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Copyright of Tunnel Construction / Suidao Jianshe (Zhong-Yingwen Ban) is the property of Tunnel Construction Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Tunnel Construction / Suidao Jianshe (Zhong-Yingwen Ban) is the property of Tunnel Construction Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Tunnel Construction / Suidao Jianshe (Zhong-Yingwen Ban) is the property of Tunnel Construction Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Tunnel Construction / Suidao Jianshe (Zhong-Yingwen Ban) is the property of Tunnel Construction Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Tunnel Construction / Suidao Jianshe (Zhong-Yingwen Ban) is the property of Tunnel Construction Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Tunnel Construction / Suidao Jianshe (Zhong-Yingwen Ban) is the property of Tunnel Construction Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Due to the high hardness and high toughness of Hetian Jade, an outside chip removal mechanical vibration deep-hole drilling system is designed. The simulation of drilling head and vibration system is also included. The theory of gun drill low frequency vibration mode deep-hole vibration drilling system is researched, which provides some support for later ultrasonic deep-hole processing mechanism study and cleft prevent strategy research. [ABSTRACT FROM AUTHOR]

With the development of the deep well, ultra deep well and extended reach drilling (ERD) technologies, the Positive Displacement Motor (PDM) has been used more and more popularly. Meanwhile, the pressure loss calculation method is paid much more attention. By concluding and summarizing the present pressure loss calculation methods, the paper divided them into two categories, general methods and model methods, for comparison and analysis in detail. In addition, the Roberston-Stiff(R-S) rheological model has been selected to deduce the pressure loss calculation method in the cylindrical model. Finally, the derivation process of the complex model, one of the model methods, has been perfected. The result shows that we can choose the complex model calculation method to get a high accuracy of pressure loss. [ABSTRACT FROM AUTHOR]

Firstly, the paper reviews the status quo of mechanical shaft boring technology overseas. Secondly, describes generation and development of shaft drilling technology used in domestic alluvium. Then drilling technology development is divided into four stages: Basic technical preparations ; field application test of drilling process ; mature technology and equipment stage and breakthrough stage. List the drilling method used in western soft rock, small diameter vertical channels in mines, municipal engineering and other mines, as well as technical problems need to be solved. Thirdly, the development of Raise Boring Machine and the difficult in drilling in coal mine was analyzed, and technical issues need to be addressed in the Raise Boring Machine construction is described. Fourthly, the development of full face shaft boring machine is prospected and performances of rock-cutter, slagging, supporting and auxiliary systems are discussed. Through analysis, conclusions are that using suitable mechanical drilling method to construct shaft under different geological and project conditions can reduce the workers in the underground construction, then complete the construction safety and efficiency. [ABSTRACT FROM AUTHOR]

Optimizing drill bit type is one of the most direct and effective method to improve the drilling speed and reduce drilling cost. Through the comprehensive consideration of the influence of weight on bit, rotary speed, torque and hydraulic parameters on rock fragmentation efficiency, and according to the theorem of energy conservation, a virtual intensity index (VSI) model is established. The model is used to calculate the VSI of different drill bits, and considering drilling footage and cost, effective index is used to quantitatively evaluating the bit use effect, and furthermore to eliminate the affecting of human factors in the process of bit type selection, which provides a scientific basis for bit type selection. The method is applied in Jiudong field of Yumen Oilfield, and according to the value of the efficiency index, different drill bit types are optimized to fit for wellbores with diameter of 311 mm and 216 mm. Field applications show that ROP is increased by 1.94 times and 2.77 times respectively, and a significant speed-up effect is achieved, which sets up a foundation for further improving drilling speed and accelerating the process of exploration and development in Jiudong field. [ABSTRACT FROM AUTHOR]

In order to overcome the challenge of deep roadway constructions of over a kilometer deep, through the analysis of the advantages and the working conditions of TBM, it is believed that TBM has can be introduced to the deep roadway construction. Therefore, the intention is to introduce TBM to the roadway construction of over a kilometer deep, after it is be improved on the basis of solving the key rock mechanics and machinery manufacturing problems involved. Deep and high stress squeezing deformation can cause the TBM shield to be easily jammed. This paper deter- mines the TBM jamming mechanism as: when the shield surrounding rock convergence exceeds the over-excavation amount, the surrounding rock begins to contact and squeeze the shield, which then produces friction when the TBM shield advanced. If the thrust force cannot overcome the frictional resistance, TBM will be jammed. This paper also puts forward the corresponding jamming state criterion and the theoretical calculation method and process; considering the working face effect, based on the Hoek-Brown failure criterion, the convergent deformation of surrounding rock along the axial variation around the shield should be investigated, the pressure of the surrounding rock on the shield, and the frictional resistance of the surrounding rock to shield shold be calculated, and finally, the shield jamming state can be assessed by the criterion. [ABSTRACT FROM AUTHOR]

In order to solve the challenge of the deep roadway construction, through comparatively analyzing the existing roadway excavation, support methods, and TBM technology, it shows that TBM has obvious advantages, and meets the needs of the roadway construction deeper than 1 000 m; modern large-scale mine is also capable of introducing TBM; the authors intends to introduce TBM to roadway construction deeper than 1 000 km, which will be improved later on the basis of the involved key rock mechanics and machinery manufacturing problems having been solved, called Full Face Roadway Boring Machine (RBM). Due to the significantly difference of the construction environment between the deep coal mine roadway and tunnel, RBM construction will face two key issues: shield jamming and the rock fragmentation. In order to reveal RBM shield jamming mechanism, this paper points out the key rock mechanics problems, including; roadway deeper than 1 000 km surrounding rock masses squeezing deformation mechanism under RBM excavation unloading paths; squeezing deformation distribution law of the rock masses around the shield; the interaction mechanism between ground, shield and support; shield jamming criterion; control theory and method for shield jamming. [ABSTRACT FROM AUTHOR]

In order to study the force variation of the drill bit in the dynamic process of rock drilling deeply, systematical dynamics analysis was presented in the paper. Differential equations which described the force fluctuations in the process of rock drilling were established and various factors which affect the force fluctuations of the drill bit were also analyzed. Based on the analysis of the process of movement in rock drilling, analytical method for force computation of the drill bit in the dynamic process was given. Analytical calculation model of penetrating force and cutting force in the dynamic process was derived respectively. Studies show that the force of drill bit is closely related to its motion state; the average penetrating force and cutting force in the dynamic process increase with the increasing of penetration speed V in the case of the other conditions remain unchanged. Calculation results show that the analytical dynamic model is more precise than the traditional method of static calculation model compared with experimental measurements, and more conducive to be a intuitive and laconic guidance in engineering practice. [ABSTRACT FROM AUTHOR]

In aerated underbalanced drilling, the attenuation of the mud pluses emitting by the underground measure-while-drilling (MWD) equipment is at a high degree, and monitoring and controlling on well trajectory cannot be measured by ground receptor. By establishing the mathematical modelling of the MWD signal transmission and analyzing the reasons of restricting the signal transmission, two solutions were proposed and was followed by field test which involve adjusting the installation site of the MWD ground sensor and transforming gas injection manner. The results show that the installation site of the MWD has no influence on the signal receiving, transforming gas injection manner through fully mixing gas and liquid could slightly improve the signal transmission and enhance the effective measurement distance of MWD. [ABSTRACT FROM AUTHOR]

The 3rd artificial island in Jidong field is surrounded by sea, with the area of 200 acres. To accelerate Oilfield development and achieve the objective of operation with multi rigs simultaneously without affecting each other, multiwell cluster is taken as the well deployment ways. Through optimizing plans, the upper wellbore collision is reasonably avoided. According to the characteristics of great number of high angle deviated wells and collapse tend of the formation with low drillability because of the big vertical section of basaltic layers in Guantao formation, the wellbore structure optimization, drilling fluid development, bid screening and drilling techniques were studied, taking Well NP13-X1046 and NP13-X1042 as examples. And it was applied in onsite drilling operations, which made the drilling process of high angle deviated wells successful in the island. [ABSTRACT FROM AUTHOR]

By establishing the state equations parameterized with transmission coefficient for the drill bit's incident waves and reflection waves, the parameter identification of the characteristics impedance of the drill bit was formulated as a nonlinear global optimization problem. A new method based on differential evolution was proposed in order to solve the global optimization problem. The effectiveness of the proposed method was investigated by using experimental data of three drill bits with variable characteristic impedance. Compared with other optimization approaches such as particle swarm optimization and genetic algorithms, the proposed method has better properties in terms of convergence and robustness, and can be used as another alternative method to the identification of the characteristics impedance of the drill bit. [ABSTRACT FROM AUTHOR]

The self-oscillating rotary percussion drilling tools are set above the bit. The drilling fluid flows through the self-oscillator with high speed and hydraulic pulse is formed and is imposed on the percussion transmission rod, following with the generation of low amplitude but high frequency mechanical shock power, which can be passed to the bit and improve the rock breaking efficiency. The generated hydraulic pulse is transmitted down further and blown off through bit ports, which will form pulse jet flow and can improve the downhole flowing domain and the efficiency of downhole cleaning. Meanwhile, the instant negative pressure pulse generates local instant underbalance and changes the rock breaking stress status of downhole rock surface, which improves the rate of penetration significantly. The system is tested in Sha-3 and Sha-4 formations in Shengli Oilfield. The results show the rate of penetration is significantly increased no matter with cone bit or PDC bit, and the rate of penetration of all the tested formation sections increases more than 30%, so the technique could be a novel method of increasing the rate of penetration. [ABSTRACT FROM AUTHOR]

Well BY-1HF is the first exploration well drilled in shale formation in He'nan Oilfield. Based on the information of adjacent wells and technical difficulties, the wellbore structure, drilling fluid and cementing technique are designed. Firstly, the pilot hole is drilled, and then backfilled and side tracked. Water based polymer drilling fluid is used in the side tracked section, and serious hole instability is encountered when drilling long distance mud shale formation. The new techniques of rotation directional tool, white oil based drilling fluid and sectional tie-back cementing were used in the third drilling section, which ensured the drilling safety, wellbore quality and cementing quality, and raised drilling speed. The footage of 1122 m is drilled with only 6 days and one trip, and the horizontal section is 1044 m with average overcut rate of 3.88%. The tripping, drifting, logging and casing running processes are successful, and the cementing work is qualified. [ABSTRACT FROM AUTHOR]

Hole slanting control has been one of the most remarkable difficulties. Through many years of research, the vertical drilling system, BH-VDT 5000, was developed. The structure, operational principle were introduced, and its application process and effect in Well Keshen 203 in Tarim oilfield were analyzed. The second section of Well Keshen 203 was finished in two runs using BH-VDT5000 system and the total footage was 1558 m, and the inclination is controlled within 0.5 degree. Compared with the adjacent wells drilled by the Power-V vertical drilling system, the average rate of penetration was 23% higher. So the conclusion was that BH-VDT5000 system can promote the rate of penetration, shorten the drilling time and satisfy the requirement of slant prevention and fast drilling in high dip angle and thrust over nappe formation, therefore, it can be used further. [ABSTRACT FROM AUTHOR]

In order to ensure the hydraulic bearing structure to press stably against the hole wall, the method to design the bearing structure and installing parameters of its. hydraulic cylinders were studied. Influences of installing parameters of the rodless drilling rig' s hydraulic cylinders on the efficiency of bearing and the earth stability were analyzed with methods of geometric analysis and force state analysis. The calculation of structural strength and earth stability proves that installing parameters of the hydraulic cylinder given in this paper are tight. The beating structure can press stably against the hole wall without shear failure when the hydraulic cylinders are installed according to the parameters given. [ABSTRACT FROM AUTHOR]