Shale oil horizontal well trajectory judgment method based on rock debris mineral parameters

Abstract

The invention relates to the technical field of horizontal well monitoring, in particular to a shale oil horizontal well trajectory judgment method based on rock debris mineral parameters, which comprises the following steps: taking to-be-analyzed rock debris of a newly drilled horizontal well for sample preparation to obtain a rock debris sample; obtaining mineral information of the rock debris sample by using an automatic mineral identification system; and screening the mineral information of the rock debris sample by using the mineral characteristic standard of each small layer to obtain the small layer to which the rock debris sample belongs. The rock debris of the horizontal well is used for manufacturing the rock debris sample, the automatic mineral recognition system is used for obtaining the mineral information of the rock debris sample, the small layer position corresponding to the mineral information of the rock debris sample is obtained in combination with the mineral characteristic standard of each small layer, and compared with rock core sampling, the mode for achieving small layer judgment is low in cost, the sample is easy to obtain, and the accuracy is high. The method is suitable for wide popularization.

Description

Technical Field

[0001] The invention relates to the technical field of horizontal well monitoring, in particular to a method for determining the trajectory of a shale oil horizontal well based on cuttings mineral parameters. Background Art

[0002] With the continuous deepening of oil and gas exploration and development, unconventional oil and gas such as shale gas and shale oil have shown great potential under the existing economic and technical conditions. The success of the US shale revolution has greatly reduced the US's dependence on foreign countries. In 2018, shale oil production accounted for 60% of US crude oil production. China's dependence on foreign countries for oil and natural gas reached 69.8% and 45.3% respectively in 2018. Therefore, vigorously promoting the development of the shale oil and gas industry is of great significance to ensuring China's oil and gas security and economic growth.

[0003] Horizontal wells are playing an increasingly important role in the development of shale oil in oil fields due to their advantages such as long oil layer section, large seepage area, effective control of edge water advancement, and significantly better actual production effect than vertical wells. However, due to the high requirements for the wellbore trajectory of horizontal wells (generally, the design requires that the vertical swing of the wellbore trajectory between the target points and the design line does not exceed 1m, and the horizontal swing does not exceed 5-10m), it is difficult to control the trajectory during construction, especially when the formation changes or the contrast marker layer is not obvious, it is often impossible to find the target layer (i.e., target point A), or the actual drilling trajectory deviates greatly from the design line, resulting in the situation of filling and re-adjusting the wellbore trajectory. Geological technicians can track and compare small layers on site, combine comprehensive analysis of logging data, judge the depth of the small layers encountered, guide engineering and technical personnel to optimize drilling parameters, reasonably adjust the wellbore trajectory, ensure that the actual drilling wellbore trajectory accurately drills the target layer and passes through the target layer, and maximize the acquisition of more oil layer sections.

[0004] Commonly used methods for judging small layers in horizontal wells are: 1. Comparison of marker layers. According to the principle that the same marker layer should belong to the same formation, the nearest marker layer of the target layer is found on the adjacent well and the comparison logging curve, and compared with regional lithofacies and other characteristics; 2. Comparison of electrical combination characteristics. Due to the basically same or similar travel conditions, the same formation also has the same or similar combination in lithology, such as thin interlayers, sedimentary laws, etc., which also reflects similar combination characteristics in electrical properties. Compare the electrical combination relationship on the standard logging curve of the adjacent well with the electrical combination characteristics of the horizontal well being drilled; 3. Comparison of lithology and electrical combination relationship. In the absence of electrical standard layers, marker layers, or when similar electrical combination characteristics are not obvious, the electrical and lithology combination relationship of the long well section between wells can be compared, taking into full account the characteristics of lithofacies, structural changes and fault distribution, and referring to the cuttings logging profile of the horizontal well being drilled, and making a comprehensive judgment. The commonly used methods for judging small layers in horizontal wells here all require cores for lithology analysis, but the cost of core sampling is very high, ranging from tens of thousands to hundreds of thousands, and sampling in horizontal wells is even more difficult. Summary of the invention

[0005] The present invention provides a method for determining the trajectory of a shale oil horizontal well based on rock cuttings mineral parameters, which overcomes the deficiencies of the above-mentioned prior art and can effectively solve the problem that the existing method for determining the trajectory of a shale oil horizontal well requires core samples to be made and is costly.

[0006] One of the technical solutions of the present invention is achieved by the following measures: A method for determining the trajectory of a shale oil horizontal well based on rock cuttings mineral parameters, comprising: Taking cuttings to be analyzed from a newly drilled horizontal well for sample preparation to obtain cuttings samples; Use automatic mineral identification system to obtain mineral information of rock cuttings samples; The mineral information of the rock cuttings samples is screened using the mineral characteristic standards of each sub-layer to obtain the sub-layer to which the rock cuttings samples belong.

[0007] The following are further optimizations and / or improvements to the above technical solutions: The cuttings to be analyzed from the newly drilled horizontal well are sampled to obtain cuttings samples, including: Pre-processing the cuttings to be analyzed from the newly drilled horizontal well to obtain pre-processed cuttings samples; Put the pre-treated rock cuttings sample into the mold, add the sample resin liquid and stir to eliminate bubbles, let it stand and solidify to obtain a rough sample; The rough sample was polished, cleaned and dried, and then subjected to conductive carbon plating to obtain the cuttings sample of the newly drilled horizontal well.

[0008] The above-mentioned pretreatment includes screening, impurity removal, cleaning and drying.

[0009] The standard formation process of the mineral characteristics of the above-mentioned sub-layers includes: Obtain the existing adjacent well cores of the newly drilled horizontal well and obtain the corresponding standard scanning samples; Use the automatic mineral identification system to obtain mineral information of standard scanned samples; Based on the mineral information of the standard scanning samples, the mineral characteristic standards for each sublayer are established.

[0010] The mineral information of the rock cuttings sample obtained by the automatic mineral identification system includes: The automatic mineral identification system technology software collects a certain frame of BSE image of the rock cuttings sample by controlling the scanning electron microscope; The automatic mineral identification system technology software processes the BSE image to determine the X-ray energy spectrum point analysis position, where the image processing includes mineral particle extraction and particle grayscale phase separation; The automatic mineral identification system technology software controls the X-ray spectrometer to automatically collect X-ray spectrum information at the specified location; Repeat the above steps, stop the loop based on the measurement termination condition, match the obtained X-ray spectrum information with the standard mineral spectrum database, and identify the corresponding mineral information.

[0011] The present invention uses rock cuttings from horizontal wells to prepare rock cuttings samples, uses an automatic mineral identification system to obtain mineral information of the rock cuttings samples, and then combines the mineral characteristic standards of each small layer to obtain the small layer corresponding to the mineral information of the rock cuttings sample. Compared with sampling the core, the present invention has a low cost for realizing small layer judgment, and samples are easy to obtain, which is suitable for wide promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Attached Figure 1 It is a schematic diagram of the flow chart of the horizontal well trajectory determination method of the present invention.

[0013] Attached Figure 2 It is a schematic diagram of the process of preparing rock cuttings samples in the present invention.

[0014] Attached Figure 3 It is a schematic diagram of the flow chart of the identification method of the automatic mineral identification system in the present invention.

[0015] Attached Figure 4 It is a schematic diagram of the process of forming the mineral characteristic standard of small and medium layers of the present invention. DETAILED DESCRIPTION

[0016] The present invention is not limited by the following embodiments, and specific implementation methods can be determined based on the technical solution of the present invention and actual conditions.

[0017] The present invention will be further described below in conjunction with embodiments and drawings: Embodiment 1: As attached Figure 1 As shown, the embodiment of the present invention discloses a method for determining the trajectory of a shale oil horizontal well based on rock cuttings mineral parameters, comprising: Step S110, taking rock cuttings to be analyzed from a newly drilled horizontal well for sample preparation to obtain rock cuttings samples; Step S120, obtaining mineral information of the rock cuttings sample using an automatic mineral identification system; Step S130, screening the mineral information of the rock cuttings sample using the mineral characteristic standards of each sub-layer to obtain the sub-layer to which the rock cuttings sample belongs.

[0018] The present invention discloses a method for determining the trajectory of a shale oil horizontal well based on cuttings mineral parameters. Cuttings samples are prepared using cuttings from horizontal wells, and mineral information of the cuttings samples is obtained using an automatic mineral identification system. The mineral characteristic standards of each sub-layer are then combined to obtain the sub-layer corresponding to the mineral information of the cuttings samples. Compared with sampling cores, the method for determining sub-layers in the present invention is low-cost, easy to obtain samples, and suitable for wide promotion.

[0019] Embodiment 2: The embodiment of the present invention discloses a method for determining the trajectory of a shale oil horizontal well based on rock cuttings mineral parameters, comprising: Step S210, taking rock cuttings to be analyzed from a newly drilled horizontal well for sample preparation to obtain rock cuttings samples.

[0020] As attached Figure 2 As shown, the above steps include: Step S211, pre-processing the cuttings to be analyzed from the newly drilled horizontal well to obtain a pre-processed cuttings sample, wherein the pre-processing includes screening, impurity removal, washing and drying; Step S212, taking the pre-treated rock cuttings sample into a mold, adding the sample resin liquid and stirring to eliminate bubbles, standing and solidifying to obtain a rough sample; Step S213, grinding and polishing the rough sample, cleaning and drying it, and then performing conductive carbon plating treatment to obtain a rock cutting sample of a newly drilled horizontal well; Step S220, using an automatic mineral identification system to obtain mineral information of the rock cuttings sample.

[0021] As attached Figure 3 As shown, the above steps include: Step S221, the automatic mineral identification system technical software collects a certain frame of BSE image of the rock cuttings sample by controlling the scanning electron microscope; Step S222, the automatic mineral identification system technology software processes the BSE image to determine the X-ray energy spectrum point analysis position, wherein the image processing includes mineral particle extraction and particle grayscale phase separation; Step S223, the automatic mineral identification system technical software controls the X-ray spectrometer to automatically collect X-ray spectrum information at the designated position; Step S224, repeat the above steps, stop the loop based on the measurement termination condition, match the obtained X-ray spectrum information with the standard mineral spectrum database, and identify the corresponding mineral information; Step S230, screening the mineral information of the rock cuttings sample using the mineral characteristic standards of each sub-layer to obtain the sub-layer to which the rock cuttings sample belongs.

[0022] As attached Figure 4 As shown, the standard formation process of the mineral characteristics of the above-mentioned small layers includes: Step S231, obtaining the existing adjacent well cores of the newly drilled horizontal well to obtain the corresponding standard scanning samples; Step S232, using an automatic mineral identification system to obtain mineral information of the standard scanned sample; Step S233, establishing the mineral characteristic standards for each sublayer based on the mineral information of the standard scanned sample.

[0023] Embodiment 3: Determine the mineral characteristic standards of each sub-layer in combination with the existing horizontal wells 1 to 3, and use the mineral characteristic standards of each sub-layer to judge the trajectory of the newly drilled horizontal well, including: (1) Take the cores to be analyzed from wells 1 to 3 for sample preparation to obtain core samples; (2) Analyze step (1) using the automatic mineral identification system to obtain the mineral information of the core (as shown in Table 1); (3) Based on the mineral information obtained in step S2, establish the standards for each geological layer (such as Table 2 and Table 3); (4) Take the cuttings to be analyzed from the newly drilled horizontal well and prepare the cuttings to obtain the cuttings sample: (5) Obtain mineral information of rock cuttings samples using an automatic mineral identification system; (6) The mineral information of the rock chip samples is screened using the mineral characteristic standards of each sublayer to obtain the sublayer to which the rock chip samples belong.

[0024] The above technical features constitute the best embodiment of the present invention, which has strong adaptability and best implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

[0025] Table 1-1 Table 1-2 Table 1-3 Table 1-4 Table 2 Table 3

Claims

1. A method for determining the trajectory of a shale oil horizontal well based on cuttings mineral parameters, characterized in that: include: Taking cuttings to be analyzed from a newly drilled horizontal well for sample preparation to obtain cuttings samples; Use automatic mineral identification system to obtain mineral information of rock cuttings samples; The mineral information of the rock cuttings samples is screened using the mineral characteristic standards of each sub-layer to obtain the sub-layer to which the rock cuttings samples belong.

2. The method for determining the trajectory of a shale oil horizontal well based on cuttings mineral parameters according to claim 1, characterized in that: The method of taking rock cuttings to be analyzed from a newly drilled horizontal well and preparing samples to obtain rock cuttings samples comprises: Pre-processing the cuttings to be analyzed from the newly drilled horizontal well to obtain pre-processed cuttings samples; Put the pre-treated rock cuttings sample into the mold, add the sample resin liquid and stir to eliminate bubbles, let it stand and solidify to obtain a rough sample; The rough sample was polished, cleaned and dried, and then subjected to conductive carbon plating to obtain the cuttings sample of the newly drilled horizontal well.

3. The method for determining the trajectory of a shale oil horizontal well based on cuttings mineral parameters according to claim 2, characterized in that: The pretreatment includes screening, impurity removal, cleaning and drying.

4. The method for determining the trajectory of a shale oil horizontal well based on cuttings mineral parameters according to claim 1, characterized in that: The standard formation process of the mineral characteristics of each sublayer includes: Obtain the existing adjacent well cores of the newly drilled horizontal well and obtain the corresponding standard scanning samples; Use the automatic mineral identification system to obtain mineral information of standard scanned samples; Based on the mineral information of the standard scanning samples, the mineral characteristic standards for each sublayer are established.

5. The method for determining the trajectory of a shale oil horizontal well based on cuttings mineral parameters according to claim 2 or 3, characterized in that: The standard formation process of the mineral characteristics of each sublayer includes: Obtain the existing adjacent well cores of the newly drilled horizontal well and obtain the corresponding standard scanning samples; Use the automatic mineral identification system to obtain mineral information of standard scanned samples; Based on the mineral information of the standard scanning samples, the mineral characteristic standards for each sublayer are established.

6. The method for determining the trajectory of a shale oil horizontal well based on cuttings mineral parameters according to any one of claims 1 to 4, characterized in that: The method of obtaining mineral information of rock cuttings samples by using an automatic mineral identification system includes: The automatic mineral identification system technology software collects a certain frame of BSE image of the rock cuttings sample by controlling the scanning electron microscope; The automatic mineral identification system technology software processes the BSE image to determine the X-ray energy spectrum point analysis position, where the image processing includes mineral particle extraction and particle grayscale phase separation; The automatic mineral identification system technology software controls the X-ray spectrometer to automatically collect X-ray spectrum information at the specified location; Repeat the above steps, stop the loop based on the measurement termination condition, match the obtained X-ray spectrum information with the standard mineral spectrum database, and identify the corresponding mineral information.

7. The method for determining the trajectory of a shale oil horizontal well based on rock cuttings mineral parameters according to claim 5, characterized in that: The method of obtaining mineral information of rock cuttings samples by using an automatic mineral identification system includes: The automatic mineral identification system technology software collects a certain frame of BSE image of the rock cuttings sample by controlling the scanning electron microscope; The automatic mineral identification system technology software processes the BSE image to determine the X-ray energy spectrum point analysis position, where the image processing includes mineral particle extraction and particle grayscale phase separation; The automatic mineral identification system technology software controls the X-ray spectrometer to automatically collect X-ray spectrum information at the specified location; Repeat the above steps, stop the loop based on the measurement termination condition, match the obtained X-ray spectrum information with the standard mineral spectrum database, and identify the corresponding mineral information.

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