Abrasive grinding can effectively prevent surface damage caused by the process of large particles, and simultaneously improve processing efficiency and accuracy

Efficient, high-precision , low surface damage has always been ultra-precision machining pursuit of the goal . With the development of modern industry, for ultra-precision  synthetic diamond  are increasingly high requirements , reduce surface damage and processing to improve the processing efficiency of the contradiction between the increasingly prominent. To alleviate this problem, the research center proposed a fixed abrasive machining and free abrasive machining of semi- solid integration with grit abrasive machining technology, the core of which is the use of having a "trap " effect of semi- fixed abrasive grinding with ultra- precision machining. The abrasive surface can effectively prevent damage to the grinding process caused by large particles , simultaneously improve processing efficiency and accuracy. References of conventional abrasive manufacturing process ,  synthetic diamond powder  the characteristics of semi- fixed abrasive grinding tools , grinding tools for semi- fixed abrasive manufacturing process has been improved, made ​​more perfect machining process. By combining experimental study and additives , determining suitable for semi- solid formulations with abrasive grit . Referring to the traditional abrasive characteristic parameter detection method chosen hardness , shear strength, compression ratio of the key parameters and spring rate , abrasive grinding of these organizations as a semi- fixed abrasive grinding evaluation index , Construction of the evaluation system of semi- fixed abrasive grains . According to the characteristic parameters of semi- fixed abrasive abrasive grit to establish a semi- fixed abrasive PFC models.

Self-oscillating flow field inside the nozzle chamber variation, internal and external flow field dynamic pressure variation

Abrasive jet formation mechanism of the pulse, the pulse characteristics and pulsed abrasive water jet abrasive jet perforating stimulation mechanism and other issues have been studied, and in the Sichuan Basin, a gas well site experiments. The main  polycrystalline diamond : first using a large eddy simulation, through in-depth analysis of the self-oscillating flow field inside the nozzle chamber variation, internal and  synthetic diamond  field dynamic pressure variation, variation of the velocity vector, turbulence intensity distribution, revealing the self-oscillating  abrasive wheels  jet generation mechanism; combined oscillation, bubble collapse on the abrasive jet impact and solid abrasive water jet in the pulse distribution of abrasive water jet pulses revealed the formation mechanism.

Using perforating fracturing methods to transform strata, increased gas production

Low-permeability gas widely distributed in China, large reserves, proven gas reservoirs representing more than 80%. However, due to porosity, permeability and pressure is low,  polycrystalline diamond low productivity and economic inefficiency. In order to increase natural gas production, to solve the "gas shortage" problem, now mostly using perforating fracturing methods to transform formation, increased  Diamond blade . However, the conventional way of perforation perforation shallow depth, hole diameter is small, the construction for a long time, can lead to gas  Synthetic diamond , resulting in low permeability gas reservoirs, yield poor. For these reasons, this paper proposes a pulsed abrasive water jet perforation penetration increased permeability gas reservoir to increase natural gas production of new ideas.

In submerged conditions before and after mixing abrasive jet impact angle, flow, pressure

Using FLUENT software, submerged abrasive jet multiphase flow simulation, calculation of different structural forms of the nozzle flow field inside and outside. Explored the submerged condition after mixing abrasive jet impact angle, flow, pressure, target distance, sand tube length, tube diameter mixed sand, abrasive concentration,  synthetic diamond  change on the nozzle flow field inside and outside the law, on the abrasive particles running track were predicted, while the flow field  polycrystalline diamond  and calculation results are analyzed. For premixed abrasive water jet, respectively, direct numerical simulation of 260,450,600 cone type nozzle and external flow field and grain motion characteristics, and submerged jet  abrasive grinding  under influence factors - target distance, angle of impact and confining pressure for the simulation analysis. The results showed that: there is a submerged abrasive jet jet core, is about (35) D, but then jet decay rapidly. Cylinder, cone, cone straight three typical straight-type nozzle nozzle cone best, and to 260 straight cone nozzle effect is better.

Water by adding abrasives (ie, abrasive water jet) is to improve the performance of an important way jet

For higher pressure jet working condition, basically limited to some of the research sector from abroad pressure generator and jet equipment research work. Attempts have been made in the high-pressure water jet technology, and continue beyond the new high record Generally said current level of technology enables people to use 200 ~ 400 MPa  synthetic diamond  while with further increase the pressure in the device and the device manufacturing, material, cost and other aspects of life will be limited, there is also the use of security .70 years, people began to note exhausted improve the work efficiency of the jet, focusing on research work  synthetic diamond powder  not too high but with a high-performance jet mechanism, for example, additives jet, 'pulse jet, resonance jet, jet and abrasive water jet cavitation in an attempt to lower operating pressure, achieve a higher economic  cutting tools , added to the water abrasive (ie, abrasive water jet) is to improve the performance of a jet important way. abrasive jet high pressure water jet and general different, it is a highly concentrated jet of energy, the working medium is water and a mixed solution of abrasive particles.

Erosion in the nozzle inlet end face wear play a major role

From the nozzle wear mechanisms and effects of two parts for rotary drilling abrasive jet conducted exploratory research. Through  polycrystalline diamond  analysis, the rotating abrasive jet nozzle wear plays a decisive role in the abrasive wear and erosion. Where  cutting tools  is the main form of the nozzle inner wear, and erosion in the nozzle inlet end face wear plays a major role, and were the two wear mechanisms were discussed.  synthetic diamond  method analysis of the stress state in the nozzle. The results showed that: the maximum stress in the nozzle cone section at the beginning of the end of the straight section, the stress cone section is smaller and showed an increasing trend, the average stress is greater than the straight section cone section, in addition to the entrance face of stress as well.

Rotating water jet diffusion angle measured experimental analysis of all relevant parameters on the jet spread angle of the law

Combined rotary abrasive jet casing window casing window mechanism and a set of practical requirements designed impeller, nozzle suitable for indoor as well as experimental research tools, and its strength check. Checking results show that the designed tools to meet the requirements. By  abrasive wheels  jet diffusion angle measured  synthetic diamond  analysis of all relevant parameters on the jet spread angle is studied. The experimental results showed that: rotating water jet pump is larger in the diffusion angle does not vary with the pump pressure is changed, the proliferation of  cutting tools  with water jet nozzle diameter, the impeller blade outlet angle and the number increases. By rotating the casing window abrasive jet experimental analysis of all relevant parameters on the effect of regular windows and preferably out of the relevant parameters.

Small screw motor driven mechanical gimbal drive alloy drill fenestration

In a variety of technology to improve oil recovery, the radial horizontal well technology with its operating procedures are simple, the process cycle is short, less investment, etc. showed good technical and  abrasive grinding . Applications at home and abroad to open a small window radius horizontal well technology uses small screw driver alloy  synthetic diamond  driven mechanical drill fenestration, because underground space constraints, the level of domestic screw motor technology is difficult to meet the requirements. To this end we introduce rotating abrasive jet  cutting tools , and its realization casing window, expand the relevant theoretical analysis and experimental research tools designed to promote open small window radial level technology application in China.

Based abrasive water jet cutting efficiency and high rotating jet good scalability characteristics

The traditional radial drilling technology requires forging mill and a large diameter casing reaming, operating procedures and more difficult construction. Casing window radial horizontal well technology simply open the casing with a diameter of about 30 mm of the window, to the formation of radial drilling channels. At present, foreign multi-use mechanical window. Based abrasive water jet cutting efficiency and high rotating jet good scalability characteristics, the author proposes a  synthetic diamond  jet technology line window, and through numerical simulation and laboratory tests to analyze the combination of means for the further development and improvement of open  Polycrystalline diamond  technique provides a theoretical basis. Injury and damage criterion variable in metallic materials RVE, assuming a  Abrasive grinding  area A normal vector is n, the micro-cracks or micro-voids exist, resulting in an effective bearing area A Zhou ratio A small, that Zhou A = A-AD. AD is considering stress concentration defects and defect area after interaction. In the assumption of isotropy of the premise, the damage variable defined as a defect area and the total area ratio, i.e. D = ADA = A-Zhou AA. (2) when D = 0, the metal material is non-destructive condition; D = 1 , the metal material is completely broken;

Combination of different impeller nozzle to simulate structural characteristics and results rotating jets of various factors

The newly developed rotary abrasive jet casing window tool, using numerical simulation method, the tools to optimize the structure and size of the design . Rotate tool abrasive jet casing window is the core component of the jet nozzle and rotating impeller . From the nozzle and impeller geometry and basic characterization can be seen, leaf number, as well as export-oriented angle nozzle diameter and other parameters that affect the efficiency of rotating abrasive jet major factor . Numerical method, the combination of different impeller nozzle simulation results and the structural  Diamond blade  of rotating jets of various  synthetic diamond  jet spread angle of rotation rule ; through the individual abrasive particle erosion simulation casing , the casing draw stress , strain change process , abrasive particles displacement, velocity change process , as well as the depth of various factors on the impact of erosion pits law ; abrasive jet by  abrasive grinding  window full-size simulation tool , draw nozzle phase fluids inside and outside the field distribution of the casing and a rotating abrasive jet erosion damage process . Finally, the structural parameters of the impeller nozzle size optimization , preferably windows meet the requirements of the impeller and the nozzle , and the simulation and experimental results are compared to verify the accuracy of the simulation results .

Abrasive water jet cutting metal materials physics

Abrasive jet cutting is not subject to the cutting position and the eccentric bushing restrictions, thus becoming obsolete wellhead and riser removal and effective means. Based on the theoretical analysis of cavity expansion abrasive jet cutting metal materials physical process, the establishment of a single abrasive particle  synthetic diamond powder  depth calculation model, obtained the higher jet pressure, the use of high density and with a sharp angular abrasive can significantly improve the cutting efficiency of the law, as the construction work is  synthetic diamond  category provides a theoretical basis. Were submerged jet under pressure, nozzle diameter, number of nozzles, cutting head speed, cutting duration, standoff distance, abrasive quality copies, abrasive type on cutting depth effect.

Mainstream mechanical cutting techniques in cutting, shaped cutting and blasting abrasive jet cutting

With the offshore oil and gas exploration and development progresses, a number of offshore platforms have completed their mission, platform removal has become a hot project. Platform is one of the key technologies demolition waste wellhead and riser  synthetic diamond  of the current foreign mainstream mechanical cutting techniques in cutting, drilling tablets cable cut, shaped blasting abrasive jet cutting and cutting. As is by the multi-layer casing and  Diamond blade  cemented together and there may be eccentric, but need to cut at 5m below the seabed, drilling and mechanical cable cutter grain cutting method is difficult to meet the project needs, and shaped cutting due to blasting a greater damage to the environment, gradually limit the use of;

Mainstream mechanical cutting techniques in cutting, shaped cutting and blasting abrasive jet cutting

With the offshore oil and gas exploration and development progresses, a number of offshore platforms have completed their mission, platform removal has become a hot project. Platform is one of the key technologies demolition waste wellhead and riser  synthetic diamond  of the current foreign mainstream mechanical cutting techniques in cutting, drilling tablets cable cut, shaped blasting abrasive jet cutting and cutting. As is  synthetic diamond powder  by the multi-layer casing and  Diamond blade  cemented together and there may be eccentric, but need to cut at 5m below the seabed, drilling and mechanical cable cutter grain cutting method is difficult to meet the project needs, and shaped cutting due to blasting a greater damage to the environment, gradually limit the use of;

Mainstream mechanical cutting techniques in cutting, shaped cutting and blasting abrasive jet cutting

With the offshore oil and gas exploration and development progresses, a number of offshore platforms have completed their mission, platform removal has become a hot project. Platform is one of the key technologies demolition waste wellhead and riser  synthetic diamond  of the current foreign mainstream mechanical cutting techniques in cutting, drilling tablets cable cut, shaped blasting abrasive jet cutting and cutting. As is  synthetic diamond powder  by the multi-layer casing and  Diamond blade  cemented together and there may be eccentric, but need to cut at 5m below the seabed, drilling and mechanical cable cutter grain cutting method is difficult to meet the project needs, and shaped cutting due to blasting a greater damage to the environment, gradually limit the use of;

Mainstream mechanical cutting techniques in cutting, drilling tablets cable cut, shaped cutting and blasting abrasive jet cutting

With the offshore oil and gas exploration and development progresses, a number of offshore platforms have completed their mission, platform removal has become a hot project. Platform is one of the key technologies demolition waste wellhead and riser  synthetic diamond  of the current foreign mainstream mechanical cutting techniques in cutting, drilling tablets cable cut, shaped blasting abrasive jet cutting and cutting. As is  synthetic diamond powder  by the multi-layer casing and wellhead riser cemented together and there may be eccentric, but need to cut at 5m below the seabed, drilling and mechanical cable cutter grain cutting method is difficult to meet the project needs, and shaped cutting due to blasting a greater damage to the environment, gradually limit the use of;

Abrasive jet cutting seam technology of theoretical research

Wells on the wall in the implementation of abrasive jet cutting seam injection technology to increase production, so that the economic benefits of oil has been great, so a lot of engineering and technical personnel in research on this technology. For abrasive jet cutting seam cutting tools , we must first study abrasive jet cutting cracks in the flow, and then study the material under the action of the jet damage, so as to determine the jet parameters, the development of  synthetic diamond provide a theoretical basis and foundation, so for abrasive water jet cutting theoretical study of sewing techniques, both academic value but also practical significance. When the jet of fluid flow in slotting the basic initial Abrasive grinding wheel segment dissipate when the sand pressure water ejected from the nozzle while moving from top to bottom on the wall casing to be cut, because the casing diameter slotted equipment space is filled with water jet fluid motion can be considered as free submerged jet. Because the nozzle orifice is circular cross section which is circular jet, the jet can be classified into several sections.

Application abrasive jet cutting technology in the underground rock formations on the wall surrounding the cutting

Abrasive jet slotting processing technology is the application of near-wellbore abrasive jet cutting technology in the underground rock formations on the wall surrounding the well cut with deep seam parallel to the axis, so that the well-storey week to  polycrystalline diamond , relieve compaction effect, the near-wellbore to restore the original permeability formations. Meanwhile, it penetrates deep seam produced by the well construction  abrasive wheels  workover wells near wellbore blockage, a new clean oil flow channel, thereby improving near-wellbore permeability  synthetic diamond  pressure, increased oil production and oil recovery . After several ground simulation test and field applications, and achieved good results, after the construction of a general increase oil production wells more than 1 times, can be maintained for 2 years or more.

Wells abrasive jet cutting seam, sew the body fluid in the flow

Abrasive jet cutting seam technology is developed in an eighty year-end for releasing pollution and expand the near-wellbore permeability reservoir permeability of the new technology , with a penetration depth , no secondary pollution, the discharge area, the effect is significant construction and so on. But there are still many problems with the air compared to the free water jet , underwater jet  synthetic diamond  is also less . Especially for submerged conditions, high-speed non-free two -phase jet theory needs further study. The abrasive jet wells slotted body fluid flow at the seam , the movement of the solid particles ,  synthetic diamond powder  changes with time , the second return and the jet of fluid as the direction along the kerf attenuation rate few studies . To solve the above problems , this paper uses a theoretical and numerical investigation of the combination of research methods. The use of two -phase jet theory and   Diamond blade fluid dynamics and other basic knowledge , analysis wells abrasive jet slotting two-phase fluid motion mechanism . Gambit pre-processing software application , based on test results to establish the ground and underground seam 2D and 3D model of the body . Based on FLUENT software carried out on the two-dimensional numerical simulation of abrasive jet slotting process provides a theoretical basis and experimental evidence .

Research abrasive jet cutting seam technology on the permeability change impact surrounding wells

Abrasive jet slotting well stimulation technique is the use of two-phase jet abrasive mechanism developed for improved oil recovery in an oil field technology. This article from the seepage - stress coupling based theory, a more comprehensive study on the abrasive jet cutting seam technology surrounding wells permeability  cutting tools  analysis slotted the impact on oil production situation. Application of rock, the effective stress and pore pressure, confining pressure and rock properties  Abrasive grinding  slotted through the rock around the well after the stress and permeability variation  synthetic diamond  and analysis, interpretation of the abrasive jet cutting seam technology to increase production wells the basic principle is the rock around the well after slotting the effective stress reduction and increased permeability of the results;

Abrasive jet with a small amount of abrasive particles formed from a mixture consisting of water jet

Abrasive jet slotting mechanism and mechanical model to study in order to establish oil ( water ) wells abrasive jet slotting theory, as the technology continues to improve and the process parameters to provide theoretical support . Slotted underground rock formations require two different types of metals and materials to be cut , so this study for universal abrasive jet cutting is also instructive significance and reference value. Abrasive jet with a small amount of abrasive  synthetic diamond  from a mixture consisting of water jet , according to the abrasive particle size , and the mass and volume of low concentration, uniform distribution , water flow rate is high, the abrasive particles can be characterized flows together with the water can be regarded as sparse balance solid-liquid two-phase flow .  cutting tools  a continuous medium , in the establishment of a solid-liquid two-phase flow on the basis of the basic differential equations , obtained with the solid-liquid two-phase equivalent single -phase fluid of the basic equations. Which can be applied to single-phase fluid mechanics and  abrasive grinding  fluid flow method problem . This paper uses polar coordinates , time-average method to create turbulence equations . By order of comparative law , the equation reduces to the corresponding turbulent boundary layer equations , namely freedom of circular cross-section turbulence abrasive jet differential equations .