Abstract:The mechanisms are complicated in the formation of fog & haze and the pollution of groundwater

Abstract:In shale gas geological survey well construction in Tongren of Guizhou, because of the complex strata structure with development of karst and dissolution in the upper limestone strata, the wall is prone to collapse with block falling and drill pipe sticking, serious leakage and difficult water supply. The depth of Xiuye2 well was designed for 1900m, but this well was halfway abandoned due to the serious lost circulation, block falling and drill pipe sticking in the process of cement slurry sealing and plugging. After drill shifting, the scheme of hole opening with large diameter, multi-stage wire-line core drilling, sublevel cementing plugging and wall protection by multi-layer casing was adopted, the hole construction was completed smoothly. This paper summarizes the drilling experience mainly in cement sealing and plugging to provide reference to shale gas well construction in this area.

Abstract:Natural gas hydrate is regarded as clean energy with research and production value, which has become a hot research topic in the world. But so far, it is still in the research and production stage, no mature and stable gas hydrate production technology system has formed. The exploitation of natural gas hydrate in land permafrost region is relatively easy in contrast with the exploitation of natural gas hydrate in sea area, and the stable hole wall can form during the drilling process. The main natural gas hydrate exploitation methods are thermal stimulation method, depressurization method, displacement method and chemical inhibitor method. SAGD technology is also known as steam assisted gravity drainage, it has been rapidly developed in heavy oil and oil sands mining with very effective results, and is considered to be the most effective way of heavy oil exploitation. In this paper, the application of SAGD technology in natural gas hydrate exploitation in land permafrost region is analyzed, it is found that SAGD technology is feasible in the application of natural gas hydrate mining; however, it is very important to determine the distance between the 2 horizontal wells, and in the application, the upper well should be changed into a production well, while the lower one into the steam injection well.

Abstract:The rescue of Pingyi mine disaster in Dec25. 2015 is the first successful rescue case by hole drilling in China. The continuous collapse and deformation result in complicated stratum conditions, which caused much difficulty to the rescue drilling hole construction. As to these special conditions, air reverse circulation drilling technology was used; and airlift reverse circulation drilling technology was used to deal with drilling accidents. This paper summarizes the experience of large diameter drilling construction and puts forward some problems to be improved in the future.

Abstract:For well pattern infill and large-scale comprehensive arrangement of newly drilled adjustment wells in LD oilfield of northern Bohai, 25 new wells cross with old well pattern and three-dimensional winding of borehole trajectory result in all the wells are three-dimensional designed with serious wellbores crossing problem, the typical case is C6H horizontal well which should be directional deflecting drilled in the Guantao formation basal conglomerate layer with extremely poor drillability. Aiming at the above, through the comparison and analysis on 3 kinds of trajectory scheme for C6H, the most favorable design is optimized; combined with the performance analysis on the screw motor and rotary steerable tools, new mode of DHA with screw motor hydro-oscillator micro eccentric stabilizer is adopted, C6H has been smoothly completed.

Abstract:CBM cave completion technology is not only a kind of open hole completion technology, but also a stimulation technology, which can greatly improve the permeability of the near well zone in the appropriate formation, so as to improve the recovery rate of coal-bed methane. This technology was applied in the high permeability coal seam of San Juan basin in the U.S. with great success, but there is no such obvious effect in other areas. The main reason is that there is certain gap in the understanding of the mechanism of the stimulation technology and reservoir adaptability. In this paper, the stimulation mechanism of the cave completion technology and the applicable conditions of coal seam in cave completion are analyzed; the reservoir selection, well structure, process flow and equipment matching are discussed in detail. The field tests situation and some useful experience obtained in China are introduced, which lay the foundation for the popularization and application of this technology.

Abstract:In recent years, with the deepening of hole drilling and the continuous increasing of complex drilling workload, drill pipe sticking and breaking accidents frequently occur. Under the conditions of broken drill rod with irregular fractures or unsuccessful fishing by conventional fishing cone, the retrievable fishing spear can be used to deal with the accident quickly and effectively. Combined with 2 engineering examples, this paper introduces the retrievable fishing spear about its use method and advantages; and puts forward some suggestions in view of the problems in using process, which can be reference for dealing with the similar downhole accidents.

Abstract:Combined with the construction process of successful completion of a directional branch hole ZKS1952 in ZKS1951 hole position of Jiangxi Wushan copper mine, this paper sums up the screw drill deflecting drilling process of directional drilling large angle branch hole in complex formation; mainly introduces the directional drilling principle, equipment selection, drilling technology and the application of screw drill. The target precision and drilling quality fully meet the geological requirements with good geological effects and economic benefits.

Abstract:For the large angle drilling construction with hole depth greater than 300m, the construction difficulty increases obviously. By improving construction chamber design in the tunnel, the smooth drilling construction and the safety are ensured. Based on the improvement of equipment selection and installation, hole structure, drilling parameters, flushing medium configuration, common accidents and the prevention, the construction technology of large apex angle drilling in tunnel is summarized, the drilling construction of borehole with apex angle 56 degree and designed depth 593m has been completed.

Abstract:To reduce construction cost and improve ventilation effect of underground tunnel, the design of large diameter cable vent is an effective means. A cable vent was designed and completed in a cold mine in Lingbao of Henan, the technologies of current vertical hydraulic shaft drill, multistage reaming drilling, borehole deviation control by pilot hole are used, the ventilation, power supply and communication are realized with good economic benefits. The construction experience is summarized in drilling equipments, drilling technology and borehole deviation and the economic benefits are also analyzed.

Abstract:Based on XY-8 drilling rig, modular design was adopted to develop DB30 multifunction drilling rig, which can be used not only for small diameter deep hole coring drilling but also for large diameter cemented carbide drilling and water drilling. This drilling machine is driven by frequency conversion motor with simplified transmission chain, the transmission efficiency is improved; by the advanced supporting technologies and mature electronic control technology, the rig automation degree is greatly improved. The paper briefly introduces this rig about its technical scheme, technical parameters, structure design, technical advantages and practical application.

Abstract:The low core recovery is the main problem in single tube drilling. That tiny mineral particle of the core being taken away by drilling fluids continually causes the deficiency of core. The reasons for low core recovery is studied from the points of velocity profile, erosion action, core recovery and cuttings removal, and a set of single tube split-flow drilling tool has been designed with flow-distributing and area increasing to improve core recovery. The 3d-fem numerical simulation shows that this modified drilling tool can reduce the velocity of drilling fluids around core by about 25% under the condition of timely cuttings removal and solve the low core recovery.

Abstract:China is a big coal mining country, most of the coal mines are by underground mining with large engineering quantities of coal mine roadway tunneling and supporting, a large number of anchor bits are needed in the tunnel support construction, and anchor bit design and manufacturing technology have been developed rapidly. This paper introduced the development and application status of anchor drill bit, analyzed the bit’s technical feature and applicability, and put forward the existed problems of anchor drill bit in the construction of hard rocks and complex formations combining with the actual needs of the coal mine roadway support. Finally, the development trend of anchor bit is expounded in the aspects of bit design and processing technology.

Abstract:On the background of practice of water gushing treatment in prospecting borehole in Yunnan Maoping lead–zinc deposit, the paper analyzes several treatment schemes according to the diamond drilling engineering practice with high water gushing pressure and large gushing flow. Based on the measured parameters of water inflow and water gushing pressure, controlled grouting technology is put forward. The paper discusses the basic composition of SJP cement slurry and the performance characteristics and controlled grouting technology, analyzes the relationship between the pressure at orifices and the circumstance of grouting slurry in borehole, and puts forward new concepts of “zero starting point”, “zero ending point” and h value in grouting pressure changing, as well as the way to determine the type of gushing-water tunnel by pressure change, etc. The research result has been successfully applied in 3 serious water gushing boreholes to ensure the smooth construction.

Abstract:Shock wave is generated by the electro-hydraulic effect in high-voltage pulsed discharge technology, and local hole reaming is built in downhole. Finally, pedestal piles with different diameters are formed via cement injection. This paper describes the high-voltage pulse discharge technique about the pile forming mechanism by hole bottom reaming, the pile forming process and the effect on the pile diameter, studies the work of shock wave and vapor expansion pressure on pile diameter. The field experiment is carried out by using a newly introduced high-voltage pulse discharge device, the results show that the theoretical formula results are in good agreement with the experimental results.

Abstract:The filling and compacting tests are made for sand gravel filled dam in southern Xinjiang to verify the rationality of dam filling design compaction standard and test the 22t self-propelled vibration roller on the applicability and the performance reliability. The test determined the number of rolling passes, compaction settlement, the corresponding compactness and other parameters mainly by indoor relative density test and field RCC. By comparing the list of test parameters, test parameters enveloping line diagram and design standard values, the best sand gravel filling scheme is obtained and the construction RCC dam filling control parameters are also determined to ensure the engineering quality.

Abstract:Taking the example of Jiangnan working shaft of Changde Yuanjiang river-crossing tunnel, based on the obtained hydrological characteristics and the surrounding strata conditions, the paper makes a preliminary analysis on various aspects such as pumping test, well location layout, anti-inrush checking, settlement analysis and recharge surrounding the foundation pit, and the technical measures related to dewatering are reviewed. The feasibility of the dewatering scheme has been demonstrated through the engineering practice, which will be meaningful to the deep foundation pit construction in the similar high water-rich and strong permeable cobble stratum.

Abstract:This paper presents the characteristics of diamond bit in deep hole drilling. The types of diamond bit, matrix design, diamond parameter design, bit structure and hot pressing parameters are analyzed, the design ideas of diamond bit in deep drilling are put forward, which have been applied in several deep holes drilling with good effects. The design of deep hole diamond bit and the practice experience are summarized, which can be a certain reference for diamond bit selection and application.

Abstract:This paper introduces the importance of pipe jacking resistance in pipe jacking construction, especially in long distance pipe jacking construction. The formulas for calculating jacking resistance in Technical Specification for Pipe Jacking in Water Supply and Drainage Engineering（CECS：2008）and Code for Construction and Acceptance of Water Supply and Drainage Pipeline Engineering（GB 50268—2008）as well as the formula for calculating jacking force of jacking reinforced concrete pipe made by Japan Sewer Association are listed. In a case of earth pressure balancing pipe jacking engineering in Zhengdong new district, the jacking resistance is tested and studied, the difference between theoretical calculation results and actual value is pointed out and new calculating method for the pipe jacking resistance suitable for Zheng Dong new district is put forward.