| With the development of the national economy, the problem of energy supply and demand becomes increasingly serious human beings demand for oil and gas resources is also increasing. The exploration of oil and gas resources, land survey and infrastructure construction, makes drilling technology particularly important. With the ever-increasing exploration workload, oil and gas resources become less and less, exploration and development are increasingly more difficult because of more and more deep drilling holes and more and more complex drilling strata. All of these require high demand of drilling tools. On the current drilling market, the cost of drilling and exploration for the research of underground oil and gas is very high all over the world, so a slight improvement in drilling performance (including the life of drill bits, drill pipe and casing wear resistance, etc.) will bring about considerable savings in drilling costs.Hard rock drilling has been a technical problem in oil and gas drilling. The conventional cone bit, PDC bit, has the phenomenon of slow speed, short life of bits, low efficiency when drilling into hard rock. National research experts at the same time consider the impact and rotary drilling method, combining the hydraulic percussive drilling with the cone bit to solve this problem, although receive a certain effect, but not very obvious. The main reason is unable to solve the problem of drilling bit. Bits are the main instrument to break rocks, whether its structure is reasonable or not, its parameters are adapted to the nature of the rock or not, it affects the drilling speed, quality and cost directly. Therefore, it has important practical significance by selecting reasonable structure of the bits and using them right. In the drilling process, we hope to minimize the bit to play a role, so as to achieve faster drilling and high efficiency. To gain this end, we give the structural changes to drilling bits from view of bionics.Bionics is one of the emerging edge of important subjects between biological science and technology, considered as the inexhaustible source of power from the original scientific and technological innovation, and it is an important means of developing high-tech. "Coupling" is a physics concept at first, that is, through a variety of interactions, two or more different systems or exercise forms affect each other and unit consistently. Biology, a number of factors such as form, structure, material of biology has multi-functional synergies, and achieves the best adaptation to the environment we call it "biological coupling". Therefore, the "bionic coupling" is more than two bionic systems (functions, features, system) coupled to build into a low energy environment for adaptive access to the largest man-made features of the technology integration system. Bionic coupling theory is the expansion of non-smooth theory, and the research areas was broken that just only for the surface morphology of biological research, which extends to the internal structure of biology, as well as the field of materials.Through a long period of natural selection and evolution, biology optimized the form of a fine structure and surface features. Advanced technologies are created by mankind to follow the object which provides a natural human study modeled. Soil animals such as dung beetle, mole cricket, pangolins and other long-term living in the soil and rocks, after millions of years of evolution, their body surface where touches soil shows the coupling patterns of concave, convex, scales and waves and it has the characteristics of good adhesion reduction, reducing the function of resistance, and high wear resistance and regeneration. Modeled the characteristics of organisms form, we apply the bionics coupling theory to the design of oil drilling bits, drilling bits can be solved in a shorter life, low efficiency, as well as the "spin" situation in drilling process and so on.This paper introduces the current used of oil drilling bit in the hard and grinding strata, and applies the bionic coupling theory to solve the problems about the drilling bits'low efficiency, short life in these strata. This article focused on an analysis of biology coupling surface wear-resistant properties, combined with diamond bit crushing rock characteristics, and the bionic coupling theory will be applied to the design of impregnated diamond bit. Through the computer analysis and a large number of small-bore (75mm) bionic bits'field test, we summarized relationship of bit matrix hardness, diamond concentration, as well as the degree of non-smooth. It has accumulated valuable experience for the design of large diameter (215.9mm) bionic oil bit. On the basis of testing and analyzing of rocks where the large-diameter bionic bit will be experimented, the bionic bit was designed according to the parameters of matrix hardness, diamond concentration, and diamond size, the degree of non-smooth and sintering parameters. In addition, the thesis also gives the analysis of the mechanism of broken rocks of bionic bits. In short, according to pre-test numerical simulation and field test, we summed up the following conclusions:Fistly, in this paper, ANSYS finite element program was used to analyze the stress, contact stress and contact friction of mutual friction of two pieces in sliding wear test process. Through the analysis of summary, we can see that it is different between the wear of smooth specimen and wear of non-smooth specimen, and along with changes of the degree of non-smooth, wear and tear also changing. The relationship between degree of non-smooth and the equivalent stress, contact stress and friction is not linear, it is basically the shape of a parabola, and that is to say there is an optimal non-smooth degree, so that the best parameters value will be got. By analyzing, we can see that the optimal non-smooth degree is 13%, also 10 percent for the non-smooth degree, the test results is good, so that our best guess for the non-smooth degree is 10-13%.Secondly, we designed and manufactured bionic small-caliber (75mm) diamond bits and tested them separately in Jiapigou gold field in Jilin and Linglong gold field in Shandong. By analyzing the experiment data, we can see that, the superiority of non-smooth structure will not be reflected better until the matrix parameters of bionic diamond bits, diamond parameters is still necessary to adapt the parameters of formation. Such as the two tests in Jiapigou gold field, bionic bits have increased their life almost double and drilling expectancy more than 30%, which fully reflects the strong wear-resistance of bionic non-smooth structure when the parameters of bits adapt to some strata. When the field test was carried out in Shandong Linglong gold mine, the life of bionic bits were increased by 30%, and the drilling speed was same with the ordinary bits, because of the super hard of bit matrix, the effect of non-smooth structure is no longer better than before. Through the test, we can see that the test result is more satisfactory when the non-smooth degree is 10% and 13%.Thirdly, the design of large-diameter (215.9mm) bionic diamond bit is on the basis of the computer simulation of finite element analysis and small-caliber diamond bionic bits achieving good field test results. Because the wall of bit is up to 55mm thick, the bit is not sintered thoroughly using one time hot press sintering method, and the strength of diamond will be injured when using the non-pressure impregnation method, so we apply the second welding process: First, hot-pressing method was used to create impregnated diamond segment, non-pressure impregnation method was used to create bit matrix, and then the impregnated diamond segments were brazed to the bit matrix. Using this method, it can ensure that the strength of diamond under high temperature is not decreased, and also the welding strength can be ensured.Fourthly, from the two aspects of qualitative analysis and quantitative calculation, the efficient broken rocks mechanism of bionic bit is analized: the structure of bionic non-smooth surface makes the pressure higher than ordinary bit on the bottom lip surface of bit and improves the cooling condition, it can improve the efficiency of drilling bits another through formula, we can see that at the same axial force and torque conditions, the footage of bit each week is inversely proportional with the area of the bottom lip surface of bit, so smaller the area of bionic bit is, larger amount of footage is. In this paper, the bionic coupling wearable mechanism was firstly applied to the design of impregnated diamond bit in hard rock of oil drilling and it increased the efficiency and bit life . First we use ANSYS finite element software to analyze the effect of bionic non-smooth pits to the wear resistance of drilling bits, put forward the best non-smooth degree, and it is same with the actual test data. The method of second welding set was used to create bionic bits: impregnated diamond segments using hot-pressing method were brazed to the bit matrix using non-pressure impregnation method, it is a new approach. In short, the three above-mentioned aspects innovation, provides a wide range of design ways for the design of bionic impregnated diamond drilling bit, and provides a new concept of creative thinking for those who are engaged in drilling researchBionics technology will be applied to the drilling project, and particularly the theory of non-smooth surface of biology will be applied to the design of drilling bit which breaks rocks, all these will provide a source of innovation for drilling technicians. THE combination of bionics engineering and drilling engineering technology will bring a new research direction, bionic drilling engineering.
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