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Gensheng Li - One of the best experts on this subject based on the ideXlab platform.
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Numerical analysis of characteristics of reaction in hydrothermal Jet Drilling for geothermal energy
Geothermics, 2020Co-Authors: Xianzhi Song, Gensheng LiAbstract:Abstract Hydrothermal Jet technology is a Drilling method, which is potentially suitable for the exploitation of geothermal energy in deep hard formations. The generation of a stable hydrothermal Jet via combustion in the reaction chamber is an important subject for successful applications. In this paper, the Peng-Robinson equation of state and four combustion models are applied to simulate the reaction in the downhole chamber. Simulation results are compared with experimental data to obtain a suitable model. The reaction flow field and effects of several factors (i.e., fuel and oxygen flow rate, mass fraction, and wall temperature) are studied. Results show that under the conditions of this paper, the finite rate model is more suitable. It may be better to inject the maximum fraction of fuel for complete reaction to obtain the highest Jet pressure and temperature simultaneously. The cooling water flow rate and temperature can be adjusted over a broad range to control the temperature of the reaction chamber within a suitable range. Results in this paper could provide guidance for further research on hydrothermal Jet Drilling.
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Model evaluation and experimental validation of thermal Jet Drilling for geothermal energy
Geothermics, 2020Co-Authors: Xianzhi Song, Gensheng LiAbstract:Abstract Thermal Jet Drilling is a technology, which has the potential to be suitable for the exploitation of geothermal energy in relatively deep formations with low costs. Several investigations on this Drilling method have been carried out for the depths of less than 1 km or deeper than 2 km. To the best of our knowledge, there is almost no specific study on simulation for thermal Jet Drilling at the depths between 1 km and 2 km. This paper focuses on investigating applications of different reaction (i.e., laminar, non-premixed, eddy dissipation concept, eddy dissipation model and finite rate), turbulence (i.e., standard k-epsilon, realizable k-epsilon, renormalization group k-epsilon and scale-adaptive simulation) and radiation (i.e., P1, discrete ordinate, discrete transfer radiation model and surface-to-surface) models to downhole reaction of thermal Jet Drilling. The objective is to identify the pros and cons of each model and determine a set of models that are the most appropriate for the reaction. Experiments are also carried out and data are collected as the benchmark for comparison. Relative errors and iteration for convergence are analyzed for each simulation model. Results show that the modified simulation temperature by considering the environmental temperature becomes more accurate compared with the experimental data. The laminar model over-predicts the temperature and yields unreasonable results. Finite rate and eddy dissipation model are the candidates with highest accuracy and acceptable computational time within selected model settings and boundary conditions. In addition, compared with renormalization group, realizable and scale-adaptive simulation turbulence models, the standard k-epsilon model is the most appropriate model under the conditions selected for this investigation. The discrete ordinate model can be applicable for the simulation if the error tolerance is 10%. The P1 model is the most suitable radiation model. Results in this paper can provide implications for the reaction simulation of thermal Jet Drilling.
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Numerical analysis of the downhole flow field with compressible fluid in hydrothermal Jet Drilling
International Journal of Thermal Sciences, 2018Co-Authors: Xianzhi Song, Gensheng LiAbstract:Abstract A novel hydrothermal Jet Drilling technology is proposed, which is expected to be suitable for the exploitation of subsurface hydrocarbon resource or geothermal energy. The flow field is analyzed with compressible fluid. Influences of Jet temperature, Jet velocity, cooling water velocity, and cooling water temperature are discussed. Gray correlation method is used to compare the effects of different factors and further verification is performed. Simulation results are validated by results from experiments and analytical models. The values of specific heat are relatively high in the annulus because the hydrothermal Jet undergoes the pseudo-critical point. Despite higher temperatures of the hydrothermal Jet, the annular high temperature fluid can be effectively cooled. Considering both thermal effect and impact, it may be better to keep the hydrothermal Jet temperature in the range of 700 K–800 K under the conditions of this paper. Under different cooling water velocities, the varying trend of the borehole wall temperature corresponds with that of the specific heat. The cooling water velocity has the most significant impact on the variation of the annular temperature, with the following sequence being Jet temperature, Jet velocity and cooling water temperature. Adjusting cooling water velocity may be the most efficient and cost-effective way for the hydrothermal Jet Drilling.
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analysis of temperature simulation in downhole reaction chamber of hydrothermal Jet Drilling
International Journal of Heat and Mass Transfer, 2018Co-Authors: Xianzhi Song, Gensheng LiAbstract:Abstract Hydrothermal Jet is an alternative Drilling method for the exploitation of oil and geothermal energy in deep hard formations. For the application of this novel technology, the successful generation of hydrothermal Jet is very important. This paper focuses on investigating applications of different reaction, turbulence and radiation models to the supercritical water oxidation process in downhole reaction chamber of hydrothermal Jet Drilling. The objective is to identify the pros and cons of each model and determine a set of models that are the most appropriate for the reaction. Simulation models are tested and optimized through two different operating conditions. Simulation results are compared with experimental data. Results show that the entire space of the reaction chamber is in a high temperature state using the laminar finite rate model. The finite rate model is suitable for the simulation compared with other reaction models discussed. The Magnussen constant A and B in the finite rate model can be modified to be 7 and 0.5 to further reduce the error. In addition, the high temperature areas in k-omega model and SAS model are more concentrated, while they are more uniform in RNG k-epsilon model and standard k-epsilon model. The RNG k-epsilon model and DO or DTRM are the most appropriate turbulence and radiation models through comparison. Results in this paper can provide implications for the reaction simulation of hydrothermal Jet Drilling.
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A Method to Double the Extension Ability of Radial Jet Drilling Technology
Journal of Energy Resources Technology-transactions of The Asme, 2018Co-Authors: Jingbin Li, Gensheng Li, Zhongwei Huang, Guangqing Zhang, Weichang LiAbstract:Radial Jet Drilling (RJD) technology is an effective method to enhance oil and gas recovery by penetrating the near-wellbore damage zone, and increasing the drainage radius greatly. Recently, it is identified as a potential technology to develop the geothermal energy. But the extension ability, one of the most critical issues of the RJD, is limited. Because only high pressure flexible hose (HPFH), which is hard to be fed in and subjected to greater resistance by the diverter, can be used as the drill stem to turn from vertical to horizontal in the casing. In this paper, an innovative method to feed in the HPFH by the drag force generated by high velocity flow in narrow annulus is proposed. The drag force model is built, validated, and modified by theoretical and experimental ways. Results show that the resulting drag force, which is equivalent to the self-propelled force, can easily achieve and feed in the HPFH. There is a power law relationship between the drag force and the average velocity; the drag force increases linearly with the length of the narrow annulus. Higher average velocity and 1–1.5 m annulus length are recommended. According to force analysis, the extension ability of the RJD can be doubled theoretically by this method. The results of this paper will greatly promote the development of RJD technology.
H S Shan - One of the best experts on this subject based on the ideXlab platform.
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electro Jet Drilling using hybrid nnga approach
Robotics and Computer-integrated Manufacturing, 2007Co-Authors: H S ShanAbstract:This paper presents a hybrid neural network and genetic algorithm (NNGA) approach for the multi-response optimization of the electro Jet Drilling (EJD) process. The approach first uses a neural network model to predict the response parameters of the process. A genetic algorithm is then applied to the trained neural network model to obtain the optimal process parameters values in which desirability function approach is used to obtain the fitness function for the genetic algorithm from the network output. The simulated results are found to have a close correlation with the experimental data.
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finite element analysis of the electro Jet Drilling process
International Journal of Modelling and Simulation, 2007Co-Authors: H S ShanAbstract:The electro Jet Drilling (EJD) process is gaining prominence in the machining of micro and macro holes in difficult-to-machine materials used in aerospace, electronics and computers, medical, and automobile industries. As the trend towards miniaturization continues, this process is gaining increasing importance as it has shown its superiority over other contemporary non-conventional micro and macro hole Drilling processes. This paper presents a two-dimensional finite element model for the analysis of the EJD process using quadrilateral (rectangular) elements. The developed model predicts the Drilling rate and radial overcut. Experimental results indicate close agreement with the simulated results.
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Response surface analysis of electro Jet drilled holes
The International Journal of Advanced Manufacturing Technology, 2006Co-Authors: H S ShanAbstract:Modern trend towards miniaturization has given a new impetus to the development of nontraditional small hole Drilling techniques. Electro Jet Drilling (EJD) is one such promising technique which is finding ever increasing applications in several industries including aerospace, space, medical, automobile and microfabrication (electronic and computers). The present study investigates the relationships and parametric interactions between three controllable variables on the material removal, radial overcut and hole taper in the EJD process. Experiments have been conducted on SUPERNI 263A workpieces. Applied voltage, electrolyte concentration and feed rate were selected as independent process variables. The responses have been modelled using a response surface model based on a central composite rotatable experimental design. The significant coefficients were obtained by performing analysis of variance (ANOVA) at 1% and 5% level of significance. It was found that applied voltage, electrolyte concentration and feed rate have significant effect on the material removal, radial overcut and hole taper.
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Analysis of Roundness Error and Surface Roughness in the Electro Jet Drilling Process
Materials and Manufacturing Processes, 2006Co-Authors: H S ShanAbstract:ABSTRACT A modern trend towards miniaturization has given a new impetus to the development of nontraditional small hole Drilling techniques. Electro Jet Drilling (EJD) is one such promising technique, and is finding ever-increasing applications in several industries including aerospace, space, medical, automobile, and microfabrication (electronics and computers). This paper reports experimental findings on the effects of important process parameters such as applied voltage, capillary outside diameter, feed rate, electrolyte concentration, and inlet electrolyte pressure on the quality of small holes (
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analysis of roundness error and surface roughness in the electro Jet Drilling process
Materials and Manufacturing Processes, 2006Co-Authors: H S ShanAbstract:ABSTRACT A modern trend towards miniaturization has given a new impetus to the development of nontraditional small hole Drilling techniques. Electro Jet Drilling (EJD) is one such promising technique, and is finding ever-increasing applications in several industries including aerospace, space, medical, automobile, and microfabrication (electronics and computers). This paper reports experimental findings on the effects of important process parameters such as applied voltage, capillary outside diameter, feed rate, electrolyte concentration, and inlet electrolyte pressure on the quality of small holes (<800 μm dia) produced by using the EJD process. Roundness error and surface roughness have been used as response parameters for evaluating the quality of the holes. The experiments were performed on SUPERNI 263A material. An analysis of variance (ANOVA) performed to test the significance of the variables at the 5% level indicates that applied voltage and electrolyte concentration significantly affect the respo...
Xianzhi Song - One of the best experts on this subject based on the ideXlab platform.
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Model evaluation and experimental validation of thermal Jet Drilling for geothermal energy
Geothermics, 2020Co-Authors: Xianzhi Song, Gensheng LiAbstract:Abstract Thermal Jet Drilling is a technology, which has the potential to be suitable for the exploitation of geothermal energy in relatively deep formations with low costs. Several investigations on this Drilling method have been carried out for the depths of less than 1 km or deeper than 2 km. To the best of our knowledge, there is almost no specific study on simulation for thermal Jet Drilling at the depths between 1 km and 2 km. This paper focuses on investigating applications of different reaction (i.e., laminar, non-premixed, eddy dissipation concept, eddy dissipation model and finite rate), turbulence (i.e., standard k-epsilon, realizable k-epsilon, renormalization group k-epsilon and scale-adaptive simulation) and radiation (i.e., P1, discrete ordinate, discrete transfer radiation model and surface-to-surface) models to downhole reaction of thermal Jet Drilling. The objective is to identify the pros and cons of each model and determine a set of models that are the most appropriate for the reaction. Experiments are also carried out and data are collected as the benchmark for comparison. Relative errors and iteration for convergence are analyzed for each simulation model. Results show that the modified simulation temperature by considering the environmental temperature becomes more accurate compared with the experimental data. The laminar model over-predicts the temperature and yields unreasonable results. Finite rate and eddy dissipation model are the candidates with highest accuracy and acceptable computational time within selected model settings and boundary conditions. In addition, compared with renormalization group, realizable and scale-adaptive simulation turbulence models, the standard k-epsilon model is the most appropriate model under the conditions selected for this investigation. The discrete ordinate model can be applicable for the simulation if the error tolerance is 10%. The P1 model is the most suitable radiation model. Results in this paper can provide implications for the reaction simulation of thermal Jet Drilling.
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Numerical analysis of characteristics of reaction in hydrothermal Jet Drilling for geothermal energy
Geothermics, 2020Co-Authors: Xianzhi Song, Gensheng LiAbstract:Abstract Hydrothermal Jet technology is a Drilling method, which is potentially suitable for the exploitation of geothermal energy in deep hard formations. The generation of a stable hydrothermal Jet via combustion in the reaction chamber is an important subject for successful applications. In this paper, the Peng-Robinson equation of state and four combustion models are applied to simulate the reaction in the downhole chamber. Simulation results are compared with experimental data to obtain a suitable model. The reaction flow field and effects of several factors (i.e., fuel and oxygen flow rate, mass fraction, and wall temperature) are studied. Results show that under the conditions of this paper, the finite rate model is more suitable. It may be better to inject the maximum fraction of fuel for complete reaction to obtain the highest Jet pressure and temperature simultaneously. The cooling water flow rate and temperature can be adjusted over a broad range to control the temperature of the reaction chamber within a suitable range. Results in this paper could provide guidance for further research on hydrothermal Jet Drilling.
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Numerical analysis of the downhole flow field with compressible fluid in hydrothermal Jet Drilling
International Journal of Thermal Sciences, 2018Co-Authors: Xianzhi Song, Gensheng LiAbstract:Abstract A novel hydrothermal Jet Drilling technology is proposed, which is expected to be suitable for the exploitation of subsurface hydrocarbon resource or geothermal energy. The flow field is analyzed with compressible fluid. Influences of Jet temperature, Jet velocity, cooling water velocity, and cooling water temperature are discussed. Gray correlation method is used to compare the effects of different factors and further verification is performed. Simulation results are validated by results from experiments and analytical models. The values of specific heat are relatively high in the annulus because the hydrothermal Jet undergoes the pseudo-critical point. Despite higher temperatures of the hydrothermal Jet, the annular high temperature fluid can be effectively cooled. Considering both thermal effect and impact, it may be better to keep the hydrothermal Jet temperature in the range of 700 K–800 K under the conditions of this paper. Under different cooling water velocities, the varying trend of the borehole wall temperature corresponds with that of the specific heat. The cooling water velocity has the most significant impact on the variation of the annular temperature, with the following sequence being Jet temperature, Jet velocity and cooling water temperature. Adjusting cooling water velocity may be the most efficient and cost-effective way for the hydrothermal Jet Drilling.
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analysis of temperature simulation in downhole reaction chamber of hydrothermal Jet Drilling
International Journal of Heat and Mass Transfer, 2018Co-Authors: Xianzhi Song, Gensheng LiAbstract:Abstract Hydrothermal Jet is an alternative Drilling method for the exploitation of oil and geothermal energy in deep hard formations. For the application of this novel technology, the successful generation of hydrothermal Jet is very important. This paper focuses on investigating applications of different reaction, turbulence and radiation models to the supercritical water oxidation process in downhole reaction chamber of hydrothermal Jet Drilling. The objective is to identify the pros and cons of each model and determine a set of models that are the most appropriate for the reaction. Simulation models are tested and optimized through two different operating conditions. Simulation results are compared with experimental data. Results show that the entire space of the reaction chamber is in a high temperature state using the laminar finite rate model. The finite rate model is suitable for the simulation compared with other reaction models discussed. The Magnussen constant A and B in the finite rate model can be modified to be 7 and 0.5 to further reduce the error. In addition, the high temperature areas in k-omega model and SAS model are more concentrated, while they are more uniform in RNG k-epsilon model and standard k-epsilon model. The RNG k-epsilon model and DO or DTRM are the most appropriate turbulence and radiation models through comparison. Results in this paper can provide implications for the reaction simulation of hydrothermal Jet Drilling.
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Comparison of numerical analysis on the downhole flow field for multi-orifice hydrothermal Jet Drilling technology for geothermal wells
Geothermics, 2017Co-Authors: Xianzhi Song, Gensheng Li, Guodong Ji, Zhaoyu PangAbstract:Abstract Newly developed hydrothermal Jet Drilling technology has the potential of being economically advantageous over conventional Drilling techniques for Drilling deep wells in hard formations. By applying coiled tubing techniques and modulating fluid media in the bottomhole reaction chamber, there can be a high temperature and high velocity Jet striking and conducting heat to break the rock. So far, there has been no specific study on the influence of nozzle structure on the flow field of multiple hydrothermal Jets. This paper presents hydrothermal Jet models with different numbers of orifices to investigate the features of flow field, carrying capacity, Drilling ability and cooling effect. Results show that for two models in the absence of cooling water, the bottomhole center temperature and pressure are higher than the two sides under multiple hydrothermal Jets conditions. This is similar to the flow pattern for a single Jet. Additionally, for the five-orifice nozzle with cooling water injected, the entire high temperature region is cylindrical. Ambient cooling water envelops the inner hot water. By comparing different models, the five-orifice nozzle model without cooling water shows a circular symmetric distribution of the bottomhole temperature. With cooling water injected, the central high temperature region becomes rectangular, while the margin of the well bottom is cooled by the peripheral cooling water. The bottom rock average temperature in five-orifice model is lower than for the four-orifice model due to more drastic thermal and kinetic transfer between the hydrothermal Jet and the cooling water. The five-orifice nozzle model is better than the four-orifice nozzle model in terms of bottomhole temperature, bottomhole pressure and carrying capacity. Therefore, the five-orifice nozzle should be adopted for hydrothermal Jet Drilling. It is also feasible to pump down relatively high temperature cooling water to guarantee the high temperature downhole environment. Meanwhile, the cooling water pressure should be controlled during the Drilling process for better cooling efficiency. All results in this paper are relevant to the parameters design for multi-orifice hydrothermal Jet Drilling technology.
Jefferson W. Tester - One of the best experts on this subject based on the ideXlab platform.
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Chemical Dissolution Drilling of Barre Granite Using a Sodium Hydroxide Enhanced Supercritical Water Jet
Rock Mechanics and Rock Engineering, 2019Co-Authors: Ivan Beentjes, Jay T. Bender, Adam J. Hawkins, Jefferson W. TesterAbstract:This experimental study focused on evaluating the technical feasibility of chemically enhancing rock comminution during supercritical hydrothermal Jet Drilling by increasing pH with additives. Comminution of the crystalline rock samples occurred under supercritical conditions at temperatures and pressures ranging from 535–580 °C and 22.5–27 MPa, respectively, using hydrothermal Jets with sodium hydroxide concentrations ranging from 0.0725 to 0.345 mol/kg. Impinging hydrothermal Jets induced thermal spallation and rock removal from 21 Barre granite specimens examined. These experimental conditions replicate those that would be encountered in Drilling water-filled wells at depths greater than ~ 2300 m. The combination of accelerated mineral dissolution due to the presence of hydroxide ions, high solution temperature increasing reaction rates, and thermal stresses resulted in rates of rock removal up to 5.16 g in 10 min at 410 °C and 0.345 mol/kg NaOH. Comparison with published empirical quartz dissolution rates at high pH suggests granite mass removal primarily resulted from weakening of the rock matrix as a result of the accelerated dissolution of quartz minerals. Experimentally determined heat flux and surface temperature measurements indicated that the rock comminution occurred below the empirically determined minimum levels for the onset of continuous thermal spallation resulting from impinging low-density flame Jets or high energy laser heating.
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Dissolution and Thermal Spallation of Barre Granite Using Pure Water Hydrothermal Jets
Rock Mechanics and Rock Engineering, 2019Co-Authors: Ivan Beentjes, Jay T. Bender, Jefferson W. TesterAbstract:Spallation induced by rapid hydrothermal heating was investigated as a possible method of Drilling rock. In this study, an electrically-heated hydrothermal Jet was impinged on the surface of cylindrical Barre Granite specimens (basement rock) contained in an autoclave reactor to induce localized thermal stress. Comminution of the rock surfaces was achieved at supercritical water conditions, temperatures from 535 to 580 °C and pressures of 22.5–27 MPa. These conditions simulate those encountered in Drilling deep, water-filled wells at depths greater than about 2300 m. Preferential removal of quartz grains from the rock matrix was observed. This comminution cannot be attributed to erosion by either the Jet’s momentum, or by differential pressure forces. Additionally, silica removal (primarily from quartz grains) was observed at rates greater than those that could be attributed to dissolution of quartz alone. This implied a secondary comminution mechanism associated with spallation caused by the local thermal stresses from the impinging hydrothermal Jet. The experimentally determined heat flux and surface temperature measurements indicated that hydrothermal Drilling occurred below the empirically determined minima for the onset of continuous thermal spallation reported in earlier studies for low-density, high-velocity and high-temperature flame Jet Drilling at temperatures in excess of 1000 °C Jets impinging on rock surfaces at near-atmospheric pressures.
Hamidreza M Nick - One of the best experts on this subject based on the ideXlab platform.
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a novel radial Jet Drilling stimulation technique for enhancing heat recovery from fractured geothermal reservoirs
Renewable Energy, 2019Co-Authors: Saeed Salimzadeh, M Grandahl, M Medetbekova, Hamidreza M NickAbstract:Abstract In this study, the application of the Radial Jet Drilling (RJD), a novel stimulating technique for enhancing productivity in the existing wells in deformable naturally fractured reservoirs was investigated using a robust three-dimensional finite element DFM (discrete fracture-matrix) model. Results showed that the RJD laterals were more effective in enhancing injectivity/productivity in cases with lower fracture density, i.e. lower equivalent permeability, while they had no significant effect on the heat production in these cases. In higher fracture density cases, the RJD laterals improved the heat production while had no significant effect on the injectivity/productivity. Results also showed that in reservoirs with very low permeability matrix, the RJD laterals can be used to connect the wells to the fracture network and hence enhance the well performance. The sensitivity analysis on the average net energy production rate with respect to the length of the RJD laterals showed that in the situations where the wells were not connected directly to the fractures, the length of RJD laterals played a crucial role in enhancing the average net energy rate. However, the 100 m laterals almost removed the dependency of the average net energy production rate on the well placement for low, medium and high fracture density cases.
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Radial Jet Drilling (RJD) Laterals in Fractured Geothermal Reservoirs
80th EAGE Conference and Exhibition 2018, 2018Co-Authors: M Grandahl, Saeed Salimzadeh, M Medetbekova, Hamidreza M NickAbstract:Summary The effect of RDJ laterals on the productivity of a naturally fractured geothermal system has been investigated in this study. A doublet system in a reservoir of 3 × 3 × 0.1 km. with two sets of natural fractures has been the object for the study. The preliminary results show that the placement of the well in such a system has a significant impact on the productivity of such a system. And that RDJ’s can be used to further improve the productivity of the system.
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Experimental and Numerical Study of the Stability of Radially Jet Drilled Laterals in Chalk Reservoirs
80th EAGE Conference and Exhibition 2018, 2018Co-Authors: M Medetbekova, Saeed Salimzadeh, Helle Foged Christensen, Hamidreza M NickAbstract:One way of increasing hydrocarbon production is to extend the lateral reach of the wellbore by lateral holes. The approach bypasses the potentially damaged near-wellbore area, thus improving the productivity of the well and enhancing the swept area. This has become feasible by a new technology called Radial Jet Drilling (RJD) technology, in which, relatively long, small-diameter laterals can be Jetted radially from the main wellbore. However, the success of this technology very much depends on the long-term stability of the laterals under dynamic reservoir conditions. The objective of the present work is to evaluate which geometry of the lateral hole provides the most stable production as well as to define the limit of the rock material properties that withstands lateral hole collapse. To do so, a set of advanced laboratory experiments are performed on two distinct outcrop chalks from Austin (US) and Welton (UK) that are analogues to the reservoir chalk in the North Sea. Based on rock mechanics and Jetting experiments, numerical modelling of Jetted hole behaviour is implemented and analysed for the stability in the finite element (FE) software Abaqus.