Abstract:The technology of reverse circulation continuous coring drilling with hollow-through DTH hammer has shown lots of peculiarities, such as the high drilling efficiency, good quality of borehole and low drilling cost, especially the unique adaptability while drilling in complex strata. In this paper, series of field tests have been conducted on the basis of optimized configuration of reverse circulation drill bits and drilling tools according to Tiancheng gold mine drilling project in Xiaoqinling area. The tests results have shown that the modified drilling system with hollow-through DTH hammer could be of high adaptability to drilling in complex conditions, which could effectively solve the problems of drilling in this ore district. What’s more, the results contribute to the further innovative research on the mechanism theory of hollow-through DTH hammer and the structural design of reverse circulation drilling bits. In addition, it could provide technical supports for the reasonable optimization of hollow-through DTH hammer and drilling tools configuration to achieve the high efficiency, low cost, short period and superior drilling effect in complex geological conditions.

Abstract:In order to evaluate and analyze the stratum fragmentizing situation in Yemaquan mining area of Qinghai, 6 evaluation indexes are put forward: broken specific surface, broken block, porosity of rocks, rock disintegration rate, coefficient of rock integrity, compressive strength of rock. The fragmentized stratum classification standard is established by using fuzzy mathematical evaluation system and combining with rock fragmentized degree index; and combined with the drilling site situation of Yemaquan mining area, the fragmentized stratum is divided into 5 categories. A targeted drilling fluid system is studied out for fragmentizing stratum.

Abstract:Based on the laboratory experiments, the paper introduces the experimental studies on plant glue drilling fluid in Dayangshang tunnel engineering investigation in Suzhou, Jintan mineral resources exploration in Changzhou and Tongshan coalbed exploration in Jurong. The results show that in complex formation drilling, the drilling efficiency can be greatly improved by using plant glue drilling fluid with good core quality.

Abstract:The paper introduces the drilling equipment, construction process, borehole structure, bit selection and the application of flushing fluid for 45° slant-hole construction in Conymecar copper ore district of Peru. The difficulties in the drilling process were analyzed with the treatment measures presenting and the experiences of the high angle slant-hole drilling construction were summed up.

Abstract:With the case of environmental sampling drilling in Dalinuoer Lake in Inner Mongolia, according to the accurate and original (in dimension and state) samples obtaining and the drilling efficiency, the paper introduces the selection and the optional improvement of drilling tools; analyzes and discusses the static pressure, hammer beating and cable drilling of piston drilling tool with evaluation. By the drilling and sampling characteristics of the piston drilling tool, the cable drilling and alternative sampling in double boreholes are optimized. In comparison to the above both ways, by simultaneously using piston and cable drilling, more accurate and original samples can be extract with higher efficiency.

Abstract:The paper introduces the experimental application of BH-114 casing drilling for hole ZK9501 in the complex formation of Makeng iron ore of Fujian. In the experiment, the WOB and torque were transferred by φ114mm casing instead of wire-line drill rod to drive the casing coring tools and based on the wire-line coring catching principles, core drilling was carried out and the main and auxiliary bits were replaced without drill string lifting until drilling across the complex formation to the determined depth. The wall instability caused by drill string lifting and downhole trouble were avoided to reduce the labor intensity, improve the construction environment and promote safe production.

Abstract:The formation characteristics of Longdong coalfield region are described, and based on the analysis on the main factors influencing the drilling construction, the drill bit diameter increasing, the borehole structure optimizing, the suitable drill bit for rock optimally selecting, mud system improving and other supporting technologies were adopted. The paper focuses on the prevention and treatment of the adhesive sticking drill accident.

Abstract:Putaohua reservoir is the main target layer for exploration appraisal well in middle-shallow layer of periphery of Daqing oilfield, but it is a “three low” reservoir, the conventional drilling will cause high cost and low benefit; and by the characteristics of “three low” reservoir, the filtrate under differential pressure is harmful to reservoir. The formation characteristics and overbalance drilling result in low single well production. As a circulating medium of gas drilling in the reservoir, nitrogen has obvious advantages in the reservoir discovery and protection. The nitrogen drilling practice was made in Putaohua reservoir in middle-shallow layer of periphery of Daqing oilfield in 2011, technological innovation was carried out in the well structure, drilling technology and completion methods, the average penetration rate reached 24.43m/h in the 4 test wells, which was more than 2 times of that of adjacent wells by conventional drilling technology. Oil flow was found at sand draining outlet in the drilling process with good reservoir protection effects.

Abstract:The paper introduces the large-angle declined hole construction in Lan'nigou gold deposit of Guizhou, analyzes the application process of flushing fluid and drill bit selection and sums up the experiences of large-angle declined hole drilling.

Abstract:To meet the requirements of the complex formation drilling in urban strata survey, a rotary top drive drilling system with high frequency vibration was developed for JDD-100 full hydraulic drilling rig, which has the functions of rotary drilling, high-frequency vibration drilling and rotary drilling with high-frequency vibration. The top drive drilling rotary mechanism and the vibrating mechanism are designed systematically, and the dynamic simulation analysis is made on the working process of the rotary top drive drilling system with high frequency vibration by using the ADAMS dynamics simulation software. The experiment proves that the device can satisfy the requirements of high drilling efficiency in complex formations for urban geological survey with its rational structure design, high drilling efficiency and long working life.

Abstract:Sampling in rivers and lakes is an essential work in environmental science research and resources exploration. This study provides a new drilling tool for water sampling—hydraulic piston corer. Compared with the traditional piston corer, it has the characteristics of high sampling efficiency and stratum adaptability. This article mainly introduces the design guideline and working principle of the corer.

Abstract:With a brief description about the external structure, internal composition and working principle of Power Drive Xceed rotary steerable system, this paper compared PD Xceed system with mud motor in terms of safety and timeliness. By the application of PD Xceed rotary steerable system in Bohai Oilfield, the analysis is made on the trajectory control, ROP and continuous deviation, the using pattern of commonly used horizontal well mud motor drilling tool and Power Drive Xceed rotary steerable system are obtained, which can be the experience reference to the application in other areas.

Abstract:Because of the serious gas outburst disasters in coal resources of Guizhou area, the gas drainage quantity is very large before mining. In the drainage process, due to the unskilled operation and the blind choice of the bits, a lot of bits were used without good effects. According to the special geological conditions, the improvement was made on the drill bits and good results were obtained. The service life of the drill bit is prolonged from 166.5 m to 399 m and the drilling efficiency is increased from 8 m/h to about 12.4 m/h.

Abstract:Near Huangpu river wharf, a mooring dolphin for 10000 Tons oil tanker was planed to build by an oil refinery of Shanghai, which would be constructed with bored grouting piles. Tide, riprap, mattress, mud leakage and water gushing were experienced during the construction process. Through research and exploration, by the combination of grab, clay wall building, drilling with casing and the rotary drilling method, the difficult problems of boring in riprap, mattress and the quaternary sedimentary layer were successfully overcome with completion of the construction task.

Abstract:The causes of the hole collapse in rotary drilling are analyzed with a case of pile foundation project in Fujian. According to the formation characteristics, high quality mud configuration was adopted for wall protection with good practice effects. The paper introduces the preparation methods of the high quality mud and presents the application effects.

Abstract:By the case of tamping test of dynamic compaction ground treatment with gravel and soil backfill in Laiwu 1000MW class power unit of Huaneng power plant, the construction quality difference and the treatment effects in 2 trial tamping areas with different construction processes are compared. On this basis, the construction quality, effective consolidation depth, soil compactness, deformation parameters and bearing capacity of the ground are found. According to the field tamping and backfill depth, the pre-placed depth and corresponding construction process are selected to determine the final construction plan for the further improvement of effect in dynamic compaction ground treatment, which provides an effective basis for large-area dynamic compaction with backfill and the finalized construction process.

Abstract:Based on an underground continuous wall construction project in Wuhan, this paper discusses difficulties caused by three-axis mixing pile construction in the ultra-deep rock-socketed underground continuous wall and in the joint pipe installation and drawing with corresponding solution measures. The practice proves that these measures are effective and can be reference for similar engineering in wuhan.

Abstract:In the construction of highway and railway in mountainous areas in China, the slopes with poor stability are often produced, which causes the deformation and failure cases frequently. Take the subject of a large-scale landslide in bedding rock in Guiyang to Xinzhai highway construction, by the field exploration and the investigation on the external factors of unfavorable geological environment and human being activities, the simulation is made on the characteristics of tractive landslide activity and the analysis is made on the causes of the landslide. According to the characteristics of tractive landslide, the corresponding control measures are put forward.

Abstract:Take the left line of a shield interval construction in Tianjin metro Line 3 as the example, according to the comprehensive problem of large slope and small radius curve shield construction with continuous crossing building and structure group, based on a variety of data accumulated in the process of construction, the analysis is made on the relationship with ground subsidence and geological, thrust, grouting and deflection correction parameters by summery and mathematical statistics methods. The main factors affecting building settlement are obtained to be the curve and the over excavation, shield tunneling speed, grouting parameters and grouting method; the management and technical measures of control on building settlement are summed up.

Abstract:Ajialing tunnel was planed passing the existing railway. By the comprehensive control technology of pre-support with cavern pipe shed, settlement feedback excavation method, primary support strengthening, monitoring measurement technology and monitoring on cavern pipe shed deformation, the settlement of the existing railway is effectively controlled. According to the tunnel construction conditions, this comprehensive technology breaks through the conventional construction methods and process, and provides the reference for the similar tunnel construction.