A method for establishing a logging while drilling model for horizontal wells in edge-bottom water reservoirs

Abstract

The present application relates to a method for establishing a logging model for tracking while drilling of a horizontal well in an edge-bottom water reservoir, the method comprising the steps of establishing a cross plot of a natural gamma logging curve and a resistivity curve of a target layer of a horizontal well in an edge-bottom water reservoir; determining the boundary value of the natural gamma logging curve of sandstone and mudstone in the target layer; determining the boundary value of the resistivity curve of the oil layer, the oil-water layer, the water layer and mudstone in the target layer; normalizing the natural gamma logging curve; normalizing the resistivity curve; establishing a logging model for an edge-bottom water reservoir according to the normalized processing result of the natural gamma logging curve and the normalized processing result of the resistivity curve. The present application method can effectively improve the oil layer encounter rate of a horizontal well.

Description

Technical Field

[0001] The present application relates to the field of oil and gas exploitation, and in particular to a method for establishing a tracking-while-drilling logging model for a horizontal well in an edge-bottom water reservoir. Background Art

[0002] With the deepening of exploration and development and the continuous improvement of horizontal well drilling technology, the advantages of horizontal well drilling in significantly increasing the oil leakage area, increasing the single well production and improving the oil production rate have been further reflected. The use of horizontal wells to develop oil fields has received more and more attention from petroleum geologists.

[0003] However, the logging while drilling curve of the edge-bottom water reservoir "changes little and is difficult to track". During the horizontal well drilling process, petroleum geologists often get confused when relying on the logging while drilling curve to analyze reservoir changes. In particular, if the logging while drilling curve information is not analyzed and processed in time, it is very easy to drill into the water layer. If the trajectory cannot be adjusted in time, it is very easy to cause the horizontal well to continue drilling in the water layer, affecting the oil layer encounter rate of the horizontal well, and even causing water flooding in the horizontal section and drilling failure. Summary of the invention

[0004] In order to solve the above technical problems or at least partially solve the above technical problems, the present application provides a method for establishing a tracking logging while drilling model for a horizontal well in an edge-bottom water reservoir, the method comprising the steps of:

[0005] Establish the cross plot of natural gamma logging curve and resistivity curve of target layer of horizontal well in edge-bottom water reservoir;

[0006] Determining the natural gamma logging curve boundary value of the sandstone and mudstone in the target layer;

[0007] Determine the resistivity curve boundary values ​​of the oil layer, the oil-water layer, the water layer and the mudstone in the target layer;

[0008] performing normalization processing on the natural gamma logging curve;

[0009] normalizing the resistivity curve;

[0010] A logging model for an edge-bottom water reservoir is established according to the normalized processing result of the natural gamma logging curve and the normalized processing result of the resistivity curve.

[0011] Preferably, the step of establishing a cross plot of a natural gamma logging curve and a resistivity curve of a target layer of a horizontal well in an edge-bottom water reservoir comprises the following steps:

[0012] Acquire natural gamma logging curve data of the target layer of the horizontal well in the edge-bottom water reservoir;

[0013] Obtaining resistivity logging curve data of the target layer of the horizontal well in the edge-bottom water reservoir;

[0014] Deleting abnormal values ​​in the natural gamma logging curve data and the resistivity logging curve data;

[0015] A coordinate diagram is established with the natural gamma logging curve and the resistivity curve as the horizontal and vertical coordinates respectively;

[0016] The remaining gamma ray logging curve data and the resistivity logging curve data are placed in the coordinate graph.

[0017] Preferably, the step of determining the natural gamma logging curve boundary value of the sandstone and mudstone in the target layer comprises the following steps:

[0018] Obtaining a cross plot of the natural gamma ray logging curve and the resistivity curve;

[0019] Obtaining the horizontal coordinate of the natural gamma logging curve in the crossplot;

[0020] Obtaining a distribution range of a first natural gamma logging curve of sandstone in the target layer on the horizontal axis;

[0021] Obtaining a distribution range of a second natural gamma logging curve of mudstone in the target layer on the horizontal axis;

[0022] Determining the natural gamma logging curve boundary value of the first natural gamma logging curve distribution range and the second natural gamma logging curve distribution range;

[0023] The natural gamma logging curve boundary value is used as the natural gamma logging curve boundary value of the sandstone and mudstone.

[0024] Preferably, the step of determining the resistivity curve boundary values ​​of the oil layer, the oil-water layer, the water layer and the mudstone in the target layer comprises the following steps:

[0025] Obtaining a cross plot of the natural gamma ray logging curve and the resistivity curve;

[0026] Obtaining the ordinate of the resistivity curve in the intersection diagram;

[0027] Acquire a first resistivity curve distribution range of the oil layer in the target layer on the ordinate;

[0028] Obtaining a distribution range of a second resistivity curve of the oil-water layer in the target layer on the ordinate;

[0029] Obtaining a distribution range of a third resistivity curve of a water layer in the target layer on the ordinate;

[0030] Obtaining a fourth resistivity curve distribution range of mudstone in the target layer on the ordinate;

[0031] Determine a first resistivity curve boundary value of the first resistivity curve distribution range and the second resistivity curve distribution range;

[0032] Determine a second resistivity curve boundary value of the second resistivity curve distribution range and the third resistivity curve distribution range;

[0033] Determining a third resistivity curve boundary value of the third resistivity curve distribution range and the fourth resistivity curve distribution range;

[0034] Using the first resistivity curve boundary value as the resistivity curve boundary value of the oil layer and the oil-water layer;

[0035] Using the second resistivity curve boundary value as the resistivity curve boundary value of the oil-water layer and the water layer;

[0036] The third resistivity curve boundary value is used as the resistivity curve boundary value of the water layer and the mudstone.

[0037] Preferably, the normalization process of the natural gamma logging curve comprises the following steps:

[0038] Obtaining a cross plot of the natural gamma ray logging curve and the resistivity curve;

[0039] Obtaining the horizontal coordinate of the natural gamma logging curve in the crossplot;

[0040] Obtaining an upper limit value and a lower limit value of the natural gamma logging curve on the horizontal axis;

[0041] Obtaining the natural gamma logging curve boundary value of the sandstone and mudstone in the target layer;

[0042] Obtain the normalization formula of natural gamma logging curve;

[0043] Substituting the upper limit value, the lower limit value and the natural gamma logging curve boundary value into the natural gamma logging curve normalization formula;

[0044] Obtaining the output value of the natural gamma ray logging curve normalization formula;

[0045] The output value is used as the normalization result of the natural gamma logging curve.

[0046] Preferably, the expression of the normalization formula of the natural gamma logging curve is:

[0047]

[0048] in, Represents the normalized natural gamma logging curve value, GRi Indicates the boundary value of the natural gamma logging curve, GR min Indicates the lower limit of the natural gamma logging curve, GR max Indicates the upper limit of the natural gamma logging curve.

[0049] Preferably, the normalizing process of the resistivity curve comprises the steps of:

[0050] Obtaining a cross plot of the natural gamma ray logging curve and the resistivity curve;

[0051] Obtaining the ordinate of the resistivity curve in the intersection diagram;

[0052] Obtaining an upper limit value and a lower limit value of the resistivity curve on the ordinate;

[0053] Obtaining a first resistivity curve boundary value, a second resistivity curve boundary value, and a third resistivity curve boundary value between an oil layer, an oil-water layer, a water layer, and mudstone in the target layer;

[0054] Obtain the normalization formula of resistivity curve;

[0055] Substituting the upper limit value, the lower limit value, the first resistivity curve boundary value, the second resistivity curve boundary value and the third resistivity curve boundary value into the resistivity curve normalization formula;

[0056] Obtaining an output value of the resistivity curve normalization formula;

[0057] The output value is used as the normalization result of the resistivity curve.

[0058] Preferably, the resistivity curve normalization formula is expressed as:

[0059]

[0060] in, Represents the normalized resistivity curve value, Rt i Represents the boundary value of the resistivity curve, Rt min Represents the lower limit of the resistivity curve, Rt max Indicates the upper limit of the resistivity curve.

[0061] Preferably, the expression of the edge and bottom water reservoir logging model is:

[0062]

[0063] Among them, R represents the prediction result of the logging model for edge-bottom water reservoirs, represents the normalized resistivity curve value, Represents the normalized natural gamma logging curve value.

[0064] Preferably, the method further comprises the steps of:

[0065] The actual drilling trajectory is adjusted in real time according to the edge and bottom water reservoir logging model.

[0066] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0067] The embodiment of the present application provides a method for establishing a tracking while drilling logging model for a horizontal well in an edge-bottom water reservoir. The tracking while drilling logging model for a horizontal well in an edge-bottom water reservoir can be established based on the natural gamma logging curve and resistivity curve of the target layer of the horizontal well in the edge-bottom water reservoir, providing an effective technical means and on-site implementation method for real-time tracking and adjustment of horizontal wells, and can effectively improve the oil layer encounter rate of the horizontal well. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0069] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0070] Figure 1 A flow chart of a method for establishing a tracking logging while drilling model for a horizontal well in an edge-bottom water reservoir provided in an embodiment of the present application;

[0071] Figure 2 A cross plot of a natural gamma logging curve and a resistivity curve of a target layer in a horizontal well in an edge-bottom-water reservoir in a method for establishing a tracking logging while drilling model for a horizontal well in an edge-bottom-water reservoir provided in an embodiment of the present application;

[0072] Figure 3 A schematic diagram of prediction results of a logging model for an edge-bottom-water reservoir in a method for establishing a tracking logging model while drilling for a horizontal well in an edge-bottom-water reservoir provided in an embodiment of the present application;

[0073] Figure 4 A schematic diagram of the tracking effect of a horizontal well in a bottom water reservoir in a method for establishing a tracking logging while drilling model for a horizontal well in an edge bottom water reservoir provided in an embodiment of the present application;

[0074] Figure 5 A schematic diagram of the tracking effect of a horizontal well in an edge water reservoir in a method for establishing a tracking logging while drilling model for a horizontal well in an edge water reservoir provided in an embodiment of the present application. DETAILED DESCRIPTION

[0075] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0076] Figure 1 A flow chart of a method for establishing a tracking while drilling logging model for a horizontal well in an edge-bottom water reservoir provided in an embodiment of the present application.

[0077] In an embodiment of the present application, the present application provides a method for establishing a tracking logging while drilling model for a horizontal well in an edge-bottom water reservoir, the method comprising the steps of:

[0078] S1: Establish the cross plot of natural gamma logging curve and resistivity curve of target layer of horizontal well in edge-bottom water reservoir;

[0079] In the embodiment of the present application, the step S1 of establishing the cross plot of the natural gamma logging curve and the resistivity curve of the target layer of the horizontal well in the edge-bottom water reservoir includes the following steps:

[0080] Acquire natural gamma logging curve data of the target layer of the horizontal well in the edge-bottom water reservoir;

[0081] Obtaining resistivity logging curve data of the target layer of the horizontal well in the edge-bottom water reservoir;

[0082] Deleting abnormal values ​​in the natural gamma logging curve data and the resistivity logging curve data;

[0083] A coordinate diagram is established with the natural gamma logging curve and the resistivity curve as the horizontal and vertical coordinates respectively;

[0084] The remaining gamma ray logging curve data and the resistivity logging curve data are placed in the coordinate graph.

[0085] In an embodiment of the present application, when establishing a cross plot of a natural gamma logging curve and a resistivity curve of a target layer of a horizontal well in an edge-bottom water reservoir, specifically, multiple natural gamma logging curve data and multiple resistivity logging curve data of the target layer of the horizontal well in the edge-bottom water reservoir are obtained, and then outliers in the natural gamma logging curve data and the resistivity logging curve data (such as data that deviates far from most of the data or data that does not conform to common sense) are deleted as needed, and then a coordinate graph is established with the natural gamma logging curve as the horizontal coordinate and the resistivity curve as the vertical coordinate, and all the natural gamma logging curve data and the resistivity logging curve data after deleting the outliers are placed in the coordinate graph, and the following can be obtained. Figure 2 The cross-plot shown in the figure shows that the oil layer, oil-water layer, water layer and mudstone in the target layer are represented by different symbols in the cross-plot for distinction.

[0086] S2: Determine the natural gamma logging curve boundary value of the sandstone and mudstone in the target layer;

[0087] In the embodiment of the present application, determining the natural gamma logging curve boundary value of the sandstone and mudstone in the target layer in step S2 includes the following steps:

[0088] Obtaining a cross plot of the natural gamma ray logging curve and the resistivity curve;

[0089] Obtaining the horizontal coordinate of the natural gamma logging curve in the crossplot;

[0090] Obtaining a distribution range of a first natural gamma logging curve of sandstone in the target layer on the horizontal axis;

[0091] Obtaining a distribution range of a second natural gamma logging curve of mudstone in the target layer on the horizontal axis;

[0092] Determining the natural gamma logging curve boundary value of the first natural gamma logging curve distribution range and the second natural gamma logging curve distribution range;

[0093] The natural gamma logging curve boundary value is used as the natural gamma logging curve boundary value of the sandstone and mudstone.

[0094] In the present application example, when Figure 2 After obtaining the cross-plot in the figure, the boundary value of the natural gamma logging curve of the sandstone and mudstone in the target layer can be determined according to the cross-plot. Figure 2It can be seen that the first natural gamma logging curve distribution range of the target layer sandstone (including oil layer, oil-water layer and water layer) is mainly between 0-90API, while the second natural gamma logging curve distribution range of mudstone is mainly between 90-150API. The natural gamma logging curve boundary value of the first natural gamma logging curve distribution range and the second natural gamma logging curve distribution range is 90API, so it can be determined that the natural gamma logging curve boundary value of sandstone and mudstone is 90API.

[0095] S3: determining the resistivity curve boundary values ​​of the oil layer, the oil-water layer, the water layer and the mudstone in the target layer;

[0096] In the embodiment of the present application, determining the resistivity curve boundary values ​​of the oil layer, the oil-water layer, the water layer and the mudstone in the target layer in step S3 includes the following steps:

[0097] Obtaining a cross plot of the natural gamma ray logging curve and the resistivity curve;

[0098] Obtaining the ordinate of the resistivity curve in the intersection diagram;

[0099] Acquire a first resistivity curve distribution range of the oil layer in the target layer on the ordinate;

[0100] Obtaining a distribution range of a second resistivity curve of the oil-water layer in the target layer on the ordinate;

[0101] Obtaining a distribution range of a third resistivity curve of a water layer in the target layer on the ordinate;

[0102] Obtaining a fourth resistivity curve distribution range of mudstone in the target layer on the ordinate;

[0103] Determine a first resistivity curve boundary value of the first resistivity curve distribution range and the second resistivity curve distribution range;

[0104] Determine a second resistivity curve boundary value of the second resistivity curve distribution range and the third resistivity curve distribution range;

[0105] Determining a third resistivity curve boundary value of the third resistivity curve distribution range and the fourth resistivity curve distribution range;

[0106] Using the first resistivity curve boundary value as the resistivity curve boundary value of the oil layer and the oil-water layer;

[0107] Using the second resistivity curve boundary value as the resistivity curve boundary value of the oil-water layer and the water layer;

[0108] The third resistivity curve boundary value is used as the resistivity curve boundary value of the water layer and the mudstone.

[0109] In the present application example, when Figure 2 After obtaining the cross-plot in the image, the resistivity curve boundary values ​​of the oil layer, oil-water layer, water layer and mudstone in the target layer can be determined based on the cross-plot. Figure 2 It can be seen that the first resistivity curve distribution range of the oil layer in the target layer is mainly greater than 10Ω·m, the second resistivity curve distribution range of the oil-water layer in the target layer is mainly between 8-9Ω·m, the third resistivity curve distribution range of the water layer in the target layer is mainly between 4-7Ω·m, and the fourth resistivity curve distribution range of the mudstone in the target layer is mainly between 0-3Ω·m. Further, the first resistivity curve boundary value of the first resistivity curve distribution range and the second resistivity curve distribution range is 10Ω·m, the second resistivity curve boundary value of the second resistivity curve distribution range and the third resistivity curve distribution range is 7Ω·m, and the third resistivity curve boundary value of the third resistivity curve distribution range and the fourth resistivity curve distribution range is 3Ω·m. Therefore, the analysis results are: the resistivity boundary value of the oil layer and the oil-water layer is 10Ω·m, the resistivity boundary value of the oil-water layer and the water layer is 7Ω·m, and the resistivity boundary value of the water layer and the mudstone is 3Ω·m.

[0110] S4: performing normalization processing on the natural gamma logging curve;

[0111] In the embodiment of the present application, the normalization processing of the natural gamma logging curve in step S4 includes the following steps:

[0112] Obtaining a cross plot of the natural gamma ray logging curve and the resistivity curve;

[0113] Obtaining the horizontal coordinate of the natural gamma logging curve in the crossplot;

[0114] Obtaining an upper limit value and a lower limit value of the natural gamma logging curve on the horizontal axis;

[0115] Obtaining the natural gamma logging curve boundary value of the sandstone and mudstone in the target layer;

[0116] Obtain the normalization formula of natural gamma logging curve;

[0117] Substituting the upper limit value, the lower limit value and the natural gamma logging curve boundary value into the natural gamma logging curve normalization formula;

[0118] Obtaining the output value of the natural gamma ray logging curve normalization formula;

[0119] The output value is used as the normalization result of the natural gamma logging curve.

[0120] In the embodiment of the present application, when the natural gamma logging curve is normalized, the following is first obtained: Figure 2 The cross-plot shown in the figure is used to find the upper and lower limits of the natural gamma logging curve on the horizontal axis of the natural gamma logging curve in the cross-plot. Figure 2 It can be seen that the upper limit of the natural gamma logging curve is 150API and the lower limit is 0; then obtain the boundary value of the natural gamma logging curve of the sandstone and mudstone in the target layer, that is, 90API; then obtain the normalization formula of the natural gamma logging curve, and substitute the upper limit, lower limit and boundary value of the natural gamma logging curve into the normalization formula of the natural gamma logging curve for calculation.

[0121] In the embodiment of the present application, the expression of the normalization formula of the natural gamma logging curve is:

[0122]

[0123] in, Represents the normalized natural gamma logging curve value, GR i Indicates the boundary value of the natural gamma logging curve, GR min Indicates the lower limit of the natural gamma logging curve, GR max Indicates the upper limit of the natural gamma logging curve.

[0124] like Figure 3 The coefficient of sandstone and mudstone can be obtained by calculating the normalized formula of the above natural gamma logging curve. The dividing line is 0.6, and the coefficient The value greater than or equal to 0.6 is mudstone, and the coefficient Those less than 0.6 are sandstones (including oil layers, oil-water layers and water layers).

[0125] S5: normalizing the resistivity curve;

[0126] In the embodiment of the present application, the normalization process of the resistivity curve in step S5 includes the following steps:

[0127] Obtaining a cross plot of the natural gamma ray logging curve and the resistivity curve;

[0128] Obtaining the ordinate of the resistivity curve in the intersection diagram;

[0129] Obtaining an upper limit value and a lower limit value of the resistivity curve on the ordinate;

[0130] Obtaining a first resistivity curve boundary value, a second resistivity curve boundary value, and a third resistivity curve boundary value between an oil layer, an oil-water layer, a water layer, and mudstone in the target layer;

[0131] Obtain the normalization formula of resistivity curve;

[0132] Substituting the upper limit value, the lower limit value, the first resistivity curve boundary value, the second resistivity curve boundary value and the third resistivity curve boundary value into the resistivity curve normalization formula;

[0133] Obtaining an output value of the resistivity curve normalization formula;

[0134] The output value is used as the normalization result of the resistivity curve.

[0135] In the embodiment of the present application, when the resistivity curve is normalized, the following is first obtained: Figure 2 The cross-plot shown in the figure is used to find the upper and lower limits of the resistivity curve on the ordinate of the resistivity curve in the cross-plot. Figure 2 It can be seen that the upper limit of the resistivity curve is 25Ω·m and the lower limit is 0; then obtain the first resistivity curve boundary value, the second resistivity curve boundary value and the third resistivity curve boundary value between the oil layer, the oil-water layer, the water layer and the mudstone in the target layer, among which the first resistivity curve boundary value between the oil layer and the oil-water layer is 10Ω·m, the second resistivity curve boundary value between the oil-water layer and the water layer is 7Ω·m, and the third resistivity curve boundary value between the water layer and the mudstone is 3Ω·m. Then obtain the resistivity curve normalization formula, and substitute the upper limit, lower limit and each resistivity curve boundary value into the resistivity curve normalization formula for calculation.

[0136] In the embodiment of the present application, the resistivity curve normalization formula is expressed as:

[0137]

[0138] in, Represents the normalized resistivity curve value, Rt i Represents the boundary value of the resistivity curve, Rt min Represents the lower limit of the resistivity curve, Rt max Indicates the upper limit of the resistivity curve.

[0139] like Figure 3 , through the calculation of the above resistivity curve normalization formula, we can get: the coefficient of oil layer and oil-water layer The dividing line is 0.6, and the coefficient of oil-water layer and water layer The dividing line is 0.28, and the coefficient of water layer and mudstone The dividing line is 0.12, so the coefficient The coefficient between 0 and 0.12 is mudstone. The water layer is between 0.12-0.28, and the coefficient The values ​​between 0.28 and 0.6 are for oil and water in the same layer, and the coefficient The range between 0.6-1 is the oil layer.

[0140] S6: establishing an edge-bottom water reservoir logging model according to the normalized processing result of the natural gamma logging curve and the normalized processing result of the resistivity curve.

[0141] In the embodiment of the present application, according to the above normalized natural gamma logging curve boundary value and resistivity curve boundary value, it can be determined that the high-value area of ​​the natural gamma logging curve is the mudstone area, and the high-value area of ​​the resistivity curve is the oil layer. Therefore, the combination of the two can establish a bottom water reservoir logging model. The expression of the bottom water reservoir logging model is:

[0142]

[0143] Among them, R represents the prediction result of the logging model for edge-bottom water reservoirs, represents the normalized resistivity curve value, Represents the normalized natural gamma logging curve value. This model building method can solve the problem of inaccurate prediction results caused by the insensitivity of single curve data.

[0144] like Figure 3 During the implementation of horizontal wells, the drilling curve results can be timely input into the above-mentioned edge-bottom water reservoir logging model. When the R value is less than 0.42, it can be judged that mudstone is drilled, when the R value is between 0.42 and 0.58, it can be judged that a water layer is drilled, when the R value is between 0.58 and 0.9, it can be judged that oil and water are drilled in the same layer, and when the R value is higher than 0.9, it can be judged that an oil layer is drilled.

[0145] In the embodiment of the present application, the steps are also included:

[0146] The actual drilling trajectory is adjusted in real time according to the edge and bottom water reservoir logging model.

[0147] In the embodiment of the present application, during the implementation of the horizontal well, the actual drilling trajectory can be adjusted in time according to the logging model of the edge and bottom water reservoir to ensure a sufficiently high oil layer drilling rate.

[0148] like Figure 4, when drilling into a bottom water reservoir, when the horizontal well trajectory enters the oil layer from the mudstone, if the drilling reaches point a, the R value predicted by the logging model of the edge bottom water reservoir will increase sharply. At this time, the trajectory should be kept horizontal as much as possible to drill more oil layers; when the horizontal well trajectory drills through the oil layer and reaches point b, the R value drops rapidly to the range of 0.58-0.9 during the drilling of the oil and water layers, which means drilling into the oil and water layers. At this time, the well inclination needs to be increased immediately to ensure re-entry into the oil layer; when the horizontal well trajectory drills through the oil layer and reaches point b, the R value drops rapidly to the range of 0.58-0.9 during the drilling of the oil and water layers, which means drilling into the oil and water layers. At this time, the well inclination needs to be increased immediately to ensure re-entry into the oil layer; when the trajectory returns to the oil layer and reaches point c, the R value rises rapidly to more than 0.9. At this time, the well inclination needs to be further increased to ensure that the well trajectory completely enters the oil layer;

[0149] like Figure 5 When drilling into an edge-water reservoir, when the horizontal well trajectory enters the oil layer from the mudstone, if the drilling reaches point d, the R value predicted by the model will increase sharply. At this time, it is necessary to ensure that the horizontal well trajectory is in the oil layer according to the change in the formation inclination; when the horizontal well trajectory enters the water layer and reaches point e, the R value drops rapidly to the range of 0.42-0.9. At this time, it is necessary to complete the drilling in time to avoid flooding of the horizontal section.

[0150] The embodiment of the present application provides a method for establishing a tracking while drilling logging model for a horizontal well in an edge-bottom water reservoir. The tracking while drilling logging model for a horizontal well in an edge-bottom water reservoir can be established based on the natural gamma logging curve and resistivity curve of the target layer of the horizontal well in the edge-bottom water reservoir, providing an effective technical means and on-site implementation method for real-time tracking and adjustment of horizontal wells, and can effectively improve the oil layer encounter rate of the horizontal well.

[0151] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0152] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for establishing a logging while drilling model for a horizontal well in an edge-bottom water reservoir, characterized in that: The method comprises the steps of: Establish the cross plot of natural gamma logging curve and resistivity curve of target layer of horizontal well in edge-bottom water reservoir; Determining the natural gamma logging curve boundary values ​​of sandstone and mudstone in the target layer; Determine the resistivity curve boundary values ​​of the oil layer, the oil-water layer, the water layer and the mudstone in the target layer; performing normalization processing on the natural gamma logging curve; normalizing the resistivity curve; Establishing an edge-bottom water reservoir logging model according to the normalized processing result of the natural gamma logging curve and the normalized processing result of the resistivity curve; The normalization process of the natural gamma ray logging curve comprises the following steps: Obtaining a cross plot of the natural gamma ray logging curve and the resistivity curve; Obtaining the horizontal coordinate of the natural gamma logging curve in the crossplot; Obtaining an upper limit value and a lower limit value of the natural gamma logging curve on the horizontal axis; Obtaining natural gamma logging curve boundary values ​​of sandstone and mudstone in the target layer; Obtain the normalization formula of natural gamma logging curve; Substituting the upper limit value, the lower limit value and the natural gamma logging curve boundary value into the natural gamma logging curve normalization formula; Obtaining the output value of the natural gamma ray logging curve normalization formula; Using the output value as the normalization result of the natural gamma logging curve; The normalization process of the resistivity curve comprises the following steps: Obtaining a cross plot of the natural gamma ray logging curve and the resistivity curve; Obtaining the ordinate of the resistivity curve in the intersection diagram; Obtaining an upper limit value and a lower limit value of the resistivity curve on the ordinate; Obtaining a first resistivity curve boundary value, a second resistivity curve boundary value, and a third resistivity curve boundary value between an oil layer, an oil-water layer, a water layer, and mudstone in the target layer; Obtain the normalization formula of resistivity curve; Substituting the upper limit value, the lower limit value, the first resistivity curve boundary value, the second resistivity curve boundary value and the third resistivity curve boundary value into the resistivity curve normalization formula; Obtaining an output value of the resistivity curve normalization formula; Using the output value as the normalization result of the resistivity curve; The expression of the normalization formula of the natural gamma logging curve is: in, Represents the normalized natural gamma logging curve value, GR i Indicates the boundary value of the natural gamma logging curve, GR min Indicates the lower limit of the natural gamma logging curve, GR max Indicates the upper limit of the natural gamma logging curve; The resistivity curve normalization formula is expressed as: in, Represents the normalized resistivity curve value, Rt i Represents the boundary value of the resistivity curve, Rt min Represents the lower limit of the resistivity curve, Rt max Indicates the upper limit of the resistivity curve; The expression of the edge and bottom water reservoir logging model is: Among them, R represents the prediction result of the logging model for edge-bottom water reservoirs, represents the normalized resistivity curve value, Represents the normalized natural gamma logging curve value.

2. The method for establishing a tracking logging while drilling model for a horizontal well in an edge-bottom water reservoir according to claim 1, characterized in that: The method of establishing a cross plot of a natural gamma logging curve and a resistivity curve of a target layer of a horizontal well in an edge-bottom water reservoir comprises the following steps: Acquire natural gamma logging curve data of the target layer of the horizontal well in the edge-bottom water reservoir; Obtaining resistivity logging curve data of the target layer of the horizontal well in the edge-bottom water reservoir; Deleting abnormal values ​​in the natural gamma logging curve data and the resistivity logging curve data; A coordinate diagram is established with the natural gamma logging curve and the resistivity curve as the horizontal and vertical coordinates respectively; The remaining gamma ray logging curve data and the resistivity logging curve data are placed in the coordinate graph.

3. The method for establishing a tracking logging while drilling model for a horizontal well in an edge-bottom water reservoir according to claim 1, characterized in that: Determining the natural gamma logging curve boundary value of sandstone and mudstone in the target layer comprises the steps of: Obtaining a cross plot of the natural gamma ray logging curve and the resistivity curve; Obtaining the horizontal coordinate of the natural gamma logging curve in the crossplot; Obtaining a distribution range of a first natural gamma logging curve of sandstone in the target layer on the horizontal axis; Obtaining a distribution range of a second natural gamma logging curve of mudstone in the target layer on the horizontal axis; Determining the natural gamma logging curve boundary value of the first natural gamma logging curve distribution range and the second natural gamma logging curve distribution range; The natural gamma logging curve boundary value is used as the natural gamma logging curve boundary value of the sandstone and mudstone.

4. The method for establishing a tracking logging while drilling model for a horizontal well in an edge-bottom water reservoir according to claim 1, characterized in that: Determining the resistivity curve boundary values ​​of the oil layer, the oil-water layer, the water layer and the mudstone in the target layer comprises the following steps: Obtaining a cross plot of the natural gamma ray logging curve and the resistivity curve; Obtaining the ordinate of the resistivity curve in the intersection diagram; Acquire a first resistivity curve distribution range of the oil layer in the target layer on the ordinate; Obtaining a distribution range of a second resistivity curve of the oil-water layer in the target layer on the ordinate; Obtaining a distribution range of a third resistivity curve of a water layer in the target layer on the ordinate; Obtaining a fourth resistivity curve distribution range of mudstone in the target layer on the ordinate; Determine a first resistivity curve boundary value of the first resistivity curve distribution range and the second resistivity curve distribution range; Determine a second resistivity curve boundary value of the second resistivity curve distribution range and the third resistivity curve distribution range; Determining a third resistivity curve boundary value of the third resistivity curve distribution range and the fourth resistivity curve distribution range; Using the first resistivity curve boundary value as the resistivity curve boundary value of the oil layer and the oil-water layer; Using the second resistivity curve boundary value as the resistivity curve boundary value of the oil-water layer and the water layer; The third resistivity curve boundary value is used as the resistivity curve boundary value of the water layer and the mudstone.

5. The method for establishing a tracking logging while drilling model for a horizontal well in an edge-bottom water reservoir according to claim 1, characterized in that: Also includes the steps: The actual drilling trajectory is adjusted in real time according to the edge and bottom water reservoir logging model.

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