A method and device for dividing reservoirs using amplitude differences of natural potential curves

Abstract

The present application discloses a method and device for dividing reservoirs using the amplitude difference of a natural potential curve, by determining the mudstone baseline of the natural potential curve on the well; obtaining the intersection of the natural potential curve and the mudstone baseline within the same value range; extracting the top and bottom depth values ​​of the intersection and the value on the natural potential curve; using the top and bottom depth values ​​of the intersection, dividing the natural potential curve into multiple depth intervals; obtaining the amplitude difference between the natural potential curve and the mudstone baseline during the curve amplitude change process within the depth interval; dividing the top and bottom interfaces of the reservoir according to the depth position at half the amplitude difference, and obtaining the thickness between the top and bottom interfaces of the reservoir. The method and device for dividing reservoirs using the amplitude difference of a natural potential curve provided by the present application can achieve the division of the top and bottom interfaces and thickness of the reservoir according to the midpoint position of the amplitude difference of the natural potential curve when the formation thickness is small.

Description

Technical Field

[0001] The present application relates to the field of oil exploration technology, and in particular to a method and device for dividing reservoirs by utilizing the amplitude difference of natural potential curves. Background Art

[0002] In logging interpretation, reservoir division is based on logging data, combined with its geological data, to divide the reservoir that may contain oil and gas in a well, and determine the depth and thickness of its top and bottom interfaces, so as to further evaluate the reservoir. When using logging information to divide reservoirs, firstly, the ability of logging data to identify reservoirs is considered; secondly, the degree of response of logging data to different types of reservoirs is considered. The conventional logging series can be used to divide permeable reservoirs.

[0003] When the formation is thick, the amplitude difference of the logging curve is often used to determine the upper and lower interfaces of the permeable layer. For example, when the natural potential curve is used to divide the reservoir, the amplitude of the natural potential curve of the thick formation is approximately equal to the SPC, and the depth of the curve change amplitude difference of half a point corresponds to the formation interface, so the curve change amplitude method can be used to determine the formation interface. When the permeable layer is thick and the upper and lower surrounding rocks are the same, its position from the mudstone baseline to the midpoint between the amplitude difference is exactly at the formation interface. As the formation thickness decreases, the amplitude of the natural potential curve decreases, the top of the curve becomes sharper, and the bottom becomes wider. The amplitude of the natural potential curve is smaller than the SPC, and the interface position is away from the value of half a point of the amplitude difference, resulting in the inability to achieve the division of the reservoir top and bottom interface and thickness, and the reservoir division efficiency is too low. Summary of the invention

[0004] To this end, the present application provides a method and device for dividing reservoirs using the amplitude difference of natural potential curves, so as to solve the problem in the prior art that it is impossible to divide reservoirs using natural potential curves when the thickness of the local layer becomes smaller.

[0005] In order to achieve the above objectives, this application provides the following technical solutions:

[0006] In a first aspect, a method for dividing a reservoir using a spontaneous potential curve amplitude difference comprises:

[0007] Determine the mudstone baseline of the natural potential curve on the well, and read the specific value of the mudstone baseline;

[0008] Obtaining the intersection point of the spontaneous potential curve and the mudstone baseline within the same range;

[0009] Extracting the top and bottom depth values ​​of the intersection and the value on the natural potential curve;

[0010] Using the top and bottom depth values ​​of the intersection, the natural potential curve is divided into a plurality of depth intervals;

[0011] Within the depth interval, obtaining an amplitude difference between the natural potential curve and the mudstone baseline;

[0012] The top and bottom interfaces and thickness of the reservoir are extracted according to the depth position of the point where the amplitude difference is half.

[0013] Furthermore, it also includes:

[0014] Display the extracted reservoir top and bottom interfaces and the thickness between the reservoir top and bottom interfaces, and manually adjust the reservoir top and bottom interfaces;

[0015] The top and bottom interface depths are automatically obtained based on the adjusted reservoir top and bottom interfaces.

[0016] Furthermore, the mudstone baseline is taken as the mudstone baseline when the amplitude of the natural potential curve of a large section of mudstone in the well is relatively stable.

[0017] Furthermore, the amplitude difference between the spontaneous potential curve and the mudstone baseline is obtained, specifically:

[0018] The amplitude difference is obtained by obtaining the spontaneous potential curve value of the first crest point where the amplitude change continuously increases and the spontaneous potential curve value of the last crest point where the amplitude difference continuously decreases during the amplitude change process between the spontaneous potential curve and the mudstone baseline.

[0019] In a second aspect, a device for dividing a reservoir using a natural potential curve amplitude difference comprises:

[0020] A mudstone baseline acquisition module is used to determine the mudstone baseline of the natural potential curve on the well and read the specific value of the mudstone baseline;

[0021] An intersection acquisition module, used for acquiring the intersection of the spontaneous potential curve and the mudstone baseline within the same value range;

[0022] A top and bottom surface depth extraction module, used to extract the top and bottom surface depth values ​​of the intersection and the value on the natural potential curve;

[0023] A depth interval division module, used to divide the natural potential curve into a plurality of depth interval segments by using the top and bottom depth values ​​of the intersection;

[0024] An amplitude difference acquisition module, used for acquiring the amplitude difference formed between the natural potential curve and the mudstone baseline within the depth interval;

[0025] The reservoir interface extraction module is used to extract the top and bottom interfaces and thickness of the reservoir according to the depth position of the half amplitude difference point.

[0026] Furthermore, it also includes:

[0027] A display module is used to display the extracted reservoir top and bottom interfaces and the thickness between the reservoir top and bottom interfaces, and to manually adjust the reservoir top and bottom interfaces;

[0028] The interactive editing module is used to automatically obtain the top and bottom interface depths according to the adjusted reservoir top and bottom interfaces.

[0029] Furthermore, the mudstone baseline is taken as the mudstone baseline when the amplitude of the natural potential curve of a large section of mudstone in the well is relatively stable.

[0030] Furthermore, the amplitude difference between the spontaneous potential curve and the mudstone baseline is obtained, specifically:

[0031] The amplitude difference is obtained by obtaining the spontaneous potential curve value of the first crest point where the amplitude change continuously increases and the spontaneous potential curve value of the last crest point where the amplitude difference continuously decreases during the amplitude change process between the spontaneous potential curve and the mudstone baseline.

[0032] In a third aspect, a computer device includes a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of a method for dividing a reservoir using the amplitude difference of a natural potential curve are implemented.

[0033] In a fourth aspect, a computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of a method for dividing a reservoir using the amplitude difference of a natural potential curve.

[0034] Compared with the prior art, this application has at least the following beneficial effects:

[0035] The present application provides a method and device for dividing reservoirs using the amplitude difference of the natural potential curve, including: determining the mudstone baseline of the natural potential curve on the well, and reading the specific value of the mudstone baseline; obtaining the intersection of the natural potential curve and the mudstone baseline within the same value range; extracting the top and bottom depth values ​​of the intersection and the value on the natural potential curve; using the top and bottom depth values ​​of the intersection, dividing the natural potential curve into multiple depth intervals; obtaining the amplitude difference formed between the natural potential curve and the mudstone baseline within the range of the depth interval; extracting the top and bottom interfaces and thickness of the reservoir according to the depth position of one-half of the amplitude difference point. The method and device for dividing reservoirs using the amplitude difference of the natural potential curve provided in the present application can achieve the division of the top and bottom interfaces and thickness of the reservoir according to the position of the middle point of the amplitude difference of the natural potential curve when the formation thickness is small. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more intuitively illustrate the prior art and the present application, several exemplary drawings are given below. It should be understood that the specific shapes and structures shown in the drawings should not generally be regarded as limiting conditions for implementing the present application; for example, those skilled in the art are capable of easily making conventional adjustments or further optimizations to the addition / reduction / attribution division, specific shapes, positional relationships, connection methods, dimensional ratios, etc. of certain units (components) based on the technical concepts and exemplary drawings disclosed in the present application.

[0037] Figure 1 A flow chart of a method for dividing reservoirs using the amplitude difference of natural potential curves provided in this application;

[0038] Figure 2 A schematic diagram of a mudstone baseline of a spontaneous potential curve provided in Example 1 of the present application;

[0039] Figure 3 A schematic diagram of the intersection of the mudstone baseline and the natural potential curve provided in Example 1 of the present application;

[0040] Figure 4 A schematic diagram of extracting the depth surface of the mudstone baseline and the natural potential curve provided in Example 1 of the present application;

[0041] Figure 5 A schematic diagram of a peak point on a natural potential curve provided in Example 1 of the present application;

[0042] Figure 6 A schematic diagram of the reservoir top and bottom depth interface divided by the half-amplitude difference point provided in Example 1 of the present application;

[0043] Figure 7 A schematic diagram of reservoir segment statistics and division provided in Example 1 of the present application;

[0044] Figure 8 A schematic diagram of manual adjustment and editing of a reservoir provided in Example 1 of the present application. DETAILED DESCRIPTION

[0045] The present application is further described below in detail through specific embodiments in conjunction with the accompanying drawings.

[0046] In the description of this application: unless otherwise specified, the meaning of "plurality" is two or more. The terms "first", "second", "third", etc. in this application are intended to distinguish the objects referred to, and do not have special meanings in terms of technical connotations (for example, they should not be understood as emphasizing the importance or order, etc.). Expressions such as "including", "comprising", "having", etc. also mean "not limited to" (certain units, components, materials, steps, etc.).

[0047] The terms such as "upper", "lower", "left", "right", "middle", etc. used in this application are usually used to facilitate intuitive understanding by comparing with the accompanying drawings, and are not absolute limitations on the positional relationship in the actual product. Without departing from the technical concept disclosed in this application, changes in these relative positional relationships should also be regarded as the scope of this application.

[0048] See also Figure 1 The present application provides a method for dividing reservoirs using the amplitude difference of natural potential curves, comprising:

[0049] S1: Determine the mudstone baseline of the natural potential curve on the well and read the specific value of the mudstone baseline;

[0050] Specifically, when using the SP curve amplitude difference method to identify reservoirs, the mudstone baseline of the well's SP curve must first be confirmed. In the SP logging curve, the amplitude of a large section of mudstone's SP curve is relatively stable, so it can be used as the baseline of the curve, called the mudstone baseline, and the value of the mudstone baseline is read.

[0051] S2: Obtain the intersection of the natural potential curve and the mudstone baseline within the same range;

[0052] S3: Extract the top and bottom depth values ​​of the intersection and the value on the natural potential curve;

[0053] S4: Using the top and bottom depth values ​​of the intersection, the natural potential curve is divided into multiple depth intervals;

[0054] S5: within the depth interval, obtain the amplitude difference between the natural potential curve and the mudstone baseline;

[0055] Specifically, within the depth interval segment divided by the mudstone baseline and the spontaneous potential (SP) curve, an amplitude difference will be formed between the spontaneous potential (SP) curve and the mudstone baseline. The amplitude difference will first increase and then decrease in each depth interval segment. Due to the influence of the internal heterogeneity of the reservoir segment, the spontaneous potential (SP) curve changes nonlinearly. When the amplitude difference between the spontaneous potential (SP) curve and the mudstone baseline continues to increase, the spontaneous potential (SP) curve value of the first crest point where the amplitude change continuously increases and the spontaneous potential (SP) curve value of the last crest point where the amplitude difference continues to decrease are read to obtain the amplitude difference.

[0056] S6: Extract the top and bottom interfaces and thickness of the reservoir according to the depth position of the point where the amplitude difference is half.

[0057] The present application provides a method for dividing reservoirs using the amplitude difference of a spontaneous potential curve, further comprising:

[0058] S7: Display the extracted reservoir top and bottom interfaces and the thickness between the reservoir top and bottom interfaces, and manually adjust the reservoir top and bottom interfaces;

[0059] S8: The top and bottom interface depths are automatically obtained according to the adjusted reservoir top and bottom interfaces to realize interactive editing.

[0060] Embodiment 1

[0061] In order to more clearly illustrate the method provided in the present application for dividing reservoirs using the amplitude difference of the spontaneous potential curve, the method is introduced below in conjunction with a specific embodiment.

[0062] Step 1: Please refer to Figure 2 , obtain the mudstone baseline MN when the amplitude of the spontaneous potential (SP) curve of a large section of mudstone in Well W1 is relatively stable, and obtain the specific value of the mudstone baseline MN within the curve value range;

[0063] Step 2: Please refer to Figure 3 , obtain the intersection points P1, P2, P3, and P4 of the spontaneous potential (SP) curve of well W1 and the mudstone baseline MN within the same value range;

[0064] Step 3: Extract the values ​​SP1, SP2, SP3 and SP4 of the intersection points of P1, P2, P3 and P4 on the depth surface Z1Z1', Z2Z2', Z3Z3', Z4Z4' of the W1 well and the spontaneous potential (SP) curve;

[0065] Step 4: Please refer to Figure 4 , the natural unit (SP) curve is divided into two depth intervals through the depth planes Z1Z1', Z2Z2', Z3Z3' and Z4Z4' of the intersection of the spontaneous potential (SP) curve and the mudstone baseline MN, namely the depth interval from Z1Z1' to Z2Z2' and the depth interval from Z3Z3' to Z4Z4';

[0066] Step 5: Please refer to Figure 5 , in the depth interval from Z1Z1' to Z2Z2' and from Z3Z3' to Z4Z4', read the spontaneous potential (SP) curve values ​​SPS1, SPS2, SPS3, SPS4, SPS5 and SPS6 of the peak points S1, S2, S3, S4, S5 and S6 on the spontaneous potential (SP) curve during the change of the curve amplitude between the spontaneous potential (SP) curve and the mudstone baseline;

[0067] Step 6: In the depth intervals from Z1Z1' to Z2Z2' and from Z3Z3' to Z4Z4', the reservoir top and bottom interfaces are extracted by dividing the reservoir top and bottom interfaces at the depth position where the amplitude difference of the spontaneous potential (SP) curve is half.

[0068] See also Figure 6 Specifically, the top and bottom interfaces of the reservoir in the depth interval Z1Z1' to Z2Z2' are DD' and TT', and the top and bottom interfaces of the reservoir in the depth interval Z3Z3' to Z4Z4' are D1D1' to T1T1'. The depth position of DD' on Well W1 is found The depth value corresponding to the spontaneous potential (SP) curve value, the depth position of TT' on the W1 well is found The depth value corresponding to the spontaneous potential (SP) curve value, D1D1', the depth position on the W1 well is found The depth value corresponding to the spontaneous potential (SP) curve value, the depth position of T1T1' on the W1 well is found Depth value corresponding to the spontaneous potential (SP) curve value;

[0069] Step 7: See Figure 7 , after extracting the depths of the interfaces DD', TT', D1D1' and T1T1' on the W1 well, the positions of the divided reservoir sections are displayed in the reservoir track;

[0070] Step 8: See Figure 8 , you can drag the mouse to adjust the DD' and TT' depth positions, and the depth positions from D1D1' to T1T1' to achieve manual adjustment of the reservoir top and bottom interfaces. After adjustment, the top and bottom interface depths are automatically obtained to achieve interactive editing.

[0071] The present application provides a method for dividing reservoirs using the amplitude difference of the natural potential curve. The method of calculating half the amplitude difference of the natural potential (SP) curve on the well can calculate the top and bottom interfaces and thickness of the reservoir when the formation thickness is relatively small, and can clearly display the depth range of the reservoir section on the well. The automatic identification and manual interactive editing of the reservoir effectively improve the work efficiency of dividing the reservoir by half.

[0072] The present application also provides a device for dividing reservoirs using the amplitude difference of a natural potential curve, comprising:

[0073] The mudstone baseline acquisition module is used to determine the mudstone baseline of the natural potential curve on the well and read the specific value of the mudstone baseline;

[0074] The intersection acquisition module is used to obtain the intersection of the natural potential curve and the mudstone baseline within the same range;

[0075] The top and bottom surface depth extraction module is used to extract the top and bottom surface depth values ​​of the intersection and the value on the natural potential curve;

[0076] The depth interval division module is used to divide the natural potential curve into multiple depth interval segments using the top and bottom depth values ​​of the intersection;

[0077] An amplitude difference acquisition module is used to acquire the amplitude difference between the natural potential curve and the mudstone baseline within the depth interval;

[0078] The reservoir interface extraction module is used to extract the top and bottom interfaces and thickness of the reservoir according to the depth position of the half amplitude difference point.

[0079] The device provided in the present application for dividing reservoirs using the amplitude difference of the spontaneous potential curve also includes:

[0080] A display module is used to display the extracted reservoir top and bottom interfaces and the thickness between the reservoir top and bottom interfaces, and to manually adjust the reservoir top and bottom interfaces;

[0081] The interactive editing module is used to automatically obtain the top and bottom interface depths according to the adjusted reservoir top and bottom interfaces.

[0082] The specific definition of a device for dividing reservoirs using the amplitude difference of a natural potential curve can be found in the above definition of a method for dividing reservoirs using the amplitude difference of a natural potential curve, which will not be repeated here.

[0083] The present application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the method for dividing reservoirs using the amplitude difference of a natural potential curve are implemented.

[0084] The present application also provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the method for dividing reservoirs using the amplitude difference of a natural potential curve are implemented.

[0085] The technical features of the above embodiments may be arbitrarily combined (as long as there is no contradiction in the combination of these technical features). To make the description concise, not all possible combinations of the technical features in the above embodiments are described; these embodiments that are not explicitly written should also be considered to be within the scope of this specification.

[0086] The above is a relatively specific and detailed description of the present application through general description and specific embodiments. It should be understood that, based on the technical concept of the present application, several conventional adjustments or further innovations can be made to these specific embodiments; however, as long as they do not deviate from the technical concept of the present application, the technical solutions obtained by these conventional adjustments or further innovations also fall within the scope of protection of the claims of the present application.

Claims

1. A method for dividing reservoirs using the amplitude difference of natural potential curves, characterized in that: include: Determine the mudstone baseline of the natural potential curve on the well, and read the specific value of the mudstone baseline; the mudstone baseline is the mudstone baseline when the amplitude of the natural potential curve of a large section of mudstone on the well is relatively stable; Obtaining the intersection point of the spontaneous potential curve and the mudstone baseline within the same range; Extracting the top and bottom depth values ​​of the intersection and the value on the natural potential curve; Using the top and bottom depth values ​​of the intersection, the natural potential curve is divided into a plurality of depth intervals; Within the range of the depth interval, the amplitude difference formed between the natural potential curve and the mudstone baseline is obtained; wherein, the amplitude difference formed between the natural potential curve and the mudstone baseline is obtained by: obtaining the natural potential curve value of the first crest point where the amplitude change continuously increases and the natural potential curve value of the last crest point where the amplitude difference continuously decreases during the curve amplitude change between the natural potential curve and the mudstone baseline, and obtaining the amplitude difference; The top and bottom interfaces and thickness of the reservoir are extracted according to the depth position of the point where the amplitude difference is half.

2. The method for dividing reservoirs by using the amplitude difference of spontaneous potential curve according to claim 1, characterized in that: Also includes: Display the extracted reservoir top and bottom interfaces and the thickness between the reservoir top and bottom interfaces, and manually adjust the reservoir top and bottom interfaces; The top and bottom interface depths are automatically obtained based on the adjusted reservoir top and bottom interfaces.

3. A device for dividing reservoirs using the amplitude difference of natural potential curves, characterized in that: include: The mudstone baseline acquisition module is used to determine the mudstone baseline of the natural potential curve on the well and read the specific value of the mudstone baseline; the mudstone baseline is the mudstone baseline when the amplitude of the natural potential curve of a large section of mudstone on the well is relatively stable; An intersection acquisition module, used for acquiring the intersection of the spontaneous potential curve and the mudstone baseline within the same range; A top and bottom surface depth extraction module, used to extract the top and bottom surface depth values ​​of the intersection and the value on the natural potential curve; A depth interval division module, used to divide the natural potential curve into a plurality of depth interval segments by using the top and bottom depth values ​​of the intersection; The amplitude difference acquisition module is used to obtain the amplitude difference formed between the natural potential curve and the mudstone baseline within the range of the depth interval; wherein, the amplitude difference formed between the natural potential curve and the mudstone baseline is obtained by: obtaining the natural potential curve value of the first crest point where the amplitude change continuously increases and the natural potential curve value of the last crest point where the amplitude difference continuously decreases during the curve amplitude change between the natural potential curve and the mudstone baseline, and obtaining the amplitude difference The reservoir interface extraction module is used to extract the top and bottom interfaces and thickness of the reservoir according to the depth position of the half amplitude difference point.

4. The device for dividing reservoirs by using the amplitude difference of natural potential curves according to claim 3, characterized in that: Also includes: A display module is used to display the extracted reservoir top and bottom interfaces and the thickness between the reservoir top and bottom interfaces, and to manually adjust the reservoir top and bottom interfaces; The interactive editing module is used to automatically obtain the top and bottom interface depths according to the adjusted reservoir top and bottom interfaces.

5. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 2 are implemented.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 2 are implemented.

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