Method for calculating absolute coincidence rate of logging profile

Abstract

The invention relates to a method for calculating the absolute coincidence rate of a logging profile, belongs to the technical field of oil and gas field development, and aims to solve the problem that the profile coincidence rate is affected by too fine rock debris particles, non-strict construction and the like along with the development of a drilling technology. The method comprises the following steps: collecting well logging and logging information of a target well section; according to the logging depth data, extracting a corresponding logging depth and a GR value; comparing logging lithology data, determining a logging sand shale GR threshold value, and defining lithology of each depth of logging; designing a depth correction range, and collecting layered top and bottom depths of a target interval; and comparing whether the logging lithology and the logging lithology are the same or not under the same depth, accumulating the logging lithology and the logging lithology, and calculating the maximum profile coincidence rate in each layer section and each depth correction, the method can quickly and accurately calculate the profile coincidence rate, and solves the problem of tedious quantitative calculation of the profile coincidence rate of multiple well sections in the new well logging data acceptance process.

Description

Technical Field

[0001] The present invention relates to a method for calculating the absolute coincidence rate of a logging profile, belonging to the technical field of oil and gas field development. Background Art

[0002] With the development of drilling technology, the mechanical drilling speed of the formation is getting faster and faster. Most drilling teams use PDC bits for construction and drilling, resulting in too fine cuttings particles, which affect the compliance of on-site logging descriptions. In addition, the non-strict implementation of technical standards and the insufficient publicity of technical standards during the construction process lead to the late arrival time not being measured according to the standard, which is also the main factor affecting the lithology profile coincidence rate. At present, the current situation of domestic oil and gas fields in calculating the profile coincidence rate is as follows: on the one hand, the drilling operation cycle is continuously shortened and the rhythm is continuously accelerated, resulting in a low logging profile coincidence rate, and everyone is researching methods to improve the profile coincidence rate; on the other hand, the methods for calculating the profile coincidence rate on-site are relatively single and cannot quantitatively calculate in batches for multiple target intervals. The progress of science and technology has made intelligent logging a trend, and the need to establish an automated and rapid calculation method is becoming increasingly obvious. Therefore, in the process of oil and gas field development, there is an urgent need for a method that can quickly and accurately calculate the profile coincidence rate to strengthen the supervision and quantitatively analyze and evaluate the profile coincidence rate of on-site logging data.

[0003] The Chinese patent application document with publication number CN114741390A discloses a method for dividing lithology profiles based on real-time drilling parameters. This solution combines the Chinese-French logging system to realize the intersection of the real-time SI index curve and the real-time torque, and the system quickly constructs a preliminary lithology profile, greatly improving the accuracy and timeliness of the establishment of geological logging profiles, and solving the problems of difficult construction of lithology profiles and low profile coincidence rate in the Neogene strata of the Bohai Sea; however, it does not consider the method for automatically and rapidly calculating the profile coincidence rate of multiple target intervals, and has certain limitations. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for calculating the absolute coincidence rate of a logging profile to solve the problem of cumbersome quantitative calculation of the profile coincidence rate for multiple well sections during the acceptance of new well logging data.

[0005] To achieve the above purpose, the solution of the present invention includes:

[0006] A method for calculating the absolute coincidence rate of a logging profile of the present invention includes the following steps:

[0007] 1) Collect logging and logging data of the target well section;

[0008] 2) Extract the corresponding logging depth and GR value according to the logging depth data;

[0009] 3) Compare the logging and logging lithology data, determine the GR threshold value of logging sandstone and mudstone, and define the lithology of each depth of logging;

[0010] 4) Design depth correction range, collect the top and bottom depths of each layer in the target interval.

[0011] 5) Compare whether the logging lithology is the same as the well logging lithology at the same depth and accumulate, calculate the maximum profile coincidence rate within each interval and each depth correction.

[0012] Further, in step 5), the maximum profile coincidence rate within each interval and each depth correction is obtained by programming and establishing an association operation under the coincidence rate database table. The programming to establish the association is realized by means of macros in the Excel table.

[0013] Further, the programming to establish the association includes uniformly modifying the logging depth respectively according to the set depth correction range, comparing the logging and well logging lithologies at the same depth, and calculating the lithology profile coincidence rate in turn according to the logging depth range and the depth ranges of multiple target intervals provided.

[0014] Further, in step 1), the target well section includes the well section where the on-site logging team collects cuttings at 1 package / meter according to the geological design requirements.

[0015] Further, in step 1), the logging and well logging data include the well depth and lithology data in the logging data; the well depth and GR data in the well logging data.

[0016] Further, in step 2), the corresponding well logging depth and GR value are extracted by extracting the depth of each whole meter section and the corresponding GR value.

[0017] Further, in step 3), the GR threshold value for sandstone and mudstone is determined to be between 85 and 95; according to the approximate same lengths of sandstone and mudstone in the logging and well logging lithologies, the GR threshold value is determined.

[0018] Further, in step 4), the designed depth correction range is to eliminate the depth range where the logging lithology depth is misaligned with the actual lithology due to the late arrival time during the on-site logging process; by setting the depth correction range, the well logging depth value is uniformly adjusted to complete the collection of the top and bottom depths of each layer in the target interval.

[0019] Further, in step 4), the top and bottom depths of each layer in the target interval include several sets of layer names of the target layer provided by the logging and the corresponding top depth data, bottom depth data, etc.

[0020] Further, in step 5), the calculation results include the profile coincidence rate calculated for each correction depth corresponding to each set layer, as well as the maximum profile coincidence rate of each layer and the corresponding depth correction value.

[0021] The beneficial effects of the present invention are as follows: Before the grading and acceptance of logging data, collect the logging and well logging data of the target well section, then program and establish an association under the calculation compliance rate database table, and run to obtain the results, which can quickly and accurately calculate the profile compliance rate, and strengthen the supervision to quantitatively analyze and evaluate the profile compliance rate of on-site logging data. This solution effectively solves the problems of cumbersome calculation of the profile compliance rate and the problem of focusing on analysis of the target well section during the acceptance of new well logging data by on-site supervision. It is particularly important for areas with fast development progress and short drilling cycles. The present invention is simple and practical, highly operable, and has good promotional effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is the flowchart of the method for calculating the absolute compliance rate of the logging profile of the present invention;

[0023] Figure 2 is the lithology comparison chart of the whole well section of the target layer of Well J1 in this embodiment (corrected depth 0m);

[0024] Figure 3 is the lithology comparison chart of the logging and well logging of the second member of the He Formation of Well J1 in this embodiment (corrected depths 0m and -1m). DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0026] The basic concept of the present invention is as follows: The present invention proposes a method for calculating the absolute compliance rate of the logging profile, which is used for managers to quickly and effectively analyze and calculate the logging and well logging lithology data of newly drilled target wells before the grading and acceptance of logging data, analyze the logging lithology description and well logging GR value, and batch process the corrected depth, so as to quickly and accurately calculate the profile compliance rate, and strengthen the supervision to quantitatively analyze and evaluate the profile compliance rate of on-site logging data.

[0027] An embodiment of a method for calculating the absolute compliance rate of the logging profile:

[0028] As Figure 1 shown, by collecting the logging and well logging data of the target well section, establish a lithology database; according to the logging depth data, extract the corresponding well logging depth and GR value; compare the logging and well logging lithology data to determine the well logging sandstone-shale GR threshold value; design the depth correction range, and collect the top and bottom depths of the target layer section; program and establish an association under the calculation compliance rate database table, and run to obtain the results; provide the results to the supervision for grading and accepting the logging data.

[0029] Step 1: Collect the logging and well logging data of the target well section and establish a lithology database; the target well section includes the well section where the on-site logging team takes cuttings at 1 package / meter according to the geological design requirements.

[0030] Among them, the logging and well logging data include two types of data, namely well depth and lithology in the logging data; and two types of data, namely well depth and GR data in the well logging data.

[0031] Step 2: Extract the corresponding well logging depth and GR value according to the logging depth data; extracting the well logging depth and GR value means extracting the depth of the whole well section in meters and the corresponding GR value for each meter section.

[0032] Step 3: Compare the logging and well logging lithology data to determine the GR threshold value for sandstone and mudstone in well logging; determining the GR threshold value for sandstone and mudstone means defining the well logging lithology section between 85 - 95; comparing the lengths of sandstone and mudstone in the logging and well logging lithology to be approximately the same, and determining the GR threshold value.

[0033] Step 4: Design the depth correction range and collect the top and bottom depths of the target layer intervals; designing the depth correction range means eliminating the dislocation between the logging lithology depth and the actual lithology during the on-site logging process due to the lag time; by setting the depth correction range, uniformly adjust the well logging depth value; generally, the depth correction error is set as an integer between (-5m - 5m).

[0034] Among them, the top and bottom depths of the target layer intervals include several sets of target layer interval names provided by logging and the corresponding top depth data, bottom depth data, etc.

[0035] Step 5: Program to establish an association under the calculation compliance rate database table and run to obtain the result;

[0036] Among them, programming to establish an association means achieving it by means of macros in the Excel table, and the specific steps are divided into the following 4 steps: ① Achieve the extraction of the depth of each meter section and the corresponding GR value in the above steps; ② Define the lithology of each depth in well logging according to the GR threshold value of sandstone and mudstone determined in the above steps; ③ Modify the depth of the batch logging data according to the correction depth range; ④ Compare whether the logging lithology and the well logging lithology are the same at the same depth and accumulate, and calculate the maximum profile compliance rate within each layer interval and each depth correction.

[0037] Step 6: Provide the result to the supervisor for rating and acceptance of the logging data.

[0038] The following further describes this embodiment in detail in combination with Well J1 in a certain basin, specifically as follows:

[0039] As Figure 2 shown, the well logging data section of Well J1 in a certain basin is 405 - 3780m (the upper non-target layer section is not shown), with a sampling interval of 0.125m; the logging lithology description section of the target layer is 3200 - 3780m, with an interval of 1m.

[0040] Collect the logging and well logging data, establish a lithology database, and collect the top and bottom depths of the target layer, Box 2 section.

[0041] Set the GR threshold value for sandstone and mudstone as 90 (>90 indicates mudstone); set the depth correction range as integers between -5m and 5m.

[0042] Run the associated macro to obtain the profile compliance rates of the entire well section and the second member of the He Formation in the target interval under 11 categories (integers between -5m and 5m), as well as the corresponding correction depths and compliance rate values at which the maximum profile compliance rates of the entire well section and the second member of the He Formation in the target interval occur, as shown in Table 1.

[0043] Table 1 Statistical table of the absolute profile compliance rate and lag time analysis of well J1

[0044]

[0045] As Figure 3 shown, the correction depth of the second member of the He Formation in the target interval is -1m, and the maximum profile compliance rate reaches 97.4%. The provided results are given to the supervisor, indicating that the profile compliance rate directly reflects the quality of on-site logging data and the rating level of logging data quality.

Claims

1. A method for calculating the absolute coincidence rate of a mud logging profile, characterized in that, it includes the following steps: 1) Collect mud logging and logging data of the target well section; 2) Extract the corresponding logging depth and GR value according to the mud logging depth data; 3) Compare the lithology data of mud logging and logging, determine the GR threshold value of logging sandstone and mudstone, and define the lithology of each depth in logging; 4) Design the depth correction range and collect the top and bottom depths of the target interval; 5) Compare whether the lithology of mud logging and logging is the same at the same depth and accumulate, and calculate the maximum profile coincidence rate within each interval and each depth correction.

2. The method for calculating the absolute coincidence rate of a mud logging profile according to claim 1, characterized in that, in the step 5), the maximum profile coincidence rate within each interval and each depth correction is obtained by programming and establishing an association operation under the calculation coincidence rate database table, and the programming and establishing the association are realized by means of macros in the Excel table.

3. The method for calculating the absolute coincidence rate of a mud logging profile according to claim 2, characterized in that, the programming and establishing the association includes uniformly modifying the mud logging depth respectively according to the set depth correction range, comparing the lithology of mud logging and logging at the same depth, and calculating the lithology profile coincidence rate in sequence according to the mud logging depth range and the depth range of multiple target intervals provided.

4. The method for calculating the absolute coincidence rate of a mud logging profile according to claim 1, characterized in that, the target well section in the step 1) includes the well section where the on-site mud logging team takes cuttings at 1 package / meter according to the geological design requirements.

5. The method for calculating the absolute coincidence rate of a mud logging profile according to claim 1, characterized in that, the mud logging and logging data in the step 1) include the well depth and lithology data in the mud logging data; the well depth and GR data in the logging data.

6. The method for calculating the absolute coincidence rate of a mud logging profile according to claim 1, characterized in that, the extraction of the corresponding logging depth and GR value in the step 2) is through extracting the depth of the whole-meter section and the corresponding GR value.

7. The method for calculating the absolute coincidence rate of a mud logging profile according to claim 1, characterized in that, the determination of the GR threshold value of sandstone and mudstone in the step 3) refers to the range between 85 and 95; according to the fact that the lengths of sandstone and mudstone in the lithology of mud logging and logging are approximately the same, the GR threshold value is determined.

8. The method for calculating the absolute coincidence rate of a mud logging profile according to claim 1, characterized in that, the designed depth correction range in the step 4) is the depth range to eliminate the dislocation of the mud logging lithology depth from the actual lithology due to the lag time during the on-site mud logging process; by setting the depth correction range, the logging depth value is uniformly adjusted to complete the collection of the top and bottom depths of the target interval.

9. The method for calculating the absolute coincidence rate of a mud logging profile according to claim 1, characterized in that, the top and bottom depths of the target interval in the step 4) include several sets of target interval stratification names provided by mud logging and the corresponding top depth data, bottom depth data, etc.

10. The method for calculating the absolute coincidence rate of a mud logging profile according to claim 1, characterized in that, the calculation results in the step 5) include the profile coincidence rate calculated for each correction depth corresponding to each interval set, as well as the maximum profile coincidence rate of each interval and the corresponding depth correction value.

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