Abstract:In order to solve the problem of precise investigation for deep-long tunnels in the ocean floor of the main channel of Shiziyang， the storage logging system was adopted to obtain parameters such as natural gamma， resistivity， well depth， well temperature， well inclination， etc. in the long reach scientific drilling hole （SZYSD-1S） with large horizontal displacement/vertical depth ratio in the main channel of Shiziyang. The logging data were correlated to accurately divide the rock （soil） properties of the formation； and the geological conditions of vertical holes and the horizontal hole were combined to accurately identify the hidden faults， and divide the surrounding rock level and weathering degree， and the permeability coefficient and permeability of the rock mass. A small-diameter geophysical logging evaluation method was established for deeply buried long tunnels （holes）. The results of SZYSD-1S hole test show that the logging response characteristics of the rock （soil） and the fault fracture zones of the Quarternary and Cretaceous strata are obviously different： the integrity coefficient of rock mass ranges from 6% to 82%， the rock mass quality falls into four levels from relatively complete to extreme fractured with the weathering degree four categories from full weathering to weak weathering， the permeability coefficient ranges from 1.01×10^-7 to 1.18×10^-3 m/s with the permeability from weak permeability to strong permeability. The logging evaluation results are basically consistent with the actual test results. This method is a necessary means to achieve accurate investigation for deep-long tunnels in the ocean floor， and effectively support the construction of the Guangdong-Hong Kong-Macao Greater Bay Area.

Abstract:It is an important part of the construction of the “Belt and Road” seismic monitoring network to carry out reaming and upgrading of CSDP-2 hole of the “Deep Marine Seismic Monitoring Network”. By summarizing the drilling process used for reaming CSDP-2 hole in the South Yellow Sea， a set of drilling technology suitable for offshore deep drilling has been developed： including rotary water well drilling rig which was used on the drilling platform to make the equipment modular and portable； Mud pulse MWD which can effectively save survey time and improve drilling quality from the single point inclinometer. Seawater based low solid polymer drilling fluid which has effectively tackled the problems such as mudstone expansion and mud production in water sensitive formation， circulation loss in broken formation， hazard gas emission from gas bearing formation so as to prevent downhole incidents. The research results can provide technical support and reference for subsequent deep ocean drilling.

Abstract:At present， China depends highly on fossil fuels in the perspective of the energy structure. In the context of global energy transformation， as a new type of clean energy， hot dry rock has the advantages of huge reserves， rich resources and wide distribution. In view of the technical difficulties in drilling of high temperature hard rock in hot dry energy exploration and development， YZX178 hydraulic DTH hammer was optimized in terms of its structure and applied in hot dry rock wells. The results show that YZX178 hammer is feasible and efficient for drilling hard formation such as hot dry rock. It has the advantages of energy saving， environmental protection， high safety， convenient maintenance， cost saving and high temperature adaptability. However， more work needs to be done to solve the problem of matching the working life of the hammer and the roller bit.

Abstract:Cementing quality plays an important role in the later development and utilization of hot dry rock. In view of the problems of high temperature and the incomplete technical system of high temperature cement in hot dry rock exploration Well GR1 in Datong Basin， this paper presents the approach to the development of the high temperature cement slurry technology system through investigation of the geological characteristics of the exploration area and the cementing experience on hot dry rock wells at home and abroad. The results show that the high temperature cementing slurry system which is suitable for Shanxi high temperature dry hot rock wells can be created with the water-gel ratio of high-temperature cementing slurry for hot dry rock wells at 0.45， and the preferred additive of high temperature water loss reducer CG82L， high temperature retarder H40L， high temperature stabilizer CF40L， defoaming agent GX-1， and silicon powder and HV-PAC. The cement slurry system has been successfully applied in Shanxi high temperature hot dry rock Well GR1， and the field cementing quality was good. The research results provide valuable experience and technical support for the same type of high-temperature cementing work in the future.

Abstract:Geostress monitoring holes function as the base of geostress measurement and monitoring； thus， the drilling quality directly affects the effect of geostress measurement， and the reaming quality is the key factor to decide whether the geostress monitoring instrument can be installed smoothly and whether the monitoring instrument can work normally. Great attention should be paid to the drilling work of geostress monitoring holes， and research on drilling technology for geostress monitoring holes should be strengthened. Taking the drilling of a geostress monitoring hole in the Beijing-Tianjin-Hebei Collaborative Development Region as an example， this paper introduces the drilling technology for geostress monitoring holes in detail， including configuration of the core drilling string， selection of the diamond bit， step reaming with the modular reaming bit； and it also proposes some concrete measures to ensure the verticality and concentricity of monitoring holes， reduce the error in hole diameter， ensure core recovery， and improve reaming efficiency and quality， which have led to good drilling results. They can provide important guide for drilling of the geostress monitoring hole in the future.

Abstract:In deep drilling， with the increasing of borehole depth， drilling conditions become more complicated， drilling rate decreases， borehole quality can not be guaranteed， and controlling the borehole direction is difficult. In Russia， the Rotary Steerable System-RSS is used actively with the deflection function of the downhole bit to achieve build-up， drop and hold of inclination. The accuracy of the system is very high（±0.1°）， the depth of the borehole can reach 13 km with the the drilling length per run up to 1000m. The system can provide reference for deep drilling， particularly for ultra deep geological drilling in China.

Abstract:As a new non-mechanical rock breaking technology， high voltage pulse discharge rock crushing technology has a broad application prospect in hard rock drilling. In this paper， based on the analysis of the mechanism of rock crushing by high voltage pulse discharge， the COMSOL Multiphusics software is used to establish the electric-thermo-mechanical multi-physical field coupling model， and to carry out the simulation research on the breaking law of granite and sandstone under the action of voltage， electrode spacing， electrolyte and other conditions. The results show that the broken area of rock increases linearly with the increase of voltage. The increase in electrode spacing results in the decrease in the rock fragmentation area. The conductivity of liquid medium has little effect on discharge results. The broken area of rock can be increased effectively by using multi-electrode pair discharge. The results can provide reference for high voltage discharge rock crushing technology

Abstract:Three exploration boreholes have been completed in the Cangzhou Salt Mine general survey project， with the drilling depth ranging from 3000 to 3451m， and the total coring length of 3791m in Paleogene plastic-brittle formation. Based on the drilling characteristics， the proper bit selection principle was determined for the elastic-plastic interval and brittle interval in the work area. After several tests and improvements， 15 kinds of bits belonging to three categories-carbide， PDC and Balas were used. Comprehensive analysis was carried out according to the bit structure， rock fragmentation mechanism and application effect， and three kinds of bits of H-4-Ⅱ， F-3 and F-6 were optimized. These bits had high efficiency and good coring quality when drilling in Paleogene strata， which are suitable for the geological conditions in the work area， and can be recommended to popularize and apply in this area.

Abstract:Two large karst caves containing confined water were encountered during drilling of ZK27A07 borehole for Baijian iron ore exploration in Shahe City， Hebei Province. In the placement process of ?89mm casing， the casing unscrewed and fell downhole. In the process of accident treatment， the casing fell downhole again， with fishing tools breakingoken and falling downhole for several times， forming a superposition of multiple movable accident heads in the karst cave. We successfully handled the casing falling accident by casting concrete and natural by-pass drilling， so as to avoid scrapping the drilling hole. In this paper， the whole process of accident treatment is described in detail. Through careful analysis of the process and causes of the accident， the specific method is presented for safe placement of the casing string with excessive length and overweight. At the same time， how to realize reliable borehole wall sealing with the casing string in drilling through multiple karst caves containing confined water is discussed， which is intended to provide reference for similar projects.

Abstract:In order to solve the problems with uranium exploration equipment，such as backwardness， high labor intensity， many safety hazards， difficulty in drilling efficiency improvement in Xinjiang， XD-10DK small diameter electric top drive drill has been developed. The drill adopts many advanced technologies， such as modular design， AC variable frequency motor direct drive， dual channel load， digital detection， top drive， etc. The field test for 3 boreholes in the Chepaizi area of the Junggar basin has improved the automation degree and drilling efficiency in uranium exploration with reduced labor intensity and improved working environment of workers， ensuring the safety of drilling equipment and personnel.

Abstract:The research progress on sonic drilling technology in theory and application is discussed. Firstly， the development history of sonic drilling technology is described. Secondly， the typical sonic drilling rigs at home and abroad are investigated and compared with analysis of the shortcomings of domestic sonic drilling rigs. Thirdly， analysis of the application of sonic drilling rigs in soil environmental investigation show that they can meet the requirement for continuous， complete and in-situ weak disturbance sampling of different soil layers. Finally， the research and development direction of sonic drilling rigs are discussed， including development of the high-frequency sonic power head with the dual vibrator structure and the composite rubber damping material to stabilize the high frequency of 150 Hz and prolong the life of the power head， development of anti-fatigue and anti-impact chromium-molybdenum alloy materials to solve the fatigue damage of drilling tools at high vibration frequencies， development of the malfunction diagnosis and auto-repair， remote operation and control， and volatile organic compound online monitoring systems to improve the intelligence and automation level of high-frequency sonic drilling rigs.

Abstract:In view of much time consumption and high risk in pile hole construction for signal tower foundations by the manual water grinding drill combined with air pick in mountainous areas in China， the market is in urgent need of a kind of equipment which can reduce the labor intensity， has high safety factor and fast cutting speed， and is portable and modular. At present， the commonly used foundation pile drilling equipment on level ground mainly includes： shaft drilling machines， raise boring machines and shaft boring machines， etc. These equipment is featured of heavy weight and large overall dimension， difficult handling and poor adaptability to complex terrain and mountainous conditions. To this end， the YXW-2000 hydromill has been developed. It can effectively improve the mechanization degree of pile hole construction in mountainous areas， reduce the labor intensity of workers， and improve the safety of equipment operation. This paper mainly introduces the main technical parameters， the structural layout characteristics and the hydraulic system of the hydromill. The test results showed that YXW-2000 hydromill can meet the mechanization requirements of drilling construction with ease in disassembly and convenient handling， and has a good application prospect.

Abstract:There are abundant reef limestone strata in the South China Sea. Coral reef strata have large primary pores， high compressibility， easy deformation and insufficient strength； so they are prone to filtration， breaking and collapsing. Drilling incidents， such as broken drilling string， hole caving， and bit burial， often happen during drilling on islands and reefs. In drilling marine reef limestone formations， it is not only necessary to overcome the problems encountered on land， but also to tackle the more complex marine environment. In order to solve the coring difficulty in special marine stratum， core drilling with the marine top double-drive linkage riser system was developed on the basis of the ship-borne riserless drilling system. Marine drilling test was carried out at four different stations in the Xisha waters， and the field tests show that this technology can take cores from offshore reef limestone with high efficiency and high recovery； and the coring footage up to 130.75m， which has a broad prospect for promotion.

Abstract:Real-time measurement of downhole temperature and pressure is helpful to improve the coring process and increase core recovery during wireline core drilling. At the same time， the downhole in-situ measurement data is of great significance to understand the physical characteristics of core， especially in the exploration of gas hydrate in the sea. The structure and working principle of the temperature and pressure collector are introduced in this paper. The collector is powered by dry battery and can work for a measurement run more than 72h. It can collect and store temperature and pressure parameters in the core barrel during the whole sampling process. The data can be obtained when it is connected with the computer. The collector completed a test run onborad the Marine Geology 10 drilling vessel， and obtained temperature and pressure data for the entire wire-line coring process. Analysis shows that the data is consistent with the actual coring process， and the collected data is stable and reliable.

Abstract:Liujia gully is a narrow-steep and high-frequency debris flow gully which is located in Jinchuan county， Aba Prefecture， Sichuan Province. Every raining season，rainfall will lead to debris flow disaster chains. In this paper， the author analyzes the characteristics and the environment of debris flow on the basis of field investigation and field survey. Debris flow parameters under different rainfall frequency are calculated by the rain flood method. The paper also analyzes the possibility of debris flow blocking the main river （Kasa gully） to provide the volume weight required. Many difficulties in treatment of debris flow in narrow-steep gullies and are discussed with the case-dependent measures. The Wenchuan earthquake induced a great mass of collapse and landslide with unit-area loose solid materials in Liujia gully up to 98.11×10⁴ m³， and debris flow happened at higher frequency and amplifed volume at the average longitudinal slope of 409.8‰ leading to the formation of the valley disaster chain consisting of rain + runoff erosion-landslide-landslide dam-weir burst-increasing debris flow-barrier lake-hazardous Kasa gullies. To solve the disaster， we suggest comprehensive treatment measures which include using Gabion stone cage to stabilize the slope and the gully， construction of retaining dams and drainage canals. They can provide reference for treatment of high-frequency narrow steep debris flow disasters in small watersheds.

Abstract:Water gushing after the closure of Wangtaipu Mine has threaten the safety production of adjacent mines. Water drainage with large-diameter straight drainage wells is an important approach to reduce the above impact. According to the coal seam geology and water inflow， the diameter of the straight drainage well is designed as ?650 mm. Since the target stratum is a roadway and passes through the goaf of No.3 coal seam， the conventional drilling method will somehow compromise the safety of the target stratum， and it also has slow drilling speed with high cost. To this end， this paper proposes a new casing drilling technology with the large-diameter DTH hammer， where the rock is broken by the DTH hammer， and the casing is used to reduce the up-hole annulus area， hence the the air consumption， eliminating effectively the technical problems of large air volume demand and high cost in large-diameter air drilling. This paper expounds the working principle， characteristics and equipment composition of the technology， and analyzes its application results in the construction of three large diameter straight drainage wells in Wangtaipu Mine. Field application shows that this technology has low air consumption， good cleaning of cuttings and excellent sealing performance. The average well construction period of the 3 large diameter straight drainage wells is 20 days with the average drilling efficiency of 10m/h. It greatly improves the large diameter drilling efficiency， reduces the drilling cost and provides important reference for large diameter drilling.

Abstract:Geothermal energy is a kind of clean and renewable energy， and replacing high carbon energy with geothermal energy is one of the effective ways to reduce carbon emission. Underground pipe insulation technology is one of the key technologies that influence efficiency of geothermal energy exploitation. This paper describes the development situation of underground thermal insulation pipe in terms of the structure， pipe materials， insulation materials， and production process； and points out that the blend of nano insulation materials and vacuum pipe will be the development trend in the future with vacuum nano insulated pipe as the first choice for deep geothermal energy exploitation； meanwhile， it is pointed out that research should be focused on the influence mechanism of basic structure factors on thermal insulation performance of vacuum nano insulated pipe， which has guiding significance for optimization of the production process of thermal insulation tube， reduction of cost and increase of efficiency.

Abstract:Geothermal well reinjection is one of the key steps to ensure the sustainable development and utilization of geothermal resources. This paper， in reference to the geological conditions of thermal reservoir， water quality characteristics and geothermal well pipe material in Lankao， Henan province， presents the indoor corrosion observation experiment and PHREEQC geochemical simulation software. The influencing factors of reinjection effect are analyzed from the aspects of chemical precipitation trend， corrosiveness of geothermal water， drilling and well completion technology. Suggestions are put forward to improve geothermal reinjection effect in terms of geothermal water quality treatment， geothermal well pipe material selection， drilling and well completion technology optimization， reinjection temperature， site selection.

Abstract:Groundwater recharge is an unavoidable step in shallow geothermal development and utilization. The reinjection well is the key facility to carry out reinjection， and its drilling technology is an important factor affecting the effect of reinjection. Taking the recharge wells for shallow geothermal development in the new districts of eastern and western Zhengzhou as the research objects， the differences in geological conditions in different regions are analyzed. The mechanism of groundwater recharge is analyzed in the perspective of the recharge well structure. The factors affecting the effect of reinjection are discussed. With regard to test well construction， this paper discusses the applicable conditions and problems of different drilling techniques， such as mud positive circulation drilling， pump suction reverse circulation drilling and percussive drilling， as well as the impact of the reinforced concrete pipe， steel pipe and U-PVC pipe and other different well pipes on the reinjection effect. To explore the targeted measures to increase the rate of unit recharge. It provides a reference for the construction of shallow geothermal development recharge wells in Zhengzhou and its surrounding areas.

Abstract:The WR-1 geothermal exploration well in Henan province is designed for two exploration target zones， the Neogene Guantao Formation and the Ordovician， which is necessary to be completed and tested separately. After the completion of the Guantao Formation well test， it is necessary to continue drilling to complete the Ordovician section. In the design of the wellbore structure， optimization and improvement were conducted on various aspects， including casing design， cementing structure， to address completion tubing string cementing， matching of the wellbore and casing sizes and filter parameter design for the Guantao Formation section， and verified with actual drilling. This paper mainly introduces the key elements that need to be considered and the design process in the design of the geothermal exploration well structure. The design of the well structure was adjusted and optimized in regard to the actual drilling works， so that it will be operable on site and provide theoretical and practical guidance for other similar two geothermal reservoirs exploration wells.

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