Abstract:With the extensive application of the SmartMag system in various fields, the requirement on the precision of target-hitting is getting higher. How to enhance the measurement precision of SmartMag to realize ultra-high precision target-hitting is a problem that must be solved during horizontal well intersection. In the paper, analysis of the factors that may affect the measurement precision is conducted, including the tool face of the mud motor, magnetic environment of the measurement, vibration of the probe, and position of the probe in the borehole; and the solutions are provided accordingly. Then, a series of field tests were conducted at surface for horizontal well intersection, and the results showed that the measurement precision of SmartMag is significantly improved and ultra-high precision target-hitting is realized. The test results in the paper can be used as reference for improvement of the trajectory control for horizontal well intersection and the one-time success rate of target-hitting where the target cavity size is limited or undeveloped.

Abstract:The Drilog? LWD developed by COSL consists of MWD, DSM and ACPR, and have already been put into operation for hundreds of times. In order to improve ROP and incorporation of more high-end imaging instruments, COSL has independently developed the HSVP? high-speed mud pulse telemetry system which includes the downhole instrument and the surface decoding system. Water circulation testing and field trial demonstrate that it can realize real-time decoding at 12bps. In the exploration and development of oil and gas fields, the HSVP? can improve the transmission efficiency from downhole to surface; thus, helping to control the drilling trajectory real time, and contributing to the single well productivity and recovery. This paper introduces the use of the high-speed mud pulse tool over the 81/2in section of a Shanxi shale gas well. According to the data from the MWD system, analysis is made of the results from trajectory control, dynamic trajectory measurement and logging while drilling quality. The results show that the HSVP? system has high drilling efficiency, fast transmission rate and timely and accurate orientation. It has been proven that the logging quality of the system is excellent during the drilling process. The field use of the tool has also accumulated experience for the further use of the system.

Abstract:D03 geothermal exploration well is deployed at the axis of Niutuo Town Uplift in Xiong County, Xiongan New Area with the design depth of 2500m and the completion depth 2511.10m. The purpose of this project is to find out the geological structure and distribution of carbonate reservoir in the Jixian System, obtain geothermal hydrogeological parameters and calculate geothermal resource potential. This paper mainly introduces the drilling work of D03 geothermal exploration well, where sidetracking was carried out against lost circulation with the PDM single point orientation, the difficulty in sidetracking in the lost circulation section was resolved, and the application research for cementation in the lost circulation section was explored, the cuttings and cores from Yangzhuang Formation were obtained with the dolomite of Wumishan Formation distinguished from Gaoyuzhuang Formation, achieving the exploration purpose. Through drilling work, coring, cuttings logging and thin section identification, the geological structure and main lithologic characteristics at D03 were basically identified. Through pumping test, hydrogeological parameters are obtained and exploitable resources were evaluated.

Abstract:This paper addresses the performance requirements on oil-based drilling fluid for drilling of the horizontal well Wanye1HF. The drilling fluid system with density of 1.3g/cm3 and temperature resistance of 120℃ was optimized and evaluated. The effects of 5 main components: emulsifier, auxiliary emulsifier, wetting agent, organic clay and filter loss reducer on the system performance were analyzed to find out the optimum ratio of the 5 components. Then the density gradient and temperature gradient were evaluated for the optimum formula to determine the drilling fluid system suitable for the shale gas block. The system was applied in the field at Well Wanye1HF, and achieved good performance.

Abstract:The 3000m deep scientific drilling project of Jiajika Lithium Mine in west Sichuan is located in the high-altitude areas of western Sichuan Province. According to the technical requirements, the borehole is designed with three drilling sections. A set of economical and practical drilling equipment was used, mainly including HXY9 drill rig, K2790 drilling tower,BW300/16 mud pump. Drilling technology, the coring method, the drilling assembly and the drilling fluid plan were examined and developed. For implementation of the concept of green exploration, necessary measures have been developed to protect the ecological environment of the construction site.

Abstract:The Well Chaoye1 is the first shale gas resource survey well deployed in the Chaoshui Basin. It requires high quality coring. There are large sections of shale in the strata, which are easily hydrated and spalled, making drilling difficult. This article focuses on the experience of the coring process, bit selection, drilling fluids technology and well deviation control technology for the Well Chao1. Large-diameter wireline coring was used Chaoye1, and the full well section below the Quartenary formation was cored. Though there were very few cases with this technology for reference in Gansu, core recovery was achieved close to 90%. During the drilling process, by choosing reasonable drilling parameters and a drilling fluid with strong wall protection performance, the technical difficulties encountered in the formation such as formation slippage and poor wellbore wall stability were solved, and the smooth completion of the well was ensured.

Abstract:According to the requirements of environmental protection and drilling of geothermal exploration and production Well D20 in Xiongan New Area, the research and application effect analysis of the drilling fluid solid control circulation system are carried out. The whole system is composed of a “4+1” modular closed tank body equipped with five-level purification facilities, which can meet the process requirements for treatment of downhole complex situations, such as drilling fluid make-up, storage, circulation, purification, replenishment, dosing, weighting; as well as the environmental requirements for closed-loop circulation. The field application shows that the system can meet the requirements of green exploration and drilling of exploration and production Well D20, but it needs to be further improved in terms of structural design and optimal configuration. Some suggestions are put forward in the hope of providing reference and guidance for the reasonable practicability of system design and configuration and the economy of drilling engineering.

Abstract:With the development of high-pressure jet grouting technology, a new dual high-pressure jet grouting process, namely RJP construction method, has appeared. In order to meet the requirements of the RJP method, the XLT-230 full hydraulic crawler jet grouting drill was designed and developed. The drill is easy to operate and meets the RJP process. It is equipped with a large torque and large through-bore power head, with functions of intermittent lifting and directional jet grouting, which is suitable for various engineering conditions. The overall structure and technical parameters of XLT-230 drilling rig as well as the design of main components of the drilling rig are discussed in detail. The hydraulic and electrical systems of the whole rig are also introduced.

Abstract:The intelligent drilling technology and equipment for coal mine is the advanced technology and equipment that is badly needed by coal enterprises. This paper introduces some milestone achievements in drilling automation made by research institutes and enterprises. However, many key technologies are still unsolved due to the multitude of drilling steps, the complicated drilling process and the changing site conditions, and the intelligent degree, reliability, adaptability and practicability need to be further improved. The adaptability of drilling rig equipment, the complexity of drilling processes and the diversity of demand, explosion-proof and drill pipe make-up and supply are analyzed. It is pointed out that research efforts should be put on navigation and positioning, program control, automatic drilling, automatic loading and unloading of drill pipes, real-time monitoring and transmission of parameters to achieve the goal of practical function, high efficiency and stable performance of intelligent drilling rig. At the same time, it is pointed out that it takes continuous research and development investment and years of time to make intelligent drilling rig commercially available, and that it is proposed to realize intelligent drilling step by step in three stages: automatic drilling stage, intelligent drilling stage and drilling robot.

Abstract:Taking the reinforced typical high cutting slope along Lanzhou South Ring Expressway as the research object, a three-dimensional numerical model is established for the selected typical slope by using AutoCAD and ANSYS software. On this basis, the finite differential software FLAC3D is used to evaluate the stability of the slope under the earthquake condition, so as to provide reference for the protection and safety design of loess-like high slope works. It is concluded that the slope is stable when the horizontal earthquake acceleration is 0.1g and 0.2g; the slope is basically stable when the horizontal earthquake acceleration is 0.3g; and the slope is unstable when the horizontal earthquake acceleration is 0.4g. The lattice bolt support bears large part of the tensile stress and shear strain increment, et al., with remarkable effect, and it plays an important role in slope stability. The specified seismic intensity for the highway construction region is 8 degrees with the designed seismic acceleration of 0.2g; thus, the selected lattice-supported slope is in a stable state (the stability coefficient is 1.15) under earthquake conditions, which can meet the specification.

Abstract:With the development of the country and society, people pay more and more attention to the ecological environment. In the process of economic development, there are a large number of abandoned pits left by mining, and the treatment of these pits is urgent. As an effective method for treating high, steep and smooth rock walls, the floating platform is widely used in practice. However, most analysis of the stability of the platform is based on simple formula. In this paper, a kind of concrete floating platform structure suitable for the treatment of steep rock walls in mines is designed, and the formula for calculating the stability of the floating platform is refined, and the stability of the floating platform is analyzed by combining with FLAC3D numerical simulation software. The research results show that the concrete floating platform is more practical for the treatment of steep rock walls in mines.

Abstract:With the rapid development of economy and society, steel pipe micro-piles as a support structure are used more and more in the deep foundation pit. According to the construction technology and field use of the steel pipe micro-piles, this paper summarizes the main characteristics of the steel pipe micro-piles applied in the foundation pit support works, analyzes the role and effect of the steel pipe micro-piles in the foundation pit support works with regard to the field cases. It is demonstrated that the advantages of the micro-pipe steel piles can be fully exploited in the foundation pit support works in case of the limited surrounding environment conditions of the foundation pit, emergency reinforcement, etc. with significant economic and social results.

Abstract:A thick layer of silty fine sand is present at the Liangye Tower foundation pit in Guangzhou, and when the anchor point of the prestressed anchor cable is in the fine sand layer, water and sand kicks are prone to happen in the construction of the anchor cable, leading to the foundation pit incidents. The drilling with casing process was combined with dry-drilling to make the borehole, and behind the wall both the grout stopping bag was set at the borehole head and grouting was performed to ensure reduction in water and sand kicks during anchor cable construction; thus avoiding the foundation pit incident caused by the external ground subsidence.

Abstract:The Longquan Dingfeng Yicheng pile foundation project was featured of large pile diameter and high ultimate bearing capacity of the single pile where the maximum pile diameter was 2400mm, and the vertical ultimate bearing capacity of the single pile was 89600kN. There is little reference experience in the construction field. The pile foundation project mainly faced three challenges: easy caving in the sand layer and pebble layer, difficulty in bedrock penetration, and difficulty in clearing sediment. In reference to the pile foundation construction experience of bridges and railways in China, the key technologies such as stabilization of the sand layer and pebble layer, step reaming, bailing out hole bottom sediments, were purposely targeted to solve the construction problems. Testing after the waiting period showed that most of the bored piles were Class I piles. The summary of the construction experience of this project can provide reference for the application of large diameter rotary bored piles in the construction field.

Abstract:According to the ground conditions of the chemical wharf project in the Zhuangyuan’ao Port area of Wenzhou and special requirements of the wharf, slant rock-socketed piles with a slope of 1∶5～1∶6 were designed for the pile foundation. The construction job was successfully completed through taking very specific construction measures, such as the self-designed steel casing guide frame to control pile-hole inclination, percussion drilling with the cylindrical hollow hammer to sink the borehole, the rugby type tremie pipe to pour concrete, and so on. Pile-foundation inspection shows that the pile-foundation quality fully meets the specification. It provides valuable experiences for similar projects.

Abstract:In this paper, the correlation analysis between the measured standard penetration test （SPT） number and the depth of the test hole, the compression modulus and the shear strength of the reticulated laterite in Jiujiang City was carried out. The analysis results showed that the SPT number of the reticulated laterite is positively and significant linearly correlated with the test hole depth, positively and weakly linearly correlated with the compression modulus of the soil, positively and weakly correlated with the shear strength of the soil. The analysis results provide good guidance and reference for geotechnical engineering survey activities in Jiujiang.