Si Baitang
(Nonferrous Metals Geology and Minerals Bureau of Henan Province)
Finding big and good mines for the country is the basic duty of the geological exploration unit and the foundation of its survival; developing mining industry and taking the road of integration of prospecting and mining is the direction of enhancing the strength of the geological exploration unit under the new situation; prospecting project is not only an indispensable method of geological prospecting, but also an important means of obtaining economic benefits and improving the comprehensive competitiveness. Prospecting project is not only an indispensable method of geological prospecting, but also an important means to obtain economic benefits and improve comprehensive competitiveness. In my bureau to develop the "highlight the main industry, broaden the industry, the development of auxiliary industry, rich family business" development goals, will be drilling, pit prospecting and other prospecting technology is located in the auxiliary industry, now on the status of drilling units, the role of drilling and deep-hole drilling construction technology and management of a brief discussion, in order to discuss with you.
One, the status of drilling engineering in geological prospecting
As a geological exploration unit, geological work is the core, geophysics, geochemistry, remote sensing, surveying, slotting wells to explore the surface of the surface engineering and other indispensable methods and means of geological work in the early stages. When the local, physical, chemical and remote work is carried out to a certain extent, drilling will begin to verify the size, shape and thickness of the ore body for control, while taking out the rock and ore cores to submit to the laboratory to determine the grade of the ore, and the physical exploration wells to obtain a multitude of geological information. At this stage, when the physical exploration and other methods and means of the spatial location of the ore body and ore grade failed to accurately control, drilling project is an indispensable and important means of deep-searching for minerals.
Drilling is an important means of finding minerals is well known, "information to find minerals strategy and exploration of 100 cases" book introduced in foreign countries, 100 large, extra-large deposits of the discovery of the inextricably linked with drilling. 1957 began geological work in Australia, the Olympic Dam copper-gold-uranium deposits, in 1975 after the start of the drilling engineering system to control the party to achieve a major breakthrough, the mine has become the largest uranium deposits and the sixth largest copper-gold-uranium deposits in the world. uranium deposit and the sixth largest copper deposit in the world. In Australia, South Africa, Canada, the United States and other countries in the exploration of mineral resources, pit exploration work in the preliminary exploration is less applied, deep verification is mainly based on drilling work. The famous Baiyun Ebo mining area in China, the molybdenum field, coal field and numerous bauxite mining areas in Henan Province were proved to determine the high-level reserves after using a large number of drilling works. In the past, drilling has played an important role in geological exploration, at this stage in the "attacking deep blind, explore the edge of the bottom of the" exploration, drilling is the means that must be relied on to find the geology, and therefore, improve the level of drilling technology and equipment and quality of staff is particularly important.
Two, drilling project is to expand the economic scale, an important means of obtaining economic benefits
In recent years, the annual government and social geological exploration projects undertaken by the Bureau, the annual geological project design drilling workload of about 70,000 ~ 80,000 m. According to the Bureau's statistics in 1979, the year 28 drilling rigs opened in 16 mining areas to complete the drilling workload of 69,997 m, the technical drilling workers and the services provided by the Bureau, and the drilling workload. There were more than 1,000 drilling technical workers and service personnel. The drilling work not only serves the geological search for minerals, but also resettles a large number of workers and maintains the stability of the team and the continuation and development of the drilling technology. During the "Ninth Five-Year Plan" period, the geological work was in the doldrums, so that the drilling workload decreased sharply, and the total drilling workload of 10,722m was completed in 5 years under the plan, and a large amount of equipments were left idle or used for other purposes, and the personnel were laid off, and the technical equipments were seriously weakened. In the past four years, our province has injected a large amount of funds for the equipment renewal of geological exploration units by using the project fund of "two rights price", and the drilling equipment of our bureau has been strengthened accordingly, and at present there are more than 30 sets of core drilling equipments in formed units, and according to the scale of the existing equipments, we can complete drilling workload of about 100,000m per year after reasonable organization. In 2008, the designed drilling workload of 130,000m in the planned and social geological projects of the Bureau, if all of them are constructed by the drilling team of the Bureau, the output value can be about 50 million yuan, which will play a larger role in the placement of personnel, training team, improving the technical level of drilling, and obtaining economic benefits.
The Bureau of Coalfield Geology of Henan Province has five units with drilling construction power, and about 150 sets of drilling rigs with a drilling depth capacity of more than 1,000m, forming a strong production capacity, and the construction technology of large-caliber, ultra-deep coal mine ventilation, dry evacuation, and ice delivery holes, and horizontal drilling for coalbed methane has reached the national advanced level. In recent years, the company has been engaged in the drilling of coal field geology, coal bed methane, shallow petroleum, oil shale, coal mine ventilation and dry holes in eight provinces (regions), including Henan, Xinjiang, Shaanxi, Shanxi, Inner Mongolia, Jilin, Guizhou, Yunnan, etc. The annual drilling workload of the company is about 700,000 to 1,000,000m, and the annual output value of the company is 300,000,000 to 400,000,000 yuan, which not only resettles a large number of workers and improves the drilling technology level, but also obtains significant economic benefits. The economic benefits have also been significant. Coalfield Geology Team No.2 has used the income from drilling to renovate the old base, which has made the residential area of the workers become a national civilized community. The 4th Coalfield Geology Team utilized the drilling income to fund 15 million RMB to complete the renovation of water lines, installation of gas and heating in the residential area of the workers in Pingdingshan, and the quality of life of the workers has been improved. A number of domestic drilling companies and geological teams in the successful experience of drilling construction is worth our serious study and reference, their practice has proved that the geological exploration unit drilling equipment, drilling skilled workers is not a burden, drilling industry not only provides a guarantee for geological prospecting, but also to resettle the staff and maintain the stability of the team, and more importantly, it can enhance the unit's overall competitiveness, improve the unit's visibility and obtain huge economic benefits from the drilling construction. The construction of the huge economic benefits.
Three, deep hole drilling technology equipment and construction technology
Nonferrous metal geological exploration team has its own characteristics, in the exploration of endogenous metal deposits has accumulated rich experience. Due to the complexity of the cause of endogenous metal deposits, mineralization is severely restricted by the geological structure, so the integrity of the rock and mechanical properties of the large differences in drilling construction is easy to meet such as broken zone and alteration zone coring, hard rock drilling, drilling bending, drilling collapse leakage and other technical problems. Especially in the work of "attacking the depth to find the blind, explore the edge of the bottom", the drilling depth is relatively deep, and the technical problems encountered in the drilling will be multiplied. If the survey in the periphery and the bottom of the old mining area, by the influence of the previous mining, the hollow area is densely populated, the rock is loose, the problems encountered in the drilling construction will be beyond imagination.
Fujiwen academician, the second depth of the lithosphere within the space of metal mineral resources detection depth is 500 ~ 2000 m. If the design of the drilling depth of 2000 m, according to the 0 ~ 500m hole section, the market price of 500 yuan per meter drilling costs as the basis for the depth of each increase of 300m drilling costs increased by 30% calculation, 1701 ~ 2000m holes, the average price of 1856.47 yuan per meter ($1856.47) (the average price per meter, the average price per meter). 1856.47 yuan (see Table 1 for the calculation of drilling cost of each hole section), then the cost of a single hole will require 2.013 million yuan. If every 300m hole section, drilling cost increase 40% calculation, then the single hole cost will need 2.548 million yuan.
Table 1 Calculation of drilling cost for single hole section
The calculation of single hole cost is only based on the market price, and if it is based on the "Budget Standard for Land Resource Survey", the single hole cost will be increased. More than 2 million RMB is invested in one drill hole, which is a huge cost for the decision-making and investment departments of the geological survey, and at the same time, high expectations are placed on the drilling construction.
(A) deep hole drilling equipment and instruments
1. Selection of drilling rig
Survey depth of 1500 ~ 2000m of drilling, by the integrity of the stratum, the mechanical properties of the rock, the borehole caliber, the top angle of the borehole design, and other factors, the performance of the drilling rig puts forward a higher demand, the selection of a lower center of gravity, wider range of variable speed, the vertical axis of the stroke of the oil pressure is more suitable. The hydraulic drilling rig with lower center of gravity, wider speed range and larger stroke of vertical shaft is more suitable. The existing XY-5 and XY-6B vertical shaft drilling rigs and CS1000P6 and CS3001 fully hydraulic drilling rigs can meet the drilling requirements of 1000-2000m deep holes, and the drilling rigs are selected according to the design depth of the holes in actual work (Table 2). It should be noted that CS3001 type fully hydraulic drilling rig belongs to self-contained, poor detachability, climbing capacity of 25 °, the width of the drilling rig body 2.7m, crawling weight 22t, suitable for plains, hills, if the construction of the mountainous areas must be repaired construction right-of-way.
Table 2: Selection of drilling equipment
Note: The final hole caliber is φ75mm.
2. Other supporting equipment
In order to improve the construction speed and quality, often using rope coring drilling process. In view of the drilling depth is large, the annular gap in the drill hole is small, the pressure loss of flushing fluid or mud is large, take measures to increase the outer diameter of the drill bit, BW320 type mud pump can basically meet the 2000m deep hole drilling pressure requirements. And the power machine should be matched with the demand of drilling rig and mud pump. As for the drilling tower in addition to the strict requirements for strength and bearing capacity, its height can be appropriately relaxed.
3. Specification and type of drill pipe
Deep hole drilling construction uncertainties are more, the drill pipe force is complex, bear torque is larger, the material used for the drill pipe and joints should have enough tensile, compressive, torsion, bending, shear strength; the connection of the wire fastener must be firm and reliable, easy to unscrew and good sealing performance. In order to improve the strength of the drill pipe, you can increase the wall thickness of the drill pipe, but it is bound to increase the weight of the drill pipe, increase the rotary resistance, which correspondingly reduces the drilling depth of the same type of drilling rig. Foreign countries in the deep hole core drilling mostly use aluminum alloy drill pipe, the weight of about 1/2 of the steel drill pipe. due to the increase in wall thickness, wear resistance, life expectancy increases, impact resistance, corrosion resistance. It is recommended to purchase aluminum alloy drill pipes for bold attempts when increasing technical equipment.
At present, the deep hole drilling of endogenous metal, commonly used diamond rope core drilling process, φ75mm caliber is the conventional drilling caliber, foreign drill pipe adopts NQ series (φ69.9mm), and the domestic drill pipe adopts φ71×5mm drill pipe.
In order to ensure that the deep hole construction to reach the design depth, φ60mm caliber as a backup caliber, each geological exploration unit should be equipped with a set of φ56 × 4.75mm rope drilling rod to meet the requirements of the depth of the hole and core drilling tools; in order to meet the needs of complex formations of the wall plugging, should also be equipped with a set of φ54 × 6mm ordinary drilling rods and the corresponding drilling tools.
4. Requirements for coring tools
Existing rope coring drilling tools can ensure the rate of core taking in the general stratum, but for the alteration zone, crushing zone core taking should be developed or introduced to the quality of reliable coring drilling tools. The quality of oil drilling coring tools is reliable, but the outer diameter is large. How to develop the quality drilling tools with φ75mm caliber according to the structure of oil coring drilling tools will be the content of exploration and research in practice.
5. Requirements for the structure and life of the drill bit
Deep hole drilling using rope coring drilling process, due to the outer diameter of the drill pipe and the hole wall annular clearance is small, the flushing fluid circulates in the bottom of the hole with a large loss of pressure, with the deepening of the hole, the pumping pressure will be sharply increased, affecting the normal operation. According to the depth of the hole, the degree of rock looseness and fragmentation, whether to use mud and other specific circumstances, appropriately increase the outer diameter of the drill bit, control between 2 to 5mm. At the same time should also follow the drill bit queue use and other technical rules.
Deep hole drilling drill bit, to have a high service life and drilling speed, extend the working time of the drill bit in the bottom of the hole, minimize the number of times up and down drilling. At present, the drill bits used for diamond mechanical core drilling in China are mostly domestic artificial diamond pregnant drill bits, with low diamond level and short life span of the drill bits. In the drilling depth of more than 1,000m, rotary resistance increases, pregnant diamond drill bit needs high speed can not open up, can consider the use of natural diamond table inlaid drill bit or the development of high life of man-made diamond pregnant inlaid drill bit. In order to improve the efficiency of hard rock drilling, more preparation of anisotropic lip diamond bits.
(2) Deep hole drilling construction design and technology
1. Deep hole drilling construction technology design
Deep hole drilling has a large investment and high geological expectations. To ensure that each drill hole achieves the design purpose, there must be a complete set of construction technology program, that is, the preparation of "single-hole construction organization design" according to the drill hole. The design includes the stratigraphic conditions of the mine and the physical and mechanical properties of the rock, the selection of equipment and power, the selection of drilling rigs and drilling methods, the design of the drilling structure and technical casing, the flushing fluid and drilling parameters, the quality and safety measures, the design of the efficiency and the construction schedule, the construction organization and management, and so on.
2. Borehole structure and borehole caliber
According to the geological design requirements, the final borehole caliber of the borehole is determined firstly, and then the borehole structure is determined according to the complexity of the stratum, the type of flushing fluid used, the method of borehole protection, and the process technology, and according to the principle of economy and practicality.
The rocks of endogenous metal deposits are hard, and there may be a large number of fracture zones, and a drill hole can see several layers or dozens of layers of ore.
The final hole caliber of the drill hole is determined at φ75mm for the drill holes with a shallow depth of 2,000m, and if it is larger than 2,000m, the final hole caliber is determined at φ60mm.
The rocks are relatively intact, and the structure of the drill holes is simple. The opening caliber of the hole is φ110mm, φ75mm rope core drilling to the final hole, φ60mm caliber as a backup.
The rock of the drilling hole is relatively broken, joints and fissures are developed, fracture zones and faults appear frequently, and mud must be used to protect the wall effectively. This kind of drill hole opening caliber can be designed to φ150mm or φ130mm, prepare φ127mm, φ108mm, φ89mm technical casing. Still take φ75mm as the regular caliber and φ60mm as the backup caliber. Under special circumstances, φ75mm rope coring drill pipe can also be used as technical casing.
When the geological design requires in-hole logging or in-well physical exploration method test, the final borehole caliber should be determined according to the outer diameter of the incoming instrument, and the upper borehole structure should be determined in turn. Deep hole construction cost is higher, one-time investment is larger, but the amount of geological information obtained is also a large amount, when the geological department has special requirements on the borehole caliber, the geological department design should prevail.
3. Formulation and performance index of flushing fluid for deep hole drilling
The complexity of rock formation for deep hole drilling is several times higher than that of shallow holes, and the construction is difficult, thus the performance of flushing fluid should meet the requirements of deep hole drilling. When entering a new zone and lacking deep formation information, mud is used as flushing fluid from the opening of the hole to ensure the stability of the hole wall while simplifying the drilling structure and reducing the amount of technical casing into the well. According to different formation conditions, mud formulation and performance indexes are recommended as follows:
(1) Non-dispersed low-solid-phase mud is used for more stable formations. Preparation of 1m3 mud, plus clay powder 30 ~ 40kg, Na2CO31 ~ 2kg, hydrolyzed polyacrylamide (PHP) 0.2kg, calcium polyacrylate (CPA) 0.2kg. mud performance: relative density of 1.02, viscosity 18 ~ 20s, water loss of less than 20mL/30min.
(2) water-sensitive formations, collapsed fallout formations of mud(). Potassium humate mud). Preparation of 1m3 potassium humate mud, plus clay powder 50 ~ 80kg, Na2CO33 ~ 4kg, potassium humate 3 ~ 5kg, Na-CMC0.5 ~ 0.8kg. mud performance: relative density 1.15 ~ 1.20, viscosity 20 ~ 30s, water loss 4 ~ 10mL/30min, pH 9 ~ 10.
(3) fissure stratum, Mud (sodium carboxymethyl cellulose mud) of water-surge strata. To prepare 1m3 of mud, add 150-200kg of clay powder, 5-10kg of soda ash, and 6kg of Na-CMC.
Mud performance:Relative density of 1.3, viscosity of 30-40s, and water loss of less than 8mL/30min.
When there is information on the deep rock strata, the intact strata can be selected from the clear water with lubricant or non-solid-phase flushing fluid to realize rapid drilling.
Deep hole drilling should be reasonably configured for the complexity of the formation mud and maintain good wall protection performance, will be conducive to the improvement of drilling efficiency and drilling quality. Deep hole drilling must be equipped with mud performance index tester, establish a good mud circulation system, and equipped with effective desanding equipment. The mud performance index is adjusted appropriately with the gradual deepening of the drilling and the change of lithology.
4. Technical parameters of drilling
The drilling pressure and rotating speed of deep hole drilling are different from those of ordinary shallow holes, and conventional drilling parameters can be adopted in the hole section before 800m, when the depth of the hole is greater than 800m, as long as the drill rig has the ability to maintain a high rotating speed as much as possible, and the pressure should be adjusted according to the mechanical properties of the rock, the drillability, the shape of the bit's lip, and the need to prevent the slanting of the pumping volume according to the ring gap and the drilling efficiency. ring gap and drilling efficiency moderately adjusted.
5. Preventive measures against hole slanting
The stratum promotes slanting effect, which leads to serious bending of the drill hole. Tongbai County, Henan Province, large river copper mine design hole top angle of 8 °, hole depth of 400m when the drilling trajectory deviated from the exploration line of 60m; a domestic drilling company in Africa construction, hole depth of 1300m when the deviation from the exploration line of 300m, the drilling serious bending led to the failure to drill through the expected hidden ore body, so that the huge investment has not reached the geological purpose. Deep hole drilling in the anti-skew should take the following measures: control the clearance between the drill pipe and the hole wall; use different types of drill bits and control the drilling pressure; when using a larger size drill bit, use the righting device; change the diameter of the use of guide drilling tools.
6. Logging technology of deep drilling
Deep hole drilling in addition to taking rock and mineral core, geological compilation, should also be used in the hole physical exploration logging technology, improve the utilization of the drilling holes, and obtain more geological information for the geological search for minerals.
7. Carry out deep hole drilling technology research activities
Deep hole drilling investment, long cycle, high risk, drilling construction unit should be combined with specific conditions to form a drilling technology research group, focusing on the development and research to solve the following technologies: old mine around the hollow area drilling and wall protection, deep hole drilling structural design, technical casing into the hole and pulling, with the drilling of slanting and correcting the slanting technology, deep hole drilling and branch hole construction technology, complex ground directional drilling and branch hole construction technology. and branch hole construction technology, complex stratum drilling and coring technology.
Four, the organization and management of deep hole drilling
1. Management of deep hole drilling construction
Deep hole drilling includes two aspects of construction organization and drilling technology. Drilling technology and equipment selection and matching has been described earlier, the organization and management of production is also very necessary. The construction of ultra-deep drilling, our bureau has little experience, the third team in Shanxi Province, Yicheng County, iron ore anomaly verification drilling construction this year, completed a depth of 1076.50m of drilling, is our bureau in the endogenous metal drilling construction of the first deep holes, has accumulated a certain amount of experience in deep hole construction. However, this hole has more accidents, the construction time is too long, and the economic benefits are not high.
Deep hole drilling construction in the equipment and apparatus supporting the premise, to have a high level of technical management personnel to guide the drilling operation construction, but also need skilled technical workers to operate. In the future in the deep exploration, will design more ultra-deep drilling, drilling construction how to ensure the completion of the task, will be the problem we face. Under the present circumstances, the management departments at the bureau and team levels should have drilling technicians in charge of the management and technical research of drilling production, and need to train a group of skilled technical workers. In terms of equipment purchase, technical research and personnel training, the focus is on deep hole drilling construction.
2. Cultivation and use of drilling skilled workers
In order to give full play to the role of the existing hydraulic drilling rigs and all-hydraulic drilling rigs, and to actively serve the geological search for minerals and to achieve economic benefits, optimization of the organizational and management methods is needed. There should be technical and managerial personnel responsible for the use and maintenance of drilling rigs, and it is recommended that each drilling rig for kilometer drilling be equipped with 7 technical workers (1 captain, 3 shift supervisors, 3 drillers), and the other 8 to 10 workers can be resolved by hiring temporary workers. Drilling skilled workers should be trained and fixed. Work operation mode according to three shifts of eight hours of work, not only to ensure the normal production and keep the workers have good physical strength, maximize the potential of equipment and human resources. 1500 ~ 2000m deep hole construction, the use of four shifts of six hours of work, the full allocation of skilled workers, and equipped with two to three technicians.
At present, there are 30 sets of core drilling rigs in the whole bureau, and each drilling rig needs 210 people according to the configuration of 7 skilled workers, but at present, there are fewer skilled workers capable of drilling and they are older, so it is necessary to recruit a group of contract workers to operate the drilling rigs. The experience of Henan Coalfield Geological Bureau in recruiting contract workers is worth our reference. Firstly, this group of workers passes the technical training of drilling specialty in technical school; secondly, a long-term employment contract is signed between the social security department and the workers; thirdly, the contract workers are managed according to the way of enterprise employment, and the unit pays the basic pension insurance, medical insurance, unemployment, work-related injury and maternity insurance for the workers, and the base of contribution, the proportion of contribution, and the enjoyment of treatment etc. are all equal to those of social enterprise workers; and finally Contract workers enjoy the same treatment during their working life. The status of the recruited workers is contractual and subordinate to the local labor security department. In addition to contractual technical workers, the drilling rigs also need ordinary workers, taking into account the special nature of the work of the geological exploration industry, this group of people can be used on an as-you-go basis, and sign a temporary employment contract with the workers, in order to ensure that the rigs are fully staffed, and to try to play a role in the role of technical equipment.
3. Drilling equipment supporting
In recent years the two rights price equipment purchase cost injection, so that our drilling equipment has been updated, but in the application of the existence of drilling rod mismatch problem. For example, XY-5 drilling rig is equipped with φ71mm rope drilling rods at the time of purchase, which can guarantee the construction under normal circumstances, and the rope drilling rods lose their advantages when the rock layer is complicated, the drilling hole collapses and leaks, and frequent lifting of the drilling hole or injection of water and mud to protect the wall is required. It is recommended that each geological team should be equipped with a set of ordinary drill rods to meet the needs of drilling production.
4. Preferential policies and requirements
In order to ensure that the existing drilling equipment of the whole bureau to play its due role, in the drilling workload of the geophysical units of the Bureau of contracting out, give priority to their own internal drilling rigs, and create a more relaxed internal environment for them. The use of drilling equipment within the bureau at this stage is based on the team as a unit, if we concentrate our efforts on contracting projects to the society, we will take Geotechnical Company and the four teams as the leading ones, and give full play to the advantages of their Class A qualification and management. Bureau within the various types of equipment should be established accounts, improve the effective utilization of equipment, on time to extract the depreciation of equipment, equipment shall not be leased to individuals to operate.