construction conditions, so as to ensure that the hole of the radial micro-borehole 10 is as vertical as possible to the natural fracture 9.

[0168] Step S43, performing fracturing transformation and potential tapping construction according to the construction process of fracturing transformation;

[0169] In this embodiment, the fracturing transformation and potential tapping construction are carried out according to different situations:

[0170] Step S431: When all the holes (i.e., target layers) of the radial micro-well boreholes 10 are distributed at the lower end of the primary perforation section formed by the primary perforation holes 19 or 29, the fracturing construction steps are as follows:

[0171] If there are other fracturing and transformation layers below the target layer, a certain amount of proppant is injected into the bottom of the well at a low displacement before the secondary transformation tool is lowered into the fracturing wellbore to completely plug the primary fracturing section of the lower layer. The addition of proppant dosage ensures the plugging of the primary fracturing and transformation layer below.

[0172] The position of the packer 20 and the fracturing tubing 15 is determined according to the position of the primary perforation section and the position of the radial micro-wellbore 10, and then the packer 20 and the fracturing tubing 15 are lowered to the isolation position to set the packer 20.

[0173] Fracturing construction. Inject fracturing fluid and proppant according to the construction displacement and construction fluid volume designed in the fracturing construction plan until the designed fluid volume is reached.

[0174] Fracturing flowback and test production. After the secondary fracturing transformation is completed, fracturing flowback and post-fracturing test production are carried out. The parameters of fracturing flowback and post-fracturing test production are determined according to the reservoir characteristics and fracturing transformation conditions.

[0175] Step S432: When all the holes of the radial micro-wellbore drilling holes 10 are distributed at the upper end of the primary perforation section, bridge plug isolation and casing injection fracturing are used for secondary transformation, including the following process technologies:

[0176] The isolation bridge plug 28 is lowered to the upper or lower end of the primary perforation section by using a cable, and the isolation bridge plug 28 is set after reaching the predetermined position.

[0177] If the isolation bridge plug 28 is placed at the lower end of the primary perforation section, after the isolation bridge plug 28 is set, a sand-carrying fluid containing a temporary proppant 30 is pumped into the fracturing wellbore 24 at a low displacement rate to sink the temporary proppant 30 to the bottom of the well to seal the primary perforation holes 29. The amount of the temporary proppant 30 must ensure that the primary perforation holes 29 are completely sealed.

[0178] Fracturing construction. Fracturing construction is carried out according to the designed construction displacement and total liquid volume.

[0179] Fracturing flowback and test production. After the fracturing construction is completed, the fracturing fluid is flowed back and the oil and gas test production is carried out.

[0180] Step S433, when the holes of the radial micro-wellbore boreholes 10 are distributed at the upper and lower ends of the primary perforation holes, fracturing construction is performed according to the above-mentioned fracturing construction process and construction parameter design. Among them, the fracturing construction is carried out in two steps. First, the drilling and fracturing construction of the radial micro-wellbore boreholes 21 at the lower part of the primary perforation section is carried out, and the fracturing construction is carried out with reference to the above steps. After the drilling and fracturing of the radial micro-wellbore boreholes at the lower part of the primary perforation section is completed, the drilling and fracturing construction of the radial micro-wellbore boreholes 27 at the upper part of the primary perforation section is carried out, and the specific steps refer to the above-mentioned construction steps. After the construction is completed, the fracturing return and trial production work are carried out.

[0181] By determining the vertical well potential tapping process according to the vertical well potential tapping process determination method described in the above embodiment, and performing vertical well potential tapping construction according to different situations, the cost of fracturing construction can be reduced and the effect of fracturing transformation can be improved.

[0182] In addition, after the fracturing transformation, this embodiment also performs effect evaluation and analysis.

[0183] According to the reservoir mechanical characteristics of the target vertical well 6, the mechanical properties of the reservoir barrier, the distribution of natural fractures 9, the number of radial micro-wellbore drilling holes 10, the scale of fracturing, etc., the morphological analysis of the fracturing reformed fractures 13 is carried out to clarify the morphology of the fracturing reformed fractures 13. According to the reservoir physical properties, the distribution of the remaining oil and gas in the reservoir, the number of radial micro-wellbore drilling holes 10 and the scale of fracturing, the secondary potential tapping reform effect analysis is carried out. Combined with the production data after the secondary potential tapping, the fracturing reform effect is further evaluated. Analyzing the influence of the number of holes, the scale of fracturing, etc. on the production increase effect can provide support for the subsequent improvement of the potential tapping process.

[0184] Embodiment 9

[0185] Based on the above embodiments, this embodiment discloses a device for determining a vertical well potential tapping process, comprising:

[0186] The module for determining the optimal target area is used to select the optimal target area with the potential for secondary transformation and tapping potential according to the geological characteristics of the target area of ​​the fractured oil and gas reservoir and the production status of the developed vertical wells;

[0187] A target vertical well determination module is used to screen each developed vertical well based on the single well remaining oil and gas distribution results of each developed vertical well in the preferred target area and the unconnected natural fracture distribution characteristics around each developed vertical well in the preferred target area to obtain a target vertical well with secondary transformation potential;

[0188] The process determination module is used to determine the vertical well potential tapping process based on the initial fracturing transformation crack morphology and ground stress analysis of the target vertical well, as well as the residual oil and gas distribution characteristics of the target vertical well. The vertical well potential tapping process includes the radial micro-wellbore drilling process and the fracturing transformation construction process.

[0189] The vertical well potential tapping process determination device is used to execute the vertical well potential tapping process determination method described in the above embodiment. The specific description of the vertical well potential tapping process determination method can refer to the specific description of the above embodiment, and will not be repeated in this embodiment.

[0190] Embodiment 10

[0191] On the basis of the above embodiments, this embodiment further provides a storage medium, such as a flash memory, a hard disk, a multimedia card, a card-type memory (for example, an SD or DX memory, etc.), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a magnetic memory, a disk, an optical disk, a server, etc., on which a computer program is stored. When the computer program is executed, the method for determining the vertical well potential tapping process described in the above embodiments can be implemented, including:

[0192] According to the geological characteristics of the target area of ​​fractured oil and gas reservoirs and the production status of developed vertical wells, select the preferred target area with potential for secondary transformation and tapping potential;

[0193] Based on the single-well remaining oil and gas distribution results of each developed vertical well in the preferred target area and the unconnected natural fracture distribution characteristics around each developed vertical well in the preferred target area, each developed vertical well is screened to obtain target vertical wells with secondary reconstruction potential;

[0194] Based on the initial fracturing transformation crack morphology and ground stress analysis of the target vertical well, as well as the residual oil and gas distribution characteristics of the target vertical well, the vertical well potential tapping process is determined, and the vertical well potential tapping process includes the radial micro-wellbore drilling process and the fracturing transformation construction process.

[0195] In this embodiment, the preferred target areas with potential for secondary transformation and tapping are screened out based on the geological characteristics of the target area of ​​the fractured oil and gas reservoir and the production status of the developed vertical wells, including:

[0196] Based on the geological characteristics of the target area of ​​fractured oil and gas reservoirs and the production status of developed vertical wells, preliminary target areas with potential for secondary transformation and tapping are selected;

[0197] Performing regional reservoir characteristic analysis on the preliminary target area to obtain the reservoir residual oil and gas distribution characteristics and water and oil saturation distribution characteristics of the preliminary target area;

[0198] Based on the remaining oil and gas distribution characteristics of the reservoir and the water-oil saturation distribution characteristics, preferred target areas with potential for secondary transformation and tapping are screened out from the preliminary target areas.

[0199] In this embodiment, the method of selecting the preferred target area with the potential for secondary transformation and tapping potential according to the geological characteristics of the target area of ​​the fractured oil and gas reservoir and the production status of the developed vertical wells also includes:

[0200] The distribution characteristics of natural fractures in the preferred target area are analyzed to determine the distribution positions of natural fractures in the reservoir of the preferred target area.

[0201] In this embodiment, the single-well remaining oil and gas distribution results of each developed vertical well in the preferred target area are obtained by performing a primary fracturing process analysis on the developed vertical wells in the preferred target area. The primary fracturing process analysis on the developed vertical wells in the preferred target area includes:

[0202] Determine the distribution orientation and morphology of the primary fracturing fractures of each developed vertical well in the preferred target area in combination with geological characteristics, reservoir physical properties, reservoir thickness, natural fracture distribution characteristics and reservoir fracturability;

[0203] Determine the relationship between the initial fracturing process and the initial fracturing transformation effect of each developed vertical well in the preferred target area in combination with the initial fracturing fracture morphology and the communicating natural fracture conditions;

[0204] According to the initial fracturing transformation effect, the residual oil and gas distribution around each developed vertical well in the preferred target area is analyzed to obtain the single-well residual oil and gas distribution results of each developed vertical well in the preferred target area.

[0205] In this embodiment, the crack morphology and ground stress analysis based on the initial fracturing transformation of the target vertical well, as well as the analysis of the remaining oil and gas distribution characteristics of the target vertical well, determine the vertical well potential tapping process, including:

[0206] Performing an initial fracturing crack morphology and ground stress analysis on the target vertical well to obtain the initial fracturing crack morphology distribution characteristics and fracturing transformation effect;

[0207] Based on the initial fracturing crack morphology and distribution characteristics and fracturing transformation effect, determine the radial micro-wellbore drilling process, wherein the radial micro-wellbore drilling process includes at least one of the number of holes, the length, the location of the holes, and the orientation of the holes;

[0208] Based on the radial micro-borehole drilling process and the fracturing transformation process, the construction process of the fracturing transformation is determined.

[0209] In this embodiment, the process of determining radial micro-wellbore drilling based on the initial fracturing crack morphology distribution characteristics and fracturing transformation effect includes:

[0210] According to the distribution positions of the unconnected natural fractures around the target vertical well and the distribution results of the remaining oil and gas in the single well, the number of radial micro-wellbore drilling holes is designed so that all radial micro-wellbores can connect the natural fractures;

[0211] The drilling position of radial micro-wellbore is designed according to the reservoir thickness, the initial perforation position and length of the initial perforation section, and the initial fracturing fracture morphology;

[0212] Determine the drilling orientation of the radial micro-wellbore according to the distribution characteristics of the unconnected natural fractures around the developed vertical well, so that the drilling orientation of the radial micro-wellbore penetrates the middle position of the natural fracture;

[0213] According to the distance between the unconnected natural fractures around the target vertical well and the wellbore of the target vertical well, the length of the radial micro-wellbore is designed so that each radial micro-wellbore corresponds to a different natural fracture and the length of the radial micro-wellbore penetrates the corresponding natural fracture.

[0214] In this embodiment, when designing the drilling position of the radial micro-wellbore:

[0215] If the upper or lower end of the primary perforation section can be drilled with hydraulic jet radial micro-boreholes, the holes of the radial micro-boreholes are distributed at the upper and lower ends of the primary perforation section, and the difference in the number of holes at the two ends is as small as possible. At the same time, the number of radial micro-boreholes drilled at the upper end of the primary perforation section is greater than that at the lower end of the primary perforation section.

[0216] If hydraulic jet radial micro-borehole drilling is not possible at the upper or lower end of the primary perforation section, all radial micro-borehole drillings are distributed at the upper or lower end of the primary perforation section. When the radial micro-borehole drillings encounter natural fractures, the radial micro-boreholes are perpendicular or approximately perpendicular to the distribution direction of the natural fractures.

[0217] In this embodiment, based on the radial micro-wellbore drilling process and the fracturing transformation process, the construction process of the fracturing transformation is determined, including:

[0218] When all radial micro-wellbore holes are distributed at the lower end of the primary perforation section, the fracturing construction technology of packer setting and tubing injection is adopted;

[0219] When all radial micro-wellbore holes are located at the upper end of the primary perforation section, the bridge plug lower plugging and casing injection fracturing construction technology is adopted;

[0220] When the radial micro-boreholes are distributed at the upper and lower ends of the primary perforation hole, the lower radial micro-borehole drilling and fracturing construction are first carried out, and then the upper radial micro-borehole drilling and fracturing construction are carried out.

[0221] Embodiment 11

[0222] On the basis of the above embodiments, the embodiments of the present application provide an electronic device, which may be a mobile phone, a computer or a tablet computer, etc., or a potential tapping device, including a memory and a processor, wherein a computer program is stored on the memory, and when the computer program is executed by the processor, the vertical well potential tapping process determination method as described in the above embodiments is implemented. It can be understood that the electronic device may also include a multimedia component, an input / output (I / O) interface, and a communication component.

[0223] The processor is used to execute all or part of the steps in the vertical well potential tapping process determination method in the above embodiment. The memory is used to store various types of data, which may include instructions of any application or method in the electronic device, as well as data related to the application.

[0224] The processor can be an application specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field programmable gate array (FPGA), a controller, a microcontroller, a microprocessor or other electronic components, and is used to execute all or part of the steps in the vertical well potential tapping process determination method in the above embodiment.

[0225] The memory can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk or optical disk.

[0226] In the embodiments provided in the present disclosure, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the above-mentioned module, program segment or a part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0227] It should be noted that in the present disclosure, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element limited by the sentence "includes a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0228] Although the embodiments disclosed in the present disclosure are as above, the above contents are only embodiments adopted for facilitating the understanding of the present disclosure and are not intended to limit the present disclosure. Any technician in the technical field to which the present disclosure 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 disclosure, but the scope of patent protection of the present disclosure shall still be subject to the scope defined in the attached claims.

Claims

1. A method for determining a vertical well potential tapping process, characterized in that: include: According to the geological characteristics of the target area of ​​fractured oil and gas reservoirs and the production status of developed vertical wells, select the preferred target area with potential for secondary transformation and tapping potential; Based on the single-well remaining oil and gas distribution results of each developed vertical well in the preferred target area and the unconnected natural fracture distribution characteristics around each developed vertical well in the preferred target area, each developed vertical well is screened to obtain target vertical wells with secondary reconstruction potential; Based on the target vertical well, the crack morphology and ground stress analysis of the initial fracturing transformation and the remaining oil and gas distribution characteristics of the target vertical well are analyzed to determine the vertical well potential tapping process, which includes the radial micro-wellbore drilling process and the fracturing transformation construction process; The process of performing the initial fracturing reconstruction based on the target vertical well, analyzing the fracture morphology and ground stress, and analyzing the remaining oil and gas distribution characteristics of the target vertical well, and determining the vertical well potential tapping process includes: Performing an initial fracturing crack morphology and ground stress analysis on the target vertical well to obtain the initial fracturing crack morphology distribution characteristics and fracturing transformation effect; Based on the initial fracturing crack morphology and distribution characteristics and fracturing transformation effect, a radial micro-wellbore drilling process is determined, wherein the radial micro-wellbore drilling process includes the number, length, location and orientation of the drilling holes; Determine the construction process of hydraulic fracturing based on the radial micro-wellbore drilling process and hydraulic fracturing process; Wherein, the process of determining radial micro-wellbore drilling based on the initial fracturing crack morphology distribution characteristics and fracturing transformation effect includes: According to the distribution positions of the unconnected natural fractures around the target vertical well and the single well remaining oil and gas distribution results of the target vertical well, the number of radial micro-wellbore drilling holes is designed so that all radial micro-wellbores can connect the natural fractures; The drilling position of radial micro-wellbore drilling is designed according to the reservoir thickness, the initial perforation position, the initial perforation section length and the initial fracturing fracture morphology; Determine the drilling azimuth of the radial micro-wellbore according to the distribution characteristics of the unconnected natural fractures around the target vertical well, so that the drilling azimuth of the radial micro-wellbore penetrates the middle position of the natural fracture; According to the distance between the unconnected natural fractures around the target vertical well and the wellbore of the target vertical well, the length of the radial micro-wellbore drilling is designed so that each radial micro-wellbore drilling corresponds to a different natural fracture and the length of the radial micro-wellbore drilling penetrates the corresponding natural fracture.

2. The method according to claim 1, characterized in that According to the geological characteristics of the target area of ​​fractured oil and gas reservoirs and the production status of developed vertical wells, the preferred target area with the potential for secondary transformation and tapping is screened out, including: Based on the geological characteristics of the target area of ​​fractured oil and gas reservoirs and the production status of developed vertical wells, preliminary target areas with potential for secondary transformation and tapping are screened; Performing regional reservoir characteristic analysis on the preliminary target area to obtain the reservoir residual oil and gas distribution characteristics and water and oil saturation distribution characteristics of the preliminary target area; Based on the remaining oil and gas distribution characteristics of the reservoir and the water-oil saturation distribution characteristics, preferred target areas with potential for secondary transformation and tapping are screened out from the preliminary target areas.

3. The method according to claim 2, characterized in that The above-mentioned method of selecting the preferred target area with the potential for secondary transformation and tapping potential according to the geological characteristics of the target area of ​​the fractured oil and gas reservoir and the production status of the developed vertical wells also includes: The distribution characteristics of natural fractures in the preferred target area are analyzed to determine the distribution positions of natural fractures in the reservoir of the preferred target area.

4. The method according to claim 1, characterized in that: The single-well remaining oil and gas distribution results of each developed vertical well in the preferred target area are obtained by performing a primary fracturing process analysis on the developed vertical wells in the preferred target area. The primary fracturing process analysis on the developed vertical wells in the preferred target area includes: Determine the distribution orientation and morphology of the primary fracturing fractures of each developed vertical well in the preferred target area in combination with geological characteristics, reservoir physical properties, reservoir thickness, natural fracture distribution characteristics and reservoir fracturability; Determine the relationship between the initial fracturing process and the initial fracturing transformation effect of each developed vertical well in the preferred target area in combination with the initial fracturing fracture morphology and the communicating natural fracture conditions; According to the initial fracturing transformation effect, the residual oil and gas distribution around each developed vertical well in the preferred target area is analyzed to obtain the single-well residual oil and gas distribution results of each developed vertical well in the preferred target area.

5. The method according to claim 1, characterized in that When designing the drilling location for radial micro-borehole drilling: If the upper or lower end of the primary perforation section can be hydraulically jetted for radial micro-borehole drilling, the holes of the radial micro-borehole drilling are distributed at the upper and lower ends of the primary perforation section, and the difference in the number of holes at the two ends is as small as possible, and the number of radial micro-borehole drilling at the upper end of the primary perforation section is greater than the number of radial micro-borehole drilling at the lower end of the primary perforation section; If hydraulic jet radial micro-borehole drilling is not possible at the upper or lower end of the primary perforation section, all radial micro-borehole drillings are distributed at the lower or upper end of the primary perforation section. When the radial micro-borehole drillings encounter natural fractures, the radial micro-boreholes are made perpendicular or approximately perpendicular to the distribution direction of the natural fractures.

6. The method according to claim 1, characterized in that Based on the radial micro-wellbore drilling process and the fracturing transformation process, the construction process of the fracturing transformation is determined, including: When all radial micro-wellbore holes are distributed at the lower end of the primary perforation section, the fracturing construction technology of packer setting and tubing injection is adopted; When all radial micro-wellbore holes are located at the upper end of the primary perforation section, the bridge plug lower plugging and casing injection fracturing construction technology is adopted; When the radial micro-boreholes are distributed at the upper and lower ends of the primary perforation hole, the radial micro-borehole drilling and fracturing construction is first carried out at the lower end, and then the radial micro-borehole drilling and fracturing construction is carried out at the upper end.

7. A vertical well potential tapping construction method, characterized in that: include: According to the method for determining the vertical well potential tapping process according to any one of claims 1 to 6, determining the vertical well potential tapping process, the vertical well potential tapping process including the process of radial micro-wellbore drilling and the construction process of fracturing transformation; Perform radial micro-borehole drilling construction according to the radial micro-borehole drilling process; Fracturing transformation potential tapping construction is carried out according to the construction technology of fracturing transformation.

8. A device for determining a vertical well potential tapping process based on the vertical well potential tapping process determination method according to any one of claims 1 to 6, characterized in that: include: The module for determining the optimal target area is used to select the optimal target area with the potential for secondary transformation and tapping potential according to the geological characteristics of the target area of ​​the fractured oil and gas reservoir and the production status of the developed vertical wells; A target vertical well determination module is used to screen each developed vertical well based on the single well remaining oil and gas distribution results of each developed vertical well in the preferred target area and the unconnected natural fracture distribution characteristics around each developed vertical well in the preferred target area to obtain a target vertical well with secondary transformation potential; The process determination module is used to determine the vertical well potential tapping process based on the initial fracturing transformation crack morphology and ground stress analysis of the target vertical well, as well as the residual oil and gas distribution characteristics of the target vertical well. The vertical well potential tapping process includes the radial micro-wellbore drilling process and the fracturing transformation construction process.

9. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by one or more processors, the vertical well potential tapping process determination method as described in any one of claims 1 to 6 is implemented.

10. An electronic device, characterized in that: The method comprises a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the method for determining the vertical well potential tapping process according to any one of claims 1 to 6 is executed.

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