Abstract:To quickly expose shallow overburden areas of grassland and minimize the damage to environment, the shallow drilling sampling technology was used to expose the Quaternary and take the eluvial slope and bedrock layer samples, for geochemical exploration of metallic minerals shallow drilling, geochemical stereoscopic mapping and trenching replacing. A combination of shallow drilling sampling techniques in the shallow overburden area of arid and semi arid grassland was developed. The application of this method in Hua'aobaote leadzinc mine and Dongwuqi area show that through flexible and reasonable adjustment of drilling equipments and drilling process, the target layer sampling should be smooth.

Abstract:The cost and efficiency of in-situ mining of oil shale are affected by the number and size of cracks, it is necessary to build or expand fissures before hydraulic fracturing of oil shale and the fracturing pressure is an important parameter in the fracturing process. This paper takes the Nong’an oil shale as the research object, the numerical calculation of fracturing process of hydraulic fracturing process under perforation completion and numerical simulation was made on hydraulic fracturing process with 2D seepage analysis version of realistic fracturing process analysis software; the fracture pressure of oil shale was obtained. The experimental comparison was carried out on oil shale fracturing in Nong’an mining area; the validity of the numerical simulation was verified. The comparison results show that both the simulation and the experimental values are larger than the calculated ones.

Abstract:According to the difficulties of underground potash salt mining in Qinghai salt flats, the hydraulic fracturing technology was tried to use for increasing the single well yield. The paper introduces the hydraulic fracturing test about the technical principles, fracturing wells arrangement, determination of fracturing section and setting site, installation of ground equipments, fracturing operation and pumping test. The test results show that the stimulation effect is good with average increasing yield up to 559.25% for 4 wells. The hydraulic fracturing technology is introduced into the stimulation field of halogen salt mine in China for the first time, which fills a domestic gap in this field.

Abstract:Because of the importance in the process of geothermal energy development and utilization, water level monitoring of geothermal wells is generally normalized, especially for enhancing resource management and reasonable use of geothermal resources. Currently, the water level measurement is mainly carried out inside the geothermal well casing by directly putting down the measuring line or making use of measuring tubes installed side by side on the pump pipe as channels for measurement. The measuring accuracy would be affected by the tangling of submersible pump pipe & cable and measuring line with the former; and the measuring requirements could not be met because of the imperfect system with the latter. To solve these difficulties, a set of water level monitoring tube system outside casing was developed based on the communicating principle and the feasibility and practicability were proved by the installation test in test well. The paper introduces this system about its working principle, structure design and installation test process, the test results are analyzed and evaluated.

Abstract:Circulation lost is a difficult problem in drilling construction, especially in wire-line core drilling. Severe circulation lost may lead low drilling efficiency and high construction cost, directly threaten the drilling safety and even result in drill hole abandoned. Aus-Plug was an effective delay expansion drilling plugging agent introduced in 2006, by which the circulation lost was well controlled. Since 2003, according to the different formations and lost situations encountered in the tests and construction in a number of mines and through years of practice, the hazards of circulation lost and some plugging methods were explored and summed up; and the practical and effective methods to deal with circulation lost in different geological conditions by Aus-Plug plugging agent also were summarized.

Abstract:Zhunye 2 is one of the first constructed shale gas investigation wells of Xinjiang land and resources system, which was designed for 1700m in depth and completed at the depth of 1617.18m, the coring recovery is 100% at sampling section. The engineering quality fully meets the geological requirements with good gas production. The paper introduces the construction technologies used in Zhunye 2 about drilling equipments selection basis, casing program, coring tools, drill bit application, drilling technical parameters and drilling fluid selection. Some necessary discussions are carried out on the issues of technology and safe construction.

Abstract:Acidizing stimulation technology is an effective measure to improve oil production and an important means of developing oil and gas bearing formation. The water test is not ideal, after the completion of HD-39B geothermal well. The acidizing technology was used based on the analysis on the comprehensive logging data and combined with the formation conditions, cracks were extended and geothermal reservoir channels were linked up, HD-39B turned to be of high-quality with the water yield being from 5.4m3 /h to 80.83m3 /h, wellhead water temperature from 50℃ to 72℃. The application practice shows that the acidizing technology is also suitable for carbonate bedrock fracture geothermal well, which can be popularized in the similar geothermal construction according to the actual conditions and the lithologic characters.

Abstract:According to the pump blocking, hole collapse, diameter shrinkage, short footage per round trip and low core recovery appeared in the tunnel drilling of SZZK8905 which was in Wulonggou mine area in Dulan County of Qinghai with 700.20m in depth, the study on tunnel drilling was carried about rig selection, borehole structure design, coring technology in fracture zone and drilling fluid, and this hole drilling was successfully completed.

Abstract:The drilling construction of 2 deep holes was completed in a mining area of Changchun, which was in soft coal measure strata. The paper introduces the used construction method of wire-line coring with hydraulic percussive-rotary drilling and enlarged annular clearance between borehole wall and drill pipe was selected. The flushing fluid with material compounding of clay, copolymer, plant gum, ammonium salt, potassium humate, sulfonated asphalt and potassium polyacrylate was determined by experiments; daily maintenance management of flushing fluid was strengthened and equipped with centrifugal mud removal machi41ne. The casing thread connection were smeared with rosin (as plastering agent) and welded with thin steel sheet to prevent casing thread releasing. The final hole depth were 1112.45m (ZK6405) and 1359.95m (ZK3201) respectively with 100% core recovery. Coal core samples were not damaged by combustion, the geological requirement was met.

Abstract:By the radial horizontal jet drilling technology applied in oil industry, horizontal directional jet hole can be realized for water block grouting in coalmine. This technology can also be used in looking for the linked fractures in thin limestone and Ordovician limestone confined aquifer, especially in multi-branch injection in vertical well and multilateral well with slight leakage; what is more, with this technology adding appropriate amount of hydrochloric acid and acid corrosion inhibitor for local acid to fracture formation in order to reduce the grouting pressure and improve grouting effect for water blocking. The radial hydraulic jet drilling technology was applied in 9# grouting hole of Wutongzhuang mine of Fengfeng Group with some effects, which can be a means of increasing the water amount of geothermal well.

Abstract:The Ultrasonic/Sonic Driller/Corer (USDC), driven by the piezoelectric system, can take rock samples in other planets because of the light weight, low energy consumption and no rotating parts. The function of piezoelectric stacks is to convert the electric power into the dynamic power of the high-frequency mechanical vibrations, so the ultrasonic horn vibrates in ultrasonic frequency. It is complicated to design the ultrasonic horn due to electromechanical coupling. Based on the ANSYS environment, the dynamic characteristics of the ultrasonic horn under the boundary conditions of electromechanical was analyzed. The modal frequency and the excitation response of the coupling field were in good agreement with the results obtained from the single mechanical structure field. The result shows that the electromechanical coupling of USDC is very weak in the process of electrical energy converting into mechanical vibrating power and can be neglected for calculation. Therefore, the decoupling method will be adopted to design the ultrasonic horn in order to simplify the design process.

Abstract:Direct shear test is a basic experiment for geotechnical engineering investigation, which is widely used for measuring the shear strength of soil in engineering investigation for its simple and easy operation. In view of the characteristics of long duration and large amount of measurement data in direct shear test, a data collection and management system based on VB6.0 and USB7660 multifunction data acquisition modules was designed. The paper introduces this system about its design principle and realization method, and details the design ideas and realization process of each module. The experimental results show that this system can meet the requirements of measurement data acquisition and analysis in the earthwork direct shear test for geotechnical engineering investigation.

Abstract:The paper briefly introduces the characteristics of rotary percussive drilling tool and the working principle, especially the combination of mechanical compact and hydraulic pulse excavating. The drilling efficiency comparison before and after the application of this tool in 12 block of Tahe oilfield and other different formations were analyzed. The tool was used in several wells of 12 block with efficiency increasing 25% at least to nearly 45%. Through the analysis, it was found that the efficiency increasing was not ideal in Halahatang formation of 12 block, but for those well sections and formations with poor drillability and low ROP by PDC screw drill assembly, the drilling efficiency was obviously improved. For example, the drilling efficiency in Kalashayi and Donghetang formations were improved up to more than 60% and generally above 30% with uniform drilling hour per meter and homogeneous rock breaking capacity.

Abstract:In view of the loess formation, reverse circulation air-jet-cutting technique was proposed with air instead of drilling fluid. The bit structure parameters were optimized by Fluent software, the parameters of different diameters of bottom jet orifices, the number of bottom jet orifices, the diameters of bottom jet orifice enlarged sections, the number of bottom jet orifice enlarged sections and the number of bottom jet orifices were stimulation analyzed. The results show that in the case of a certain inlet air flow, air-jet-cutting and reverse circulation capacity of the drill bit would be weakened while increasing the diameter and number of bottom jet orifices. The best performance of air-jet-cutting and reverse circulation capacity can be achieved by the design structure with 2 bottom jet orifices of 3mm in diameter, the bottom jet orifice enlarged section of 8mm and 5mm in the diameter and the length respectively and 5 internal jet orifices.

Abstract:General long spiral bored grouting pile is suitable for sand layer, gravel layer, hard soil and incompetent bed, but not for those lithosphere with high hardness. By the improvement on bit with pressure system and cooling system installing, the application scope of long spiral bored grouting pile is broadened: it can be used in block filling layer, cobble layer and soft-hard bedrock. The engineering practice proves that this technology is effective with promotion value.

Abstract:Due to the construction quality problems, large area leakage and piping occurred in a red mud reservoir dam during the test run. On the basis of the analysis on the causes of the leakage, the leakage was effectively controlled by the emergency reinforcement measures of putting up additional geomembrane on inside dam slope, additional curtain grouting diaphragm wall for upstream of dam axis, additional drainage ditch and drainage prism for downstream dam slope. According to the complexity and unevenness of dam construction materials, the suitable drilling construction technologies and parameters, grouting methods, grouting pressure, grouting segments determination and water cement ratio were obtained according to the grouting test before construction, the grouting effect was ensured.

Abstract:Based on the bionic coupling theory, a kind of PDC cutter was designed according to the non-smooth surface structure of shells. In the design, the posterior slope and side rake angle were mainly considered, which have important influence on rock breaking efficiency. The bionic PDC cutters’ optimal installation angle in bit was theoretically analyzed and that in limestone drilling was further optimized by drilling test. The experimental results show that with the same rotating speed and weight on bit, the fastest rotating speed can be obtained with posterior slope 20° and side rake angle 0°. And the experimental results above may serve as a reference for PDC bit design, especially for the PDC drilling bit used in limestone stratum.

Abstract:Numerical simulation was done on the elliptic bipolar linear shaped charge (EBLSC) based on dynamics simulation software AUTODYN. First, through two-dimensional planar symmetric method and considering granite characteristics, air sandwich and decouple condition, the effects of EBLSC structure and decouple coefficient for smooth blasting were studied. Then, the effective volume work model was established to evaluate blasting results. The results indicated that the specific impulses on blasthole line connecting direction and in vertical direction were similar with deviation below 10%, so the whole energy of charge uniformly was distributed along the circumferential direction approximately. However, there were obvious penetration cracks in blasthole connecting direction with lower crushing and expanding degree of the rock. It indicated that EBLSC could improve significantly the charge energy efficiency and blasting result. In addition, with the decouple coefficient increasing, the loss or waste volume work in blasthole connection direction first decreased and then increased with the existence of maximum effective power. Through curve fitting, the optimal decouple coefficient of about 3.62 was obtained, which was similar to the result of relevant experiments.

Abstract:Instantaneous unloading is instantaneous rock mass stress release and adjustment caused by rock mass excavation. According to the instantaneous unloading process of tunnel rock mass excavation in high stress zone, the instantaneous unloading displacement formula was deduced through the energy conservation; the initial fracture and the complete rupture time of tunnel wall rock mass unloading were deduced based on brittle failure theory of Kachanov criterion, and it was obtained that the complete rupture time is equal to the completion time of rock mass excavation unloading. By the analysis on the instantaneous unloading of a tunnel in Jinping Ⅱ hydropower station, it was concluded that rock blasting would be caused under instantaneous excavation unloading conditions and the initial fracture time was shorter than the complete rupture time, but the fracture has been very clear at that time.