Method, device and equipment for determining far-shore underwater fan and storage medium

Abstract

The embodiment of the invention provides a method and device for determining a far-shore underwater fan, equipment and a storage medium, and belongs to the field of petroleum and natural gas extraction. The method comprises the following steps: determining an object source direction of a far-shore underwater fan; determining the development position of the fan root of the far-shore underwater fan on the section of the fault according to the ancient fall and the material source direction of the fault in the first stratum; determining the migration direction of the sand body according to the thickness of the first stratum of the descending disc of the fault; determining the plane distribution characteristics of the descending disc of the fault in the sandstone thickness of the first stratum; and determining the distribution characteristics of the far-shore underwater fan according to the development position of the fan root on the section of the fault, the migration direction of the sand body and the plane distribution characteristics. According to the embodiment of the invention, the fan root sub-phase, the fan middle sub-phase and the fan end sub-phase of the far-shore underwater fan can be effectively identified.

Description

Technical Field

[0001] The present disclosure relates to the field of oil and gas exploitation, and in particular to a method, device, equipment and storage medium for determining a far-shore underwater fan. Background Art

[0002] The distal underwater fan is a type of gravity flow sedimentary system, which is characterized by large scale and flaky distribution. The distal underwater fan includes three subphases: fan root, fan middle and fan tip. The distal underwater fan is not only a good reservoir, but also an important oil and gas conductor. Therefore, the identification of the distribution characteristics of the distal underwater fan and the exploration of the distal underwater fan are crucial.

[0003] In related technologies, research is conducted on the upper and lower Pangu landforms of the fault to determine the sedimentary range of the distal underwater fan.

[0004] However, the above method has low accuracy in identifying the development position of the distal underwater fan root on the fault section, which affects the identification of the distribution characteristics of the distal underwater fan and the success rate of the exploration of the distal underwater fan. Summary of the invention

[0005] The embodiments of the present disclosure provide a method, device, equipment and storage medium for determining a far-shore underwater fan, which can effectively identify the fan root, fan middle and fan end subphases of the far-shore underwater fan. The technical solution is as follows:

[0006] On the one hand, a method for determining a distal underwater fan is provided, comprising: determining the provenance direction of the distal underwater fan; determining the development position of the fan root of the distal underwater fan on the cross section of the fault according to the paleo-drop of the fault in a first stratum and the provenance direction, the first stratum being any stratum in which the fault was formed at different times; determining the migration direction of the sand body according to the thickness of the first stratum of the downthrown plate of the fault; determining the planar distribution characteristics of the sandstone thickness of the downthrown plate of the fault in the first stratum; determining the distribution characteristics of the distal underwater fan according to the development position of the fan root on the cross section of the fault, the migration direction of the sand body and the planar distribution characteristics.

[0007] Optionally, determining the provenance direction of the distal underwater fan includes: obtaining mineral distribution characteristics of multiple wells near the fault in the first formation; determining wells whose mineral distribution characteristics include the same target mineral type and content distribution as wells with the same provenance category; and determining the provenance direction of the distal underwater fan based on the wells with the same provenance category.

[0008] Optionally, determining the development position of the fan root of the distal underwater fan on the section of the fault according to the paleo-throw of the fault in the first stratum and the provenance direction comprises: selecting multiple seismic sections perpendicular to the extension direction of the fault on the oilfield structural plan view, obtaining the thickness of the first stratum at a first point in the upper wall of the fault and the thickness of the first stratum at a second point in the lower wall of the fault in each seismic section, the first point being a sampling point in the first stratum near the section of the upper wall of the fault in the seismic section, and the second point being a sampling point in the first stratum near the section of the lower wall of the fault in the seismic section; determining the paleo-throw of the fault in the multiple seismic sections according to the difference between the thickness of the first stratum of the upper wall of the fault at the first point and the thickness of the first stratum of the lower wall of the fault at the second point in the multiple seismic sections.

[0009] Optionally, the method further includes: determining the location of an ancient groove according to the ancient drop; and determining the location of the ancient groove overlapping with the provenance direction as the development position of the fan root of the distal underwater fan on the cross section of the fault.

[0010] Optionally, determining the migration direction of the sand body according to the thickness of the first stratum of the descending plate of the fault includes: taking the direction from the smaller thickness of the first stratum of the descending plate to the larger thickness of the first stratum of the descending plate as the migration direction of the sand body.

[0011] On the other hand, a device for determining a distal underwater fan is provided, comprising: a first determination module for determining the provenance direction of the distal underwater fan; a second determination module for determining the development position of the fan root of the distal underwater fan on the cross-section of the fault according to the paleo-drop of the fault in the first stratum and the provenance direction, the first stratum being any stratum in which the fault was formed at different periods; a third determination module for determining the migration direction of the sand body according to the thickness of the first stratum of the downthrown plate of the fault; a fourth determination module for determining the planar distribution characteristics of the sandstone thickness of the downthrown plate of the fault in the first stratum; and a fifth determination module for determining the distribution characteristics of the distal underwater fan according to the development position of the fan root on the cross-section of the fault, the migration direction of the sand body and the planar distribution characteristics.

[0012] Optionally, the second determination module is used to select multiple seismic sections perpendicular to the extension direction of the fault on the oilfield structural plan view, and obtain the thickness of the first stratum at a first point in the upper wall of the fault and the thickness of the first stratum at a second point in the lower wall of the fault in each of the seismic sections, the first point being a sampling point in the first stratum near the section of the upper wall of the fault in the seismic section, and the second point being a sampling point in the first stratum near the section of the lower wall of the fault in the seismic section; determine the paleo-throw of the fault at the multiple seismic sections according to the difference between the thickness of the first stratum at the first point in the upper wall of the fault and the thickness of the first stratum at the second point in the lower wall of the fault in the multiple seismic sections; determine the position of the paleo-groove according to the paleo-throw; determine the position of the paleo-groove overlapping with the provenance direction as the development position of the fan root of the distal underwater fan on the section of the fault.

[0013] On the other hand, a device for determining a far-shore underwater fan is provided, comprising: a processor; a memory for storing processor-executable instructions; wherein the processor is configured to execute the aforementioned method for determining a far-shore underwater fan.

[0014] On the other hand, a computer-readable storage medium is provided, wherein a computer program is stored in the computer-readable storage medium, and the computer program is executed by a processor to implement the aforementioned method for determining a distal underwater fan.

[0015] On the other hand, a computer program product is provided, comprising a computer program / instruction, which, when executed by a processor, implements the aforementioned method for determining a distal underwater fan.

[0016] The technical solution provided by the embodiments of the present disclosure has the following beneficial effects:

[0017] In the disclosed embodiments, the development position of the fan root of the distal underwater fan on the cross section of the fault is determined based on the paleo-drop and provenance direction of the fault, and the distribution characteristics of the distal underwater fan are determined based on the development position of the fan root on the cross section of the fault, the migration direction of the sand body and the planar distribution characteristics of the sandstone thickness of the downthrown plate of the fault in the first formation. The fan root, fan middle and fan end subphases of the distal underwater fan can be more accurately identified, the distribution direction and range of the distal underwater fan can be determined, and the success rate of exploration of the distal underwater fan can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 is a flow chart of a method for determining a far-shore underwater fan provided by an embodiment of the present disclosure;

[0020] Figure 2 is a flow chart of another method for determining a far-shore underwater fan provided by an embodiment of the present disclosure;

[0021] Figure 3 is a schematic diagram of heavy mineral content provided by an embodiment of the present disclosure;

[0022] Figure 4 It is a schematic diagram of a source direction and a selected seismic profile provided by an embodiment of the present disclosure;

[0023] Figure 5 is a schematic diagram of a seismic profile provided by an embodiment of the present disclosure;

[0024] Figure 6 It is a paleo-drop line diagram of a fault provided by an embodiment of the present disclosure;

[0025] Figure 7 is a plan view of the thickness of a first stratum of a downthrown plate of a fault provided by an embodiment of the present disclosure;

[0026] Figure 8 is a plan view of the thickness of sandstone of a first stratum of a downthrown plate of a fault provided by an embodiment of the present disclosure;

[0027] Fig. 9 is a block diagram of a device for determining a far-shore underwater fan provided by an embodiment of the present disclosure;

[0028] Fig.10 It is a block diagram of a device for determining a far-shore underwater fan provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0030] Unless otherwise defined, the technical terms or scientific terms used herein shall have the usual meanings understood by persons with ordinary skills in the field to which the present disclosure belongs. The words "first", "second", "third" and similar words used in the patent application specification and claims of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "one" do not indicate a quantity limitation, but indicate the existence of at least one. Words such as "include" or "comprise" and similar words mean that the elements or objects appearing before "include" or "comprise" include the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. Words such as "connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right", "top", "bottom" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the previously and subsequently associated objects are in an "or" relationship.

[0031] Figure 1 FIG. 1 is a flow chart of a method for determining a far-shore underwater fan provided by an embodiment of the present disclosure. Figure 1 As shown, the method includes:

[0032] Step S101: Determine the source direction of the offshore underwater fan.

[0033] Step S102: Determine the development position of the fan root of the distal underwater fan on the cross section of the fault according to the paleo-fall and provenance direction of the fault in the first stratum.

[0034] The first stratum is any stratum in which the fault is formed at different times.

[0035] Step S103: Determine the migration direction of the sand body according to the thickness of the first stratum of the downthrown plate of the fault.

[0036] Step S104: Determine the planar distribution characteristics of the sandstone thickness of the downthrown plate of the fault in the first stratum.

[0037] Step S105: Determine the distribution characteristics of the offshore underwater fan according to the development position of the fan root on the cross section of the fault, the migration direction of the sand body and the planar distribution characteristics.

[0038] In the disclosed embodiments, the development position of the fan root of the distal underwater fan on the cross section of the fault is determined based on the paleo-drop and provenance direction of the fault, and the distribution characteristics of the distal underwater fan are determined based on the development position of the fan root on the cross section of the fault, the migration direction of the sand body and the planar distribution characteristics of the sandstone thickness of the downthrown plate of the fault in the first formation. The fan root, fan middle and fan end subphases of the distal underwater fan can be more accurately identified, the distribution direction and range of the distal underwater fan can be determined, and the success rate of exploration of the distal underwater fan can be improved.

[0039] Figure 2 FIG. 1 is a flow chart of another method for determining a far-shore underwater fan provided by an embodiment of the present disclosure. Figure 2 As shown, the method includes:

[0040] Step S201: Obtain mineral distribution characteristics in the first formation from multiple wells near the fault.

[0041] Among them, the fault is a sedimentation-controlling fault, which is a long-term active fault with a large vertical fault distance and a large horizontal extension distance. A far-shore underwater fan may be formed in the sedimentation-controlling fault.

[0042] There are multiple strata near the fault, and different strata are formed at different times. The first stratum may be any one of the strata near the fault.

[0043] For example, the strata near the fault can be divided as follows:

[0044] There are many wells near the fault, which are divided into standard wells and non-standard wells. Standard wells are wells that have been divided into different strata by geological experts according to the stratum division standards, and non-standard wells are wells that are waiting for stratum division. Each well has corresponding logging curves and lithology data. The logging curves and lithology data of non-standard wells are compared with those of standard wells. Using their similarity or correlation, the non-standard wells are divided into strata corresponding to the strata of the standard wells.

[0045] After completing the stratigraphic division of multiple wells near the fault, a certain stratum formed in the same period is selected as the first stratum, and then the mineral distribution characteristics of multiple wells in the first stratum are obtained.

[0046] For example, the standard well can be pre-divided into the upper sand layer, the middle sand layer and the lower sand layer. The upper sand layer has a top depth of 2000m and a bottom depth of 2025m, the middle sand layer has a top depth of 2025m and a bottom depth of 2050m, and the lower sand layer has a top depth of 2050m and a bottom depth of 2080m. By using the similarity or correlation between the well logging curve and lithology data of the non-standard well and the well logging curve and lithology data of the standard well, the non-standard well can also be divided into the lower sand layer, the middle sand layer and the upper sand layer. For example, the lower sand layer can be selected as the first layer, and of course other layers can also be selected as the first layer, and the present disclosure does not limit this.

[0047] Mineral distribution characteristics are used to indicate the type and content distribution of target minerals.

[0048] The target minerals can be heavy minerals or light minerals. Heavy minerals refer to terrigenous detrital minerals with a specific gravity greater than 2.9, and light minerals refer to terrigenous detrital minerals with a specific gravity less than 2.9. Types of heavy minerals include zircon, tourmaline, rutile, garnet, magnetite, etc., and types of light minerals include quartz, feldspar, rock fragments, etc.

[0049] The content distribution of target minerals refers to the ranking of the contents of various target minerals. For example, if the target minerals are heavy minerals, and the contents of heavy minerals are zircon, garnet, and magnetite from high to low, this is considered to be one content distribution. If the contents of heavy minerals are garnet, zircon, and magnetite from high to low, this is considered to be another content distribution.

[0050] Each well has a plurality of sampling points arranged at intervals along the depth direction in the first formation. In step S201, when the types of target minerals obtained from the plurality of sampling points are the same and the content distribution of the target minerals is the same, the data obtained from one of the sampling points can be selected as the mineral distribution characteristics of the well in the first formation.

[0051] When the types of target minerals obtained from multiple sampling points are different or the content distribution of target minerals is different, it indicates that the well is controlled by multiple sources, and the data obtained from multiple representative sampling points can be selected as the mineral distribution characteristics of the well. Here, the representative sampling points can be determined in the following way: first classify multiple sampling points according to the type of target minerals and the content distribution of target minerals, and the same type of sampling points correspond to the same type of target minerals and the same content distribution of target minerals; select a sampling point from each type of sampling points as a representative sampling point, or select a sampling point from each type of sampling points that contains a number greater than the set value as a representative sampling point. The set value can be 1 or 2, etc., and can be set according to actual conditions.

[0052] Figure 3Schematic diagram of heavy mineral content provided by the embodiment of the present disclosure. Figure 3 As shown, a certain well has four sampling points arranged at intervals along the well depth direction in the first stratum, namely the first sampling point, the second sampling point, the third sampling point and the fourth sampling point, and the types of heavy minerals at the four sampling points include zircon, tourmaline, rutile, garnet and magnetite. The content distribution of heavy minerals in the first sampling point and the second sampling point is zircon, tourmaline, rutile, garnet and magnetite from high to low, and the content distribution of heavy minerals in the third sampling point and the fourth sampling point is garnet, zircon, tourmaline, rutile and magnetite from high to low. Therefore, the data obtained from one of the first sampling point or the second sampling point can be selected as a target mineral type and content distribution of the well in the first stratum, and the data obtained from one of the third sampling point or the fourth sampling point can be selected as another target mineral type and content distribution of the well in the first stratum. For example, the data obtained from the first sampling point and the third sampling point can be selected as the mineral distribution characteristics of the well, that is, the mineral distribution characteristics include two target mineral types and content distribution of target minerals.

[0053] Step S202: wells whose mineral distribution characteristics include the same target mineral type and content distribution are determined as wells with the same provenance category.

[0054] When multiple wells have the same target mineral type and the same content distribution of the target mineral in the first formation, these wells can be identified as wells with the same provenance category.

[0055] If the mineral distribution characteristics of the same well include multiple target mineral types or the content distribution of multiple target minerals, it indicates that the well has multiple provenance categories. If the provenance category of the well also exists in other wells, these wells can be identified as wells with the same provenance category.

[0056] The following is an illustrative explanation using the types and content distribution of heavy minerals in the first formation from multiple wells as an example.

[0057] When the types of heavy minerals in the first well and the second well both include zircon, tourmaline, rutile, garnet and magnetite, and the content distribution of the heavy minerals is zircon, rutile, tourmaline, garnet and magnetite from high to low, the first well and the second well can be determined to have the same provenance category.

[0058] When the types of heavy minerals in the third well and the fourth well include zircon, tourmaline, rutile, garnet and magnetite, two different target mineral content distributions are obtained at different sampling points in the third well. The first is that the content distribution of heavy minerals is zircon, rutile, tourmaline, garnet and magnetite from high to low, and the second is that the content distribution of heavy minerals is garnet, zircon, tourmaline, rutile and magnetite from high to low. The content distribution of heavy minerals in the fourth well is garnet, zircon, tourmaline, rutile and magnetite from high to low. At this time, the first well, the second well and the third well can be determined as wells with the same provenance category, and the third well and the fourth well can also be determined as wells with the same provenance category.

[0059] Step S203: Determine the provenance direction of the offshore underwater fan based on wells with the same provenance category.

[0060] In step S203, adjacent wells with the same provenance category can be divided together by envelope lines on the oil field structural plan map. The oil field structural plan map is used to describe the underground structural characteristics of the oil field. Within the envelope line range on the plane, the provenance direction of the offshore underwater fan points from the rising plate of the fault to the descending plate of the fault.

[0061] Figure 4 It is a schematic diagram of a source direction and a selected seismic profile provided in an embodiment of the present disclosure. Figure 4 The first envelope 10, the second envelope 11, the third envelope 12 and the fourth envelope 13 are included in the envelope. The circles in the envelope represent wells. The types of heavy minerals in the wells within the four envelopes are zircon, garnet and magnetite. Among them, in the wells within the first envelope 10 and the third envelope 12, the content of heavy minerals is distributed from high to low in the order of garnet, zircon and magnetite; in the wells within the second envelope 11 and the fourth envelope 13, the content of heavy minerals is distributed from high to low in the order of zircon, garnet and magnetite, that is, the wells within the first envelope 10 and the wells within the third envelope 12 have the same provenance category, and the wells within the second envelope 11 and the wells within the fourth envelope 13 have the same provenance category. Within the four envelopes, the provenance direction of the far-shore underwater fan points from the rising plate of the fault to the descending plate of the fault.

[0062] In some examples, the same well has multiple provenance categories, and the well can be divided into multiple envelopes. For example, a well has two provenance categories, and the types of heavy minerals in the well include zircon, garnet, and magnetite. The content distribution of two different target minerals is obtained from different sampling points of the well. The first is that the content distribution of heavy minerals is garnet, zircon, and magnetite from high to low, and the second is that the content distribution of heavy minerals is zircon, garnet, and magnetite from high to low. Then, according to the provenance categories of the well and its adjacent wells, the well can be divided into the first envelope 10 or the third envelope 12, and the well can also be divided into the second envelope 11 or the fourth envelope 13.

[0063] Through steps S201 to S203, the source direction of the far-shore underwater fan can be determined, thereby preliminarily identifying the distribution direction and distribution range of the far-shore underwater fan.

[0064] Step S204: Select multiple seismic sections perpendicular to the extension direction of the fault on the oilfield structural plane map, and obtain the thickness of the first stratum at the first point in the upper wall of the fault and the thickness of the first stratum at the second point in the lower wall of the fault in each seismic section.

[0065] The first point is a sampling point in the first stratum near the section in the upper wall of the fault layer in the seismic profile, and the second point is a sampling point in the first stratum near the section in the lower wall of the fault layer in the seismic profile. In the seismic profile, plumb lines are drawn along the first point and the second point, respectively. The plumb line at the first point intersects with the top and bottom interfaces of the first stratum in the upper wall, and the plumb line at the second point intersects with the top and bottom interfaces of the first stratum in the lower wall.

[0066] Figure 5 is a schematic diagram of a seismic profile provided by an embodiment of the present disclosure. Figure 5 As shown, the rock block above the cross section 20 is the upper plate 21, and the rock block below the cross section 20 is the lower plate 22. Both the upper plate 21 and the lower plate 22 include multiple strata. In terms of the direction of relative displacement, the relatively rising part of the fault is the rising plate, and the relatively falling part is the falling plate. Figure 5 Where D1 is the thickness of the first stratum at the first point of the upper plate 21 of the fault layer in the seismic profile, which can also be called the thickness of the first stratum at the first point of the descending plate of the fault layer in the seismic profile; D2 is the thickness of the first stratum at the second point of the lower plate 22 of the fault layer in the seismic profile, which can also be called the thickness of the first stratum at the second point of the ascending plate of the fault layer in the seismic profile.

[0067] In step S204, multiple seismic sections with equal spacing, parallel to each other, and perpendicular to the extension direction of the fault can be selected on the oilfield structural plane map along the extension direction of the fault. Since the extension direction of the fault is not a straight line, it is also possible to select seismic sections that are approximately perpendicular to the extension direction of the fault, such as Figure 4 As shown, you can follow Figure 4 Select the seismic section in the direction of the arrow.

[0068] like Figure 5 As shown, the top and bottom seismic two-way reflection times of the first stratum of the upper plate 21 of the fault at the first point of the section and the top and bottom seismic two-way reflection times of the first stratum of the lower plate 22 of the fault at the second point of the section are obtained in each seismic section. The top depth and bottom depth of the first stratum at the first point and the second point can be expressed by the following formula (1):

[0069] H=0.0000000141019945*T 3 +0.000119762957*T 2 +0.904809721*T (1);

[0070] In formula (1), T represents the seismic two-way reflection time, unit: m; H represents the depth, unit: m. The seismic two-way reflection time T can be obtained from seismic data.

[0071] According to formula (1), the top depth and bottom depth of the first stratum of the upper plate 21 of the fault layer in the seismic profile at the first point, and the top depth and bottom depth of the first stratum of the lower plate 22 of the fault layer at the second point are obtained. Then, the thickness D1 of the first stratum of the upper plate 21 of the fault layer in the seismic profile at the first point and the thickness D2 of the first stratum of the lower plate 22 of the fault layer in the seismic profile at the second point are the differences between the corresponding top depth and bottom depth.

[0072] For example, multiple seismic profiles parallel to each other and perpendicular to the extension direction of the fault can be selected at intervals of 20 line numbers along the extension direction of the fault. The line number represents the distance between the seismic survey lines, that is, Figure 4 The parallel arrows are spaced 20 line numbers apart. Of course, they can also be spaced at a smaller or larger distance, and the present disclosure does not impose any limitation on this.

[0073] Step S205: Determine the paleothrust of the fault in the multiple seismic sections according to the difference between the thickness of the first stratum at the first point of the upper wall of the fault and the thickness of the first stratum at the second point of the lower wall of the fault in the multiple seismic sections.

[0074] Paleothrust refers to the difference in thickness between the corresponding strata on the upper and lower sides of a fault at a certain period. Paleothrust can reflect the degree of activity of the fault at different periods.

[0075] like Figure 5 In the seismic profile shown, the difference between the thickness D1 of the first stratum in the upper wall of the fault and the thickness D2 of the first stratum in the lower wall of the fault is the paleo-throw of the fault at the seismic profile.

[0076] Step S206: Determine the location of the ancient groove according to the ancient drop.

[0077] According to the ancient drop of the fault at multiple seismic profiles and the line number positions of multiple seismic profiles, a line graph of the ancient drop of the fault is established. According to the peak position in the line graph, between the peak and the trough, the position interval where the difference between the ancient drop near the peak and the peak is less than the target difference is determined as the location of the ancient groove. The fault activity at the line number position where the peak is located and the position near it is relatively strong, that is, the position where the cross section of the normal fault has a large relative rise and fall, indicating that ancient grooves are formed at these positions. Therefore, the line number position where the peak is located on the cross section and the position near it can be determined as the location of the ancient groove. Exemplarily, the target difference can be 8m, of course, it can also be other differences, and the present disclosure does not limit this.

[0078] Figure 6 This is a line diagram of the paleo-fall of a fault provided by an embodiment of the present disclosure. Figure 6 As shown in the figure, the horizontal axis represents the line number of the selected seismic profile, and the vertical axis represents the size of the paleo-drop. Figure 6 There are multiple wave crests in the trough. Between the wave crests and the troughs, the position interval where the difference between the ancient drop near the wave crest and the wave crest is less than 8m is determined as the location of the ancient groove, such as Figure 6 The locations of eight ancient trenches can be determined.

[0079] Step S207: Determine the development position of the fan root of the distal underwater fan on the cross section of the fault according to the location of the ancient groove and the provenance direction.

[0080] For example, the location of the ancient groove that overlaps with the provenance direction is determined as the development position of the fan root of the distal submarine fan on the cross section of the fault.

[0081] Since the formation of a distal underwater fan requires sufficient water depth, sufficient terrain slope angle, abundant material supply and a certain triggering mechanism, not every paleo-groove will serve as a fan root to control the formation of distal underwater fan sedimentation. Therefore, based on the location of the paleo-groove and the material source direction of the distal underwater fan, the location of the paleo-groove that overlaps with the material source direction can be determined as the development position of the fan root of the distal underwater fan on the cross section of the fault.

[0082] Through steps S204 to S207, the development position of the fan root of the distal underwater fan on the cross section of the fault can be effectively identified, thereby further identifying the distribution range of the distal underwater fan.

[0083] Step S208: Obtain the thickness of the first stratum of the downthrown plate of the fault.

[0084] In step S208, the time domain data of the top interface and the bottom interface of the first stratum of the descending plate of the fault can be obtained by using seismic software. The time domain data includes the seismic two-way reflection time. Since the seismic data is used to interpret the seismic profile at certain intervals of channel numbers and line numbers, it is also necessary to interpolate the obtained time domain data, that is, encrypt it. Then, according to formula (1), the depth domain data of the top interface and the bottom interface of the first stratum of the descending plate of the fault are obtained. Then, the thickness of the first stratum of the descending plate of the fault is the difference between the depth of the bottom interface and the depth of the top interface.

[0085] Step S209: Determine the migration direction of the sand body according to the thickness of the first stratum of the downthrown plate of the fault.

[0086] The migration direction of the sand body is from the direction with smaller thickness of the first stratum of the descending plate to the direction with larger thickness of the first stratum of the descending plate.

[0087] The greater the thickness of the first stratum in the downthrown plate, the lower the terrain of the paleo-geomorphology; the smaller the thickness of the first stratum in the downthrown plate, the higher the terrain of the paleo-geomorphology. The direction from high terrain to low terrain indicates that the paleo-structure is a depression. A depression is a good sedimentary space, which is conducive to the migration and deposition of sand bodies. Therefore, the migration direction of the sand body can be determined according to the thickness of the first stratum in the downthrown plate of the fault.

[0088] Figure 7 is a plan view of the thickness of a first stratum of a downthrown plate of a fault provided by an embodiment of the present disclosure. Figure 7 As shown, different shades of color represent different thicknesses of the first stratum of the descending plate. Figure 7 The direction of the arrow in FIG. 1 is from the direction of smaller thickness of the first stratum in the descending plate to the direction of larger thickness of the first stratum in the descending plate, which indicates the migration direction of the sand body.

[0089] Through steps S208 to S209, the migration direction of the sand body can be effectively identified, thereby preliminarily identifying the fan middle and fan end subfacies of the distal underwater fan, and further determining the distribution direction and distribution range of the distal underwater fan.

[0090] Step S210: Obtain the sandstone thickness of the first formation of the downthrown plate of the fault at multiple wells.

[0091] In step S210, the sandstone thickness of the first stratum of the downthrown plate of the fault may be obtained according to the logging curve characteristics of the plurality of wells corresponding to the downthrown plate of the fault.

[0092] Step S211: determining the planar distribution characteristics of the sandstone thickness of the descent plate of the fault in the first stratum according to the sandstone thickness of the first stratum at the plurality of wells.

[0093] The plane distribution characteristics refer to the distribution of sandstone thickness of the first stratum of the downthrown plate of the fault at different positions on the plane.

[0094] Figure 8 is a plan view of the thickness of the sandstone of the first stratum of the downthrown plate of a fault provided by an embodiment of the present disclosure. Figure 8 As shown, different shades of color are used to represent the different sandstone thicknesses of the first stratum of the downthrown plate. The sandstone thickness of the fan center 301 is larger, and the sandstone thickness of the fan end 302 is smaller. Therefore, according to the distribution characteristics of the sandstone thickness at different positions on the plane, the fan center 301 and fan end 302 subphases of the far-shore underwater fan can be clearly identified.

[0095] Through steps S210 to S211, the fan center and fan end subphases of the far-shore underwater fan can be clearly and accurately identified, and the distribution range of the far-shore underwater fan is further determined.

[0096] Step S212: Determine the distribution characteristics of the offshore underwater fan according to the development position of the fan root on the cross section of the fault, the migration direction of the sand body and the planar distribution characteristics of the sandstone thickness of the downthrown plate of the fault.

[0097] The distribution characteristics of the offshore underwater fan include the fan root, fan middle and fan end subfacies. First determine the development position of the fan root, that is, determine the triggering position of the offshore underwater fan. According to the migration direction of the sand body and the plane distribution characteristics of the sandstone thickness of the downthrown plate of the fault, the fan middle and fan end subfacies of the offshore underwater fan can be further effectively identified. Therefore, by combining the determined fan root, fan middle and fan end subfacies on the plane, the distribution direction and range of the offshore underwater fan can be clearly and accurately determined.

[0098] Fig. 9 is a block diagram of a device for determining a far-shore underwater fan provided by an embodiment of the present disclosure. Fig. 9 As shown, the device 1000 for determining a far-shore underwater fan includes: a first determination module 1001 , a second determination module 1002 , a third determination module 1003 , a fourth determination module 1004 and a fifth determination module 1005 .

[0099] Among them, the first determination module 1001 is used to determine the provenance direction of the far-shore underwater fan. The second determination module 1002 is used to determine the development position of the fan root of the far-shore underwater fan on the cross section of the fault according to the paleo-drop and provenance direction of the fault in the first stratum, and the first stratum is any stratum in which the fault was formed at different times. The third determination module 1003 is used to determine the migration direction of the sand body according to the thickness of the first stratum of the downthrown plate of the fault. The fourth determination module 1004 is used to determine the planar distribution characteristics of the sandstone thickness of the downthrown plate of the fault in the first stratum. The fifth determination module 1005 is used to determine the distribution characteristics of the far-shore underwater fan according to the development position of the fan root on the cross section of the fault, the migration direction and planar distribution characteristics of the sand body.

[0100] Optionally, the first determination module 1001 is used to obtain the mineral distribution characteristics of multiple wells near the fault in the first formation; determine the wells whose mineral distribution characteristics include the same target mineral type and content distribution as wells with the same provenance category; and determine the provenance direction of the offshore underwater fan based on the wells with the same provenance category.

[0101] Optionally, the second determination module 1002 is used to select multiple seismic profiles perpendicular to the extension direction of the fault on the oil field structural plan view, and obtain the thickness of the first stratum at the first point in the upper plate of the fault and the thickness of the first stratum at the second point in the lower plate of the fault in each seismic profile, the first point being a sampling point in the first stratum near the section in the upper plate of the fault in the seismic profile, and the second point being a sampling point in the first stratum near the section in the lower plate of the fault in the seismic profile; the paleo-throw of the fault at multiple seismic profiles is determined based on the difference between the thickness of the first stratum at the first point in the upper plate of the fault and the thickness of the first stratum at the second point in the lower plate of the fault.

[0102] Optionally, the second determination module 1002 is used to determine the location of the ancient groove according to the ancient drop; and determine the location of the ancient groove overlapping with the provenance direction as the development position of the fan root of the distal underwater fan on the cross section of the fault.

[0103] Optionally, the third determination module 1003 is used to use the direction from the first stratum with smaller thickness of the descending plate to the direction with larger thickness of the first stratum of the descending plate as the migration direction of the sand body.

[0104] It should be noted that: the device 1000 for determining the far-shore underwater fan provided in the above embodiment only uses the division of the above-mentioned functional modules as an example when determining the far-shore underwater fan. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the device for determining the far-shore underwater fan provided in the above embodiment and the method embodiment for determining the far-shore underwater fan belong to the same concept. The specific implementation process is detailed in the method embodiment, which will not be repeated here.

[0105] Fig.10 is a block diagram of a device for determining a far-shore underwater fan provided by an embodiment of the present disclosure. Fig.10 As shown, the device 2000 for determining a far-shore underwater fan includes: a processor 2001 and a memory 2002. The device 2000 for determining a far-shore underwater fan may be a computer device or other types of devices.

[0106] The processor 2001 may include one or more processing cores, such as a 5-core processor, an 8-core processor, etc. The processor 2001 may be implemented in at least one hardware form of digital signal processing (DSP), field-programmable gate array (FPGA), and programmable logic array (PLA). The processor 2001 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a central processing unit (CPU); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 2001 may be integrated with a graphics processing unit (GPU), which is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 2001 may also include an artificial intelligence (AI) processor, which is used to process computing operations related to machine learning.

[0107] The memory 2002 may include one or more computer-readable storage media, which may be non-transitory. The memory 2002 may also include a high-speed random access memory, and a non-volatile memory, such as one or more disk storage devices, flash memory storage devices. In some embodiments, the non-transitory computer-readable storage medium in the memory 2002 is used to store at least one instruction, which is used to be executed by the processor 2001 to implement the method for determining the offshore underwater fan provided in the embodiments of the present disclosure.

[0108] Those skilled in the art will understand that Fig.10 The structure shown in does not constitute a limitation of the device 2000 for determining a distal underwater fan, and may include more or fewer components than shown in the figure, or combine certain components, or adopt a different component arrangement.

[0109] Exemplarily, a non-transitory computer-readable storage medium including instructions is also provided, such as a memory 2002 including instructions, and the instructions can be executed by a processor 2001 of a device 2000 for determining a distal underwater fan to perform the method for determining a distal underwater fan. For example, the non-transitory computer-readable storage medium can be a read-only memory, a random access memory, an optical disk, a magnetic tape, a floppy disk, an optical data storage device, and the like.

[0110] Exemplarily, a computer program product is also provided, including a computer program / instruction, which, when executed by a processor, implements the method for determining a distal underwater fan provided in an embodiment of the present disclosure.

[0111] The above description does not limit the present disclosure in any form. Although the present disclosure has been disclosed as above through the embodiments, it is not used to limit the present disclosure. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present disclosure. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present disclosure without departing from the content of the technical solution of the present disclosure still falls within the scope of the technical solution of the present disclosure.

Claims

1. A method for determining a far-shore underwater fan, characterized in that: include: Determine the provenance direction of the distal submarine fan; Determining the development position of the fan root of the distal underwater fan on the cross section of the fault according to the paleo-fall of the fault in the first stratum and the provenance direction, wherein the first stratum is any stratum in which the fault was formed at different times; Determining the migration direction of the sand body according to the thickness of the first stratum of the downthrown plate of the fault; Determining the planar distribution characteristics of the sandstone thickness of the downthrown plate of the fault in the first formation; The distribution characteristics of the offshore underwater fan are determined according to the development position of the fan root on the cross section of the fault, the migration direction of the sand body and the planar distribution characteristics.

2. The method for determining a distal underwater fan according to claim 1, characterized in that: Determining the provenance direction of the distal underwater fan includes: Obtaining mineral distribution characteristics of a plurality of wells near the fault in the first formation; Determine the wells whose mineral distribution characteristics include the same target mineral species and content distribution as wells with the same provenance category; The provenance direction of the offshore underwater fan is determined based on the wells with the same provenance category.

3. The method for determining a distal underwater fan according to claim 1, characterized in that: Determining the development position of the fan root of the distal underwater fan on the cross section of the fault according to the paleo-drop of the fault in the first stratum and the provenance direction comprises: Select multiple seismic sections perpendicular to the extension direction of the fault on the oilfield structural plane map, and obtain the thickness of the first stratum at a first point in the upper wall of the fault and the thickness of the first stratum at a second point in the lower wall of the fault in each of the seismic sections, wherein the first point is a sampling point in the first stratum near the section in the upper wall of the fault in the seismic section, and the second point is a sampling point in the first stratum near the section in the lower wall of the fault in the seismic section; The paleo-throws of the fault in the multiple seismic sections are determined based on the difference between the thickness of the first stratum of the upper plate of the fault at the first point and the thickness of the first stratum of the lower plate of the fault at the second point in the multiple seismic sections.

4. The method for determining a distal underwater fan according to claim 3, characterized in that: The method further comprises: According to the ancient drop, the location of the ancient trench is determined; The location of the ancient groove overlapping with the provenance direction is determined as the development location of the fan root of the distal underwater fan on the cross section of the fault.

5. The method for determining a distal underwater fan according to claim 1, characterized in that: Determining the migration direction of the sand body according to the thickness of the first stratum on the downthrown plate of the fault comprises: The direction from the direction of the first stratum thickness of the descending plate with small thickness to the direction of the first stratum thickness of the descending plate with large thickness is used as the migration direction of the sand body.

6. A device for determining a far-shore underwater fan, characterized in that: include: The first determination module is used to determine the source direction of the offshore underwater fan; A second determination module is used to determine the development position of the fan root of the distal underwater fan on the cross section of the fault according to the paleo-fall of the fault in the first stratum and the provenance direction, wherein the first stratum is any stratum in which the fault was formed at different times; A third determination module is used to determine the migration direction of the sand body according to the thickness of the first stratum of the downthrown plate of the fault; A fourth determination module is used to determine the planar distribution characteristics of the sandstone thickness of the downthrown plate of the fault in the first formation; The fifth determination module is used to determine the distribution characteristics of the offshore underwater fan according to the development position of the fan root on the cross section of the fault, the migration direction of the sand body and the planar distribution characteristics.

7. The device for determining a distal underwater fan according to claim 6, characterized in that: The second determination module is used to select multiple seismic sections perpendicular to the extension direction of the fault on the oilfield structural plane map, and obtain the thickness of the first stratum at a first point in the upper wall of the fault and the thickness of the first stratum at a second point in the lower wall of the fault in each of the seismic sections, wherein the first point is a sampling point in the first stratum near the section of the upper wall of the fault in the seismic section, and the second point is a sampling point in the first stratum near the section of the lower wall of the fault in the seismic section; determine the paleo-throw of the fault at the multiple seismic sections according to the difference between the thickness of the first stratum at the first point in the upper wall of the fault and the thickness of the first stratum at the second point in the lower wall of the fault in the multiple seismic sections; determine the position of the paleo-groove according to the paleo-throw; determine the position of the paleo-groove overlapping with the provenance direction as the development position of the fan root of the distal underwater fan on the section of the fault.

8. A device for determining a far-shore underwater fan, characterized in that: include: processor; a memory for storing processor-executable instructions; Wherein, the processor is configured to execute the method for determining a distal underwater fan as described in any one of claims 1 to 5.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and the computer program is executed by a processor to implement the method for determining a distal underwater fan as described in any one of claims 1 to 5.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by a processor, the method for determining a distal underwater fan as described in any one of claims 1 to 5 is implemented.

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