Method for determining distance between resistivity logging instrument and formation interface and related apparatus

Abstract

The application discloses a method for determining the distance between a resistivity logging instrument and a formation interface and related equipment, and the method comprises the following steps: determining the relative position of the resistivity logging instrument relative to the horizontal section of the horizontal well, and the layer thickness and resistivity of each real formation in the region based on the geological conditions of the horizontal well region where the resistivity logging instrument is located and the logging data of adjacent wells; determining the resistivity of the upper equivalent formation and the lower equivalent formation based on the relative position, the layer thickness and resistivity of each real formation; determining the distance between the resistivity logging instrument and the formation interface based on the resistivity of the upper equivalent formation and the lower equivalent formation and the separation coefficient library; presetting the layer thickness and the resistivity contrast of the virtual formation; constructing a plurality of virtual single-interface formation models; and constructing the separation coefficient library based on the plurality of virtual single-interface formation models and the parameters of the resistivity logging instrument. The accurate distance between the resistivity logging instrument and the formation interface is obtained.

Description

Technical Field

[0001] This invention relates to the field of petroleum exploration and development technology, and in particular to a method and related equipment for determining the distance between a resistivity logging instrument and the interface of the local formation. Background Technology

[0002] In the exploration and development of oil and gas fields, horizontal wells, compared to traditional vertical wells, can more effectively contact oil and gas reservoirs, expand the drainage area, and increase single-well production. Horizontal well technology has demonstrated significant advantages, particularly in the development of unconventional oil and gas resources such as thin-layer reservoirs, fractured reservoirs, heavy oil reservoirs, and shale oil and gas. With the continuous advancement of drilling technology, the cost of horizontal well drilling has gradually decreased. To improve oil and gas production and recovery rates, horizontal well drilling technology has been increasingly widely applied. However, the application of horizontal wells requires interpretation.

[0003] Horizontal wells generally consist of a vertical section, a build-up section, and a horizontal section. During horizontal well interpretation, it is necessary to determine the distance from the resistivity logging tool to the formation interface within the horizontal section. Currently, technicians acquire drilling data, analyze it based on their experience, and determine the distance from the resistivity logging tool to the formation interface within the horizontal section based on the analysis results. Summary of the Invention

[0004] During the interpretation of horizontal wells, technical personnel may lack sufficient experience. This inexperience can lead to biases or even errors in the analysis of drilling data, resulting in inaccurate determination of the distance from the resistivity logging tool to the formation interface in the horizontal section. Furthermore, this can cause errors in the interpretation of the entire project, impacting oil and gas production.

[0005] In view of the above problems, the present invention is proposed to provide a method and related equipment for determining the distance between a resistivity logging tool and the local formation interface to overcome or at least partially solve the above problems.

[0006] This invention provides a method for determining the distance between a resistivity logging tool and the interface of the formation, comprising:

[0007] Determine the horizontal well where the resistivity logging tool is located, and obtain the geological conditions of the area where the horizontal well is located and the logging data of the adjacent wells of the horizontal well;

[0008] The relative position of the resistivity logging instrument to the horizontal section is determined based on the geological conditions.

[0009] The thickness and resistivity of each actual stratum in the region are determined based on the well logging data; based on the relative position, the resistivity of the upper and lower equivalent strata simulated on the actual stratum in the horizontal section are determined based on the thickness and resistivity of each actual stratum.

[0010] Based on the resistivity of the upper and lower equivalent formations and the separation coefficient library, the distance between the resistivity logging tool and the interface of the formation is determined.

[0011] The process of constructing the separation coefficient library is as follows:

[0012] Based on the preset range of resistivity contrast and the preset layer thickness of the virtual formation, several virtual single-interface formation models are constructed; based on the several virtual single-interface formation models and the parameters of the resistivity logging tool, a separation coefficient library is constructed, which includes the resistivity of the formation and the distance from the resistivity logging tool to the formation interface.

[0013] In a further optional implementation, the geological conditions include geological structural features and sedimentary environment features;

[0014] Determining the relative position of the resistivity logging instrument with respect to the horizontal section based on the geological conditions includes:

[0015] Based on the geological structure and sedimentary environment characteristics of the region, the type of oil and gas reservoir in the region is determined;

[0016] If the oil and gas reservoir type is a light oil and gas reservoir, the resistivity logging instrument is located relatively high in the horizontal section;

[0017] If the oil and gas reservoir type is a heavy oil and gas reservoir, the resistivity logging instrument is located relatively low in the horizontal section.

[0018] In a further optional implementation, the logging data includes induction logging curves and resistivity curves;

[0019] Based on the well logging data, the thickness and resistivity of each stratum in the region are determined, including:

[0020] The induction logging curves and resistivity curves are analyzed using well logging curve analysis technology. Based on the analysis results of the induction logging curves and resistivity curves, the layer thickness and resistivity of each actual formation in the region are determined.

[0021] A further optional implementation involves determining the resistivity of the simulated upper and lower equivalent strata on the actual strata containing the horizontal segment, based on the relative position and according to the layer thickness and resistivity of each actual stratum, including:

[0022] Based on the relative position, take strata of a set thickness above and below the actual strata where the horizontal segment is located, and simulate them as the upper equivalent strata and the lower equivalent strata.

[0023] Based on the layer thickness and resistivity of each real stratum in the region, determine the layer thickness and resistivity of the upper equivalent stratum and the corresponding real stratum in the region, as well as the layer thickness and resistivity of the lower equivalent stratum and the corresponding real stratum in the region.

[0024] The resistivity of the upper equivalent stratum and the lower equivalent stratum is determined based on the layer thickness and resistivity of the upper equivalent stratum and the corresponding real stratum in the region, and the lower equivalent stratum and the corresponding real stratum in the region.

[0025] A further optional implementation, based on the relative position, takes the layers of the set thickness above and below the actual stratum where the horizontal segment is located as the upper equivalent stratum and the lower equivalent stratum, including:

[0026] If the resistivity logging tool is relatively high relative to the horizontal section, the upper interface of the actual stratum where the horizontal section is located is used as the baseline, and the stratum with the set layer thickness is taken up and down as the simulated upper and lower equivalent stratum on the actual stratum where the horizontal section is located.

[0027] If the resistivity logging tool is relatively lower than the horizontal section, the lower interface of the actual formation where the horizontal section is located is used as the baseline, and the formation with the set layer thickness is taken upward and downward as the simulated upper and lower equivalent formations on the actual formation where the horizontal section is located.

[0028] A further optional implementation involves determining the resistivity of the upper and lower equivalent strata based on the layer thickness and resistivity of the upper equivalent strata and the corresponding real strata in the region, as well as the lower equivalent strata and the corresponding real strata in the region, including:

[0029] Based on the layer thickness of the upper equivalent stratum and the corresponding real stratum in the region, determine the layer interface position between the upper equivalent stratum and the corresponding real stratum in the region; based on the interface position and resistivity of the upper equivalent stratum and the corresponding real stratum in the region, determine the resistivity of the upper equivalent stratum.

[0030] Based on the layer thickness of the lower equivalent stratum and the corresponding real stratum in the region, the location of the interface between the lower equivalent stratum and the corresponding real stratum in the region is determined; based on the interface location and resistivity of the lower equivalent stratum and the corresponding real stratum in the region, the resistivity of the lower equivalent stratum is determined.

[0031] A further optional implementation involves constructing several virtual single-interface stratigraphic models based on a preset range of resistivity contrast and a preset layer thickness of the virtual stratigraphy, including:

[0032] Select several resistivity contrast values ​​within the preset range of resistivity contrast.

[0033] Using the preset layer thickness of the virtual strata as the layer thickness of the virtual upper and lower strata, several virtual single-interface strata models are constructed by combining several resistivity contrasts.

[0034] In a further optional implementation, the parameters of the resistivity logging tool include at least one of the following: transmission frequency, source distance, coil radius, and number of coil turns;

[0035] Based on the parameters of the aforementioned virtual single-interface formation models and the resistivity logging tool, a separation coefficient library is constructed, including:

[0036] For each virtual single-interface formation model, based on the virtual single-interface formation model and combined with the parameters of the resistivity logging tool, several sub-array responses of the virtual single-interface formation model are calculated using the array resistivity logging response forward modeling algorithm; the several sub-array responses are processed using probe synthesis signal technology to obtain several synthetic signals of different probe modes; based on the synthetic signals of several different probe modes, a set of separation coefficients including the resistivity of the formation and the distance from the resistivity logging tool to the formation interface is obtained;

[0037] A separation coefficient library is constructed based on several separation coefficient sets corresponding to several virtual single-interface stratigraphic models.

[0038] A further optional implementation involves determining the distance between the resistivity logging tool and the formation interface based on the resistivity of the upper and lower equivalent formations and a separation coefficient library, including:

[0039] Based on the resistivity of the upper and lower equivalent formations and several sets of separation coefficients in the separation coefficient library, the distances between several resistivity logging tools and the interface of the formation are obtained.

[0040] Based on the distances between several resistivity logging tools and the local formation interface, the final distance between the resistivity logging tool and the local formation interface is determined.

[0041] This invention provides a device for determining the distance between a resistivity logging tool and the interface of the formation, comprising:

[0042] The data acquisition module is used to determine the horizontal well where the resistivity logging tool is located, and to acquire the geological conditions of the area where the horizontal well is located and the logging data of the adjacent wells of the horizontal well.

[0043] A position determination module is used to determine the relative position of the resistivity logging instrument with respect to the horizontal section based on the geological conditions.

[0044] The parameter determination module is used to determine the layer thickness and resistivity of each real stratum in the region based on the well logging data; and based on the relative position, determine the resistivity of the simulated upper and lower equivalent strata on the real stratum in the horizontal section according to the layer thickness and resistivity of each real stratum.

[0045] The distance determination module is used to determine the distance between the resistivity logging tool and the interface of the formation where the site is located, based on the resistivity of the upper and lower equivalent formations and the separation coefficient library.

[0046] The separation coefficient library construction module is used to construct several virtual single-interface formation models based on the preset range of resistivity contrast and the preset layer thickness of the virtual formation; and to construct a separation coefficient library based on the several virtual single-interface formation models and the parameters of the resistivity logging tool, wherein the separation coefficient library includes the resistivity of the formation and the distance from the resistivity logging tool to the formation interface.

[0047] This invention provides a computer storage medium storing computer-executable instructions. When these computer-executable instructions are executed by a processor, they implement the aforementioned method for determining the distance between a resistivity logging tool and the local formation interface.

[0048] This invention provides a distance determination device, characterized in that it includes: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the above-described method for determining the distance between the resistivity logging tool and the local formation interface.

[0049] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following:

[0050] This invention constructs multiple virtual single-interface formation models and establishes a separation coefficient library based on these models and parameters from a resistivity logging tool. This library contains formation resistivity and the distance information from the resistivity logging tool to the formation interface. These virtual single-interface formation models provide the basic model support for the construction of the separation coefficient library, while the resistivity and distance data in the library provide accurate basic data for subsequent calculation of the distance from the logging tool to the formation interface using formation resistivity. The thickness and resistivity of each actual formation within the region are determined using logging data from adjacent horizontal wells. The relative position of the logging tool to the horizontal section is determined based on the regional geological conditions. Based on the logging tool's position and the thickness and resistivity of each actual formation, the resistivity of the upper and lower equivalent formations is calculated. Matching the resistivity of the upper and lower equivalent formations with the data in the separation coefficient library allows for accurate acquisition of the distance from the resistivity logging tool to the formation interface. Furthermore, this significantly improves the efficiency of horizontal well interpretation.

[0051] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0052] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0053] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0054] Figure 1 This is a flowchart of the method for determining the distance between the resistivity logging instrument and the geological interface in Embodiment 1 of the present invention;

[0055] Figure 2 This is a flowchart illustrating the method for determining the distance between the resistivity logging tool and the geological interface in Embodiment 2 of the present invention.

[0056] Figure 3 This is a schematic diagram of the stratigraphic structure of the region in Embodiment 2 of the present invention;

[0057] Figure 4 This is a schematic diagram of the virtual single-interface stratigraphic structure in Embodiment 2 of the present invention;

[0058] Figure 5 This is a characterization diagram of the synthesized signal in Embodiment 2 of the present invention;

[0059] Figure 6 This is a schematic diagram of the device for determining the distance between the resistivity logging instrument and the geological interface in an embodiment of the present invention. Detailed Implementation

[0060] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0061] To address the problems existing in the prior art, embodiments of the present invention provide a method and related equipment for determining the distance between a resistivity logging tool and the interface of the local formation.

[0062] Example 1

[0063] Embodiment 1 of the present invention provides a method for determining the distance between a resistivity logging tool and the interface of the formation, the process of which is as follows: Figure 1 As shown, it includes the following steps:

[0064] Step S101: Determine the horizontal well where the resistivity logging tool is located, and obtain the geological conditions of the area where the horizontal well is located and the logging data of the adjacent wells.

[0065] In this embodiment, the horizontal well where the resistivity logging tool is located is determined, and the geological conditions of the area where the horizontal well is located and the logging data of adjacent wells are obtained. The geological conditions of the area where the horizontal well is located include geological structural features and sedimentary environment features, and the logging data includes induction logging curves and resistivity curves.

[0066] Step S102: Determine the relative position of the resistivity logging instrument to the horizontal section based on the geological conditions of the area.

[0067] In this embodiment, the relative position of the resistivity logging tool to the horizontal section is determined based on the geological conditions of the area. Specifically, the type of oil and gas reservoir in the area is determined based on the geological structure and sedimentary environment characteristics of the area; if the oil and gas reservoir type is a light oil and gas reservoir, the resistivity logging tool is positioned relatively high in the horizontal section; if the oil and gas reservoir type is a heavy oil and gas reservoir, the resistivity logging tool is positioned relatively low in the horizontal section.

[0068] Step S103: Determine the layer thickness and resistivity of each real formation in the area based on the logging data; based on the relative position of the resistivity logging tool relative to the horizontal section, determine the resistivity of the simulated upper and lower equivalent formations on the real formation where the horizontal section is located, according to the layer thickness and resistivity of each real formation.

[0069] In this embodiment, the thickness and resistivity of each real formation in the region are determined based on well logging data; based on the relative position of the resistivity logging tool with respect to the horizontal section, the resistivity of the simulated upper and lower equivalent formations on the real formation where the horizontal section is located is determined according to the thickness and resistivity of each real formation in the region.

[0070] Specifically, well logging curve analysis technology is used to analyze induction logging curves and resistivity curves. Based on the analysis results of the induction logging curves and resistivity curves, the layer thickness and resistivity of each actual formation in the region are determined. Based on the relative position of the resistivity logging tool relative to the horizontal section, formations of a set thickness are selected above and below the actual formation where the horizontal section is located, simulating them as upper and lower equivalent formations. Based on the layer thickness and resistivity of each actual formation in the region, the layer thickness and resistivity of the upper equivalent formation and the corresponding actual formation in the region, as well as the layer thickness and resistivity of the lower equivalent formation and the corresponding actual formation in the region, are determined. Based on the layer thickness and resistivity of the upper equivalent formation and the corresponding actual formation in the region, the resistivity of the upper and lower equivalent formations is determined.

[0071] The process of simulating upper and lower equivalent formations based on the relative position of the resistivity logging tool with respect to the horizontal section involves taking formations of a set thickness above and below the actual formation where the horizontal section is located: If the resistivity logging tool is relatively high relative to the horizontal section, the upper interface of the actual formation where the horizontal section is located is used as the baseline, and formations of a set thickness are taken above and below the horizontal section to simulate the upper and lower equivalent formations; if the resistivity logging tool is relatively low relative to the horizontal section, the lower interface of the actual formation where the horizontal section is located is used as the baseline, and formations of a set thickness are taken above and below the horizontal section to simulate the upper and lower equivalent formations.

[0072] The process of determining the resistivity of the upper and lower equivalent strata based on their thickness and resistivity relative to the corresponding real strata in the region is as follows: The layer thickness of the upper equivalent strata relative to the corresponding real strata in the region is used to determine the layer interface position; the resistivity of the upper equivalent strata is determined based on the interface position and resistivity; the layer thickness of the lower equivalent strata relative to the corresponding real strata in the region is used to determine the interface position; and the resistivity of the lower equivalent strata is determined based on the interface position and resistivity.

[0073] Step S104: Determine the distance between the resistivity logging tool and the interface of the formation based on the resistivity of the upper and lower equivalent formations and the separation coefficient library.

[0074] In this embodiment, the distance between the resistivity logging tool and the formation interface is determined based on the resistivity of the upper and lower equivalent formations and a separation coefficient library. Specifically, several distances between the resistivity logging tool and the formation interface are obtained based on the resistivity of the upper and lower equivalent formations and several separation coefficient sets in the separation coefficient library; based on these several distances, the final distance between the resistivity logging tool and the formation interface is determined.

[0075] In this embodiment, the process of constructing the separation coefficient library is as follows:

[0076] In this embodiment, several virtual single-interface formation models are constructed based on a preset range of resistivity contrast values ​​and a preset layer thickness for the virtual formation. A separation coefficient library is then constructed based on these single-interface formation models and the parameters of the resistivity logging tool. This library includes the resistivity of the formation and the distance from the resistivity logging tool to the formation interface. Specifically, several resistivity contrast values ​​are selected within the preset range of resistivity contrast values. Using the preset layer thickness of the virtual formation as the layer thickness of the virtual upper and lower formations, several virtual single-interface formation models are constructed in conjunction with these resistivity contrast values.

[0077] The process of building a separation coefficient library:

[0078] The parameters of the resistivity logging tool include at least one of the following: transmission frequency, source distance, coil radius, and number of coil turns. Several resistivity contrast values ​​are selected within a preset range. Using the preset layer thickness of the virtual formation as the layer thickness of the virtual upper and lower formations, several virtual single-interface formation models are constructed based on the resistivity contrast values. For each virtual single-interface formation model, based on the model and the parameters of the resistivity logging tool, several sub-array responses of the virtual single-interface formation model are calculated using the array resistivity logging response forward modeling algorithm. The sub-array responses are processed using probe synthesis signal technology to obtain several synthesized signals of different probe modes. A set of separation coefficients, including the resistivity of the formation and the distance from the resistivity logging tool to the formation interface, is obtained based on the synthesized signals of the several different probe modes. A separation coefficient library is constructed based on the several separation coefficient sets corresponding to the several virtual single-interface formation models.

[0079] In this implementation, multiple virtual single-interface formation models were constructed, and a separation coefficient library was established based on these models and the parameters of the resistivity logging tool. This library contains formation resistivity and the distance information from the resistivity logging tool to the formation interface. These virtual single-interface formation models provide the basic model support for the construction of the separation coefficient library, while the resistivity and distance data in the library provide accurate basic data for subsequent calculation of the distance from the logging tool to the formation interface using formation resistivity. The thickness and resistivity of each actual formation in the region are determined using logging data from adjacent wells in the horizontal well area. The relative position of the logging tool to the horizontal section is determined according to the regional geological conditions. Based on the position of the logging tool and the thickness and resistivity of each actual formation, the resistivity of the upper and lower equivalent formations is calculated. By matching the resistivity of the upper and lower equivalent formations with the data in the separation coefficient library, the distance from the resistivity logging tool to the formation interface can be accurately obtained. Furthermore, this significantly improves the efficiency of horizontal well interpretation.

[0080] Example 2

[0081] Embodiment 2 of the present invention provides a specific implementation process for a method of determining the distance between a resistivity logging tool and the interface of the formation, the process of which is as follows: Figure 2 As shown, it includes the following steps:

[0082] Step S201: Determine the horizontal well where the resistivity logging tool is located, and obtain the geological conditions of the area where the horizontal well is located and the logging data of the adjacent wells.

[0083] In this embodiment, the details of step S201 are the same as those of step S101.

[0084] Step S202: Determine the type of oil and gas reservoir in the region based on the geological structure and sedimentary environment characteristics of the region; if the oil and gas reservoir type is light oil and gas reservoir, the resistivity logging tool should be positioned relatively high in the horizontal section; if the oil and gas reservoir type is heavy oil and gas reservoir, the resistivity logging tool should be positioned relatively low in the horizontal section.

[0085] In this embodiment, taking area A as an example, based on the geological structure and sedimentary environment characteristics of area A, it is determined that area A is a light oil and gas reservoir, and the resistivity logging tool is positioned relatively high in the horizontal section. Taking area B as an example, based on the geological structure and sedimentary environment characteristics of area B, it is determined that area B is a heavy oil and gas reservoir, and the resistivity logging tool is positioned relatively low in the horizontal section. This example is only one example in this embodiment, and this implementation is not limited to this example.

[0086] Step S203: Analyze the induction logging curves and resistivity curves using well logging curve analysis technology, and determine the layer thickness and resistivity of each actual formation in the area based on the analysis results of the induction logging curves and resistivity curves.

[0087] In this embodiment, taking region C as an example, well logging curve analysis technology is used to analyze the induction logging curves and resistivity curves; based on the analysis results of the induction logging curves and resistivity curves, the layer thickness and resistivity of each actual formation in region A are determined. The layer thickness and resistivity of each actual formation in region C are as follows: Figure 3 As shown, region C comprises six real geological strata, arranged from top to bottom: the first real geological stratum has a thickness of 8 meters and a resistivity of 50 Ω·m; the second real geological stratum has a thickness of 2 meters and a resistivity of 200 Ω·m; the third real geological stratum has a thickness of 0.5 meters and a resistivity of 100 Ω·m; the fourth real geological stratum has a thickness of 5 meters and a resistivity of 50 Ω·m; the fifth real geological stratum has a thickness of 3 meters and a resistivity of 43 Ω·m; and the sixth real geological stratum has a thickness of 9 meters and a resistivity of 20 Ω·m. This example is merely one illustration in this embodiment, and the implementation is not limited to this example.

[0088] Step S204: Based on the relative position of the resistivity logging tool with respect to the horizontal section, take formations of a set thickness above and below the actual formation where the horizontal section is located, and simulate them as the upper equivalent formation and the lower equivalent formation; determine the thickness and resistivity of the upper equivalent formation and the corresponding actual formation in the region, as well as the thickness and resistivity of the lower equivalent formation and the corresponding actual formation in the region, according to the thickness and resistivity of each actual formation in the region.

[0089] In this embodiment, if the resistivity logging tool is relatively high relative to the horizontal section, the upper interface of the actual formation where the horizontal section is located is used as the baseline, and the formation with a set layer thickness is taken upward and downward as the simulated upper and lower equivalent formations on the actual formation where the horizontal section is located; if the resistivity logging tool is relatively low relative to the horizontal section, the lower interface of the actual formation where the horizontal section is located is used as the baseline, and the formation with a set layer thickness is taken upward and downward as the simulated upper and lower equivalent formations on the actual formation where the horizontal section is located.

[0090] In this embodiment, taking region C as an example, the fourth real formation in region C is the formation of the horizontal section where the resistivity logging tool is located. If the resistivity logging tool is relatively high relative to the horizontal section, the upper interface of the fourth real formation is used as the baseline, and formations with a set layer thickness (10 meters in this case) are taken upwards and downwards to form the simulated upper and lower equivalent formations on the formation where the horizontal section is located. If the resistivity logging tool is relatively low within the horizontal section, the lower interface of the fourth real formation is used as the baseline, and formations with a set layer thickness are taken upwards and downwards to form the simulated upper and lower equivalent formations on the formation where the horizontal section is located. Based on the resistivity and layer thickness of the first to sixth real formations in region C, the layer thickness and resistivity of the upper equivalent formation and the corresponding real formation in the region are determined. This example is only one example in this embodiment, and this implementation is not limited to this example.

[0091] Step S205: Determine the resistivity of the upper equivalent stratum and the lower equivalent stratum based on the layer thickness and resistivity of the upper equivalent stratum and the corresponding real stratum in the region, as well as the layer thickness and resistivity of the lower equivalent stratum and the corresponding real stratum in the region.

[0092] In this implementation, the layer interface between the upper equivalent stratum and the corresponding real stratum in the region is determined based on the layer thickness of the upper equivalent stratum and the corresponding real stratum in the region; the resistivity of the upper equivalent stratum is determined based on the interface location and resistivity of the upper equivalent stratum and the corresponding real stratum in the region; the interface location of the lower equivalent stratum and the corresponding real stratum in the region is determined based on the layer thickness of the lower equivalent stratum and the corresponding real stratum in the region; and the resistivity of the lower equivalent stratum is determined based on the interface location and resistivity of the lower equivalent stratum and the corresponding real stratum in the region.

[0093] In this embodiment, taking region C as an example, if the resistivity logging tool is relatively high within the horizontal section, the upper equivalent formation corresponds to the first to third real formations in region C, and the lower equivalent formation corresponds to the fourth to sixth real formations in region C. If the resistivity logging tool is relatively low within the horizontal section, the upper equivalent formation corresponds to the first to second real formations in region C, and the lower equivalent formation corresponds to the third to sixth real formations in region C. When the resistivity logging tool is relatively high within the horizontal section, the resistivity of the upper and lower equivalent formations is calculated. The counting method for the upper equivalent formation corresponding to the real formations in region C is as follows: starting from the baseline, the formation immediately adjacent to the baseline is counted as the u1 formation, and so on, with the last formation counted as the uU layer, where u represents the upper equivalent formation. The resistivity of the upper equivalent formation is... Perform calculations. G represents the resistivity of the upper equivalent formation. 10inch R is the geometric factor for longitudinal integration. u,1 Let R be the resistivity of the u1 formation. u,U-1 Let R be the resistivity of the formation u(U-1). u,U Let Z be the resistivity of the U-type formation. u,1 Z represents the location of the bedding plane of stratum 1. u,U-1 The location of the boundary between the u(U-1) stratum and the actual strata corresponding to region C is as follows: Starting from the baseline, the strata immediately adjacent to the baseline are designated as d1 stratum, and so on, with the last stratum designated as dD stratum, where d represents the lower equivalent stratum; the resistivity of the lower equivalent stratum is represented by... Perform calculations. G represents the resistivity of the lower equivalent formation. 10inch R is the geometric factor for longitudinal integration. d,1 R is the resistivity of the d1 formation. d,D-1 Let R be the resistivity of the d(D-1) formation. d,D Let Z be the resistivity of the dD formation. d,1 Z represents the location of the layer boundary of stratum d1. d,D-1 The location of the layer boundary of the d(D-1) stratum.

[0094] Step S206: Based on the resistivity of the upper and lower equivalent formations and several separation coefficient sets in the separation coefficient library, obtain the distances between several resistivity logging tools and the interface of the formation; based on the distances between several resistivity logging tools and the interface of the formation, finally determine the distance between the resistivity logging tool and the interface of the formation.

[0095] In this embodiment, based on the resistivity of the upper and lower equivalent formations and several separation coefficient sets in the separation coefficient library, the distances between several resistivity logging tools and the formation interface are obtained. Based on these distances, the final distance between the resistivity logging tool and the formation interface is determined. Specifically, the resistivity of the upper equivalent formation is matched against each separation coefficient set in the separation coefficient library to obtain the distance between the resistivity logging tool and the upper interface of the formation corresponding to each separation coefficient set. Based on this distance, the final distance between the resistivity logging tool and the upper interface of the formation is determined. Similarly, the resistivity of the lower equivalent formation is matched against each separation coefficient set in the separation coefficient library to obtain the distance between the resistivity logging tool and the lower interface of the formation corresponding to each separation coefficient set. Based on this distance, the final distance between the resistivity logging tool and the lower interface of the formation is determined.

[0096] The specific execution process for obtaining the distance between the resistivity logging tool and the lower interface of the formation corresponding to each set of separation coefficients is as follows: a weighting coefficient is assigned to the distance between the resistivity logging tool and the lower interface of the formation corresponding to each set of separation coefficients, and the final calculation result is used as the distance between the resistivity logging tool and the lower interface of the formation.

[0097] In this embodiment, the process of constructing the separation coefficient library is as follows:

[0098] Several resistivity contrast values ​​are selected within a preset range. Using the preset layer thickness of the virtual formation as the layer thickness of the virtual upper and lower formations, several virtual single-interface formation models are constructed based on these resistivity contrast values. For each virtual single-interface formation model, based on the model and the parameters of the resistivity logging tool, several sub-array responses of the virtual single-interface formation model are calculated using the array resistivity logging response forward modeling algorithm. The sub-array responses are processed using probe synthesis signal technology to obtain synthesized signals for several different probe modes. A set of separation coefficients, including the resistivity of the formation and the distance from the resistivity logging tool to the formation interface, is obtained based on the synthesized signals of the different probe modes. A separation coefficient library is constructed based on the separation coefficient sets corresponding to the several virtual single-interface formation models. The parameters of the resistivity logging tool include at least one of the following: transmission frequency, source distance, coil radius, and number of coil turns.

[0099] For example, the thickness of the virtual stratum is set to 10 meters, and the range of resistivity contrast is set to [1, 10]. Ten resistivity contrasts are selected within the range of [1, 10], and these ten resistivity contrasts are 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Based on the 10-meter thickness of the stratum, ten virtual single-interface stratum models are constructed according to the ten resistivity contrasts. The virtual single-interface stratum models are as follows: Figure 4 As shown, the horizontal line represents the interface of the virtual single-interface formation model. The thickness of the virtual upper stratum is 10 meters, and the thickness of the virtual lower stratum is 10 meters. For each of the 10 virtual single-interface formation models, several sampling points are taken at equal intervals from top to bottom. At each sampling point, combined with the transmission frequency, source distance, coil radius, and number of coil turns of the resistivity logging tool, the forward modeling algorithm of array resistivity logging response is used to calculate the 7 sub-array responses of the single-interface formation model. The 7 sub-array responses of the single-interface formation are processed using the detection synthetic signal technology to obtain 5 synthetic signals of different detection modes. The synthetic signals of the 5 different detection modes are represented by R. 10inch R 20inch R 30inch R 60inch R 90inch This indicates that the composite signal from five different detection modes is as follows: Figure 5 As shown, the horizontal axis represents resistivity, and the vertical axis represents distance. 10 inches represents R. 10inch Synthetic signal, 20in represents R 20inch Synthetic signal, 30in represents R 30inch Synthetic signal, 60in represents R 60inch Synthetic signal, 90in represents R 90inch Synthetic signal.

[0100] Using polynomial fitting tools to fit R 10inch / R 20inch R 30inch / R 20inch R 60inch / R 20inch R 90inch / R 20inch The data is processed to obtain separation coefficients of 20 inches, 30 inches, 60 inches, and 90 inches for four different detection modes at the sampled point. These separation coefficients include the formation resistivity and the distance from the resistivity logging tool to the formation interface. Based on the separation coefficients of the four different detection modes at several sampled points, a set of separation coefficients corresponding to the virtual single-interface formation model is obtained. All separation coefficient sets for the 10 virtual single-interface formations constitute a separation coefficient library. This example is a specific example in this embodiment, and this embodiment is not limited to this example.

[0101] This embodiment overcomes the problem of insufficient experience of technical personnel and obtains the accurate distance between the resistivity logging tool and the local formation interface; furthermore, it improves work efficiency and saves costs.

[0102] Based on the same inventive concept, embodiments of the present invention provide a device for determining the distance between a resistivity logging tool and the interface of the formation, the structure of which is as follows: Figure 6 As shown, it includes: a data acquisition module 601, a location determination module 602, a parameter determination module 603, a distance determination module 604, and a separation coefficient library construction module 605.

[0103] The data acquisition module 601 is used to determine the horizontal well where the resistivity logging tool is located, and to acquire the geological conditions of the area where the horizontal well is located and the logging data of the adjacent wells of the horizontal well.

[0104] The position determination module 602 is used to determine the relative position of the resistivity logging instrument with respect to the horizontal section based on the geological conditions.

[0105] The parameter determination module 603 is used to determine the layer thickness and resistivity of each real stratum in the region based on the well logging data; and based on the relative position, determine the resistivity of the simulated upper and lower equivalent strata on the real stratum in the horizontal section according to the layer thickness and resistivity of each real stratum.

[0106] The distance determination module 604 is used to determine the distance between the resistivity logging tool and the interface of the formation where it is located, based on the resistivity of the upper and lower equivalent formations and the separation coefficient library.

[0107] The separation coefficient library construction module 605 is used to construct several virtual single-interface formation models based on the preset range of resistivity contrast and the preset layer thickness of the virtual formation; and to construct a separation coefficient library based on the several virtual single-interface formation models and the parameters of the resistivity logging tool, wherein the separation coefficient library includes the resistivity of the formation and the distance from the resistivity logging tool to the formation interface.

[0108] Based on the same inventive concept, this embodiment of the invention provides a computer storage medium storing computer-executable instructions, which, when executed by a processor, implement the above-described method for determining the distance between a resistivity logging tool and the local formation interface.

[0109] Based on the same inventive concept, this invention provides a distance determination device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the above-described method for determining the distance between the resistivity logging instrument and the local formation interface.

[0110] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0111] Unless otherwise specifically stated, terms such as processing, calculation, operation, determination, display, etc., may refer to the actions and / or processes of one or more processing or computing systems or similar devices that represent the manipulation and conversion of data representing physical (e.g., electronic) quantities within the registers or memory of the processing system into other data similarly representing physical quantities within the memory, registers, or other such information storage, transmission, or display devices of the processing system. Information and signals can be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0112] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process may be rearranged without departing from the scope of this disclosure. The appended method claims provide elements of various steps in an exemplary order and are not intended to limit the scope to the specific order or hierarchy described.

[0113] In the detailed description above, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features in a single disclosed embodiment. Therefore, the appended claims are hereby explicitly incorporated into the detailed description, with each claim representing a separate preferred embodiment of the invention.

[0114] Those skilled in the art will also understand that the various illustrative logic blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments herein can be implemented as electronic hardware, computer software, or a combination thereof. To clearly illustrate the interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps described above are generally described in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art can implement the described functionality in alternative ways for each specific application; however, such implementation decisions should not be construed as departing from the scope of this disclosure.

[0115] The steps of the methods or algorithms described in conjunction with the embodiments herein can be directly embodied in hardware, software modules executed by a processor, or a combination thereof. The software modules can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium well known in the art. An exemplary storage medium is connected to the processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. The ASIC can reside in a user terminal. Alternatively, the processor and storage medium can exist as discrete components in the user terminal.

[0116] For software implementation, the techniques described in this application can be implemented using modules (e.g., procedures, functions, etc.) that perform the functions described in this application. This software code can be stored in memory units and executed by a processor. The memory units can be implemented within the processor or outside the processor; in the latter case, they are communicatively coupled to the processor via various means, as is well known in the art.

[0117] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," as interpreted when used as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."

Claims

1. A method for determining the distance between a resistivity logging tool and the interface of the formation, characterized in that, include: Determine the horizontal well where the resistivity logging tool is located, and obtain the geological conditions of the area where the horizontal well is located and the logging data of the adjacent wells of the horizontal well; The relative position of the resistivity logging instrument to the horizontal section is determined based on the geological conditions. The thickness and resistivity of each actual stratum in the region are determined based on the well logging data; based on the relative position, the resistivity of the upper and lower equivalent strata simulated on the actual stratum in the horizontal section are determined based on the thickness and resistivity of each actual stratum. Based on the resistivity of the upper and lower equivalent formations and the separation coefficient library, the distance between the resistivity logging tool and the interface of the formation is determined. The process of constructing the separation coefficient library is as follows: Based on the preset range of resistivity contrast and the preset layer thickness of the virtual formation, several virtual single-interface formation models are constructed; based on the several virtual single-interface formation models and the parameters of the resistivity logging tool, a separation coefficient library is constructed, which includes the resistivity of the formation and the distance from the resistivity logging tool to the formation interface.

2. The method as described in claim 1, characterized in that, The geological conditions include geological structural features and sedimentary environment features; Determining the relative position of the resistivity logging instrument with respect to the horizontal section based on the geological conditions includes: Based on the geological structure and sedimentary environment characteristics of the region, the type of oil and gas reservoir in the region is determined; If the oil and gas reservoir type is a light oil and gas reservoir, the resistivity logging instrument is located relatively high in the horizontal section; If the oil and gas reservoir type is a heavy oil and gas reservoir, the resistivity logging instrument is located relatively low in the horizontal section.

3. The method as described in claim 1, characterized in that, The logging data includes induction logging curves and resistivity curves; Based on the well logging data, the thickness and resistivity of each stratum in the region are determined, including: The induction logging curves and resistivity curves are analyzed using well logging curve analysis technology. Based on the analysis results of the induction logging curves and resistivity curves, the layer thickness and resistivity of each actual formation in the region are determined.

4. The method as described in claim 3, characterized in that, Based on the relative position, and according to the layer thickness and resistivity of each real stratum, the resistivity of the simulated upper and lower equivalent strata on the real stratum where the horizontal segment is located is determined, including: Based on the relative position, take strata of a set thickness above and below the actual strata where the horizontal segment is located, and simulate them as the upper equivalent strata and the lower equivalent strata. Based on the layer thickness and resistivity of each real stratum in the region, determine the layer thickness and resistivity of the upper equivalent stratum and the corresponding real stratum in the region, as well as the layer thickness and resistivity of the lower equivalent stratum and the corresponding real stratum in the region. The resistivity of the upper equivalent stratum and the lower equivalent stratum is determined based on the layer thickness and resistivity of the upper equivalent stratum and the corresponding real stratum in the region, and the lower equivalent stratum and the corresponding real stratum in the region.

5. The method as described in claim 4, characterized in that, Based on the relative position, the upper and lower equivalent strata are taken above and below the actual strata where the horizontal segment is located, respectively, and include: If the resistivity logging tool is relatively high relative to the horizontal section, the upper interface of the actual stratum where the horizontal section is located is used as the baseline, and the stratum with the set layer thickness is taken up and down as the simulated upper and lower equivalent stratum on the actual stratum where the horizontal section is located. If the resistivity logging tool is relatively lower than the horizontal section, the lower interface of the actual formation where the horizontal section is located is used as the baseline, and the formation with the set layer thickness is taken upward and downward as the simulated upper and lower equivalent formations on the actual formation where the horizontal section is located.

6. The method as described in claim 5, characterized in that, Based on the layer thickness and resistivity of the upper equivalent stratum and the corresponding real stratum in the region, and the lower equivalent stratum and the corresponding real stratum in the region, the resistivity of the upper and lower equivalent strata is determined, including: Based on the layer thickness of the upper equivalent stratum and the corresponding real stratum in the region, determine the layer interface position between the upper equivalent stratum and the corresponding real stratum in the region; based on the interface position and resistivity of the upper equivalent stratum and the corresponding real stratum in the region, determine the resistivity of the upper equivalent stratum. Based on the layer thickness of the lower equivalent stratum and the corresponding real stratum in the region, the location of the interface between the lower equivalent stratum and the corresponding real stratum in the region is determined; based on the interface location and resistivity of the lower equivalent stratum and the corresponding real stratum in the region, the resistivity of the lower equivalent stratum is determined.

7. The method as described in claim 1, characterized in that, Based on the preset range of resistivity contrast and the preset layer thickness of the virtual strata, several virtual single-interface strata models are constructed, including: Select several resistivity contrast values ​​within the preset range of resistivity contrast. Using the preset layer thickness of the virtual strata as the layer thickness of the virtual upper and lower strata, several virtual single-interface strata models are constructed by combining several resistivity contrasts.

8. The method as described in claim 7, characterized in that, The parameters of the resistivity logging tool include at least one of the following: transmission frequency, source distance, coil radius, and number of coil turns; Based on the parameters of the aforementioned virtual single-interface formation models and the resistivity logging tool, a separation coefficient library is constructed, including: For each virtual single-interface formation model, based on the virtual single-interface formation model and combined with the parameters of the resistivity logging tool, several sub-array responses of the virtual single-interface formation model are calculated using the array resistivity logging response forward modeling algorithm; the several sub-array responses are processed using probe synthesis signal technology to obtain several synthetic signals of different probe modes; based on the synthetic signals of several different probe modes, a set of separation coefficients including the resistivity of the formation and the distance from the resistivity logging tool to the formation interface is obtained; A separation coefficient library is constructed based on several separation coefficient sets corresponding to several virtual single-interface stratigraphic models.

9. The method as described in claim 8, characterized in that, Based on the resistivity of the upper and lower equivalent formations and the separation coefficient library, the distance between the resistivity logging tool and the formation interface is determined, including: Based on the resistivity of the upper and lower equivalent formations and several sets of separation coefficients in the separation coefficient library, the distances between several resistivity logging tools and the interface of the formation are obtained. Based on the distances between several resistivity logging tools and the local formation interface, the final distance between the resistivity logging tool and the local formation interface is determined.

10. A device for determining the distance between a resistivity logging tool and the interface of the formation, characterized in that, include: The data acquisition module is used to determine the horizontal well where the resistivity logging tool is located, and to acquire the geological conditions of the area where the horizontal well is located and the logging data of the adjacent wells of the horizontal well. A position determination module is used to determine the relative position of the resistivity logging instrument with respect to the horizontal section based on the geological conditions. The parameter determination module is used to determine the layer thickness and resistivity of each real stratum in the region based on the well logging data; and based on the relative position, determine the resistivity of the simulated upper and lower equivalent strata on the real stratum in the horizontal section according to the layer thickness and resistivity of each real stratum. The distance determination module is used to determine the distance between the resistivity logging tool and the interface of the formation where the site is located, based on the resistivity of the upper and lower equivalent formations and the separation coefficient library. The separation coefficient library construction module is used to construct several virtual single-interface formation models based on the preset range of resistivity contrast and the preset layer thickness of the virtual formation; and to construct a separation coefficient library based on the several virtual single-interface formation models and the parameters of the resistivity logging tool, wherein the separation coefficient library includes the resistivity of the formation and the distance from the resistivity logging tool to the formation interface.

11. A computer storage medium, characterized in that, The computer storage medium stores computer-executable instructions, which, when executed by a processor, implement the method for determining the distance between the resistivity logging instrument and the local formation interface as described in any one of claims 1-9.

12. A distance determining device, characterized in that, include: The memory, the processor, and the computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements the method for determining the distance between the resistivity logging instrument and the local formation interface as described in any one of claims 1-9.

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