(Senior Consulting Center of Science and Technology Committee of Ministry of Geology and Mineral Resources, Beijing 1008 12)
Since 1990s, preparations for Chinese mainland Scientific Drilling (CSDC) have made rapid progress:
Hold a seminar on "Key Geological Problems in Deep Geological Research of China" (199 1.3).
The "Pioneer Project of Chinese mainland Scientific Drilling" began to be implemented (199 1.7). 1994165438+10. Through the evaluation, it is considered that the conditions for China to carry out continental scientific drilling are ripe, and it will strive to be included in the "Ninth Five-Year Plan" national major scientific engineering projects.
The National Medium-and Long-Term Outline of Science and Technology Development issued by the State Council pointed out that technical preparations should be made for the implementation of geological science (ultra-deep) drilling engineering before 2000, and it should be implemented before 2020 (1992.3).
The first (1992.4) and the second (1993.5) "Chinese mainland Scientific Drilling Seminar" were held successively to discuss the site selection of scientific drilling in China, and the selection area was reduced from 12 to four, and finally Dabie-Jiaonan was selected as the first target area.
The National Professional Laboratory of China Geological Ultra-deep Drilling (now called Scientific Drilling) was built in China Geo University (Beijing), and the equipment was installed and debugged (1993.5) to carry out scientific research.
China sent a delegation to the International Continental Scientific Drilling Conference held in Potsdam (1993.8) and participated in the preparatory meeting of ICDP (1993.9). Since then, the Ministry of Geology and Mineral Resources has recommended Academician Xiao Xuchang as the Chinese member (1994.438+0). The Ministry of Geology and Mineral Resources sent Xiao Xuchang and Zhi Min to Stanford University to attend the ICDP conference (1995+02).
"The implementation and scientific research of the first scientific drilling in Chinese mainland, China" was officially listed as a major national scientific project in the Ninth Five-Year Plan. The State Science and Technology Commission organized senior experts to comment and vote, ranking third (1995.2). The Ministry of Finance agreed to pay the ICDP membership fee (1995.7). The 36th Xiangshan Science Conference with the theme of "Continental Dynamics and Continental Scientific Drilling" was held. Geological circles in China have gained knowledge of scientific drilling in Chinese mainland (1995.5).
The third symposium on Chinese mainland's first scientific drilling was held again (1996+0). Further choose the goal of Dabie-Jiaonan; And organize experts to conduct on-site inspections.
(1996.2.26 ~ 3. 1) Attended the 8th International Conference on Continental Scientific Drilling in Tsukuba Science City, Tokyo, Japan. The Ministry of Geology and Minerals sent a six-member delegation to attend the meeting. During the meeting: ① Attend the presentation of conference papers of academic groups 1 6; ② Attend the signing ceremony of the memorandum of understanding between China and the United States at ICDP, and participate in the organization and management of the plan and the large-scale discussion of future international cooperation; (3) Liu Guangzhi attended the report meeting hosted by Professor M.D. Zobak, Chairman of the International Lithospheric CC-4 Group, exchanged the activities of CC-4 Group in various countries, and put forward future activities.
According to the site selection of the first continental scientific drilling in China, the "Pre-research and development plan of coring drilling engineering technology for the first continental scientific drilling in China" (1996.3) was put forward.
1 technical scheme for pilot hole construction of Chinese mainland scientific drilling
1. 1 construction conditions
(1) The drilling depth shall not exceed 5000m. In advance, the geological department will put forward the expected borehole histogram and related geophysical data.
(2) The main rock strata penetrated by drilling holes are crystalline rocks, such as gneiss, eclogite, jadeite quartzite and marble.
(3) Through the main physical and mechanical properties of rock stratum, the uniaxial compressive strength may be as high as 100 ~ 150 MPa, and in some cases it may be as high as 150 ~ 200 MPa, which belongs to 7 ~ 12 hard rock stratum in the drillability classification of geological drilling rocks, and in some cases it belongs to extremely hard rock stratum. The abrasiveness of rock strata may be polarized, mostly with strong and high abrasiveness; A few are hard, dense and weakly abrasive sliding layers. Some contain inclusions.
(4) Core is an "information source" for extracting a large amount of geological information, and it is the material data for studying the lower crust and upper mantle. The diameter of the borehole should be large enough to obtain the core with the largest diameter as possible.
Borehole is also the channel of geophysical and geochemical exploration wells in the well, and its diameter and hole wall stability should meet the requirements of advanced high-tech logging instruments.
1.2 Main tasks and functions of scientific drilling pilot holes
(1) Except overburden, core, rock sample, liquid sample (mineralized water, crystal water, oil, etc. ) and gas samples (H2, O2, CO2, He, CH4, Cl, H2S, SO2 and other possible gases) shall be continuously tested and analyzed.
(2) Carry out systematic geophysical and chemical exploration wells in different intervals.
(3) Reduce the workload of deep hole coring and logging in this interval in the future.
(4) Measuring geothermal profile, drilling one or several temperature measuring holes with a depth greater than 100 ~ 300m around the pilot hole, measuring geothermal thermal conductivity and heat flux density, thus establishing a geothermal mathematical model, inferring the geothermal profile of the pilot hole, the temperature of the final hole and the geothermal change, which is very important for selecting coring tools, logging instruments and various samplers in deep drilling and enhancing the structural performance of weak links.
(5) Test various newly developed drills, drilling tools and instruments in the pilot hole.
(6) Test the formation pressure gradient and fracturing strength, and provide reference position and parameters for wellbore stability and deviation tendency.
(7) Check whether various instruments and methods used in drilling sedimentary rocks in the past are effective in drilling crystalline rocks.
(8) Exercise the drilling team and cultivate deep-hole and ultra-deep-hole drilling talents.
1.3 structural design of pilot hole drilling
At the "International Continental Scientific Drilling Conference" held in September, 1993 in Germany/KLOC-0, the delegates almost agreed that, according to the international experience of scientific drilling in construction for many years, in order to save a lot of investment and drill scientific drilling more scientifically, it is necessary to vigorously promote the use of hundreds of exploration and drilling experiences with depths of 4000 ~ 5000 m built in South Africa and Canada. Mr. John Beswick of KENTING Drilling Company in the United Kingdom introduced that there are 150 deep-well rigs with drilling capacity exceeding 5000m m in South Africa, and there are more than 20 rigs with drilling capacity exceeding 5,000 m. According to the drilling experience in South Africa, scientific drilling of 2,000 ~ 6,000 m with this deep geological core rig can achieve scientific and economic benefits quickly and economically.
Some experts put forward to adopt HS- 150 drilling rig of Heath&Sherwood drilling company in Canada (drilling depth is 4,570 meters, and the maximum drilling has reached 5,424 meters) and their specially designed HNQ and NBQ inner and outer large annular rope coring system, which has the following special advantages: ① reducing flushing hydraulic pressure drop; ② After the inner tube is put into the outer tube, it can quickly reach the positioning position of the outer tube at the bottom of the hole (Table
Table 1 pilot hole drilling structure in the first scheme
Note: RTB-drilling tool with reaming, without lifting and replacing the drill bit.
If the first scheme is adopted, two sets of HNQ, HNQ and NBQ drilling tools should be designed, developed or purchased.
Table 2 Drilling Structure of Pilot Hole in Scheme 2
1.4 construction technical route
(1) With reference to foreign construction experience and China's national conditions, we should consider that China is a developing country and its financial and economic situation is not plentiful. All equipment, instruments and technological methods should be based on "self-reliance" and make full use of the successful experience accumulated in drilling engineering over the past 40 years. Those that can be improved and upgraded and developed by themselves should give full play to the potential of their own prospecting machinery and instrument factories (Table 3). In line with the principle of "imported, not imported", we will introduce foreign key products, digest and absorb them, and make up for urgent needs.
(2) The rope coring system must be adopted to greatly reduce the tripping time and effectively shorten the construction period; Improve the core quality, realize the replacement of drill bit without lifting drill string or less lifting drill string, and reduce the labor intensity of workers. The construction cost can be saved by 1/3.
(3) Give full play to China's technical advantages in using small-diameter downhole power machine and matching with wireline coring system, develop and adopt wireline coring drilling tools driven by small-diameter PDM and hydraulic hammer to realize non-rotating or slow-rotating drilling of drill pipe, which can save power, reduce the wear of drill pipe and casing, and effectively prevent well deviation (Figure 1).
Table 3 Domestic treatment agents with temperature resistance of nearly 300℃
Figure 1 Rope coring system driven by bottom power machine
(4) Vigorously adopt physical and chemical methods to stabilize the hole wall, and try to use long open hole drilling (rock self-stabilization) in the crystalline rock in the lower interval, except for some casing in the upper interval. Once the complex stratum is encountered and the stratum is unstable, the small gap casing scheme should be adopted.
(5) Play the role of multi-information carrier of drilling fluid (oil and gas, mineralized water, crystal water, fresh water, salt water and cuttings) and transport a large amount of geological information (Figure 2).
Fig. 2 Function of drilling fluid multi-information carrier
(1) refers to prevent kick, blowout, collapse, shrinkage, etc. ② refers to the transportation of cuttings and rock powder. ③ refers to deep fluids (oil and gas, water, etc.). ) such as H2, O2, CO2, CH4, He, H2S, CO2, SO2 and Na, K, Ca, Mg micropowder, etc. They were brought to the ground at 300℃ and 1000× 105Pa.
The pilot hole drilling project of China Scientific Drilling is an urgent scientific research project.
2. 1 ground equipment
(1) The rope coring system adopts top-driven long-stroke drilling rig with mast.
(2) Microcomputer control winch.
(3) Fully automatic pipe bending.
(4) Automatic pipe extruder
(5) Borehole detector for drill pipe fatigue and fracture.
(6) Drilling operation automation console (including monitoring, acquisition, optimization and feedback system).
(7) BOP stack (totally enclosed 1 set, 2 sets of drill pipe seals).
2.2 the basic theory of deep hole drilling
(1) Physical and mechanical properties of rocks, drillability classification of crystalline rocks and fracture mechanism under high temperature and high pressure.
(2) Establish high temperature and high pressure test facilities.
(3) New lightweight high-strength pipes.
(4) Drill pipe fracture mechanics and monitoring system.
(5) Wear law and mechanism of drill bit.
(6) High temperature and high pressure drilling fluid theory: ① drilling fluid (solid-free) polymer formula, treatment agent, additive, high temperature stability, solid control equipment and theory; ② Theory and practice of hydraulics, rheology and colloid chemistry of high temperature and high pressure drilling fluid.
(7) Drilling mechanics.
(8) Establish the opportunity well database.
2.3 Research on Deep Hole Drilling Technology
(1) Deep hole drilling structure and management program design.
(2) The drilling tools with different hole depths are stable.
(3) Prevention and control of deep hole deviation.
(4) Computer-aided drilling system.
(5) Core sampling technology, liquid and gaseous radioactive sample collection technology, and automatic radioactive detection technology.
(6) Selection scheme of drill bit and drilling tool and determination of corresponding drilling parameters.
(7) Ground temperature detection and temperature gradient law in different hole sections.
(8) Determination of rock fracture law and rock physical and mechanical properties in different hole sections.
2.4 in-well system
(1) Long-life diamond bits and reamers.
(2) Develop new tools and coring bits made of superhard materials.
(3) Cable coring system driven by 3)BHM: ① Cable coring system driven by screw drilling tools; ② hydraulic hammer-driven wireline coring system; ③ "Three-in-one" coring system (rope+screw drilling tool+no bit change).
(4) Hole wall coring device: ① hydraulic or sample scraper; ② The motor at the bottom of the hole drives the horizontal sampler.
(5) High temperature and high pressure gas or liquid sampler.
(6) Small-caliber MWD instrument.
(7) Small-diameter vertical drilling deviation prevention system (VDS).
(8) High temperature cement and its cementing technology.
(9) Drilling fluid with high temperature stability, high lubricity and corrosion resistance and its additives.
(10) Formation tester, deep fluid flowmeter, etc.
(1 1) high-precision deep-hole core orientation instrument and method.
(12) iron-containing aluminum alloy drill pipe and its alloy steel joint.
2.5 Modern management of deep holes
(1) System engineering management in deep hole design, construction and research data (including engineering and economy).
(2) Database in the process of design, construction and research.
(3) Data editing, sorting, publishing and information exchange.
2.6 Information acquisition
Consciously taking representative samples and obtaining more data is a prerequisite for the success of scientific drilling projects. The collected data can be further divided into two parts: underground and surface. The part in the hole includes coring, sand taking, logging, drilling and hydrostatic test, as well as geophysical test in the hole (from the bottom of the hole to the ground or between two holes). The ground part includes solid and liquid samples obtained from the orifice and mud testing device, including the first and preliminary geological description, chemical and physical analysis. Logging project is ambitious and time-consuming. When drilling pilot holes, the drilling cost is equal to the logging plan cost. In order to reduce the risk of loss of production information, logging procedures should be executed one by one. After drilling, long-term measurement and testing will be carried out (Figure 3).
Figure 3
According to KTB's field data, it was completed in the field laboratory until the scientific research report was put forward, and the long-term observation station was built by digging holes.
3. National Professional Laboratory of Geological Ultra-deep Drilling (Scientific Drilling)
3. 1 nature and tasks of the laboratory
The National Professional Laboratory of Geological Ultra-deep Drilling Technology, affiliated to China Geo University (Beijing), was newly established in June 1989 with the approval of the State Planning Commission and the State Education Commission. It is also an open research laboratory of the Ministry of Geology and Mineral Resources, and it is a relatively independent research entity academically. Our laboratory is an important base for basic research and applied basic research in this discipline and related disciplines, and it is also the cradle for cultivating senior scientific and technological talents in this discipline.
According to the principle of "openness, mobility and union", the laboratory is open to the same industry at home and abroad. Experts and scholars at home and abroad are welcome to apply for research topics within the scope of the topic guide issued by the laboratory, and the laboratory will carry out scientific research after approval by the academic Committee. You can also bring your own projects and funds and supporting instruments and equipment to open research laboratories for scientific research activities.
3.2 Research fields of laboratory topics
(1) Continental Scientific Drilling
Construction and preparation of scientific drilling project in mainland China
East Asia Continental Environmental Science Drilling Project
High temperature and high pressure geoscience simulation experimental device (also called HTHP wellbore) (Figure 4)
Fig. 4 High temperature and high pressure geoscience simulation experimental device
(2) New drilling techniques and methods
Based on the study of rock mechanics, new drilling technology, equipment and methods are studied by using high and new technologies such as computers.
AC variable frequency speed regulating drilling rig
Rope coring and bit replacement without drilling
Design and research of rock-breaking tools
New drilling technology of high temperature hot melting method
3.3 Research facilities and equipment
Research on rock-breaking mechanism and tools: mainly engaged in the study of rock physical and mechanical properties, rock-breaking mechanism, rock-breaking tools and new technologies of downhole drilling tools. The main equipment is the rock mechanics testing machine of MTS company in the United States and the medium frequency induction sintering equipment with continuous adjustment of 0 ~ 8000 Hz.
Computer application technology research part: mainly engaged in computer application technology research in drilling engineering and other related departments. The main equipment includes computer-controlled drilling experiment system, microcomputer group and its peripheral equipment, and HP9000 series computer workstations.
In addition to the above facilities, the laboratory has also set up a hot melt drilling test bench.
In order to realize international exchange, a small academic lecture hall and expert studio have been set up in the laboratory.
Lithospheric structure and deep action
3.4 Laboratory Management and Organization
The National Professional Laboratory of Geological Ultra-deep Drilling Technology is under the dual leadership of the State Education Commission and the Ministry of Geology and Minerals, and its administration is subordinate to China Geo University (Beijing).
The laboratory implements the director responsibility system. The director of the laboratory is fully responsible for organizing and leading the scientific research, academic activities, personnel appointment, personnel training, capital use and administrative management of the open research laboratory.
The laboratory has an academic committee, which is an academic accreditation body. Its main responsibilities are: to determine the research direction of the laboratory, formulate project guidelines, examine and approve research projects, review scientific and technological achievements, consider the funding plan of the laboratory, and organize major academic activities.
The regular staff and visiting researchers of the laboratory are appointed by the director of the laboratory. And the implementation of life tenure, outstanding achievements can be hired.
3.5 Main research results of the laboratory
(1) Microcomputer-controlled drilling test rig.
(2) Microcomputer analysis system of drilling technology.
(3) Research on diamond drilling principle and optimized drilling technology.
(4) Research on new electric drive system of geological drilling rig.
(5) Research on methods of improving drill string performance and effectively controlling bottom hole load.
(6) Don't mention the bit changing technology at the bottom of drilling.
(7) New hot melt drilling technology.
(8) Research on high temperature drilling fluid.
Management and research personnel
Lithospheric structure and deep action
Composition of academic committees
Lithospheric structure and deep action