Construction Parameters Research Articles

Simulation of temporary plugging agent transport and optimization of fracturing parameters based on fiber optic monitoring data

Temporary plugging and fracturing is an important technology for the efficient development of unconventional reservoirs. Due to the diverse physical properties of unconventional reservoirs and the complex stress environment, the evaluation of temporary plugging effect needs to consider the working conditions in the wells, and it also needs to focus on the transport and placement of temporary plugging agent in the near-well fracture region, so it is impossible to predict the effect of temporary plugging and fracturing effectively. In this paper, a numerical simulation study is carried out to investigate the transport and placement of temporary plugging agent in the near-well area, and a finite element model of “wellbore-near-well fracture” is established based on computational fluid dynamics, and numerical simulation and verification of temporary plugging and fracturing are carried out based on the fiber-optic monitoring data of temporary plugging and fracturing in Well A, as well as the optimization of some construction parameters. The results show that: as the volume concentration of temporary plugging agent increases, the temporary plugging effect is weakened and then strengthened, and the temporary plugging agent will enter into the heel cluster in advance when the concentration is small; at the initial stage, the increase in the quality of temporary plugging agent will cause some clusters to form incomplete plugging, but the quality of the plugging agent will not be changed after the quality is greater than 360kg; the temporary plugging effect is mainly reflected in the heel cluster, and the toe cluster is not obvious. This paper forms a set of temporary plugging and fracturing simulation methods based on the actual fiber-optic monitoring data in the field, which provides a reference for the optimization design of the type, particle size and dosage of temporary plugging agent during the temporary plugging construction process.

Formation mechanism of micro-seismicity difference between rockbursts in deep-seated parallel tunnels

Deep-seated parallel tunnels are highly susceptible to rockbursts owing to the geological environment and engineering disturbances caused by adjacent tunnel excavations. However, accurately predicting these is challenging. The temporal and spatial characteristics of microseismic (MS) events and rockbursts in parallel tunnels can be jointly analyzed owing to their similar occurrence environments. However, although the left and right tunnels exhibited similar rockburst features during the construction of the Gaoloushan highway tunnel, noticeable differences in the MS events were observed. To clarify the cause of this phenomenon, the mechanisms of the influences of the buried depth, rock mass structure, hydrogeological conditions, construction parameters, blasting disturbance, and other factors on the MS activities of the left and right tunnels were investigated. Our findings suggested that the original geological occurrence environments, including the buried depth, rock mass structure, and hydrogeological conditions, were the primary reasons for the MS differences between the left and right tunnels. There was no obvious correspondence between the tunneling speed and evolution of the MS events. The influences of the section change and blasting on the MS anomaly were restricted by the geological environment and surrounding rocks. The results provide valuable insights into the effects of geological conditions and construction parameters on the formation mechanisms of rockbursts and MS events and may assist in developing an effective early warning strategy, as well as in preventing and controlling rockbursts in parallel tunnels or tunnel groups.

Modelling Wear Phenomena Specific to Mixer Blades in Concrete Production Plants

In the cement concrete manufacturing industry, mixers are critical pieces of equipment that play an essential role. Mixers ensure, by mechanically mixing the materials that make up the concrete, the homogeneity of the mixture. Since the active elements of the mixer in the concrete industry—the mixing blades—come into permanent contact with the mineral aggregates in the mixture formed by water and cement, they are permanently subjected to a strong abrasive–erosive wear process. The authors of this article were concerned with the establishment of tribological models for studying the wear of mixing blades, in order to identify the influence of their constructive parameters on the wear intensity. A complex model (Kraghelsky–Nepomnyashchi model) was adopted for the study. The modeling results revealed that the wear intensity decreases with an increasing blade angle of attack and increases linearly with increasing speed, as well as with an increasing friction coefficient. The modeling results confirm that the wear intensity is lowest when the mixing blade is inclined at a 60° angle, while the highest value is recorded for 30°. By identifying the angle at which the greatest wear of blades occurs, interventions can be made in the design of a more durable mixer (with the optimal installation angle of the mixer blades), thus requiring fewer corrective maintenance interventions. Based on these findings, we conclude that the complex model used in the experiment can provide a convenient and efficient tool for the study of erosive–abrasive phenomena.

Numerical Simulation of Proppant Transportation and Placement Law In Fractured Coal Reservoirs

Hydraulic fracturing technology has been widely used in the development of low-permeability oil fields, gas fields, and coalbed methane. The morphology of the sand dike formed by proppant deposition in the fracture determines the effective shape of the fracture, the effective volume, the flow conductivity, and the validity period of the fracture, and the research on the proppant transport law in the fracture is of great significance in optimizing the fracturing construction parameters and improving the fracturing production increase effect. In this paper, a systematic study on the proppant transport law in hydraulic fracturing fracture is carried out by numerical simulation, which reveals the mechanism of proppant settling and transport, clarifies the proppant transport and placement law under different working conditions, and puts forward the optimization strategy of hydraulic fracturing process on the basis of this study.

Analysis of sensor parameters for ultra close range lateral penetration of subway tunnel full section sand layer soil pressure shield tunneling

In order to solve the problem of large disturbance to the stratum caused by shield tunneling in the full face sand layer geology by using the earth pressure balance full bin tunneling technology in the subway tunnel shield construction, this paper presents a parameter analysis of the ultra close side penetration of the full face sand layer earth pressure shield in the subway tunnel. By analyzing the monitoring data of surface settlement caused by subway shield construction, it is concluded that the law of surface horizontal settlement basically conforms to peak settlement theory, and the law of surface vertical settlement basically shows a steady downward trend. Through the mathematical modeling of the cumulative settlement data affected by the shield passing of the right line tunnel at the surface monitoring point, the influence of the shield passing of the left line tunnel on the surface settlement is predicted, and the prediction result is accurate. The experimental results show that the maximum deviation is 1.47 mm and the minimum deviation is 0.03 mm. The prediction accuracy is high and meets the accuracy requirements of practical engineering. Under the same geological conditions and construction parameters, the disturbance law of tunnel shield construction on the ground surface has important guiding significance in practical engineering.

Surrogate numerical prediction method of TBM position via FEM simulation and machine learning

The position of the tunnel boring machine (TBM) during tunnel construction is critical and must be precisely controlled. Owing to the geological uncertainty and complexity of the interaction between the ground and the TBM, controlling the position of the TBM is challenging. Hence, a surrogate numerical method is proposed to predict the position of the TBM using the finite element method (FEM) and machine learning method. First, a refined three-dimensional FEM model was established. Different values of the property parameters of the ground and the thrust force of the TBM were input into the FEM model, generating a database that includes 1000 cases. Subsequently, the database is used to train a gradient boosting regression (GBR) model. The GBR model learns from the database and establishes the relationship between the construction parameters, ground parameters, and TBM position as a surrogate model. The surrogate model exhibited high accuracy on the test set. With a geological survey and a construction parameter monitoring system, the TBM position could be predicted quickly and precisely using a surrogate model. The construction parameters were adjusted if the TBM position did not satisfy the requirements.

Evaluating the influence of functional unit on life cycle assessment (LCA) reliability of concrete

The linear lifecycle of concrete, from production through usage to disposal, highlights its status as one of the most carbon-, energy-, and resource-intensive processes in the industry. The development of life cycle assessment (LCA) models to quantify concrete’s embodied and buildings’ operational emissions is strongly influenced by the selection of the functional unit (FU) since it dictates the magnitude and significance of the environmental burdens from concrete and buildings' life span. The chosen FU should comprehensively capture the concrete's functionalities and construction parameters. Nonetheless, establishing a FU that encompasses spatial, temporal, and intensity aspects of cement/concrete and its applications remains a significant limitation in the practice of current LCA models. This study analyzed the FU influence on the environmental footprint of concrete samples with specific compressive strengths (material level) via LCA. The LCA was conducted in OneClick LCA using the environmental product declaration (EPD) provided by the software for each ready-mix concrete sample. From the LCA results, the C 30/37 concrete mix (lowest compressive strength) exhibited the lowest carbon footprint for all the environmental indicators when a volume-based FU was considered. In contrast, the results were more favorable for the C 65/70 concrete specimen when the compressive strength (28 curing days) was chosen because less cement is needed to achieve one MPa of strength. This behavior was also observed in the modeling of a column in a building, where the mixture with the highest compressive strength (C 65/70) showed the lowest environmental impact for all the indicators. However, this assessment does not represent the actual building system's footprint. Thus, regionally specific functional units need to be established, considering not just concrete functionalities but also national regulations, stakeholder needs, and local resource availability.

An o-Phenylenediamine and MWCNT-Based Electrochemical Sensor for the Detection of Triclosan by Cyclic Voltammetry

Selectivity and sensitivity are the two key parameters for construction of a sensor. In this work, a novel electrochemical sensor based on molecularly-imprinted composites synthesized from o-phenylenediamine (o-PD) and multiwalled carbon nanotube (MWCNT) to detect triclosan is reported. Two different sensors were developed MIC/GC and MIC/cf-MWCNT/GC. To fabricate MIC/GC, molecularly imprinted composite (MIC) was synthesized by cyclic voltammetry using o-PD, COOH-functionalized MWCNT (cf-MWCNT) and triclosan on glassy carbon (GC) electrode, following removal of surface triclosan. MIC/cf-MWCNT/GC was fabricated by synthesizing MIC on cf-MWCNT coated GC. Template removal was performed using NaOH solution. MIC/GC could detect triclosan till 40 ppb while using MIC/cf-MWCNT/GC, 10 ppb of limit of detection (LOD) was achieved. Adsorption isotherms were constructed for both the films. Langmuir adsorption isotherm gave the best fit for MIC/cf-MWCNT/GC with -ΔGads value of 54.952 kJ mol−1 indicating stronger chemisorption. To understand the role of cf-MWCNT in detection of triclosan, electrochemical band gap studies, electrochemical impedance spectroscopy, and cyclic voltammetry studies were conducted. Both the sensors were found to be efficient for detection of triclosan in the presence of interfering ions.

Methodology for determining the design parameters of combined type plasma-chemical reactor for gasification of carbon-containing raw materials

The paper shows the advantages of combined type reactors for plasma-chemical allothermic processes of carbon-containing raw materials gasification. The methodology for determining the design parameters of combined type plasma-chemical reactor for gasification of carbon-containing raw materials is developed. Analytical dependences for determination of time and constructive parameters of the combined type plasma-chemical reactor are established. Dependences contain interrelation between the main technological parameters of the process of thermo-conversion of carbon-containing raw materials taking into account thermochemical reactions. Dependences of constructive parameters of reaction zone of combined type plasma-chemical reactor for steam plasma gasification of carbon-containing media are obtained. It is established that at steam gasification of carbon-containing raw materials with the maximum particle size of 150 microns and the temperature in the reaction zone of 5000 K the volume of the reaction zone depends on the productivity of carbon-containing raw materials, which has a significant effect on the design parameters of the reaction zone.

Research on construction parameters of stone columns for liquefaction mitigation in coral reef sand areas

For loose coral reef sand with high fines content located in strong earthquake zones, it is necessary to choose stone columns as a liquefaction mitigation ground improvement method that can consider both drainage and densification functions. Taking the Tibar Bay Port project in East Timor as an example, the bottom-feed technology of vibrating stone columns was developed, and typical coral reef sand sites with different fines contents were selected as trial test areas. Experimental research was performed to study the construction parameters for onshore and offshore stone column processes. Tests showed that the vibratory process control parameters, quality acceptance standards, and control procedures proposed through research meet the anti-liquefaction requirements for both drainage and densification effectiveness. The different construction characteristics of onshore and offshore stone columns were also analyzed. Considering the particularity of underwater stone column construction, the research results can be used for stone columns reinforced grounds similar to coral sand onshore and offshore.

Study on the Damage Mechanism of Coal under Hydraulic Load

Hydraulic fracturing is extensively utilized for the prevention and control of gas outbursts and rockbursts in the deep sections of coal mines. The determination of fracturing construction parameters based on the coal seam conditions and stress environments merits further investigation. This paper constructs a damage analysis model for coal under hydraulic loads, factoring in the influence of the intermediate principal stress, grounded in the unified strength theory analysis approach. It deduces the theoretical analytical equation for the damage distribution of a coal medium subjected to small-flow-rate hydraulic fracturing in underground coal mines. Laboratory experiments yielded the mechanical parameters of coal in the study area and facilitated the fitting of the intermediate principal stress coefficient. Leveraging these datasets, the study probes into the interaction between hydraulic loads and damage radius under assorted influence ranges, porosity, far-field crustal stresses, and brittle damage coefficients. The findings underscore that hydraulic load escalates exponentially with the damage radius. Within the variable range of geological conditions in the test area, the effects of varying influence range, porosity level, far-field stress, and brittle damage coefficient on the outcomes intensify one by one; a larger hydraulic load diminishes the impact of far-field stress variations on the damage radius, inversely to the influence range, porosity, and brittle damage. The damage radius derived through the gas pressure reduction method in field applications corroborates the theoretical calculations, affirming the precision of the theoretical model. These findings render pivotal guidance for the design and efficacy assessment of small-scale hydraulic fracturing in underground coal mines.

Effect of Stress Relief on Coal Seam Gas Migration: Experiment and Application Discussion.

Stress relief-induced enhanced permeability is one of the crucial measures for promoting gas desorption flow and strengthening gas extraction. In order to examine the impact of stress relief and its magnitude on gas migration, this article explores the gas desorption flow during the stress relief process and elucidates the influence of stress relief degree on gas extraction. The results indicate that considering the analysis of the pore structure effect on gas seepage, the four coal samples' permeability is ranked as PDS > CSL > JZS > GHS. Throughout the stress relief process, the gas desorption rates of different coal samples under various stress paths exhibit varying degrees of increase. As an illustration, following 3600 s of stress alterations, the gas desorption rate of CSL1# experiences a notable increase, surging by 2.57 times; PDS2# shows 55.93 times increase after 4200 s, and JZS3# exhibits 3.13 times increase after 5400 s. A stress relief degree model is established to investigate the variation of horizontal stress and stress relief degrees under different borehole spacings, vertical stresses, cohesion, and internal friction angles for various borehole diameters (coal output). Optimal stress relief is achieved with a borehole diameter greater than 1.52 m with a borehole spacing set at 4 m. When the stress relief degree exceeds 30%, the corresponding borehole diameter ranges for different vertical stresses are 1.49-1.6 m. Similarly, for cohesion, the ranges are 1.25-1.68 m, and for internal friction angles, the ranges are 1.39-1.53 m. The research results can provide valuable insights for determining parameters in the on-site construction of stress relief boreholes.

SIMULATION OF THE STRESSED-DEFORMED STATE OF THE ELASTIC DISCTOR RACK WITH A STIFFNESS REGULATOR

The paper involves the physical-mathematical modeling of the stress-strain state of an elastic stand of a developed disc harrow equipped with a stiffness regulator. The use of disc tools with individual attachment to elastic stands contributes to improving the quality and reducing the energy consumption of soil processing. This is due to the formation of oscillatory motion of the discs caused by the uneven resistance of the soil in the direction of the unit's movement. The goal of theoretical research is three-dimensional modeling of the stress-strain state of the elastic stand of the disc harrow with a stiffness regulator and substantiation of the range of its rational design parameters. To evaluate the interaction process between elastic working elements and the soil, a harmonic analysis was performed to determine the peak response of the system in a steady state to harmonic loads. In each step of the solution, all applied loads and base excitations have the same frequency, and the values are determined by the corresponding frequency curves. Using the SOLIDWORKS Simulation software package, the relevant physical-mathematical apparatus was compiled. On the basis of this approach, already at the stage of designing disk working bodies on elastic risers, it is possible to conclude about the possibility of them performing specific technological tasks, when by changing the parameters of the risers and conducting repeated studies, it is possible to obtain the corresponding dependencies in the form of regression equations. The results of numerical modeling provide visualization of the change in stress distribution over time in the stand. The dynamics of the change in maximum stress, located on the bend of the stand (R2) and the stiffness regulator (R1), were determined as the stress changes according to the law of damped oscillation with a specified natural frequency. In order to ensure the best working conditions of the elastic riser, it is necessary to ensure the greatest deformation of the riser at the place of attachment of the disc ΔL1 and, at the same time, the smallest value of the deformation of the tool frame ΔL2, by solving the trade-off problem in the Wolfram Cloud software package by maximizing the multiplicative function, the rational geometric dimensions of the diskator riser and constructive parameters of its placement in space.

Data-driven intelligent prediction of TBM surrounding rock and personalized evaluation of disaster-inducing factors

With the widespread application of tunnel boring machines (TBM) in underground tunnel construction, the accurate and real-time identification of geological indicators has become a key factor for ensuring construction safety. In this study, we introduced the nomogram method into the field of civil engineering for the first time to predict surrounding rock grades. Against the backdrop of a major water conservancy project in China, an in-depth analysis of construction data from the ascending phase was conducted to establish the relationship between surrounding rock grade predictions and key construction parameters. Compared with traditional models, the nomogram method has shown advantages in terms of prediction accuracy. Furthermore, by providing a personalized scoring mechanism for specific construction data, the nomogram method not only achieves the real-time prediction of rock grades but also clearly reveals the dynamic relationships between input parameters and rock grades, clarifying the entire prediction process. We identified the main factors related to rock grade prediction among TBM construction parameters, including the slurry conveyor belt speed, jacking pressure, cutterhead torque, cutterhead thrust, thrust pressure, and actual rotation speed. The training process revealed that the nomogram prediction model achieved optimal performance with seven input parameters, balancing accuracy and training time. According to the prediction results, the nomogram model’s area under the curve index is 0.92, providing greater accuracy than the traditional random forest model (0.89). Therefore, this study enhances the transparency and interpretability of model predictions by providing personalized assessments of construction parameters for predicting surrounding rock grades, overcoming the black-box issue of existing prediction methods and offering a novel and effective tool for rock grade prediction.

Customized and high-performing acoustic levitators for contact-free experiments

Acoustic levitators are becoming increasingly common research instrumentation for contact-free, lab-in-a-droplet studies. Recently, levitators that employ multiple, small, ultrasonic transducers have gained popularity, given their low price, temperature and spatial stability, low voltage, and accessibility. Yet, the current state-of-the-art device, TinyLev, presents limitations for certain applications in terms of stability, strength, and compactness. Herein, we developed three new levitators and evaluated the effect of the construction parameters (e.g., distance of opposing arrays, number and arrangement of transducers, etc.) on their performance. The best performing levitator from this work had half the number of transducers, compared to TinyLev, though presented 1.7 and 3.5 times higher levitation capacity along the horizontal and vertical configurations, respectively, and 4.7 and 2.0 times higher horizontal and vertical stability of a levitated object, respectively. Additionally, we present a direct means to evaluate the acoustic radiation net force acting on a deformable object for uniaxial levitators, without the use of a microphone or a schlieren deflectometer for this type of levitators. The theoretical and experimental observations provide insights for adapting the acoustic levitator design for specific applications. Finally, we developed an open-source software which allows the evaluation of the acoustic pressure field generated by customized designs and provides the necessary files for 3D printing the scaffold of the levitator. This study aims to increase accessibility and promote further developments in contact-free experiments.

A Logging Data Based Method for Evaluating the Fracability of a Gas Storage in Eastern China

Underground storage of natural gas has the characteristics of clean and low-carbon, and has the ability to provide a sustainable and stable supply. It is a very high-quality green energy that can increase the storage efficiency of gas storage through fracturing, achieving the sustainable development goal of “Carbon Peaking and Carbon Neutrality”. To improve the storage efficiency of natural gas, it is necessary to carry out refracturing. Moreover, it is of great significance to estimate the fracability of the potential refracturing formation. At present, research on fracability is mainly based on qualitative characterization or quantitative evaluation based on rock mechanics and fracturing construction parameters, which cannot fully reflect the rock composition and structure of each stage. Firstly, based on logging data, this paper analyzes the evolution laws of strain energy such as elastic properties, pre-peak dissipation energy, and post-peak fracture energy during the transition of rock materials from plastic deformation to brittle fracture from an energy perspective, and determines the key energy that affects the brittle characteristics of rocks. Secondly, a brittleness index evaluation approach has been established that can comprehensively reflect the mechanical properties of rocks during pre-peak deformation and post-peak damage stages. In addition, this article focuses on the impact of a reservoir stratigraphic environment by combining the influence of geo-stresses with the rock brittleness index, and proposes a new method for evaluating reservoir fracability. Finally, this paper conducts a study on the fracability evaluation of three wells in a gas storage facility in Eastern China. The results indicate that low modulus and fracability index are beneficial for fracturing, thereby improving the gas production and peak shaving ability of gas storage.

Viscous dissipation and Joule heating effects of Carreau nanofluid axisymmetric flow past unsteady radially stretching porous disk

In this piece of communication, a theoretical investigation of two dimensional boundary layer flow of Magnetohydrodynamics (MHD) Carreau nanofluid axisymmetric flow past unsteady radially stretching porous disk is made. The investigation includes the effects of viscous dissipation, Joule heating, thermal radiation, suction/injection, Darcy–Forchheimer porosity model and binary chemical reaction with activation energy, etc. To examine the impacts of the aforementioned effects, the conservation laws are formulated with strongly nonlinear partial differential equations (PDEs), which are then transformed into a system of initial value problems (IVPs) using appropriate similarity transformations and techniques. The 5th order Runge–Kutta with the shooting technique is used to find numerical solutions aided by Python programming with built in program “fsolve”. The method is validated with other published articles under common assumptions and it agrees nicely. The impacts of the pertinent parameters on velocity, temperature, concentration, skin friction coefficient and the rates of mass and heat transfers with in the flow regime are displayed using graphs and tables. The main outcomes include the motivation of local Nusselt and Sherwood numbers for shear thickening (n=1.5) than shear thinning (n=0.5) cases of the Carreau nanofluid. The momentum boundary layer of the Carreau nanofluid gets thinner with an increase in Forchheimer number, unsteady and suction parameters. A dual nature is observed for concentration of the Carreau nanofluid with a rise in Eckert number, i.e increasing in concentration around the wall and decreasing far away from the wall. The rise in destructive and constructive chemical reaction parameters disperse and accumulate the concentration of the system, respectively.

A Multifunctional Approach to Optimizing Woven Fabrics for Thermal Protective Clothing

This paper presents a detailed exploration of the development and characterization of multifunctional dual-purpose woven fabrics for thermal protective clothing. Through this research, 69 woven fabric prototypes have been carefully designed and produced, integrating various raw materials, yarn, and woven fabric construction parameters, with the aim of optimizing thermal protection properties while ensuring comfort and durability. The analysis led to the identification of two optimal woven fabric samples, which, upon further testing, exhibited exceptional dimensional stability, crease recovery, tear resistance, as well as abrasion and water resistance. Furthermore, the thermal properties were evaluated, demonstrating exceptional flame resistance, limited heat transmission, and high thermal insulation. Additionally, the study evaluated dynamic thermal properties, contact conductive heat transfer, air permeability, water vapour resistance, and thermal resistance of two clothing systems constructed from selected woven fabrics. Statistical analysis confirms significant differences between clothing systems, highlighting the influence of yarn composition and fabric structure on thermal performance and comfort, where one system exhibits better thermal insulation characteristics suitable for colder environments while the other excels in breathability for warmer climates. The developed woven fabrics meet high standards for protective clothing against heat and flame, surpassing currently available comparable woven fabrics on the market in terms of efficacy and performance. This research provides insights into the intricate balance between protection, comfort, and durability of woven fabrics, contributing to advancements in protective textile technology.

Prediction of Thermal Conductivity of Elastic Single Jersey Knitted Fabric

ABSTRACT This work aims to derive a mathematical model that describes the thermal conductivity of the elastic single jersey knitted fabric (SJKF) based on the loop geometry and the yarn and fibers inclination on the direction of heat flow, and to assist the manufactures of elastic SJKF to predict the thermal conductivity from the fabric construction parameters. The main fabric construction parameters in this model are yarn count, loop length, and spandex weight percent. To validate the proposed model, elastic SJKF samples were produced at two different counts and five levels of loop length and spandex weight percent. The thermal conductivity of these samples was measured and compared to the predicted values from the new model rather than the previous three models (Maxwell – Eucken 2, Schuhmeister, Militky models). From the results, it could be concluded that the values of thermal conductivity from the model are very closed to the experimental values; therefore, the new model could be used to predict the thermal conductivity of elastic SJKF.

Rock Breaking Mechanism and Process Optimisation of Jet Cutting Basic Roof Rock under Submerged Jet Condition

The destruction of rock under the condition of a close submerged jet has become a hot topic of scientific research and engineering application in the past decade. With the unremitting efforts of a large number of experts and scholars around the world, gratifying progress has been made in the research of computational fluid dynamics (CFD) on the internal and external flow fields of the jet nozzle, the theoretical derivation of rock mechanics on the fracture initiation and propagation criteria of hydraulic fracturing, and the numerical simulation of jet erosion mechanism under the coupling of fluid and solid fields, however, for the rock mechanics hydraulic fracturing cutting engineering scale of non-oil drilling fracturing technology, the research on the fluid-solid coupling boundary conditions of fracturing fluid and hard dense rock under the flow state conditions of the submerged field inside and outside the borehole is not sufficient. In the calculation of the fluid-solid coupling boundary flow field under the non-submerged jet state, the control equation with Reynolds number between 2300-4000 shall be selected, while it belongs to the laminar flow state in the stage of hole sealing and pressurised fracturing. Therefore, Von-Mises equivalent plastic stress is selected in the mechanical model to calibrate the failure state of the rock-solid boundary, and the control equations of laminar flow and turbulent flow are selected to calibrate the fluid boundary. The mechanism of different stages of rock breaking by hydraulic fracturing jet can be further analysed in detail, and Comsol 6.0 multi-physical field simulation software is selected for verification. The research results will help deepen the understanding of rock breaking mechanism by jet and optimise the selection of parameters for field construction.