(Land and Resources Natural Geological Information Center)

The author made a field trip to the Delhi Core Library in New South Wales, Australia, and got a comprehensive understanding of Australia's core management policies, storage facilities, core sources, core types and quantities, selection conditions, preservation methods, information organization and development technologies, and the service areas of Delhi Core Library in London. This paper briefly introduces these contents.

Keywords Australia; New South Wales; London, Delhi; Core bank; operate

Australia has a vast territory and rich mineral resources. In the geological exploration of petroleum, coal, metallic minerals, nonmetallic minerals, strata and paleontology, a large number of physical geological data such as cores, cuttings, specimens, samples and optical slices have been obtained. These physical geological data have been effectively protected and utilized.

According to the decentralized resource management system stipulated in the Australian Constitution, the federal government is responsible for the exploration and development management of offshore oil and gas resources and uranium mines in the northern region, and the state governments are responsible for the exploration and development management of mineral resources within the jurisdiction of each state. Accordingly, the construction and management of its core banks are also divided into two levels.

The first is the federal core bank, which is mainly handled by the Australian Geological Survey (AGSO) under the Ministry of Primary Industries and Energy and the Resource Science Bureau (BRS) under the Ministry of Primary Industries and Energy. The main collection focuses on two aspects: the physical geological data formed by the public welfare geological work carried out by the Australian Geological Survey; Core samples of offshore oil and gas drilling conducted by mining and oil and gas companies. At present, the Federation manages two core sample banks: offshore oil core bank, which not only collects core samples obtained by offshore drilling of all oil companies, but also a small number of onshore drilling cores voluntarily donated by mining companies; The rock sample and core library managed by AGSO contains 76,000 rock samples and some formation core samples.

Second, the national core bank is mainly established by the national mineral and energy departments (some are managed by the geological survey institute under the Ministry, and some are managed by the exploration data center of the Ministry). The main collection contents also include two aspects: the physical geological data formed by the exploration work of the National Geological Survey; Physical geological data submitted by the mining right holder in accordance with the provisions of the national mining law. Australia * * * is divided into six states and 1 autonomous region (northern region). The number and scale of core banks in different States are different, and the types and composition of physical geological data collected are also different.

In February, 2004, the author went to Australia with the geological survey team of China to inspect the London Delhi core bank in New South Wales and the DPI core bank in Victoria, among which the London Delhi core bank in New South Wales has the largest scale, the largest number of cores, the most scientific and modern management. This paper briefly introduces the core management of the core database, hoping to help the management of physical geological data in China.

I. Basic information

The London Delhi Core Bank in New South Wales is located just north of Penris, about 100 km from Sydney. The core library was built in 1964, and the overall design is divided into five construction stages. The facility with an initial investment of about US$ 8 million was put into operation on 1984, and subsequent projects were implemented one after another. By June 1999, the fourth stage was completed, and it is expected to meet the storage demand for 20 years. The fifth stage project has not yet been implemented.

This core library is the largest and most modern core library in the world. The stored cores are about 94× 104m, taken from 6 160 boreholes, and these cores are stored in about 140000 core boxes. Core types include: coal core accounts for about 40%; Metal mineral cores account for about 50%, and other cores (petroleum, nonmetallic minerals, stratigraphy, paleontology, hydrogeology, etc.). ) accounts for about 10%. The replacement drilling cost of these cores exceeds tens of millions of dollars.

The core bank is managed by the New South Wales Department of Mineral Resources. New South Wales combines centralized management with regional management. The core bank of London and Delhi is a centralized national management institution. In addition to this core bank, NSW has also established four smaller regional core banks in Rockenhill and Barker mining areas, which are built near large exploration projects or mines. At present, the total core stored is about 16× 104m. Once the exploration project is completed or the mine is closed, the cores stored in these temporary core banks will be handed over to Delhi core bank in London.

Second, the core management policy

Australia implements a federal system, and each state has relatively independent administrative power. In terms of core management, some states have formulated special laws and regulations to regulate it, while New South Wales has no special legislation. In this case, in 1982, the Committee composed of D.M.Thompson and others was entrusted by the Ministry of Mineral Resources to formulate a report entitled "Policy Suggestions on Core Collection, Preservation and Treatment", which was approved by the Minister as the policy of the Ministry and the knowledge of relevant parties, and accordingly, core collection, collection, storage and service were carried out.

The guiding ideology and practice of core management put forward in this report are as follows.

1) Core management is a part of the whole information service plan of the Ministry of Mineral Resources. The construction of core banks is an important part of the first task of the plan. The task of the core bank is to preserve the representative cores obtained by drilling in New South Wales by the State Department of Mineral Resources and other units outside the Department, so as to minimize the cost for users of mineral exploration and mining in New South Wales to expect earlier drilling results.

2) According to the expected value analysis, the mineral resources department should keep the core. Providing reserved representative cores is an integral part of the information plan of the Ministry of Mineral Resources and should be continued.

3) Mineral resources departments select existing cores according to certain principles and standards, so as to improve the relative availability of cores.

4) Whether to keep the core will be decided according to its representativeness and/or unique scientific value.

5) In order to save more representative cores in the core repository, we should consider adding appropriate clauses in the authorization conditions applicable to exploration qualification, requiring that cores must be sent to the Ministry of Mineral Resources for storage in the core repository of the Ministry before making a decision to deal with such cores.

6) When the mineral resources department receives a new core, it shall notify the exploration industry department. The notice shall be issued once every six months in the form of a notice, which shall include a brief introduction to the core property.

7) The confidential core shall be kept by the Ministry of Mineral Resources, and the confidentiality period shall not exceed 5 years.

8) With the Ministry of Mineral Resources participating in some new major drilling plans, he should comprehensively evaluate the costs and benefits of long-term centralized storage of cores in these drilling plans. The cores produced by the drilling plan of the Ministry of Mineral Resources should be kept in situ at least before the end of exploration.

9) Cores shall be stored in a centralized way and in different regions. The centralized storage place is Delhi Core Library in London, which is the centralized storage place for all drilling cores. Partition storage can determine the number and scale of regional libraries according to needs. The purpose of the regional library is to preserve the cores obtained by the drilling plan of the Ministry of Mines and a small number of cores obtained by drilling in neighboring companies with the consent of the Ministry of Mines. These cores should be preserved for a long time before being treated by bidding or invitation in the exploration area. These cores were selected and handed over to Delhi Core Library in London for permanent preservation.

10) All drilled cores are provided by the Information and Foreign Affairs Bureau. The acquisition of cores can be recommended from various bureaus of the Ministry of Mineral Resources. The Information and Foreign Affairs Bureau will keep and publish all the recently obtained core records. The Bureau of Information and Foreign Affairs publishes a registration form of all drilling cores obtained from mineral resources every six months. These registration forms are published twice a year in the Ministry's publications and mailed to mining or exploration companies so that they can obtain catalogue registration forms.

1 1) All contracts of the Ministry of Mineral Resources or other government agencies should include a clause that the driller should send the core to the appropriate regional warehouse or the core warehouse in London and Delhi. Any expenses related to the further transportation of cores obtained by the Ministry of Mines can be obtained from the freight allocation of the Ministry of Mines.

12) The Committee suggested that the current work should ensure that all drilling cores in New South Wales can be submitted to the Ministry of Mineral Resources at the end of the drilling plan or after the qualification expires. The Committee also proposed an appropriate amendment to the Mining Law. It is expected that the revised Mining Law will require the company to submit the cores obtained from exploration work to the Ministry of Mineral Resources after the qualification expires or the plan is completed.

13) Core retention or selection is coordinated by the Information and Foreign Affairs Service Bureau, so that accurate records of all cores in the Ministry of Mineral Resources can be kept, and the selected cores can be submitted in an appropriate way and published in the publications of the Ministry.

Three. Engineering facilities and main equipment

Core warehouse consists of main warehouse, auxiliary warehouse, garage and other engineering facilities. The main warehouse is 52.8 meters long and 32.5 meters wide, with steel frame structure and good lighting and rain-proof facilities. The library is divided into storage area, observation and sorting area, sampling room, testing room, computer room, office and reception room. The reservoir area can be expanded according to the construction plan and needs.

The main equipment for storing cores is shelves, trays and core boxes. The shelf is made of steel, 7.5m high and 0.998m wide. The shelf is divided into 10 floors, and the shelf spacing is 1.5 12m ... This tray is made of wood. The core box is made of iron, the length is 1. 1m, and the width and height are different, depending on the core thickness, specimen and sample size. The number of layers of core boxes discharged from each pallet varies from 3 to 5 to 8 to 15. The number and weight of cores stored on the core rack are different-the weight below 5 floors is light, and the weight above it is heavy.

The core is completed by stacker and forklift, which is mechanized at present and has not been automated yet.

The arrangement and observation facilities are a row of platforms with pulleys, and the front end of the platform is a spring-type lifting platform that can automatically expand and contract at high speed-the core is placed on this platform, which can automatically lift according to the weight of the core, so that the top layer of the core box is flush with the observation platform, which is very convenient to carry.

The sampling inspection room is equipped with a drilling rig prototype, etc. Used by sampler.

The computer room is used to input the core catalogue and main information, as well as search and query.

Four, core source, type and selection and removal conditions

1. Core source

The core comes from the exploration engineering deployed by the Ministry of Mineral Resources and the exploration engineering carried out by mining exploration companies and development companies. Because there is no statutory requirement for mining companies to hand over cores, all mining companies voluntarily hand over cores to the Ministry of Mines, so the types and areas represented by these cores are limited and random.

At present, about 6.5438+0.4 million boxes of cores have been collected, of which about 90,000 boxes were collected before 654.38+0.98654.38+0.04 m, and about 50,000 boxes were collected in recent 20 years, with an average of about 3,700 boxes per year.

2. Iron core type

(1) metal ore core

It accounts for about 50% of the total core. It is distributed in more than 30 sheets of1∶ 250,000, but it is very uneven. A large number of boreholes come from several exploration areas such as bathurst. On the contrary, most maps like Cobar, Burke, Brokenshire, Cargrigo and New England have a few holes (Table 1).

Table 1 London Delhi metal ore cores are distributed according to1∶ 250,000 sheets.

(2) Coal core

The cores drilled under the coal exploration plan account for about 40% of the total cores in Delhi Core Library in London, and a large number of holes were drilled during the exploration in Sydney, Gunnedah, Clarence, Moretunt and Oaklands basins. These boreholes include not only the cores of coal measures strata themselves, but also the cores of overlying strata (such as in Sydney and Kennedy Basin).

The coal cores stored in London and Delhi include a large number of cores produced by the Ministry of Mineral Resources' own coal exploration plan and cores produced by some coal mining and exploration companies.

All cores produced by the implementation of the coal exploration plan by the Ministry of Mines shall be permanently preserved. However, the situation of core submission by private mining companies is similar to that of metal mine cores, that is, there is no statutory requirement for private mining companies to send the obtained cores to the core repository, and there is no systematic policy or plan to obtain cores from this source.

Only 6% of the coal mines drilled in New South Wales are kept in the Delhi Core Library in London. Therefore, the stored cores are not representative of all coal fields in New South Wales. In Clarence-Moreton, southern and western coalfields, about 65,438+0/4 wells have retained cores, and these wells cover the coalfields like patches. There are not many cores from Newcastle, huntly Valley and Gunnedach coalfields in London Delhi Core Library, which is not enough to cover these coalfields adequately. Although only 12% of the drilling cores in Auckland Basin are collected in Delhi Core Library in London, these wells are scattered all over the basin, and the well spacing is an integer multiple of 4 km, so many wells are needed to completely cover this basin. There are no cores from Great Australia Basin and Gloucester Basin in the core library.

(3) Oil and other cores

In the core library, this kind of core accounts for about 10% of all cores. A small amount of cores and cuttings from early oil exploration and drilling in New South Wales are kept in the core library. Due to the unsystematic collection, it can not completely cover all rock types obtained by oil drilling in the expected sedimentary basin.

In addition to the above cores, there are also various cores planned for formation drilling, engineering drilling and water supply drilling in the core library. This includes cores obtained from investigations conducted by Xueshan Hydropower Bureau in 1950s and 1960s, cores obtained from some boreholes completed by Murray Basin Water Resources Committee, cores obtained by the Ministry of Mineral Resources in the formation drilling plan of Greater Australia Basin, and cores obtained by public companies in the exploration of Pejar Dam and other dam sites.

In addition, because there is no systematic policy to collect these types of cores, the core collection work is also random.

3. Core selection and reservation conditions

The main factors considered in core selection are: drilling position; Representativeness of drilling holes; The borehole represents the mineralization form in this area; Borehole represents the development stage of the explored deposits in this area; Boreholes represent land rights in this area. According to the above factors, the selection and retention conditions of different types of cores are determined.

(1) metal ore core

—— All the cores with large spacing drilled in the early stage should be kept; Boreholes with spacing greater than 0.5 km are considered as initial exploration holes.

—— Select holes with spacing greater than 0.5km from the closely-spaced drilling plan to keep cores; However, each scheme needs to be investigated separately, and whether the core is retained or not depends on its representativeness or unique scientific value. In areas with great changes in geological characteristics, it is necessary to select holes with close spacing.

-Confidential cores that meet the above requirements should be kept, but if an agreement is reached, such cores will not be kept confidential for up to 5 years.

(2) Coal core

—— Keep all initial drilling cores with wide spacing; Boreholes with spacing greater than 4 km can be regarded as preliminary exploration boreholes.

—— Select the drilling holes with spacing greater than 4 km from the drilling holes with relatively close spacing and keep them.

-As a general rule, if you choose between two wells, you should first choose the deepest core as the spare core.

—— Keep drilling cores of coal measures strata with close spacing until the exploration area votes or invites treatment; At that time, this kind of core should be provided to the recipients in this field. If the recipient doesn't want these cores, only the cores of the roof and floor rocks of important coal seams will be kept.

-The confidential core meeting the above requirements shall be retained. If an agreement is reached with the owner of the core, such core will no longer be kept secret for a maximum of 5 years.

(3) Oil, strata and other cores

—— All oil exploration cores and cuttings should be preserved unless the drilling interval is less than 4 kilometers.

—— All formation cores with spacing greater than 4 km shall be reserved.

—— The core in the project site investigation plan shall be kept until the necessary construction works are completed; After completion, representative cores should be selected and retained according to the degree of borehole spacing suitable for engineering investigation and the change of field geological conditions.

-The confidential core that meets the above requirements will be kept, but if an agreement is reached, the core will not be kept confidential for at most 5 years.

4. Core removal

The following cores should be discarded or removed:

Cores with over-dense borehole spacing (generally, the borehole spacing of metal minerals is less than 0.5km, and that of coal is less than 4km).

The core is in poor condition and difficult to identify.

The core that is particularly accessible to the public.

The core that is no longer representative.

All confidential cores should be discarded; Unless an agreement is reached, the core can be decrypted within 5 years at most.

Verb (abbreviation of verb) the meaning of core preservation

The significance of core preservation is mainly reflected in the following aspects:

The core library is a world-class core library, and the core in the library is the result of drilling projects carried out by industry and government. The priceless information resources contained in these cores are an important supplement to the earth science database provided by the state government to promote exploration.

Core preservation has realized the permanent three-dimensional material record of rocks and minerals in New South Wales. This record cost the state government and private mining industry huge investments. It is preserved so that those who can't get the huge funds needed for drilling can check this record, thus making further contributions to improving the geological understanding of New South Wales.

The coal drilling plan of the Ministry of Mineral Resources provides a comprehensive record of coal resources in New South Wales; It is extremely important to preserve these cores for geological research, shaft investigation and understanding the roof and floor conditions that may be encountered in coal mine development.

About half of the "geological surface" in New South Wales is covered by Quaternary caprock, and the only permanent records of the underlying rocks are the records of drilled cores and cuttings, rather than manual samples obtained from exploration wells and shafts.

Core preservation makes the human eye, the most important analysis tool of all, play a role. For geologists, whether macroscopic or microscopic, naked eye inspection can reveal more things than other methods, unless the particles of the inspected substance are extremely fine, even in these cases, the acquisition of raw materials is extremely important for the application of new technologies. People can't use photos or geological records for X-ray diffraction, chemical analysis or extraction of microbial fossils.

Unable to copy the stored core.

For engineering geological research, the preserved cores can be used to plan further tests most effectively according to the unrecorded information during core cataloging.

When the mine is abandoned or mined, the borehole core is usually the only organized geological environment record.

Technological innovation, like the change of metal price, will lead to the re-evaluation of preserved drilling cores.

In the past, it was sometimes impossible to check old cores, which meant that it would cost a lot of money to start a new drilling plan.

There is no alternative to core preservation. The data obtained by photography, geophysical logging, geological logging and analysis are only part of the information obtained by drilling, or represent the interpretation of the original data.

Cost-effective mineral exploration depends on the evaluation of all previously obtained information. By storing cores and providing facilities for testing and sampling cores, the New South Wales government has provided mining companies with information that cannot be obtained by other methods or can only be obtained at a high price, which can reproduce the early work. In many cases where there is no core, only samples collected from areas that are currently inaccessible or completely mined can be provided. Therefore, the core archives play an important role in finding important new mineral resources in this state.

Information development and foreign service of intransitive verbs

1. Information collection and development

The core library in Delhi, London has compiled the stored cores into a catalogue and established a basic information database for users to find and query. The core library is not equipped with core scanning and image management system, and preparations are being made at present. It is planned to purchase core scanning or photography equipment as soon as possible after the investigation, and introduce and develop core image management system to realize the integration of core graphics and images.

At present, the main information collection and development work of the core library includes: collection; Classification, maintenance and storage; Extraction, release and recovery; Popularize geological information.

After receiving the cores, the core library first labels the cores, generally repackages them, and then indexes them according to the mine name, company name, drilling type and location. The method of indexing and storage is similar to the method of storing important documents and books in archives and libraries. This can ensure that the core is properly preserved, which is convenient for future location and rapid extraction.

At present, the core retrieval database is jointly managed by core archives and geological survey. Its retrieval system is a part of the information system of the Ministry of Mineral Resources and has been made into an electronic version with BRS software. The database is called Corefinder, which can be accessed in the following three ways: internal computer system; Online; CD-ROM. Cores can be searched by region,1∶ 250,000 map, borehole type, company or exploration area name.

Soon, the database will cover all drilling activities in New South Wales and link to the core database of exploration reports. The confidentiality of cores is exactly the same as that of exploration reports. When the exploration license expires, the core documents will be made public. Core files generally do not accept the core within the confidentiality period. Generally speaking, except for two remote areas, Brokenshire and Koba, the core database does not provide information on the core storage locations that have not been saved by the Ministry of Mineral Resources.

2. Service targets and service areas

About hundreds of people use the data of the core library every year.

The main service targets and service areas are as follows:

Minister of mineral resources; Officials of the Ministry of Mineral Resources; Other government departments; Mining and mining exploration company; Potential land users seeking geoscience information; Ordinary citizens seeking mineral resources and mining knowledge in New South Wales.

Provide the ownership and land use information of existing exploration and mining rights for applying for exploration and mining rights.

Describe the laws and regulations related to mineral resources exploration and exploitation in New South Wales.

Provides statistical information on mining activities in New South Wales.

To provide public publications to inform the society of the latest development of the mining and exploration industry in New South Wales and to raise public awareness of the importance of mining in New South Wales.

3. Service function

The core library in Delhi, London takes protecting the core and serving the society as its basic purpose, which can provide users with the greatest convenience. These measures mainly include:

In principle, the core library does not accept confidential cores. So at present, only a few cores in the core library are confidential. It is estimated that there is1.5% in the metal ore core; 1.5% in coal core; There is 1% in the oil core.

The identity and purpose of users are not restricted.

Sampling on the core is allowed: you can take half of it wholeheartedly; Half heart can take1/4; 1/4 cores are no longer allowed to sample.

Experimental analysis is allowed, but the results of experimental analysis must be returned to the core library.

All services are charged at a nominal fee.