Abstract:This paper conducts comparison and visual analysis of the published literature about drilling fluid from 2000 to 2019, and reviews the research fields, research institutions, etc. on the basis of Web of Science with the research hotspots in drilling fluids analyzed by Citespace. The results show that the publications on drilling fluids have been increasing in the past 20 years, and the United States takes lead in the number of publications with a total of 1,803 papers each cited 22.06 times, indicating its influence. China contributes a total of 1,586 articles on drilling fluids, but its academic level is insufficient. Engineering and energy fuels are the key research areas of drilling fluids. Journal of Petroleum Science and Engineering is the most authoritative journal in the field of drilling fluids and is widely recognized by the academic community.

Abstract:Adit exploration is a technical method to obtain the geological parameters of the region around the mountain and comprehensively understand the geology in survey for water conservancy and hydropower works. In the exploration work, the first goal is to find out the engineering geological conditions or special geological problems for the works, such as fault, interlayer, etc, and carry out in-situ tests. Therefore, adit exploration and construction technology occupies a very important position in important engineering investigation. How to speed up the construction progress, shorten the construction period and solve the problems in adit construction is the main research focus in this field. At present, construction technology and excavation equipment for the adit has advanced to a certain extent, but the research and related special equipment is still in the initial stage. This paper mainly discusses the advances in adit construction technology and equipment, and analyzes their characteristics and limitations by comparison of the comprehensive performance of different construction methods. Discussion is also made on the actual problems in the development of exploration adit technology, including the advantage and applicability of the drilling-splitting method in exploration adit construction. Finally, the development trend of exploration adit excavation equipment is envisioned based on construction technology.

Abstract:In order to solve the problems of strong abrasiveness and slow ROP in drilling ultra deep formation, an ultra short high energy turbodrill was developed and field-tested. A multi curved 3D rotor blade was innovatively designed for the turbodrill. Based on the fluid dynamics software CFX, the spatial configuration layout of the rotor blade was optimized to increase the hydraulic energy conversion efficiency of the blade by 45%, and the torque by 43.55%. With integration of the power end with the thrust bearing, the split turbine mandrel was modified into a one-piece structure with the length of the rotor blade cut short to 8.3m from 15m of the imported one; thus greatly improving passage and safety of the turbodrill, and reducing reaming and gauging time. The torque and thread connection strength of the turbodrill were calibrated by the linear element simulation. The turbodrill has been successfully applied in 48 wells in quartz sandstone, igneous rock and gravel formation in Bozi and Yuanba blocks with an average increase of 100% in ROP, which provides a strong support for deep and ultra deep drilling in China.

Abstract:This paper describes the development background and performance requirements for geotechnical drilling data acquisition equipment. The main structure and performance parameters of geotechnical drilling data acquisition equipment are introduced together with the selection of the electrical control system and the important electrical components. The automatic closed-loop control scheme for constant rpm output at the drill bit is described in detail. Field test has verified that the geotechnical drilling data acquisition equipment can output a constant drilling rate, and accurately collect and store four main drilling parameters.

Abstract:In order to realize remote monitoring of the drilling process at each drilling station by the drilling headquarters, on the basis of the single station for automatic real-time drilling monitoring developed in the early stage, TIA portal software was applied to develope the master-slave station for drilling monitoring with Siemens1200PLC used as the master control equipment, and Siemens200PLC as the slave control equipment to monitor the drilling parameters at each drilling station. Master-slave controlling is realized through the configuration of the master control equipment and slave control equipment at each station. Internet was used to test transmission after the master-slave station was set up, and the results showed that internet can provide continuous transmission from breakpoint and short-distance transmission of real-time monitoring data on drilling.

Abstract:The formation in the Xiangyangping area of Guangxi is complex. There are large sections of water-sensitive altered formation and broken formation. Kaolinite and chlorite altered formation is prone to expand and shrink or break off after water absorption, leading to frequent downhole incidents, such as rock falling, borehole collapsing, drilling string sticking or burial. Through the lithological analysis of the core samples from the formation, the film-forming anti-collapsing solid-free drilling fluid system was adopted, which effectively solved the expanding and shrinking problems of water-sensitive altered formation with remarkable enhancement of borehole wall stability and significant improvement of borehole wall protection. As a result, the cores taken out were intact with high core recovery; down-hole incidents were avoided; and drilling efficiency was greatly improved with shorter construction time and less construction cost.

Abstract:Temperature is an important indicator for evaluation of hot dry rock geothermal resources. At present, most temperature measuring instruments for geological survey work only can work below 180℃. However, with the increase of the depth and temperature in hot dry rock drilling, downhole temperature may exceed the tool measurement range, or error may occur in temperature measurement due to high temperature and high pressure. During drilling of hot dry rock Well-GR1 in Qinghai Gonghe hot dry rock, single-point temperature measurement was performed with BZM electronic multi-point thermometer, MTCHT-H thermometer and multiple groups of thermometers in conjunction with multi-point continuous temperature measurement with the SKD-3000B logging truck and GRY-1 borehole inclinometer. Comparison of the measurement results show that single-point temperature measurement is closer to the real temperature, but it has low efficiency and poor accuracy; the GRY-1 tool gives lower temperature due to slow temperature transmission caused by heat insulation. It is necessary to develop accurate, effective and economical high-temperature measuring instruments or methods.

Abstract:Replacement of trenching with drilling is effective technical means to solve the conflict between mineral exploration and ecological environment protection in the overburden zone. In view of the problems with shallow sampling technology in the overburden zone, with review of the advanced portable sampling drilling equipment and technology for surface exploration at home and abroad, and taking into account of the requirements of ecological civilization construction and green exploration, small angle （≤30°） drilling technology has been researched and applied successfully.

Abstract:Borehole ZK88-19 in the Xiling exploration area of Shandong Laizhou was designed with depth of 2500m, and drilling started in December 2016. Bit-burning happened at depth of 2034m, and it happened again when dealing with the downhole tool, resulting in two sets of drill tools and two sets of inner tube assemblies stuck at the bottom of the hole. In August 2017, drilling was forced to suspend due to the delineation of the environmental protection zone, and was resumed until March 2020. It was very difficult to continue to deal with the fish lost in the hole. Through feasibility study and verification, the self-developed deep-hole same-diameter directional drilling technology for obstacle bypassing, including design of the deflection wedge and deflection drill bit, and development of the deflection wedge placement technique, was applied and successfully bypassed the incident section, and drilling resumed.

Abstract:The deep-buried long tunnel group at Jinping Ⅱ Hydropower Station has an average buried depth of 1500～2000m with high stress and complex engineering geological conditions which lead to difficult groundwater treatment. Groundwater treatment for this project was done in stages. First, survey was performed for the outlet tunnel section; then, the outlet points and sections with small flow and sub-large flow were blocked on the surface, and the deep surrounding rock was reinforced to form a uniform anti-seepage consolidated ring of some thickness; finally, the concentrated water gushing point was sealed off. After treatment, the inspection results all met the standard and achieved the expected treatment effect.

Abstract:Taking a civil air defense tunnel project in Jiangsu Province as the background, a construction technology with the large span steel truss formwork for chamber excavation has been developed by study and integration of the steel formwork trolley, load-bearing scaffold, steel truss and steel formwork through field use and comprehensive comparison of safety, economy and maneuverability, the construction methods. Technical study and application of the system in underground chamber excavation is discussed, with emphasis on the process principle, formwork design and stress analysis, engineering application, etc. The construction method can improve efficiency, save cost and improve construction quality.

Abstract:Landslide is one of the major geological hazards which seriously endangers the safety of human life and property. Site investigation for landslide prevention and control is important basic work in landslide prevention and control design. In this paper, the engineering geological surveying and investigation of the landslide area were carried out for the Pinghe County Xihuan Road landslide prevention and control project in Fujian Province. With engineering geological drilling results, the cause of landslides, and the calculation and evaluation of landslide stability were analyzed with proper prevention measures proposed. Inferring the position of the sliding surface, determining the geotechnical design parameters, and selecting the appropriate safety factor are very important for comprehensive prevention and control of landslides.

Abstract:Slope-cutting and load-reducing for mountain bodies of various lithologies is an important job in the mine geological environment control project. Taking a mine environmental control project in Jiangsu Province as an example, comparison and optimization is made of four methods: open rock blasting method, expanding agent crushing method, carbon dioxide fracturing method, and mechanical crushing method for cutting hard rock on high slopes. Based on the analysis of the key points and difficulties on the project, carbon dioxide cracking was selected. This paper introduces the construction technology and process of the project in detail, summarizes the relevant experience, and presents further thought on the carbon dioxide cracking method.

Abstract:In regard to Zhonglan Real Estate Residential Land Project, analysis of the formation mechanism of “rubber soil” led to the conclusion that treatment of “rubber soil” is to change the flow-plastic properties of “rubber soil” and reduce the moisture content in the soil layer. The measures to change the flow plasticity of soil layer include replacing with different soil, adding cement and quicklime with deep mixing to enhance the consolidation performance, or pressing in gravel and pebble to increase the stability. The measures to change water content include replacement with different soil, digging and drain water to dry, dewatering with pumping. For this project, mixing replacement and dewatering with pumping has been performed to achieve the purpose of eliminating the “rubber soil” characteristics, which met the requirement for construction ground.