| Trenchless Technology is not digging in the ground situation, using technical means such as soil excavation, laying, repair or replacement of underground pipes of a high-tech pipeline of new techniques. Trenchless Technology by construction technology consists of:Horizontal Directional Drilling Technology, or pass the shuttle spear pipe laying technology, micro-tunneling method, pound tube, horizontal spiral drilling method, pipe jacking pipe laying technology. It is widely used does not allow digging or excavation conditions do not have all kinds of pipelines laid across the highway, railway, buildings, rivers, lakes, and in the urban areas, heritage conservation areas, crops or vegetation in protected areas, etc. sewage, water, gas, electricity, telecommunications, oil and natural gas underground pipeline construction. In addition, precipitation can also be used trenchless technology engineering,tunnel engineering, foundation engineering and environmental improvement works. Has not pollute the environment, does not affect traffic, the underlying structural damage is small, safe and reliable construction, short cycle, low cost, social and economic advantages of a significant, specific performance in the following ways.1.To avoid the traditional excavation and construction work on people's daily life and interference, reducing traffic, based on the destruction of surrounding buildings and adverse effects.2.Using trenchless technology can accurately control the direction of pipe laying pipelines, buried, while allowing the pipeline to be laid underground to bypass or avoid obstacles (such as rock and underground structures, etc.) and existing underground pipeline.3.In the traditional method of excavation of road construction can not work or do not allow the construction of the region (such as crossing the river, railway, highway, square, airport runway, heritage conservation areas, etc.) from the bottom of trenchless technology is available through the laying can be designed in the project pipeline pipeline capacity at least, the location of the best route through.4.Has good economic returns, in the same objective conditions, the use of trenchless technology for pipeline laying the comprehensive cost is significantly lower than conventional excavation method, from the perspective of urban development, modern city of underground pipelines and pipeline very dense and crowded, the city again laying new pipe lines can only increase the depth, and deep excavation with the increasing cost of the surge, this time using trenchless technology construction will be more economical and save time. Through many practical engineering practice can be learned, in most cases, especially in the pipeline or pipeline laying downtown intensive deep lots, Trenchless Excavation is an excellent place of traditional methods. In exceptional circumstances, non-excavation is the only viable and economical construction method.The horizontal directional drilling technology is used in trenchless technology at home and abroad the main technical methods, horizontal directional drilling construction on the construction site did not affect the surrounding environment, easy to adjust and change the direction and depth of laying of pipelines, pipeline arc shaped section of laying long distance, and can bypass the underground pipes of obstructions, construction site can be flexibly adjusted, less land occupation, construction speed, short cycle, low construction cost. Many domestic and foreign Trenchless Drilling projects are using this method works, its basic principles are: pre-installed in the penetrability drill point on one side, from the point of beginning be buried along the designed route, according to pre-underground pipe-laying track through the pilot hole drilling, and forming a point to be buried unearthed from the point of crossing the curve, as pre-reaming, and pipe lines of the boot back to drag curve, and then exit in the direction of the drill holes of different diameter reaming front-end installation reaming device further pull back, when the reaming to reach the pre-designed size requirements, the back-end connectivity in the reamer rotary joint, trombone head and pipe, pulling back laying underground pipelines.However, the horizontal directional drilling construction process, we encountered some of the more difficult problems, which run the slurry is one of the major common problems.Particularly in large diameter, long distance Trenchless Directional Drilling project, ground has been taking a very prominent paste it very difficult to solve. Most of the ground run the pulp in the process of pilot hole drilling, ground paste to take place, does not return orifice hole plasma causes the slag can not be discharged drilling, drilling footage difficulties affecting the construction schedule, will result in the non-serious excavation horizontal directional drilling projects can not, while also seriously pollute the environment, to the construction side caused great economic losses, so anti-run slurry into Trenchless horizontal directional drilling construction of a very important issue, since lead to formation to take pulp many factors (including the drilled formation conditions, site construction parameters, drilling fluid formulation, etc.), the situation is very complex, currently at home and abroad have not formed a system, effective anti-technology system to take slurry,therefore, developed a set of effective anti-technology system to take slurry of great significance.In this paper, advanced soil mechanics, elastic-plastic mechanics, fluid mechanics, and theoretical knowledge, on the horizontal directional drilling technology to carry out anti-pulp take a more in-depth research, and through laboratory experiments and practical projects on the income of the technology was validated.This total is divided into seven chapters:The first chapter is at home and abroad to take on the anti-pulp technology, research status, in-depth understanding of previous research work has been done and the results and the results from previous studies based on plasma technology to carry out anti-risk new research.The second chapter introduces the different strata of risk slurry drilled failure mechanism, according to soil mechanics, fracture mechanics and fluid mechanics analyzed viscous closed formation, leakage crack formation and failure mechanism of plasma formation of risk. Then to design and process simulation of formation to take plasma instrument, and to take plasma simulation experiments, different soil, different thickness corresponding to the pressure to take slurry, slurry through the simulation run can be more intuitive to observe a variety of soil layer to take slurry process. Through the above failure mechanism of plasma formation and risk taking slurry simulation experiment, for the establishment of the critical formation pressure calculation model to take slurry basis.The third chapter introduces the drilling fluid in the horizontal Directional Drilling the importance of engineering, and drilling fluid rheology, fluid and flow pattern for a simple set. Then on the basis of previous research, the establishment of drilling fluid pressure calculation model of the energy flow of drilling fluid pressure in several different formulas, and then the establishment of the drilling fluid pressure calculation model is part of the amendment, proposed reaming shunt The new model and preliminary study of the cuttings on the drilling fluid pressure. Through the laboratory and practical works on the above models were used to validate the proposed model inadequacies and the need to improve.The use of advanced soil mechanics, elastic-plastic mechanics theory of knowledge, through mathematical analysis method to establish the critical pressure plasma formation to take calculated model, and engineering test data to verify the model. Finally, the formation fluid pressure calculation model and risk calculation model of critical pressure slurry to form a slurry formation predict risk technology and engineering through on-site verification of the technology.Chapter IV first defense mechanism to take slurry drilling fluid was analyzed, then the laboratory tests conducted on a variety of drilling fluid formulation of high shear dilution experiment with different treatment by agents of the drilling fluid rheological curves and the corresponding performance parameters.Then they were plugging the preferred drilling fluid formulation, through laboratory experiment, optimized plugging drilling fluid formulation. Finally, high shear dilution as the main performance indicators, taking into account the strong fluid loss, strong inhibition, strong lubrication and effective performance of slagging, etc.,optimized set of the strata of different anti-risk drilling mud slurry formulation system.The fifth chapter is taking anti-pulp technology optimized design, including through the optimum design, drilling diameter gradation design and construction of parameter optimization, optimization of these three aspects, in order to prevent the construction of the slurry to provide favorable conditions for the ground run. First, through the optimum design, primarily from the formation of the choices, pilot hole track parameter optimization (including the angle be buried, unearthed angle, drilling depth and through the curve length of the optimization). Second,based on a variety of construction and experience, the proper reaming series and method for determining the final hole diameter. And through a mathematical model, the new reaming diameter grading design optimization method, namely the use of principles such as torque reaming gradation design method, engineering example of validation, and preliminary validation of the proposed expansion pore size distribution optimization model is reasonable. Third, in considering the different content of cuttings, the establishment of a pump capacity and the penetration rate to match the calculation model to calculate the amount of construction and drilling the optimal pump speed to optimize the construction parameters to reduce the annulus mud pressure to prevent the formation take slurry, and finally through the site works on the calculation model was verified.Chapter VI is the anti-drilling technology to take field application of slurry, slurry drilling fluid through the defense to run through the formula applied to the project site in two, have achieved good results. Validation through the construction site, the anti-risk slurry drilling fluid technology can effectively reduce the annulus mud pressure and prevent plasma formation take place to ensure the smooth progress of the project and complete.Chapter VII is the full text of the conclusions and innovation have been summarized and made the inadequacies of the paper and further research ideas. Some of the results obtained in this paper is as follows:1.Analysis of the strata of varying risk slurry drilling mechanism.2.The establishment of drill pipe and drilling within the annulus fluid pressure calculation model.3.To establish the critical formation pressure calculation model to take slurry.4.Combined with drilling fluid annulus pressure calculation model and the critical pressure slurry formation risk calculation model, are run through the slurry pipe laying predict formation technology.5.Through a large number of laboratory experiment, optimized for different characteristics of the encountered formation level sets of directional drilling, drilling fluid formulation.6.Through the laboratory optimized plugging drilling fluid formulation.7.Reaming diameter derived grading design calculation model.8.Derived from volume and drilling mud pump speed to match the computational model,9.To Visual C++ as the software platform, combined with the above conclusions and findings, develop a set of horizontal directional drilling slurry design software risk prevention.Innovation of this paper in the following areas:1.Combination of drilling fluid annulus pressure calculation model and the critical pressure slurry formation calculated risk model, to predict ground slurry technology risk.2. Consider the content of cuttings derived horizontal directional drilling construction of the drilling mud pump volume and speed to match the formula.3.Through targeted laboratory experiment, optimized for different characteristics of the encountered formation level sets of directional drilling, drilling fluid formulation.
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