Abstract:Exploiting gas hydrate is based on the evaluation, and sample drilling is the most direct method. The sampling method for gas hydrate by hole bottom freezing is the way that the temperature of the gas hydrate core is decreased by cold source. Active cooling can reduce the critical dissociated pressure of gas hydrate to inhibit gas hydrate dissociating by passive decompression. The result of temperature decreasing is the same as pressure increasing to retain the core of gas hydrates. But it is easy to decrease temperature of core by external cold source at the well bottom. Firstly, the feasibility of freezing method for sampling gas hydrates is verified by the analysis on the temperaturepressure property; secondly, dry ice is confirmed as coolant, alcohol as positive freezing catalyst and cooling medium by means of indoor freezing simulation; and finally, based on the above experiment, the prototype of FCS hole bottom freezing sampler for gas hydrates was developed. Freezing loess sample is achieved by freezing sample experiment. The research puts forward freezing method for sampling gas hydrates, and provides a new idea for the design of gas hydrates core sampler.

Abstract:The paper discussed the reseach results of drilling technology combination in complex conditions of mesocenozonic basin sedimentary rocks in Northwest China: drilling equipments, drilling techniques, drilling technologies in target bed, drilling flushing medium and circulation system, noncoring drilling technology and prevention process.

Abstract:With many good performance of the natural plant extract, plant glue drilling fluid is applied more and more extensively in drilling engineering for geological disaster prevention. The environmental protection performance was studied in raw material structure, pollution by polyacrylamide and the toxicity to evaluate accurately on the influence degree on environment. The study proved that main raw material of KL plant glue drilling fluid and drilling fluid system met the environmental requirement with characteristics of no-pollution, natural degradation and being harmless to human and animal.

Abstract:Drilling mud can clean out the cuttings by its circulation, especially for horizontal hole, it can avoid the sand-bed formation and reduce downhole troubles. Based on the laboratory experiment and engineering application, analysis was made on various parameters which affect cutting movement in horizontal hole with hydraulics, and suggestion was made to establish the overall framework for laboratory experiment evaluation system.

Abstract:According to the formation conditions and drilling cost control, 2 different mud systems were applied in drilling in Sanshui salt mine of Guangdong with satisfied drilling efficiency, accident prevention and cost control. The paper introduced the 2 drilling mud systems in the construction and the system conversion process.

Abstract:According to the study on drilling fluid for years, a set of standardized operation program was summed up, which was applied in several important projects with satisfied result.

Abstract:In the process of drilling monitoring，when well bottom approaches the target point，rectification trajectory is generally designed with ‘line segment-arc method’. The mathematic model has been established, and analytic solutions of mathematic model are given for 4 solving combinations. One application of analytic solutions is illustrated: drawing graphics of analytic solutions can enable the user of computer software to design rectification trajectory rationally. Actual calculated cases indicated that accurate rectification trajectory could be quickly designed by analytic solutions, which has guiding significance in drilling monitoring.

Abstract:Nanfu 273-Ping 253 well is an important experimental well in Daqing oil field, which was drilled by whole process unbalanced technology with the target layer of F15 oil reservoir. Unbalanced state was kept at the bottom of the well by downhole casing shut-off valve in whole process unbalanced drilling operation, the oil reservoir was protected by unbalanced drilling and non-snubbing service. The paper introduced the whole process unbalanced technology, well trajectory control, equipment selection, the difficult problems in field and the countermeasures.

Abstract:The paper introduced the drilling construction technology of drainage holes in Wutongzhuang mine. The 2 holes were of great depth and large diameter in soft-hard alternant stratum, construction was difficult with diameter shrinking and slant borehole. Small-diameter drilling and post-reaming were adopted with reasonable drilling tool assembly, drilling mud and effective deviation preventing measures, and the drainage hole construction was successfully completed.

Abstract:Compared to the vibrating sampling on the ground, there are problems of seawater damping and seawater vibrating during seabed vibrating drilling. Simplified mechanical model and modified coefficients were taken into account of the specific conditions in the seabed, the effects on vibrating penetration by various vibrating parameters of seabed vibrating sampler had been discussed in this paper. A seabed vibrating sampler suitable for seabed soil at 500 m depth had been designed according to the design theory discussed in this paper.

Abstract:Based on the characteristics of coastal zone in China, HK-1 full hydraulic portable drilling rig was developed. The paper introduced the design concept, main technical parameters, structural features, testing and the application.

Abstract:Analysis was made on advantages and disadvantages of vehiclemounted geophysical exploration rig in the market, and the problems to be solved for the new type were put forward. The paper introduced TW100 vehiclemounted geophysical exploration rig about the main components, characteristics, technical parameters and the testing running.

Abstract:Disadvantages of ∮60mm wire-line coring drilling rod in medium-deep inclined hole drilling include: low mechanical strength, poor wear-resistance and inconvenient drilling rod disassembling. Quenching and tempering treatment was adopted to wire-line coring drilling rod, the mechanical strength was greatly improved; high-frequency quenching was made to the surface of drilling rod, the hardness and wear-resistance were increased; and the difficulty of disassembling for wire-line coring drilling rod was preliminary solved by heavy wire-line coring joint with mill groove.

Abstract:Development and utilization of groundwater resource is important for social economic development in water shortage area. Groundwater exploitation has mainly been with drilling for a long time, the paper introduced a new idea of reservoir formed by subterranean stream blocking. Investigation and analysis were made on the karst depression reservoir formation conditions and submergence & dry-out mechanism; the scheme of reservoir formation by subterranean stream blocking was put forward with discussion on the construction technology.

Abstract:Finite element numerical simulation was conducted to investigate the time-dependent behavior of geo-synthetics pile-supported reinforced embankments. Based on comparative study on 3 different cases: (1) un-reinforced embankment; (2) reinforced with geo-synthetics; (3) reinforced with both geo-synthetics and pile walls, analysis was made on the variations of excess pore water pressure induced by the embankment load in soft ground and discussion was carried on the variation of the lateral displacement of embankment, construction settlement and settlement after construction, the maximum tension in geo-synthetics and the load sharing ratio of pile walls. The research conclusion can be the valuable reference for the design or construction of embankments in soft ground.

Abstract:Based on the geological condition, environmental condition, and the depth of excavation, by comparison and demonstration on the schemes, the design of one ‘deep foundation pit’ was changed into tow ‘shallow foundation pits’. The upper foundation pit was constructed with the composite support plan; the lower part was supported with bored grouting pile and an annular horizontal inner bracing reinforcement with concrete. This optimal combination of multiple support techniques was proved safe and economical, could be the reference to the similar design of ultra 100m depth excavations in the same area.

Abstract:Aimed at the present technical difficulty in multiple anchor installation in deep hole, study was made on the installation technology and the installation device, and composite anchor installation device with spline rod and spherical bit was developed. The technical problems were effectively resolved, such as anchor installation and grouting at the bottom in ultra-deep hole in collapsing, block-falling and hole diameter-shrinking formation. The paper detailed the rotary composite anchor installation device with spline rod and spherical bit about the structure, working principle and application effect.

Abstract:Based on the engineering practice of pressure grouting for control on land subsidence and crack in and out of a workshop and the crack in retaining wall, this paper suggested that comprehensive analysis should be made on construction experience, theoretical calculation, testing data and field engineering for scheme establishing, parameter selection and engineering construction. Treatment scheme was put forward and the technical measures were detailed.

Abstract:Chemical grouting is one of the effective technologies for soft ground treatment. The paper introduced chemical grouting principle; construction technology, design and the control with field cases, and put forward the discussion on the former construction experiences.

Abstract:The composite structure with lattice beam and anchor cable grouting is an effective engineering measure in landslide treatment. The paper elaborated the mechanism of lattice beam and anchor cable grouting, calculation principle and steps of lattice beam being simplified as Winkler elastic foundation beam with concentrated forces and design & construction process of anchor cable grouting in fractured rock reinforcement. The composite structure was applied in side slope reinforcement, satisfactory results were obtained.

Abstract:Aiming at the low drilling efficiency and short service life of bit for drilling in hard and compact rocks and the high price of conventional matrix materials for diamond bit, the paper introduced mixing regression design method. Experimental study was made on the replacement of tungsten carbidebased matrix with a new ironbased matrix material; analysis was made on the relationship between the diamond exposure of hotpressed bit and rock abrasiveness properties, the matrix components and the performances were determined to be important. Based on the study of matrix components and performances of hot pressed diamond bit, high phosphorus iron based matrix material was developed and diamond bits with this kind of alloy as matrix were manufactured. The results of indoor drilling test on rock with drillability of grade Ⅸ showed that the average penetration rate reached 1.91m/h and average service life was 60.26m. Therefore, high phosphorus iron based matrix is a economical choice with good performance.

Abstract:Good results were achieved in PD103 adit of Yangshan mining area in South Gansu by smooth blasting and new Austrian method. The paper introduced the blasting parameters and construction technology for small section tunnel in crumbly strata.