Abstract:In the past 63 years since the establishment of Bureau of Geology and Mineral Exploration and Development of Guizhou Province， drilling engineering as an important means of geological prospecting has developed into a professional system with complete categories，sophisticated equipment and exquisite technology. On the basis of summarizing the brilliant achievements in geological prospecting of Bureau of Geology and Mineral Exploration and Development of Guizhou Province，this paper reviews in detail the development process of drilling engineering in several key directions，such as small diameter core drilling， large-diameter deep well drilling， mechanized water well drilling，shallow geothermal drilling， etc.； presents a prospect on the future development trend； and puts forward relevant suggestions as reference for future work.

Abstract:In order to solve the problem of accidents in the hole encountered in the drilling project， cutters are used for accident drills. However， rocks could be cut when drills are cut. Therefore， the friction and wear tests of polycrystalline cubic boron nitride （PCBN） against the Si₃N₄ ball are designed at different annealing temperatures based on the complex working conditions. Optical microscope， X-ray diffractometer （XRD）， scanning electron microscope （SEM）， X-ray energy spectrometer （EDS） were used to analyze the influence of heat treatment on PCBN and the tribological behavior of PCBN against the Si₃N₄ ball. The results show that： After annealing treatment above 800℃， PCBN binder oxidation generates TiO₂. Furthermore， there is slight adhesive wear after PCBN at annealing treatment of 800℃ against Si₃N₄ ball. Adhesive wear is more serious after PCBN at annealing treatment of 900℃ against Si₃N₄ ball. However， abrasive wear and adhesive wear coexist after PCBN at annealing treatment of 1000℃ against Si₃N₄ ball. In addition， friction coefficients of PCBN against Si₃N₄ ball are associated with the annealing temperatures.

Abstract:Prediction of ROP is of great significance for optimizing drilling technology， reducing operating costs， and realizing scientific drilling， and it is also an important part of drilling operations. The accuracy of ROP prediction with artificial intelligence technology is remarkable， but the massive data required by this technology puts forward higher requirements for the traditional drilling operations. To determine the minimum amount of data for ROP modeling based on artificial intelligence， analysis was carried out based on 21917 data samples collected from 10 wells at South China Sea. Through correlation analysis， all input parameters were divided into three categories： high， medium and low correlation. By gradually introducing parameters to establish a prediction model to compare the accuracy， it was found that when the number of parameters was sufficient， the parameters in all three categories can be used to establish a high-precision （≥85%） prediction model； however， the higher the correlation of the parameters， the less the number of the parameters required to set up a high accuracy prediction model. When the sampling interval is gradually expanded， comparison found that the accuracy of all the prediction models decreased with the sampling interval increased. The lower limit of the data sampling interval for setting up the prediction model can be obtained through finding out the downward inflection point of prediction accuracy. It is verified that the BP neural network prediction model based on any of the three correlation parameters can still obtain high prediction accuracy when both data dimension and sampling accuracy are at the lower limits.

Abstract:In this study， the feasibility of applying the lattice structure fabricated by selective laser melting to drilling tools is analyzed. The development status of lunar drilling sampling tools， the lightweight 3D metal lattice structures and the basic methods and advantages of selective laser melting technology are summarized. It is proposed to apply the 3D lattice structure to manufacture lightweight lunar drilling sampling tools with selective laser melting manufacturing technology. The adaptability of the drilling tools of the lattice structure to the lunar drilling process is discussed and the development trend of lightweight lunar drilling tools is envisioned. The analysis shows that the 3D lattice structure prepared by selective laser melting has great application potential in lunar drilling sampling tools.

Abstract:Ultrasonic vibration rock fragmentation technology is a new method to solve hard rock drilling problems. Its technical feasibility has been verified by a large number of scholars at home and abroad. However， there is still insufficient understanding of the hard rock fragmentation mechanism under ultrasonic vibration. There is an inevitable connection between the surface radial response displacement of rock and its internal damage state under ultrasonic vibration. In this paper， by monitoring the radial response displacement of rock surface at different depths during ultrasonic vibration， the relationship between the spatial-temporal evolution of surface radial response displacement of rock at different depths and the development of its internal damage is analyzed by using the theory of stress wave propagation. The results show that the damage of rock under ultrasonic vibration is mainly caused by Hertz cone-shaped circular crack caused by high-frequency impact of the vibrating head and fatigue damage caused by the alternating stress of ultrasonic vibration. The propagation depth of Hertz cone-shaped circular crack is 10mm， and the fatigue damage crack mainly occurs at the depth of 10 to 20mm. There is obvious indication of radial response before the local macro fracture of rock under ultrasonic vibration. The radial response displacement of rock surface can be used as the failure criterion under ultrasonic vibration. The research in this paper is of great significance for enriching the mechanism of hard rock breaking under ultrasonic vibration

Abstract:Ultrasonic vibration-assisted technology is widely concerned for its advantages of weakening rock strength， reducing cutting force and accelerating drilling speed. The combination of ultrasonic vibration technology and the disc cutter can effectively improve the construction efficiency in hard rock in tunneling. The process of rock breaking by the disc cutter assisted by ultrasonic vibration is simulated with the particle flow discrete element software. The results show that ultrasonic vibration can produce a periodic stress wave and propagate into rock with strong tensile stress appearing in the near surface area of rock， which is conducive to the tensile failure of shallow rock. Ultrasonic vibration can enhance the crack formation scale inside rock， accelerate the crack formation speed， and advance the crack initiation time， amplifying the rock breaking performance of the disc cutter. With ultrasonic vibration， cracks grow more stable in rock， which reduces the phenomenon of leap-forward crushing， and can avoid the abnormal wear and damage of the disc cutter caused by the impact load caused by the violent vibration， which can help extend the life of the disc cutter.

Abstract:In view of the problems with impregnated diamond bits in deep hard formation such as short service life， low drilling efficiency， a new type of ultrahigh matrix eccentric-cutter impregnate bit was developed. The working pressure of each impregnated cutter is improved through strip or quasi strip design. The eccentric cutter distribution design improves the cutter stress state during the drilling process， which not only improves the working strength of the bit， but also provides a more smooth mud circulation. The supporting structure ensures that the bit has an ultrahigh matrix working height， which is up to 30mm.The combination of pressureless sintering， hot pressing sintering and secondary inlay welding is carried out. The diamond bit has lower thermal damage， high strength and good gauge protection， which provides technical support for deep hard rock drilling.

Abstract:The drilling efficiency of air DTH hammer drilling technology is 10 to 20 times higher than that of conventional drilling technology， which is of great significance for improving mineral resource exploration and development efficiency， and promoting the economic development of Guizhou Province. The southwest （Guizhou） karst area is the largest karst continuous area in the world， where carbonate strata is widely distributed， and karst caves， dissolution fissures and fractures are developed. When drilling with air DTH hammer drilling technology， air leakage is prone to occur， which leads to difficulty in return of cuttings， and even bit sticking and burial accidents. Though the partial reverse circulation drilling process with dual-wall drill rods and the air DTH hammer can effectively solve the difficulty in application of the air DTH hammer drilling process in the Karst area， but the existing sealing device is prone to wear， which limits the application of the process in deep well drilling. With the sealing device for partial reverse circulation drilling with the dual-wall drill rod and the air DTH hammer as the subject of study， through adjusting the structure of the sealing device and improving the rotation performance of the sealing ring， modification and optimization is conducted of the sealing ring to extend the service life of the sealing tool so that local reverse circulation drilling with the dual-wall drill rod and the air DTH hammer can be applied in deep well drilling.

Abstract:Green exploration is a powerful practice of strengthening ecological civilization construction in geological exploration. As an important exploration method， drilling should take lead in green exploration. This paper introduces the application of green exploration in the whole drilling works in the case of Guizhou Zheng''an bauxite fine exploration project， compares and analyzes the field results of the main types of drilling rig in the market in green exploration， and probes into the problems with the current exploration drilling works.

Abstract:In order to better serve deep drilling engineering and accurately understand the plugging performance of the drilling fluid， six film-forming plugging agents were optimized and evaluated by sand bed test， API static water loss test， rheological property test and temperature resistance test in different drilling fluid systems. The results showed that 2^# and 4^# film-forming plugging agents had the best plugging performance among the six film-forming plugging agents， and the optimal dosage of them in the basic drilling fluid was 2%.The drilling fluid added with 2^# and 4^# plugging agents at 100℃ had better temperature resistance. The bentonite content and the additive are two important factors affecting the plugging performance of the drilling fluid： the higher the bentonite content， the better the plugging performance of the drilling fluid， and the plugging performance of the drilling fluid can be improved by adding polymer and the filtrate reducer. Sand bed experiment is an important basis to evaluate the plugging performance of the drilling fluid.

Abstract:At Danping Bauxite Mine in Zhengan county， Guizhou province， formation is broken and karst is developed， leading to drilling problems such as bit sticking by falling stones， difficult pull-up of casing. The drilling targets and tasks were completed on schedule through implementation of various technical measures， including optimization of the hole structure， proper selection of drilling parameters， combination of casing while drilling with wireline coring to provide wall protection in the karst cave deposit with higher borehole completion rate， sealing of borehole wall with polymer gel to reduces bit sticking in broken formation， use of reverse thread casing to reduce casing loss in collapsed formation with higher drilling efficiency and lower drilling cost， detection of spatial distribution of karst caves with the geophysical transient electromagnetic method to reduce the risk of encountering large karst caves. This paper sums up the drilling experience from the mine to provide reference for similar drilling works.

Abstract:The screw drill tool is a shaft system consisting of a number of rotating shafts connected by a universal coupling， which is used to transfer torque to drive the bit motion. However， owing to the installation or wear and tear of the universal coupling itself， the axial misalignment of the drilling tool will appear， leading to a series of failures， such as offset of the screw motor rotor coupling， bearing movement， shaft deformation， oil film instability， etc.， leading to vibration of the tool and a series of hazards. Therefore， it is of great significance to study the failure mechanism of downhole power drilling tool misalignment， grasp the characteristics of different failures， and timely diagnose the failures under laboratory conditions， so as to reduce or avoid the failures caused by misalignment of the rotor coupling. In this paper， the DHRMT double-span rotor bench is used to simulate various downhole drilling tool failures through setting of rotor misalignment， and the vibration characteristics caused by rotor misalignment is obtained through experiments so as to provide a reference for downhole power drilling tool design and improvement.

Abstract:Reasonable particle size distribution is the key to improve the internal compactness， early mechanical strength and interfacial bonding ability of cementing cement sheath. Based on this， Dinger-Funk equation （hereinafter referred to as “DFE”） is selected to design cementing slurry system from several typical close packing theory of continuous particle gradation. Through a large number of experiments， the optimal range of n value suitable for the design of cement slurry for oil and gas wells is determined for the first time： 0.33~0.40. Combined with the measured results of laser particle size analyzer， nano CaCO₃ （hereinafter referred to as “NC”）， grade G oil well cement and floating beads are successively used in the three particle size ranges of ≤3.38μm， 3.38~70.70μm and ≥70.70μm， and mixed according to the volume distribution curve of DFE （n=0.33~0.40）. On this basis， a low-cost， low-temperature and early strength ternary solid-phase graded cement slurry with a density of 1.50g/cm³ was proposed， and its performance is compared with that of the floating bead binary cement slurry and NC binary cement slurry. The results show that： the compressive strength， flexural strength and interfacial bonding strength of the ternary system are increased by 7%~21.1%，13.4%~51.9% and 41.4%~122.2% respectively compared with the binary system of floating beads and NC. The maximum vertical density difference of cementing cement is 0.022g/cm³. The ternary system based on DFE has good rheology， stability and mechanical properties. DFE has certain guiding significance for guiding the design and application of multiple cementing cement slurry system， and can effectively improve the early strength and comprehensive performance of cementing cement under the premise of ensuring low density.

Abstract:In view of greatly heterogeneous lithology， poor drillability， low mechanical drilling efficiency and short service life of the bit in the massive gravel layer of the Bozi Block， Tarim Oilfield， a new surface impregnated diamond bit for the high-speed turbodrill is designed and studied from the aspects of the blade structure， central strengthening， multi-stage surface impregnated synthetic diamond formula and separate sintering process. The average ROP of the bit is 2.01m/h with the service life up to 300m， which is equivalent to that of the imported impregnated diamond bit， while the cost is far lower than that of the imported bit. The new bit greatly improves the construction efficiency of exploration and development of the formation and reduces the exploration cost.

Abstract:In order to explore the geothermal resources in the Rongcheng geothermal field， the Geological Survey of China has deployed a geothermal exploration well D15 in Xiong’an New Area with the design depth of 3000m and the completion depth 3111.58m. It is intended to reveal the development of the strata in the northern slope zone of the Rongcheng uplift and serve the geothermal development planning of Xiong’an New Area. This paper describes the drilling achievements， including completion of the drilling tasks， assurance of drilling quality； and summarizes hydrothermal well drilling fluid technology， selection of the coring tools， and acquisition of the physical data such as core， cuttings and other. Perforation operation was performed for pumping test to obtain formation parameters on water temperature and volume so as to provide data for the investigation and evaluation of geothermal resources in Xiong’an New Area.

Abstract:In order to achieve efficient and convenient acquisition of various submarine formation samples in marine geological drilling， mud static pressure piston wireline coring tools， marine sand wireline coring tools and hydraulic percussion wireline coring tools were designed， and tested in the South China Sea. The test results showed that the mud static pressure piston wireline coring tools can effectively reduce disturbance of the sample with the in-situ structure relatively maintained. The marine sand coring tools and the hydraulic percussive coring tools had higher recovery in the silt and sand layers， which was better than the specification and can meet the drilling requirements.

Abstract:When deep-sea cementing is performed in the natural gas hydrate formation， hydration heat release of cement slurry will change the phase transition equilibrium conditions of hydrate， and induce hydrate decomposition， causing the quality of cementation at the two interfaces to decrease. In order to improve the cementing quality in hydrate formation， phase change microcapsules with endothermic temperature control can be added to cement slurry to effectively reduce the hydration temperature of cementing slurry. Based on this， a temperature-controlled microcapsule for cementing slurry in deep water hydrate formation was prepared with the self-assembly method. The temperature-controlled core material with single phase transition temperature is easy to fail due to the complex external temperature environment of cementing cement slurry in the process of reaching hydrate formation. For expanding the temperature control range， paraffin and white oil were selected as the mixed core material with the temperature control range from 14.8℃ to 39.8℃ achieved. Study shows that the microcapsule has good apparent morphology and no agglomeration with each other， so it is not prone to leakage during thermal cycling. After mixed with cement slurry， it doesn’t affect obviously the rheological properties of cement slurry. At low dosage， microcapsules mainly reduces the peak temperature of cement slurry and improves the overall mechanical strength of cement stone. At high dosage， microcapsules can not only effectively reduce the peak temperature of cement slurry， but also delay the heat release rate of cement slurry.

Abstract:The artificially filled coral islands and reefs have a special stratigraphic structure， mainly of coral sand and coral debris， which makes it difficult to core and form holes. Taking the geological drilling and coring project on an island and reef in the South China Sea as an example， a series of corresponding technical measures were adopted according to the lithological characteristics of the formation： casing while drilling and dry core drilling for the upper loose or weakly cemented sand and gravel； a sand-bailing tool designed for complete circulation loss formation to ensure a clean borehole in reef limestone； drill bits with advance side nozzles for the soft and hard alternate beds； small-diameter dry core drilling for the silt-sand layer. The technology has achieved good results in drilling of 18 boreholes， which can provide a reference for subsequent coring in coral reef formations.

Abstract:Exploration of the deep earth is indispensable to improve the ability of deep resources exploration and the level and rank of deep geological research of China. Deep scientific drilling is the only engineering method to accurately obtain the physical data from the deep earth. The core and key of deep scientific drilling technology is the drill string， and the size combination of drill string components and the selection of drill pipe joints determine the remaining strength of the drill pipe after balancing its own weight and the ability to cope with the complex situation in the hole； in particular， the performance of the drill pipe joint connecting each drill pipe directly determines the maximum drilling depth of the drill string. This paper reviews the high-performance drill pipe from the aspects of product types and joint structures， and analyzes the shortcomings and failure causes of existing drill pipe joints. The improvement plan is put forward for the drill pipe joint structure， which is of scientific significance and engineering value for improving the reliability， service life and safety of the drill string to make it better used in deep scientific drilling.

Abstract:In view of the difficulty in application of aluminum alloy drill pipes to deep drilling due to their poor wear resistance and corrosion resistance， the basalt fiber reinforced aluminum based composite material was prepared with the 7075 aluminum alloy powder as the base and basalt fibers as the reinforcement by vacuum hot pressing sintering technology. Study was conducted on its microstructure， density and micro-hardness， and the results showed that the basalt fiber is uniformly dispersed in the aluminum base， and substitution reaction takes place between SiO₂ and Al at the interface so as to obtain good interface bonding strength with higher density； meanwhile the addition of basalt fiber significantly improves the micro-hardness of the composite material.

Abstract:The sealing technology for confined-artesian monitoring wells is developed for urgent problems in drilling of groundwater monitoring wells， such as sealing， monitoring， sampling and well development. With the technology， a stainless steel sealing cover plate with multiple functional components is installed at the wellhead of the monitoring well to meet the requirements of the artesian monitoring well. This paper introduces the sealing technology principle， system composition， installation process and sealing method for the confined-artesian monitoring well. The field demonstration shows that the technology can effectively solve a series of problems， such as wellhead sealing， water sampling， well development， maintenance of probes； provide the advantages of good sealing effect， zero water pollution， convenient operation and low cost， and realize long-term automatic collection and transmission of groundwater data from artesian monitoring wells with different characteristics. It can provide a approach for the sealing work of similar wells.

Abstract:Based on the 1∶50000 scale hydrogeological survey carried out in the bedrock area of the low mountains and hills in the central and southern part of Shandong province， the hydrogeological characteristics are analyzed by means of hydrogeological survey， hydrogeological drilling， geophysical exploration， pumping test， water quality analysis and other technical methods. The results show that the groundwater types in the area can be divided into four types： loose rock pore water， clastic rock pore fissure water， carbonate rock fissure karst water and bedrock fissure water. The groundwater recharge， runoff， discharge conditions and their evolution as well as environmental hydrogeology are also analyzed. Three quaternary pore water rich zones with the capacity of centralized water supply are delineated， and two types of bedrock water storage structures：the stratigraphic water-retaining structure and the fault water-storage structure， are summarized. Groundwater quality is dominated with Class Ⅲ， Ⅳ and Ⅴ， and the components higher than the Class Ⅲ standard include mainly nitrate， total hardness， iron， followed by fluoride， etc. With the water prospecting model developed for the area， a total of 10 hydrogeological boreholes with water supply capacity were constructed， with a total water yield of 7017.84m³/d， which can meet portable water supply for nearly 100，000 people and irrigation for more than 5900 mu farmland. The results can be used as guide for exploring new target aquifers for water supply and to locating water wells.

Abstract:Water gushing is one of the main disasters in the mine. It happens fiercely， and often in a short period of time will flood the mining gallery， leading damage to mine production and casualties. In water-rich karst water-filled mining areas and the mining areas where thick and high-pressure aquifers are distributed in the roof and the floor formation， water gushing is prone to happen. However， as long as the hydrogeological conditions are identified and the relevant measures are taken， water gushing in the mine can be prevented and treated. Water gushing was encountered with a large volume at the 1313 working face of Shandong Xiaoyun Coal Mine where there were no boreholes in the working face， and the nine faults discovered in the excavation of the two parallel channels also didn’t conduct water. Analysis of the water level， water temperature and water quality confirmed that it was the ordovician limestone water and the water channel was the hidden collapse column. By capping the water gushing point and grouting the water gushing passage， the water gushing passage was effectively blocked， and the results met the requirements of “Detailed rules for water prevention and control in coal mines” .

Abstract:Guizhou province is rich in shallow geothermal resource with huge exploitation potential. However， widespread carbonate strata and well-developed karst fractures in shallow formation cause great difficulties in placement of shallow underground heat pipes. In the case of placement of the underground heat pipes for the shallow low ground temperature central air conditioner of Maternity and Childcare Hospital of Huairen， Guizhou， various technical measures， including eccentric DTH （down-the-hole） hammer drilling with simultaneous casing， DTH hammer drilling， dust removal by the simple dust remover， sealing off karst caves with cement and logs， RIH of pipes with the auxiliary winch， have been adopted to solve the technical problems such as difficulty in borehole completion， environmental pollution by dust from DTH hammer drilling without underground water over full holes， laying the heat pipes （PE pipe） through karst caves due to presence of loose shallow backfilling and karst weak formation encountered in placement of underground heat pipes in the dewatered karst area characterized by local karst development and water shortage（produced by dissolution， rupture structure， and deep cutting by the river） over the length of the underground heat pipes. This not only guarantees project quality and safety， but also improves construction efficiency， providing construction experience for similar projects.