Brief introduction of core image acquisition system (excerpt)

(Tianjin Dagang Oilfield Geological Research Institute, Tianjin 300280)

Starting from 1998, Dagang Oilfield started core scanning and collected a large number of core image information, which laid the foundation for the construction of physical geological data management information system. This paper mainly introduces the high-resolution acquisition of core images and the management and analysis system of core graphic information, and puts forward some suggestions for improvement.

1. Core image high-resolution acquisition system and its function introduction

Core image high-resolution acquisition instrument is a mechatronics equipment specially used for core image high-resolution acquisition. The instrument consists of three CCD high-resolution linear digital cameras, professional light source without stroboscopic high color development, core driving mechanism, automatic control of core image acquisition, interface between acquisition device and core image library, etc. Through the operation of the core image collection and processing interface of the core image comprehensive management, analysis and processing system, the core image can be automatically collected, edited and processed, and the core image can be directly stored in the core image database in the normal image format or JPEG standard compression format.

The system includes core image acquisition, editing, 3D core recovery, rotating display, image compression and storage, warehousing and various image processing functions (including: ① adjusting the brightness/saturation/chromaticity of core images; ② Adjust the brightness/contrast/gray level of the core image; ③ Adjust the image distribution curve; ④ Arbitrarily rotate the direction of the image; ⑤ Change the size of the image at will; ⑥ Measure the length, width, direction and area of geological features over 0.2mm; ⑦ Interface of various image acquisition devices).

Second, the system characteristics

1) meets the actual needs of domestic oil fields for core collection, management and application. It can ensure that instruments, equipment and system software can establish a good data interface with the exploration database and development database of China Petroleum and Natural Gas Group Company, and be compatible with various common database systems (sQL, ORACAL, etc.). ) In the oil field, it forms data sharing with the oil field exploration database and development database, which conforms to the Ministry (industry) standards.

2) Conforming to China's national conditions: the full Chinese operation interface is suitable for the operation habits of domestic oil exploration and development professionals (including menu commands, shortcut keys, toolbars and user selection windows).

3) The core image compression and storage function with high compression ratio and low distortion rate is realized, which provides conditions for the storage and management of a large number of core images; It provides conditions for multi-users to share core graphic data in oilfield network.

4) Provide a core image network viewing and application system, which can realize online transmission, browsing and application of core graphic data.

5) Provide single window and multi-view to comprehensively query and compare the graphic information of multi-well cores. It has the comprehensive comparative analysis ability of macro core, rock micro data, analysis test data, logging data and test data.

6) A core image analysis and processing system is provided, which realizes the description, measurement and statistical calculation of qualitative and quantitative geological parameters such as core fracture, grain size and sedimentary structure, and the description accuracy is below centimeter level.

7) The core sedimentary structure image-knowledge base system provided is the crystallization of theoretical knowledge, practical experience and a large number of teaching and scientific research achievements accumulated by the Department of Petroleum Geology of Jianghan Petroleum Institute for decades, which will certainly bring some help to users' production and scientific research.

This product is jointly developed by the Department of Petroleum Geology of Jianghan Petroleum Institute, which can ensure the professional applicability of this equipment.

Third, the effectiveness of the work

After nearly eight years of practical application and research and development, the construction of physical geological data management information system has made remarkable achievements. According to the statistics from 1999 to 2005, the total length of scanned core images is 4219.60 m. Using image processing technology, computer technology and mathematical geology methods, the automatic collection of core images has been realized. The functions of permanent storage, comprehensive management, quantitative analysis and processing of core (macro and micro) maps, documents and related geological data are realized. Because the system adopts open database technology, it can be compatible with other database management systems (such as Oracle, dBase, FoxPro, etc. ) and achieve the purpose of database sharing. At the same time, through the function of oilfield network, the system can conveniently transmit pictures and texts online, and realize the sharing of core maps, documents and related geological data by users. People can easily observe the core information without leaving home. It laid a foundation for the construction of the management information system of physical geological data.

Fourth, suggestions for improvement.

1. Expand the utilization function of rock microscopic images.

The database management system of rock microscopic image is an application software system for rock microscopic image, text description, data information storage and comprehensive management. It should have all the functions of a general graphic database, such as graphic input, editing, management, query and display. It should also have special functions such as multi-well rock microscopic (natural light, fluorescence) image comparison and rock microscopic image album.

2. Enrich the core information base.

According to the requirements of exploration and development database of China Petroleum and Natural Gas Group Company, the core information database should include: basic database of stratigraphic system, core (macro and micro) graphic database, logging database, core analysis and test database, geological logging graphic database, core test graphic database, geological feature graphic database, common geological graphic database, etc.

3. Develop the comprehensive information query and display system of core physical profile.

Core and outcrop profile are the most intuitive first-hand physical data reflecting the underground and regional geological information of the oilfield. Carefully selected cores and outcrop rock samples are generally stored in geological museum or underground palaces established in various oil fields for exhibition and visit. Because the physical storage of cores and rock samples takes up a lot of space, is easy to be weathered and difficult to be preserved, it is difficult to realize a series of comprehensive exhibitions with pictures and texts in geological museum due to the limitations of exhibition venues and related conditions, and it is also impossible for different personnel to visit the library or inquire information indefinitely; It is even more difficult to connect microscopic geological features with microfossil data. Therefore, it is very necessary to establish a digital comprehensive information display system of core physical profile that can be queried and browsed in the oilfield local area network, which can be used for information query of relevant scientific research and production personnel, oilfield external window display and popular science education.