Abstract:Rock blasting technology plays an important role in the construction of infrastructural projects such as tunnel excavation and mining. The plasma rock breaking technology is characterized with no pollution, no flying stones or harmful gases in the blasting process, easy operation and high efficiency, and is the most effective and feasible method to replace the explosive. In this paper, the rock breaking mechanism of plasma generated by underwater wire explosion is studied. The process of copper wire melting during high-voltage pulse discharge is analyzed. The resistance model of copper wires changes at various stages is established. Numerical simulation analysis is performed of the current of the discharge circuit at different stages with MATLAB and compared with the experimental current waveform. The study finds that the shorter the rising edge time of the current waveform, the better the pulse discharge effect. During the process of generating a plasma by a copper wire, the plasma channel has certain electrical resistance. The experimental results are basically consistent with the model numerical calculation results.

Abstract:Through the research and analysis of the water-based and oil-based mud non-landing systems, the treatment process and core technology of two non-landing systems are summarized. In light of the actual situation of Well DY-4, a mud non-landing treatment plan based on the ordinary solid control systems has been designed, and implemented. Through modification, the non-landing system eliminated the mud pit and the settlement tank, avoiding any leakage from the whole mud circulation process of mud circulation, purification and recycling; hence, very environmentally friendly.

Abstract:In view of the extra-large water kick volume in tunnel drilling at Shuiyindong Gold Mine in Southwest Guizhou, this paper summarizes the challenges in tunnel drilling, and examines the effect of super-large water kicks on drilling efficiency. In order to overcome these challenges, the practical significance of using the core-lifting coefficient in conventional core drilling is discussed and the countermeasures of “draining”, “blocking”, and “dredging” in wire-line core drilling are put forward, forming the tunnel drilling technology suitable for the Ⅰa ore seam of the mine. It may provide technical support for other tunnel drilling in similar formation conditions.

Abstract:According to the long-term deep drilling experience, this paper analyzes the main criteria and principle of deep geological drilling design. Through typical cases of deep drilling structure design and implementation, a few drilling structure implementation procedures are summarized. First, for the familiar mine where geological prediction is not far from the reality, drilling can be performed as the experience-based design. Second, if the complex conditions of the lower strata cannot predicted, the exploratory method is adopted, including pilot drilling combined with reaming, adjustment of the drilling structure according to the actual situation. Third, larger diameter drilling should proceed as deep as possible. It may provide some experience reference for the structure design and construction of deep holes and ultra-deep holes.

Abstract:The small-diameter oil and gas geology survey well, when used as a geological survey method, faces a lot of problems and difficulties in the drilling process. Based on the completed Well Yang D1, Well Heifudi-1, and Well Heifudi-2, the drilling characteristics, requirements and difficulty in the oil and gas geological survey well are analyzed. The risks in oil and gas geological survey drilling and the impact on evaluation of the oil and gas occurrence due to incomplete drilling equipment, drilling processes and related safety regulations are explained.

Abstract:For conventional single-tube coring in coal mine underground drilling, there are several disadvantages such as low core recovery, low efficiency and high labor intensity, and difficulty in drilling holes in the near-horizontal coal seam floor with clean water as the drilling medium. Field tests were carried out by selecting and using professional near-horizontal wire-line core drilling rigs and wire-line core drilling tools. Three boreholes were drilled, and two of them were completed at the depth of 151.5m and 194.5m with the average core recovery of 77% and 89% respectively, more than 24% higher than that with the single tube. Average daily footage was 22.7m/d and 36.6m/d, more than 10% higher than that with the single tube. The wire-line coring drilling equipment and technologies for near-horizontal boreholes with clear water as the drilling medium in complex coal mine tunnels was optimized through the above field experiments.

Abstract:In recent years, with the continuous development of directional drilling technology, measurement while drilling (MWD) technology and the manufacturing process of controlled directional positive displacement motor (PDM) drill have become increasingly mature. Surface directional horizontal drilling is widely used in oil, gas, shale gas, salt and other fields. The application of surface directional horizontal branch hole grouting to prevention and control of water in coal mines has been widely promoted. In the drilling process, various incidents cause a large number of human, material and financial losses, and even lead to the abandonment of the whole well and casualties. Therefore, taking proper measures to reduce or avoid incidents and ensure the smooth progress of the drilling work is an important task for drilling engineering. In this paper, in the context of successful treatment of the drill rod sticking and bruying incident during drilling the DB2-E3 directional horizontal well in the first stage of grouting transformation of the Ordovician limestone aquifer in the 9400 mining area of Dongpang Mine by Jizhong Energy Resources Co., Ltd., the preventive measures of the drill rod sticking and bruying incident in the horizontal grouting hole are summarized, providing some guide for the safe construction of the horizontal well.

Abstract:Mechanical automatic vertical drilling tools provide the advantages of high temperature resistance, low cost, wide application range, etc.; however, since the deviation correction and deviation prevention are realized by the gravitational and mechanical structure, the working accuracy under the condition of stick-slip vibration is greatly affected. This paper, with introduction to the stick-slip vibration mechanism, summarizes its concrete influence factors, and compares the existing methods to limit stick-slip vibration at home and abroad to explore suitable stick-slip vibration suppression methods for the mechanical automatic vertical drilling tools so as to provide reliable technical support for improvement of deviation prevention and correction capability.

Abstract:During core drilling, blockage and sticking often occurs when conventional three-wing reaming bits are used for reaming in broken strata such as gravel (boulder), which results in low reaming efficiency. For this purpose, a reaming bit with guiding and gauge protection functions was designed, and was applied in a comprehensive geological hole in Lingwu, Ningxia, with good reaming effect, and the average reaming footage up to 3.5m/h. The reamed hole was highly coaxial with the original hole, and had a regular gauge, leading to smooth casing running. The Quaternary broken formation was effectively separated to ensure smooth performance of subsequent core drilling and geophysical logging.

Abstract:Hydraulic percussive-rotary drilling technology has been widely used in the field of geological exploration; however, this technology finds less application in other drilling fields, such as petroleum, geothermal energy, coal bed gas, etc., because the pump volume, pump pressure, output impact work and impact frequency required for normal operation of existing hydraulic down-hole hammers cannot meet the requirements of the above drilling industries. In order to solve this problem, the relationship between impact energy and impact force was analyzed. The piezoelectric quartz sensor was used to measure the impact energy of hydraulic down-hole hammer with the performance test bench of hydraulic down-hole hammer developed to investigate the influence of hammer structural parameters on its input and output performance parameters so as to meet the requirements of drilling technology in different fields. The newly developed performance test bench is composed of three main modules: data acquisition and processing module, circulation power supply module and mechanical fixing module. The test bench can monitor the output impact work, impact frequency, pump volume, upper and lower chamber pressure, back pressure and other parameters without damaging the hydraulic hammer structure; thus, it can carry out further theoretical research of hydraulic down-hole hammers, improving its research level and applicable field.

Abstract:As the development trend, drilling engineering will become intelligent, automated and IT based. In order to obtain safe, accurate and efficient real-time data at the drilling site, an wireless real-time transmission system for deep-hole intelligent drilling parameters, which combines three wireless transmission modes was researched. With modular programming based on the LabVIEW software platform, the wireless real-time transmission system composed of five major modules was developed, including a wireless transmission and reception module, a remote network transmission module, a database module, a complex drilling condition recognition module and an accident diagnosis module. Indoor simulation tests and field application showed that it meets the requirements of field application, and can be applied to complex, deep-hole, and intelligent drilling sites, which may meet the needs of deep resource exploration engineering, and provide support for national important energy resource exploration projects.

Abstract:In order to ensure that the recharge water in the foundation pit dewatering project meets the water quality requirements of the spring groundwater system in Jinan, an integrated dewatering and recharge apparatus for foundation pit projects has been developed. The apparatus consists of two parts: recharge engine and water collection tank. The main components are water pump, filter, pressurizing tank, electronic control system, water collection tank and recharge well tubing. The working principle and technical characteristics of the recharge apparatus are introduced. Through the successful application in the foundation pit dewatering project of Dayangzhuang Station on Line R1 of Jinan Rail Transit, the integrated dewatering and recharge apparatus for the foundation pit project has achieved good environmental and social benefits.

Abstract:The pile skin friction design parameters for the mudstone foundation are scant. According to the test data of large diameter deep piles of the Songhua River large bridge by means of the Osterberg cell pile test in Jilin Province, and in conjunction with the medium-scale shear test between the pile and mudstone, the interaction mechanism and load characteristics of mudstone skin friction were revealed, leading to some constructive conclusions for the design and in-depth research of the cast-in-place pile for mudstone foundation. The results show that: the end resistance of large diameter deep piles only accounts for a small part of the bearing capacity of the total load, so it belongs to the friction type pile. By means of the Osterberg cell pile test, skin friction in completely weathered mudstone, strongly weathered mudstone and moderately weathered mudstone reached 173kPa, 279kPa and 336kPa respectively. These values of mudstone skin friction are greater than specified reference ones. In the design of pile foundation, it is recommended that the mudstone skin friction estimated using the shear strength parameter measured by medium-scale shear tests, and based on the Mohr-Coulomb criterion, can provide economical and reliable parameters for estimating the bearing capacity of piles.

Abstract:In this paper, the commercial crude oil reserve base project of Caofeidian was taken as the study subject. Based on the characteristics of the project, vibro-replacement stone piles were selected to reinforce the storage tank foundation. Due to the hydraulic pressure and vibro-flotation disturbance and the other causes, part of the pile-soil composite foundation was observed of large settlement, which did not meet the design requirements. The reinforcement measures with sinking pipe stone piles were adopted. It was proved that the foundation treatment method by the sinking pipe stone pile reinforcement can eliminate the insufficiency bearing capacity issue of the in-situ consolidated foundation and it is an economical and reasonable reinforcement method for the foundation.

Abstract:With the rapid development in urban construction, it is the general trend to intensify underground space development and utilization, leading to deeper foundation pits and more complex surrounding conditions. Double-row piles have found more wider usage due to many advantages. Based on a field case, this article briefly introduces the characteristics, the plan, and the concept; as well as problems of the double-row pile support combined with anchors, and treatment measures.