| Hole flushing is a very important component in the course of drilling, The main functions of drilling fluid are discharging cuttings, cooling and lubricating rock broken tools and drilling instruments, additionally, which can protect hole wall in some conditions.A lot of water will be consumed adopting conventional drilling technology. Water is one of important factors that puzzling normal drilling in droughty area and leak stratum all the time. When drilling in droughty, water scarce area, we must transport plenty of water from other place if take traditional drilling technology. It often happens that stopping drilling waiting for water at the condition a set of drilling machine equipped with two water tank cars when drilling in west water scarce area, in this way drilling cost will increase greatly. Besides, if take traditional drilling technology and methods in leak stratum, we must deal with leak sect by ways of using casing isolate or blocking up with special stuff, consequently, construction cost and consumed time will be increased greatly, furthermore, the stuff used for blocking up will cause environmental pollution. If drilling at the same time of leaking not only wastes plenty of water but also increases drilling cost, even it is possible to burst stratum and induce geological disasters such as coast etc. At present, the most economical method of drilling leakers is implementing drilling fluid downhole local circulation, that is, on the condition that not consume surface water, using water contained in stratum in the hole as drilling fluid accomplish the roles of cooling bit, discharging cuttings and protecting hole wall, achieving the aim of normally drilling.The water -saving drilling technology that the article studies may exactly implement circulation drilling locally in the hole. The use of the equipment for drilling can make the process of drilling water consumption drop 5 to 20 times. Water -saving drilling New Technology uses traditional drilling rigs ,slurry pump ,power rigs and artificial diamond as its base ,making efforts in drilling rigs and tools innovation ,on the premise of no reducing drilling efficiency and no increasing big rigs ,obtaining effect of saving a lot of water ,without disturbing stratum This technology that is about installing pulsator on the mud pump water valve on the ground, with the help of the water hammer made by the pulsator ,to drive submersible pump piston to achieve groundwater at the end of the hole partial-cycle, ensure the drilling normal. However, in the drilling process, because of water in the hole that does not return to the ground, it is hard to judge the working condition in the hole on the ground . Judging by the change of surface pressure gauge, it is not quantified, so the judgment precision is not high. This study that ultimately solve the problem that judging the value of the operation in the hole by the changes of the surface pressure gauge can judge the value of the operation in the hole more accurately , forecast accidents and reduce accidents better. The study can make the drilling set more practical, thus, it can apply to the actual project more quickly.The paper combines geological investigation project of water -saving drilling technology research for geological disaster prevention and cure, the project belong to China geological investigation bureau of ministry of land and resources, the goal is studying water-saving drilling instrument with downhole local circulation in virtue of assist of project fund, synthesize utilizing knowledge, such as drilling expertise, hydrodynamics, hydraulic transmission science mechanical and physical knowledge and so on. The mainly researched contents as follow: Firstly, the study on the structure and the working principle of the new water-Saving hole drilling system ;Secondly, the development of the calculation formula about the pressure loss of every part of the new water drilling system ; Thirdly, establish the pressure loss mathematical model of a new circulation of water-saving hole drilling system in a local hole. Based on the work , calculate the range of the theory pressure of the surface gauge pressure of different depths, and do experiments to verify its accuracy; Fourthly, discuss the influence of the biggest pressure of the surface that made by the submersible pumps depth, the hole depth and the groundwater depth. Sum up some laws of the usage of the equipment.There are six chapters in the paper, main contents of each chapter as follow:1. Introduce the resource, the purpose and significance, the background, the feasibility, computer simulation technology and main contents of research have been introduced in this part.2. Introduce the components of the new water-saving hole drilling system, the structure and the work principle of the components, and explain the principle.3. Explain the concept and principle related to the fluid of the study on the Hydraulic mechanical properties of the new water-saving technology, classify the fluid in accordance with the related concepts, improve the three major principles of fluid dynamics ,and derive the calculation formulae of the pressure loss along the way and of the local pressure loss.4. Based on the in-depth study of water-saving hole drilling system and the theoretical foundation of the third chapter, calculate the pressure loss of all the parts, as the water drilling system at work.. After it, analyze the pressure changes of the whole system and obtain the formulas.5. By the comparison between the data from the lab experiments and the data from calculating, analyze the reasons on the difference between the outcome and actual situation. Improve the detailed measures. Then, authenticate the differences of the outcomes between the calculating and the lab experiments.6. By assuming it, calculate surface pressure changes in different work situations, with changes on the submersible pumps depth, the hole depth and the groundwater depth , obtain some laws of the usage of this equipment and analyze the reasons theoretically. 7. Conclusions and recommendations, sum up the main research results of the full text, point out that the deficiencies in the course of the study subjects, and put forward a number of recommendations for further research.
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