Earth's application in the preliminary study of oil and gas pipeline engineering. Petroleum planning and design, 201 oil and gas pipeline preliminary research accuracy requirements are relatively loose, using the geographic information data published on the Internet, taking GoogleEarth software as an example, introducing its application in the preliminary research of oil and gas pipeline engineering. After a comprehensive comparison, it is feasible to use GoogleEarth software in the preliminary study of pipeline routes. Introducing it into the preliminary study of pipelines can effectively improve the efficiency of internal industry route selection and field survey. The data range, data quality, and timeliness of the software can basically meet the requirements of oil and gas pipeline planning, pre-feasibility study, and some feasibility study stages. However, limited by the overall accuracy, it is still necessary to purchase high-definition remote sensing data and large-scale topographic maps at the design stage to optimize the pipeline route. In recent years, with the vigorous development of China's petroleum industry, the construction of oil and gas pipeline networks has shown rapid development. Taking PetroChina as an example, the total length of its oil and gas pipeline construction during the 11th Five-Year Plan period exceeded 2.7X104km, which was 1.65 times that of the 15th Five-Year Plan period. During the 12th Five-Year Plan period, the scale of oil and gas pipeline construction will be further expanded. At the same time as the construction of main pipelines, the construction of branch lines and branch lines is also advancing rapidly, and the requirements for pipeline planning and design, construction, operation and management are becoming increasingly high. In this situation, the cycle of the preliminary work of the pipeline is shortened, and the efficiency requirements are higher. The emergence of GoogleEarth satellite map software provides pipeline personnel with rich geographic information data and improves the efficiency of pipeline preliminary work. A virtual earth software developed by Google, which arranges satellite photos, aerial photos and GIS (geographic information system) data on the same three-dimensional model of the earth, so that terrain and buildings can be displayed in the state of three-dimensional images. GE software has launched three different versions for personal computer desktop systems: Free version, Plus version and Pro version. After continuous improvement of GE software, the current version has been upgraded to version 6.2. 1.1 Data source and resolution The satellite imagery of GE software is not a single data source, but the integration of satellite imagery and aerial photography data. The effective resolution of global satellite imagery on GE is at least 100m, usually 1530m. However, it can provide high-definition images with a resolution of about 1m or 0.5m for large and medium-sized cities and famous scenic spots. Since 2010, GE software has widely promoted sub-HD satellite images with a resolution of about 2.5m, and the corresponding map scale is within 1: 50,000. GE software satellite image ground resolution and ground Liu Dingzhi, male, engineer. In 2003, he graduated from Southwest Petroleum University with a master's degree in storage and transportation. At present, the general relationship between the scale of the pre-study map of the oil and gas pipeline project undertaken by the General Planning Institute of China National Petroleum Corporation is shown in Table 1. Table 1. The correspondence between the map scale and the image ground resolution. Timeliness is good At present, most of the topographic maps commonly used in pipeline engineering are drawn before the 1980s. In view of the complexity and high investment of topographic map drawing, the update of traditional topographic maps is often slow. The GE software satellite data has better timeliness. In recent years, Google has gradually increased the frequency of satellite data updates, providing partial updates almost every month. Up to now, many areas in China have been updated with satellite images from 2005 to 2010. 1.3 Wide data coverage Compared with traditional paper maps, GE software has a wide data coverage. It integrates global satellite image resources including South Pole and North Pole. This has obvious advantages for the long-distance research of transnational oil and gas pipelines, especially foreign oil and gas pipelines. 1.4 Intuitive browsing, high-resolution images (space shuttle radar terrain mapping task) elevation data and satellite remote sensing images, GE software can display topography and landforms in three-dimensional way, easy to browse. In terms of resolution, except for some areas in southeastern Xinjiang, southwestern Qinghai, and eastern Tibet, the resolution is still about 15m, and the rest of the regions have been sub-high definition (resolution 2.5m) and high definition (resolution 0.51 m) Satellite image coverage. 1.5 Data is free At present, most remote sensing companies charge for satellite images. For pipeline projects with long lines and a wide range, the overall cost of purchasing satellite remote sensing data, especially high-resolution remote sensing data, is relatively high. The GE software is completely free for viewing satellite images, and only charges a fee for advanced applications based on satellite data. This greatly facilitates oil and gas pipeline engineers who focus on topography and topography and mainly browse satellite images. 1.6 At the preliminary research level, the overall accuracy meets the requirements. After several field surveys (see Table 2), the horizontal accuracy and vertical accuracy of most areas in China are within 50m. For the preliminary research of the pipeline, the overall accuracy meets the requirements. GE software pictures are composed of multiple satellite data. The stitching effect is better in most areas, but there are also special cases where the stitching is misaligned and the terrain is distorted. Therefore, in the feasibility study stage and the subsequent design stage, it is still necessary to evaluate the comparison of the horizontal accuracy and vertical accuracy of the 2GE software through site surveys + location horizontal error / m vertical error / m somewhere in Horgos, Xinjiang. Nagenla Pass, Tibet, Mila Pass, Qinghai, Yushu, Manitui, Qinghai, Kunlun Pass, Yunnan, Nujiang, Inner Mongolia, Ejina Banner, Heihe, Shanxi, Qinshui, Mohe, Heilongjiang, Heilongjiang, Heilongjiang, Humahe, Shanghai, Huangpu, Liaoning, Laha. Refers to the comparison between GE software and GPS collection points. Horizontal accuracy refers to the distance between the GE coordinates and GPS coordinates of the same feature; vertical accuracy refers to the difference between the GE altitude and GPS altitude at the same coordinate. Price error situation. 1.7 Powerful supporting functions In addition to displaying satellite images and elevation data, GE software also includes place names, administrative divisions, major water systems, railway and road networks, famous mountain peak names, famous protected area names, historical earthquake distribution, future weather, satellite cloud images, and some Live photos and panoramic photos of the place. In addition, GE software also provides auxiliary functions such as landmark setting, path drawing, length measurement, area measurement, slope measurement, GPS data import, and 3D animation browsing. 2 Application in the preliminary study of oil and gas pipeline line engineering 2.1 Indoor auxiliary line selection 2.1.1 General direction of line selection The characteristics of newer GE software data, more complete landmark display, intuitive terrain and landform, etc., can facilitate indoor line selection. The main steps are as follows: In the first step, run GE software to find the first and last station area of ​​the pipeline. According to the surrounding terrain, landforms, structures and other information provided by the software, the location of the first and last stations is preliminarily selected. In the second step, the "path" drawing function of the GE software is used to draw the pipelines according to the location of the first and last stations and the main control points along the line. The general direction; the third step, according to the general direction of the pipeline, through the zoom function of the GE software, detailed view of the terrain, roads, railways, city limits, distribution of water systems, etc. along the line, segment and gradually adjust the pipeline position until the pipeline is finally determined Towards. 2.1.2 Local analysis In the vicinity of difficult points such as the tunnel entrances and exits of large and medium-sized rivers, the feasibility of the passage of pipelines needs to be analyzed in detail. Some functions of GE software can be helpful for local analysis. In recent years, GE software has covered more and more high-definition satellite images in China. Using high-definition pictures and terrain data, you can conduct detailed investigations indoors, compare and select the passage method of local areas of the pipeline, and optimize the direction of the route, such as tunnel entrances, river crossing points, dense construction areas, water networks and other sections. Like "function. Using the historical image function, you can intuitively investigate changes in river channels, lakes, waterways, roads and railway networks, and changes in urban structures. At present, the main problem is that the domestic historical image data is far less than foreign countries, many The region has not even provided historical images; second, GE software provides Google ’s ocean functions. GE software provides subsea elevation data, which can be used to investigate the elevation changes along the submarine pipeline. Although the accuracy of GE software ’s subsea elevation is lower than that of land elevation, In the early stage of pipeline research, it still has certain value. You can use the real photo function of the GE software to open the real photo. Through the actual photos, you can learn the actual scenes of the local areas of the pipeline before the survey. At the same time, due to the lack of geographic location check in the uploading process, some photos do not exactly correspond to the geographic location and can only be used. Specific scenes need to be obtained through site surveys. 2.1.3 Mileage and Elevation Collection along the Line It is an important task for the line professional to provide mileage and elevation data along the pipeline. Previously, mileage and elevation data along the route were mainly obtained through topographic maps. The use of paper topographic maps requires manual calculation of the elevation along the line, with lower efficiency; the use of electronic topographic maps and GIS software for higher efficiency. However, the current price of electronic topographic maps is relatively high, and ordinary engineering projects are unbearable. On the other hand, in recent years, the state has tightened the management of topographic maps, the purchase approval process is complicated, and the cycle is longer. In view of the relatively loose accuracy requirements of the previous research stage, GE software can quickly extract mileage and elevation data along the pipeline according to the drawn pipeline path. There are mainly the following methods. 2.1.3.1 Use the measurement function of the "Scale" tool to read the elevation value at the mouse through the GE main window, and then obtain the mileage elevation data along the pipeline. This method is the simplest to use, but there is also a certain degree of randomness. Due to the need to manually measure and read data, different personnel may get different mileage and elevation results. 2.1.3.2 Using the "Display Altitude Configuration File" function and the "Display Altitude Configuration File" function, the randomness of reading mileage and elevation data is solved. Through the operation of the GE software, the mileage elevation curve along the pipeline path can be displayed, and the topography, minimum elevation, and slope range can be displayed. The method still has the following deficiencies: yes, the collected mileage and elevation paths do not completely coincide with the original path, and there is a slight deviation; second, the collected mileage and elevation points are distributed at equal intervals, and the distance between complex terrain and simple terrain is the same It may appear that the sampling points in areas with simple terrain are too dense and the sampling points in areas with complex terrain are too sparse; third, after testing, the number of collection points of the "show height profile" function is 9001300 points, the path is too long, and the collection error will increase. Therefore, for long-distance pipelines, it is recommended to draw paths in sections and collect mileage and elevation data in sections. The function can flexibly control GoogleEarth, and realize the functions of controlling view height, center latitude and longitude, saving pictures, reading elevation information and so on. At the application level, after several years of development, the majority of GE software enthusiasts have developed a series of elevation extraction tools using the GoogleCOMAPI function, such as "Google Earth-Get Point Tool", "Google Earth Elevation Extraction Professional Edition", and "Elevation Data Download" (DEM) assistant "etc. These tools are combined with the path analysis function included in the GIS software, which can flexibly realize the functions of "collecting mileage elevations at equal intervals", "collecting mileage elevations by inflection point", and "collecting elevations by designated area". This method has flexible control and many small softwares available. However, you need to be familiar with GoogleCOMAP 丨 grammar or familiar with related elevation acquisition software and GIS software. 2.1.3.4 Use GIS software and third-party elevation data to obtain the mileage elevation of the pipeline through GIS software and download third-party elevation data. First, roughly determine the latitude and longitude range along the pipeline in the GE software, and export the pipeline path as a kml file; second, download the SRTMDEM elevation data or ASTERGDEM elevation data from the Internet according to the latitude and longitude range of the pipeline; finally, in the GIS software Medium (such as ArcInfo, Global Mapper, etc.), load the elevation data and pipeline path kml file, you can use the path analysis function of GIS software to automatically extract the mileage elevation data of the pipeline. The advantage of this method is that the data is flexible and can be compared and verified with elevation data from different sources. The disadvantage is that users need to download elevation data specifically and need to be familiar with GIS software. It is simple and convenient to use, with moderate accuracy, and can meet the requirements in the planning and pre-feasibility study stage. In the feasibility study stage, it is necessary to verify and check the errors of the GE software through site survey. For the cases where mileage and elevation need to be submitted according to the inflection point, the elevation extraction tool developed by GoogleCOMAP 丨 function can be used. In addition, for special cases where high accuracy is required, other high-precision digital elevation models (DEM) can be considered in conjunction with GIS software to collect mileage and elevation data. 2.1.4 Engineering volume statistics After the pipeline direction is determined, the line major also needs to provide river crossing length and frequency; railway highway crossing length and frequency, administrative division crossing length; various areas crossing length and other engineering quantities. In actual use, the number of crossings is usually counted manually, and the crossing length is measured by the "scale" tool of GE software. With the increasingly powerful functions of GIS software, the spatial query and spatial analysis functions of GIS software can be used to realize automatic statistics of various engineering quantities. At present, GIS data such as small rivers, ditches, newly constructed highways and railways, town-level administrative divisions, and river widths are difficult to obtain, which restricts the automatic statistics of engineering volume. 2.2 Combined with GPS, after assisting in surveying and selecting lines indoors, it is often necessary for line personnel to survey on site to confirm whether the route selection is reasonable. Combined with GPS tools, GE software can play a significant role in the exploration process. 2.2.1 Intuitively display the route and key points of the survey. In the process of surveying, in order to facilitate the recording and recall of the route and location of the passing, the GPS track is usually used to record the trajectory of the survey and the points of interest are used to record the coordinates of the key points. These data are stored in the GPS and are not intuitive to display. The GE software provides a complete, visual, and intuitive display platform for surveying routes and coordinate collection points. Open to use. In the GE software, in the "Import via GPS" dialog box, select "Import from File" to import the GPS data file. At present, due to the widespread use of GE, GPS supporting software basically provides the function of directly converting stored data into kml files. 2.2.2 Using GPS waypoints to guide and survey traditional paper topographic maps can also achieve this function. However, the coordinates of each waypoint need to be manually input. Using GE software, you can directly convert landmarks into waypoints, improving work efficiency. Specific steps: In the first step, before the survey, first find out the key survey sites on the GE software, and add corresponding landmarks, such as tunnel entrances and river crossing points, etc. In the second step, export all landmarks as kml files. Use the GPS supporting software and GIS software to import kml landmarks as waypoints into the GPS; the third step is to use the GPS waypoint function during the survey to determine the distance, azimuth, and expected arrival of the current location and the target location Parameters such as time help to find points. 2.2.3 Making track and navigating vehicles At present, the road network of handheld and vehicle-mounted GPS navigation software is relatively comprehensive, and the navigation function is powerful, but usually does not include low-grade highways such as wild gravel roads and dirt roads. In unmanned areas, finding a road is one of the important tasks of surveying. Especially for dirt roads with many bifurcations and chaotic chaos, it is easy to get lost and go the wrong way when surveying. At this time, you can use the high-definition and sub-high-definition satellite images of GE software to create road tracks and navigate the vehicles. Specific steps: In the first step, before the survey, first use the high-definition and sub-high-definition satellite images of GE software to draw the estimated driving path according to the displayed road traces and topography; in the second step, save the driving path as a kml file. Use GPS supporting software and GIS software to import kml files into the GPS as a track; the third step is to use the GPS load track display function during the survey to directly navigate the vehicle. In 2011, this method was well applied in the unmanned area during the survey of the "Hami-Malangshan-Ejin Banner-Bayannaoer" route. Through the survey, the overall accuracy of GE data was also checked from another angle. 2.2.4 Real-time display of the relationship between the current location and the planned pipeline In the process of surveying, the relationship between the current location and the pipeline line position is often investigated through GPS combined with the topographic map with the pipeline line position. When using it, it is necessary to manually compare the coordinates of GPS and topographic map, which is more tedious. In actual use, the pipeline route planned by GE software can be imported into GPS, and the relationship between the current position and the planned pipeline position can be displayed in real time. Specific steps: the first step, before the survey, first use the "path" function of GE software to plan the pipeline route and save the path as a kml file; second step, use the GPS software and GIS software to use the kml file as the track Import into GPS; In the third step, during the survey, you can view the relationship between the current position and the pipeline's proposed line position in real time through GPS. Combined with the site topography and landform, the rationality of indoor route selection was investigated. 2.3 Line achievement display 2.3.1 Making satellite remote sensing map Compared with the line drawing based on administrative divisions, line satellite remote sensing map can more vividly display the topography and landform along the pipeline, which is the current commonly used line achievement display method. Using GoogleEarth data, a satellite remote-sensing map of the pipeline route can be produced. In the case where the picture size is not large, you can first browse through the GE software to obtain the required image by screenshot. The complete remote sensing image of the satellite can be stitched by the image software, but this manual method is inefficient. It is recommended to use software such as "Electronic Map Grab" to automatically capture and stitch pictures. The map obtained by direct stitching has no latitude and longitude information, and can only be used as a schematic diagram. Degree, to achieve accurate and active positioning, and provide tools for automatic puzzles. The main principle: First, use the GoogleCOMAPI function to accurately locate to a fixed height, zero azimuth, and vertical viewing angle; second, to avoid the effect of elevation changes on the stitching, use the GoogleCOM API function to turn off the terrain, and wait for the data download progress to reach 100 %, Prepare to call the screen capture program; three, take the center point (0, 0) of the GE software interface as the center to take a rectangular screen capture; fourth, reposition the center point with the length or width of the rectangle, and then take the same size rectangular screen capture Fifth, loop until the screenshot of the entire area is completed; Sixth, call the picture stitching program to stitch the captured rectangular pictures. The software realizes automatic splicing. It should be noted that, because the GE software displays in a spherical manner, when stitching large-scale, small-scale plane pictures, the pictures are prone to misalignment. It is recommended to use GoogleEarth data only when stitching small-scale and large-scale local high-definition satellite images. Use other data when stitching large-scale, small-scale satellite images. 2.3.2 Production of 3D flight animation When discussing the direction of oil and gas pipelines, three-dimensional flight animation video is usually used to display the typical features such as topography, important crossing points, and main administrative divisions along the pipeline. After version 5.0, GE software provides tour tools with audio and video recording capabilities. According to their own needs, through the operation of GE software, design and record various forms of three-dimensional flight mode. If you want to create a video animation that is separate from GE software, you can use the "Video Production Program" of GE Software Pro or third-party screen recording software. In addition, GE software needs to download a lot of data during the tour. In order to improve the picture quality, it is recommended to first go through the designed flight path and download the data to the local cache. During the second tour, the video file is then recorded. 3 Existing deficiencies Despite the comprehensive and powerful data of the GE software, there are still problems with low satellite image resolution, early shooting time, excessive cloud cover, poor imaging quality, and large deviations in road networks and landmarks in certain regions. , Need to use other satellite data to make up for the lack of GE data. At present, the advantages and disadvantages of common satellite images on the Internet are shown in Table 3.4. Conclusion The application of star image display technology to the planning of oil and gas pipelines has a positive significance. In the preliminary projects of multiple pipelines, after comparing GE data with traditional maps and on-site survey verification, the following conclusions can be drawn: Table 3 Comparison of common satellite images on the Internet Data sources Advantages and disadvantages Baidu, Sogou and other domestic high-definition, rich road networks The national definition low-sky map has the most high-definition in the country and the richest road network. Other countries have low-definition foreign images such as Bing maps and Yahoo maps. There are relatively few domestic high-definition images, and the road network is relatively single. There are certain deformations. Sometimes Russia maps can be found. At present, there is no mention of high-definition satellite networks and place names for cloud coverage and no road DG maps on GE. For the user's high calculation level, road maps, topographic maps, and high-definition satellite images are provided with Google watermarks. Various maps such as unattractive satellite maps, small deviations in road networks and landmarks, and beautifully displayed place names-yes, it is feasible to use GE software in the preliminary study of oil and gas pipeline engineering. Its data range, data quality, and timeliness can basically meet the requirements. However, due to the limitation of its data accuracy, it can only meet the requirements of the oil and gas pipeline planning, pre-feasibility study and part of the feasibility study stage. In the design stage, it is still necessary to purchase high-resolution remote sensing data and large-scale topographic maps to optimize the route. The second is that GE software satellites are rich in data and the supporting GIS is powerful. Introducing it into the pre-study of oil and gas pipelines can effectively improve the efficiency of route selection, and provide a professional and intuitive indoor operation platform for line professionals to help designers achieve The transformation from two-dimensional line selection to three-dimensional line selection. At the same time, combined with GPS, GE software can fully apply the results of the internal industry to the exploration process and improve the efficiency of the field work. Basic Baby High Chair,Multifunction Baby Chair,Baby Sitting Chair,Unique Baby High Chair Zhejiang Lamon Technology Inc. , https://www.chairesbaby.com
1 Features of Google Earth