Grout Holes Research Articles

Study on the Diffusion Characteristics of Polymer Grouting Materials Applied for Crack Filling in Underground Mines Based on Numerical Simulation and Experimental Methods.

Polymer grouting materials are increasingly used in the filling of mine fissures. Unlike conventional inorganic grouting materials, the self-expansion of polymers adds complexity to their diffusion process within the crack. The objective of this research was to examine how polymer grouting material spreads in cracks at ambient temperatures and pressure. The investigation involved conducting grouting tests and performing numerical fluid simulation calculations using the finite-volume method in the computational fluid dynamics software, ANSYS FLUENT 2022 R1. The fluid volume approach was employed to determine the boundary between fluid and air and to ascertain the variation patterns of density in the slurry and the fracture system. This study applied the principles of fluid mechanics to investigate the patterns of variation in the physical characteristics of polymer grouting materials, including their density, pressure, flow velocity, and movement distance, during the diffusion process. The results indicated that the density of the polymer grouting material decreased exponentially over time throughout the diffusion process. With the increase in the grouting's volume, the grout's pressure and the permeable distance of the grout increased. The slurry's pressure near the grouting hole exceeded the other points' pressure. The physical parameters of the slurry were numerically simulated by ANSYS FLUENT 2022 R1 software, and the results were compared with the experimental data. After comparing the numerical simulation results with the test data, it was clear that the numerical simulation method was superior in accurately predicting the distribution pattern of each parameter of the polymer slurry during diffusion. The grouting volume, pressure distribution, and real-time change in the position of the flow of slurry could be efficiently determined through numerical calculation and simulated grouting tests. This work can offer valuable information for designing polymer grouting materials used in underground mine fissures.

Repair of Underwater Concrete Cracks on Dam Surface: Optimization Analysis of the Grouting Process with Surface Sealing.

The grouting repair process of the sealing baffle on the surface of dam cracks can improve the repair slurry diffusion distance in the cracks; however, the process must be optimized. To address the problem of crack repair technology of underwater dam concrete with one section open and the other closed, a grouting analysis model was established. By adjusting various parameters in the grouting process, the influences of the grouting pressure, position of the grouting hole, diameter of the grouting hole, and water pressure on the diffusion of the Bingham fluid repair slurry in these cracks were studied. The results show that the grouting pressure and diameter of the grouting hole significantly influence the limited diffusion distance of Bingham fluid cement slurry in cracks. With an increase in grouting pressure and grouting hole diameter, the limiting distance of the front surface increases. The influences of the water pressure and position of the grouting hole are small. In addition, through correlation analysis, the degrees of influence of different factors can be sorted, providing the priority factors for actual operation construction.

Study on the causes of interface damage of CRTS II slab ballastless track CA mortar based on grouting operation

In this work, the relationship between cement asphalt mortar (CAM) grouting operation and interface damage of CRTS II slab ballastless track was explored. The test method for the time-varying viscosity of CAM during the solidification process was optimized, and the curves of the time-varying viscosity of CAM at different temperatures were obtained through experiments. A generalized time-varying viscosity constitutive model with CAM temperature and time as parameters was constructed. A fluid dynamics model to simulate CAM grouting operation based on finite element method was established, which could take into account the time-varying viscosity of CAM. The influences of various grouting parameters on the interface state were analyzed with the dynamics model. The results show that the correlation coefficients between the time-varying viscosity constitutive model and the test results are greater than 0.96. It is verified that the CAM grouting operation is an important cause of interlayer damage. The time-varying viscosity of CAM is beneficial in reducing the area of the interface damage zone caused by CAM grouting operation. The area of the interface damage zone decreases with the reduction of the distance between the end vent and the end of prefabricated slab and the rise of grouting temperature. When the height of the prevent vortex grille cylinder is close to 0.4 m, the vortex effect at the position of the grouting hole can be effectively controlled, and the area of the interface damage zone can be significantly reduced.

Study on the Diffusion Parameters of Newtonian Fluid in High-Pressure Jet Disturbance Grouting

In order to investigate the diffusion mechanism of slurry in post-pile grouting, this study develops a formula for calculating the diameter and the climb height of the cement core of jet grouting (CCJG). This research conducts field orthogonal tests using a self-developed grouting nozzle to analyze the effects of disturbance pressure (DP), disturbance time (DT), grouting pressure (GP), and the water–cement ratio (W/C) on the dimensions and strength of the CCJG. The findings revealed that the theoretical formula for calculating the diameter of the CCJG deviates by approximately 8% from the field test results, confirming the formula’s validity. In addition, the DP and DT significantly influence the volume of the CCJG, displaying a linear increase with their augmentation. Conversely, the W/C and DP predominantly affect the CCJG’s strength. Notably, an increase in the W/C results in diminished strength, whereas an increase in the DP enhances it. In addition, soil reinforcement is achieved through replacement, mixing, and compaction as the grout flows outward from the center of the grouting hole. These insights offer a theoretical foundation and technical support for effective grouting construction practices.

Numerical and experimental study of new fully prefabricated ballastless track

Reducing the workload of cast-in-place construction of ballastless tracks can effectively reduce diseases. This study designed the limiting structures of the prefabricated slabs and base plates. A new fully prefabricated ballastless track was proposed. And the track limiting capacity tests and fatigue tests were carried out to verify its service performance. Results indicated that it is necessary to insert two limiting steel bars into the grouting holes for slab limitation, and double piles with a diameter of 0.2 m for base plate limitation. The field tests demonstrated it could withstand large loads from freight trains, and the limiting capabilities of limiting structures were satisfactory. The track structure showed no fatigue damage after 3 million fatigue load cycles. This research can provide insights for low-damage and high-efficiency construction of ballastless tracks for new lines.

Analytical spatiotemporal distribution equations of viscous slurry grouting pressure during the grouting process in rock fissures

To give a simpler theoretical solving approach for modeling the grouting process of viscous slurry in porous/broken rocks, this work derives two theoretical spatiotemporal distribution equations of viscous slurry penetration in rock fissures based on the Darcy seepage model (DM) and the Bingham fluid model (BM) through a hypothetical micro-element model. Through a two-dimensional (2D) conceptual grouting hole model with porous media, the applicability of the two proposed theoretical spatiotemporal distribution equations of viscous slurry pressure is validated by comparing the analytical results with the numerical results obtained from the two-phase flow simulation. The results indicate that the analysis results obtained from two proposed theoretical spatiotemporal distribution equations are well consistent with the simulation results at different times and under different grouting velocities. That means the time-consuming numerical simulation of the porous/broken rocks grouting process can be replaced by two proposed theoretical spatiotemporal distribution equations, which will greatly reduce the difficulty of real-time evaluation of the grouting effects in engineering practice and shorten the assessment time.

Constructing a cut-off dam inside a water-filled circular tunnel with backfill grouting

This study employs laboratory model tests for backfill grouting and numerical analyses (coupled analysis of the discrete element method and computational fluid dynamics, DEM-CFD coupling analysis) to investigate the feasibility of constructing a cut-off dam inside a water-filled circular tunnel using the backfill grouting method from the ground surface. Several improved backfill methods were studied to enhance the effectiveness of the cut-off dam. These methods include: (a) adding an additional backfill grouting hole between the double-row cut-off dam and applying pressurized grouting; (b) adjusting the number of backfill grouting holes per row of the cut-off dam; (c) simultaneously grouting the double-row cut-off dams to minimize the formation of interface fissures and voids; (d) adjusting the grout hole spacing of the double-row cut-off dams to reduce the volume of backfill material. Additionally, pressurized mortar grouting is a critical mass to ensure the water tightness of the cut-off dam. The implementation of these backfilling arrangements improves the effectiveness and watertight of the cut-off dam, thereby reducing the construction time and cost. The findings of this study can serve as a reference for water-filled tunnels and subsequent rehabilitation works in the future.

Bearing Capacity of a Concrete Grouting Pad on the Working Surface of a Highway Tunnel Shaft

A grouting pad is the key structure for the construction of water inrush grouting on the shaft working surface. Previous methods of calculating the bearing capacity have limitations due to a lack of understanding of the failure mode. To investigate the bearing capacity of a concrete grouting pad on the working surface of a shaft, this paper establishes a mechanical model for the punching shear failure of a grouting pad under symmetrical loading conditions. A unified solution for the bearing capacity is derived, and the influence of parameters is discussed. In addition, a new method for designing the plastic limit thickness is proposed based on this research. The results show that the reason for the grouting pads’ punching shear failure resulted from the formation of peripheral grouting holes “weak ring” caused by the reduction of the bearing capacity. When the thickness of B0 remains constant, the bearing capacity qu of the grouting pad is inversely proportional to the ratio of the diameter and the area of the bottom load. Therefore, following the method of “dividing, interval, and jumping holes” during grouting construction is recommended. The greater the thickness of the grouting pad, the greater the bearing capacity qu will be. When the grouting pad diameter is 2r2 and the thickness B0 is constant, the bearing capacity qu increases with the material tensile strength ft. When designing grouting pads, following the principles of “large thickness, uniform strength theory, high strength materials” will improve bearing performance. The findings have been implemented in the design of the grouting pad thickness for the Tianshan Shengli Tunnel shaft project, which can successfully solve the problem of frequent cracking caused by the weak bearing capacity of a grouting pad. The findings can provide a theoretical basis and reference for the design and construction of grouting pads in a highway tunnel shaft.

Propagation Analysis of Polymer Grout in Vertical Fractures: An Experimental and Numerical Study

The use of non-aqueous reactive polymer grouting is a proven technique for preventing gravity erosion in Pisha sandstone through the filling of vertical fracture. However, the diffusion behavior of the polymer grout within vertical fractures remains unclear and requires further investigation for effective grouting design. This study conducts laboratory experiments to examine the effects of grouting quantity on the spread pattern, diffusion distance, and pressure distribution of polymer grout within a visual vertical fracture. The maximum pressure is 6.25 kPa for a grouting quantity of 120 g, 7.5 kPa for 227 g, and reaches about 9.4 kPa for a quantity of 350 g. A numerical model, incorporating time-dependent density and viscosity, is then developed and validated using experimental results. Finally, the influence of initial viscosity 0.05 Pa·s, 0.1 Pa·s, and 0.5 Pa·s on the flow pattern of polymer grout within the vertical fracture is analyzed. The results show that initially gravity causes a dominant downward flow of polymer grout in a vertical fracture. However, as the grout expands due to the chemical reaction, it propagates in all directions. Furthermore, the gravity causing the dominant downward flow of polymer grout decreases with increasing initial viscosity, and the diffusion distance increases in the horizonal direction but decreases in the vertical direction. On this basis, suggestions for optimal grouting hole arrangement are provided to enhance grouting design.

Experimental Study on the Diffusion Law of Coal-Based Solid Waste Slurry with Grouting Filling in the Gangue Voids of the Caving Zone.

Due to the concealment of the caving zone, it is difficult to detect and grasp the diffusion law of the slurry in the voids of the gangue pile. On the preparation of reasonable grouting filling materials, a large-scale three-dimensional gangue grouting filling test system has been established to detect the slurry pressure and resistivity inside the gangue pile and analyze the flow pattern of the slurry in the voids of the gangue pile. The research results show that the slump and bleeding rate of the filling slurry are significantly reduced with the increase of the fly ash content. The optimal ratio of fly ash, coal gangue, and gasification slag is 7:2:1, with a mass fraction of 72%. In the process of grouting, the internal pressure of the gangue pile can be divided into the initial stable stage, the step growth stage, and the pressure stability stage, and the change curve of the pressure sensor at the lower level is similar. The resistance value of the original broken gangue in the experiment is approximately 1600 Ω. Grouting filling forms a slurry-rock mixture, and its resistance continuously decreases with the stable injection of the slurry (minimum value 150 Ω). It is determined that the slurry near the grouting hole mainly diffuses longitudinally with a good void filling effect. The void channels of slurry diffusion are randomly distributed and have different shapes, which hinder slurry flow and diffusion. Slurry particles accumulate and settle at local small voids. Meanwhile, the surface of the gangue blocks is dry, and the slurry absorbs part of the water during diffusion, resulting in the increase of the slurry concentration and the weakening of the lateral diffusion ability. Secondary or multiple grouting can effectively fill the void of the broken gangue and further improve the filling effect.

Influences of cement asphalt emulsified mortar construction on track slab geometry status

PurposeThe construction of cement asphalt (CA) emulsified mortar can obviously disturb the slab status after the fine adjustment. To decrease or eliminate the influence of CA mortar grouting on track slab geometry status, the effects of grouting funnel, slab pressing method, mortar expansion ratio, seepage ratio and grouting area on China Railway Track System Type (CRTS I) track slab geometry status were discussed in this paper.Design/methodology/approachCombined with engineering practice, this paper studied the expansion law of filling layer mortar, the liquid level height of the filling funnel, the pressure plate device and the amount of exudation water and systematically analyzed the influence of filling layer mortar construction on the state of track slab. Relevant precautions and countermeasures were put forward.FindingsThe results showed that the track slab floating values of four corners were different with the CA mortar grouting and the track slab corner near CA mortar grouting hole had the maximum floating values. The anti-floating effect of “7” shaped slab pressing device was more efficient than fixed-joint angle iron, and the slab floating value could be further decreased by increasing the amount of “7” shaped slab pressing devices. After CA mortar grouting, the track slab floating pattern had a close correlation with the expansion rate and water seepage rate of CA mortar over time and the expansion and water seepage rate of the mortar were faster when the temperature was high. Furthermore, the use of strip CA mortar filling under the rail bearing platform on both sides could effectively reduce the float under the track slab, and it could also save mortar consumption and reduce costs.Originality/valueThis study plays an important role in controlling the floating values, CA mortar dosage and the building cost of projects by grouting CA mortar at two flanks of filling space. The research results have guiding significance for the design and construction of China's CRTS I, CRTS II and CRTS III track slab.

Comparative Study of Conventional Rotary and Rotary-Percussion Techniques in Grout Hole Drilling from the Perspectives of Time, Cost, and Quality

A dam foundation structure is usually strengthened by grouting, which begins with grout hole drilling. This paper aims to examine a comparison between conventional rotary and rotary-percussion drilling techniques in a drilling case study of the Tugu Dam Project, from the perspective of time, cost, and quality comprehensively. Primary data was obtained from the field investigation and interviews. Secondary data was gathered from available project documents of the PT Wijaya Karya-APTA KSO Project Contractor. The findings have highlighted that the implementation of the rotary-percussion technique for grout hole drilling is better than conventional rotary drilling. There are 16 days of time-saving and 3.84% cost-savings for the rotary-percussion technique, as a result of faster rate of penetration. The quality of grouting work using the rotary-percussion drilling technique tends to be of better quality, although there is a shortcoming due to the limited drilling depth of only 5m particularly.

Research on distresses detection, evaluation and maintenance decision-making for highway pavement in reconstruction and expansion project

Artificial walking survey, ground penetrating radar (GPR) and falling weight deflectometer (FWD) were used to test the actual condition of the highway pavement in reconstruction and expansion project for better maintenance decision-making. Therefore, a decision-making system with the application of four evaluation indexes including deflection value (DV), pavement surface condition within 20 m(PCI20), maintenance effect (ME) and internal crack rate (ICR) was constructed. Through the pavement empirical-mechanical calculation and the Delphi method analysis, the corresponding threshold for the DV, PCI20 and ICR were 27 (0.01 mm), 80, and 20 m/100 m2 respectively. Then, the decision-making system was applied for the 5.5 km section with the detection and evaluation results, and the advised maintenance plans of different lanes were determined. Lastly, the effect of the decision-making system was analyzed. Results show that the decision-making system can scientifically decide the treatment plans and save the maintenance cost by about 30.1 %. The deflection near the grouting holes significantly decreases resulting from the high-density cement slurry distribution. The milling and repaving have a high structural reinforcement ability of reducing deflection up to more than 66 %, which is positively related to the milling depth.

Numerical simulation analysis of tunnel backfill grout based on DEM-FDM coupling and particle inlet

Shield tunnel backfill grouting is vital to stabilize tunnel settlement at a later stage; however, most shield tunnel backfill grouting designs lack a complete theoretical reference, and numerical simulations of the grouting process are rarely conducted. This study presents the fundamental theories of grout diffusion and pressure variation for backfill grouting during shield construction. Moreover, the numerical simulation methods coupled with discrete element methods (DEM) and finite difference methods (FDM) are achieved to simulate the process of grout injection from the grouting hole into the shield tail gap and generate grout pressure on the surrounding rock. The diffusion state of the grout in the shield tail gap and the squeezing effect on the surrounding rock under two shield tail disengagement modes are analyzed, as well as the impact of various grouting pressure on the surface settlement. The results indicated that the grout diffusion in the shield tail gap can be divided into three stages: the stage of diffusion with each grouting hole as the starting point, the stage of interconnection and contact of the grout injected in each grouting hole, and the final gap filling stage. Each of the three stages can be described using the proposed equation. During the grouting process, the grout is injected into the shield tail gap at a certain pressure, but the grout diffuses slowly to both sides and upwards, which causes a rapid rise of the principal stresses in the soil around the tunnel. After grouting is complete, the grout pressure gradually dissipates and stabilizes, and the principal stress decreases. In addition, backfill grouting can reduce surface settlement, but it does not affect its distribution width.

GL-Net: Semantic segmentation for point clouds of shield tunnel via global feature learning and local feature discriminative aggregation

has gradually become the first choice of modern urban public transportation due to its advantages of safety and high-efficiency. Shield tunnel is an important type of subway tunnel, and its structural stability and safety play an important role in subway operation. The shield tunnels are prone to problems such as water leakage and tunnel collapse, which affect the safe operation of subways. Efficient monitoring methods are required to detect the status of subway tunnels. The data collection and accurate segmentation of key components of shield tunnels are the basis and key to the automatic monitoring of subway tunnels. This research presents a novel semantic segmentation method of three-dimensional (3-D) point clouds of typical structural elements (e.g., longitudinal joint, circumferential joints, bolt hole and grouting hole) in shield tunnel based on deep learning. In this method, we focus on how to make the network learn robust global features and complex local distribution patterns. Further, we propose a global and local feature encoding block (namely GL-block) to discriminatively aggregate local features while learning global representation. After multiple encodings by the GL-block, we design a global correlation modeling (GCM) module to establish a global awareness of each point. Finally, a weighted cross-entropy loss function is designed to solve the problem of unbalanced number of samples in each category of shield tunnel. In the experiments, we make a dataset of shield tunnel point clouds with a length of about 1,000 m collected by CNU-TS-1 (DU et al., 2018) mobile tunnel monitoring system, and use the dataset to train and test the segmentation ability of our method on the typical structural elements of shield tunnels. Experiments verify the effectiveness of our method by comparing with the other state-of-the-art 3-D point cloud semantic segmentation methods, and our method has an mIoU score of 73.02 %, which is at least 14.54 % higher than the other compared state-of-the-art networks. Also, we further verify the adaptability of our method to different tunnels and different laser scanning equipment, such as FARO, Leica and Z + F, and achieve very advanced performance.

Numerical Study on the Dynamic Behaviors of Masonry Wall under Far-Range Explosions

As a common enclosure structure, masonry walls are widely used in various types of buildings. However, due to the weak out-of-plane resistance of masonry walls and the generally brittle properties of the materials used for blocks, they are highly susceptible to collapse under blast loads and produce high-speed splash fragments, which seriously threatens the safety of personnel and equipment inside buildings. In this paper, based on the existing tests, a refined numerical simulation model was established to carry out numerical studies of clay tile walls and grouted CMU masonry infill walls under far-range blast loads, and the applicability of the finite element model and parameters were verified. Further, the effects of wall boundary configuration, constraints and dimensions on the dynamic response of the walls were carried out. The results show that: the load distribution on the wall is relatively uniform under the far-range explosion and can be considered as uniform load; the blast-resistant performance of the wall can be enhanced by increasing the grouting rate and the uniformity of grout hole distribution; the boundary configuration of the wall has little effect on the blast resistance, while the boundary constraints and the length and width are the main factors affecting the blast resistance of the wall.

Prediction of Grouting Method for Decreasing the Lugeon Value of Dam Foundation

This research aims to predict the grouting method to decrease the Lugeon value on the dam foundation. The methodology consisting of grouting is evaluated by comparing the first permeability (permeability before grouting) and secondary permeability (permeability after grouting). Grouting is critical in improving the dam foundation and reducing the permeability in Lugeon values. Because of the concealment and uncertainty of dam foundation grouting, the accurate evaluation of the quality of grouting construction has become a major concern. The effectiveness of the grouting method for decreasing Lugeon values in the dam foundation has not been certainly revealed. The foundation of the dam with weathered lapilli tuff and gravelly sand is a typical porous weathered rock. The grouting was performed as a down-stage, in which the grout hole is drilled in stages using a pneumatic packer. The improvement of the dam foundation by grouting is evaluated by comparing the first permeability (permeability before grouting) and secondary permeability (permeability after grouting) by using Lugeon values with a water pressure test. This test employed 534 data, which included the first permeability, depth, grout take, and secondary permeability. This paper focuses on modeling to predict the secondary permeability. The result is developing the secondary permeability that considers the relation between the parameters, which can affect and represent the characteristics of grouting quality in the non-linear regression equation that is SP = FP – f(GT) in the depth conditions of 5, 10, 15, 20, 25, and 30 m. R-squared is the coefficient of determination. The R-squared value for depths of 5, 10, 15, 20, 25, and 30 m is 87.52%, 83.18%, 72.29%, 60.20%, 42.25%, and 30.03%. Thus, the results are applicable to assess the quality of curtain grouting.

Numerical investigation on grout spread and grouting parameter analysis in fracture with flowing water

Grouting is crucial for oil and gas extraction as an economical and effective method for preventing subsurface water seepage in rock fractures. In this study, rough fracture surfaces were established based on the Synfrac program, and a modified Bingham model charactering the time-varying viscosity of grout was employed. The two-phase flows were numerically investigated using the level set method to capture the dynamic evolution of the interface by varying the parameters. Four types of grout spread and flow fields were analysed in the orthogonal simulation. The results indicate that the contact ratio α, grouting pressure P, diameter of the grouting hole b and water velocity vw have significantly influences the grout spread and sealing efficiency δ. The propagation pattern becomes irregular as the grout is continuously injected into the fractures owing to various parameters. Vortex zones emerge at the slurry-water interface, where dynamic water tends to be blocked in the fracture. The rapid increase in grout volume results in a longer spread distance and greater spread pressure. The diameter of the grouting hole and contact ratio have a greater influence on the grout volume. Compared with the grouting pressure, increasing the diameter of the grouting hole can appropriately improve the sealing efficiency of the slurry in the fracture. The volume reduction of water was calculated to provide a comprehensive understanding of the sealing efficiency of the grout under flow conditions. Finally, the relationship between the plugging efficiency and the four factors was obtained.

Mechanism and Control of Grout Propagation in Horizontal Holes in Fractured Rock

It is important to control grout propagation and ensure the engineering effectiveness of the advanced regional grouting process in the Middle Ordovician limestone (MOL) aquifer. In our study, we found that the physical and mechanical properties of cement grout are affected mainly by the water–cement ratio, followed by water glass content and finally by hydro-chemical type. In a horizontal grouting hole inclined single fracture, the grout spread over time depended on the water–cement ratio, grouting pressure, width of fracture and angle between fracture and grouting hole and the rate of spread increased over time. However, when the grout propagation length was hundreds of meters or more, the length in the fracture above the grouting hole was greater than that in the fracture below. The sensitivity sequence of influencing factors of grout propagation length in an inclined fracture of a horizontal grouting hole was as follows, from large to small: width of fracture, fracture angle, water–cement ratio, grouting pressure.

Study on Gas Hydrate Reservoir Reconstruction for Enhanced Gas Production in the Shenhu Area of the South China Sea Based on a 3D Heterogeneous Geological Model

Natural gas hydrate (NGH) has the huge exploitation potential for clean energy in the current world energy pattern. Its total organic carbon storage is about twice the sum of carbon content of oil, gas, and coal and hence attracts the attention of the world. China has carried out some gas hydrate exploitation works and delineation of three gas hydrate deposits whose reserve scale is over 100 billion cubic meters, and the NGH resource is abundant. The NGH reservoir in the South China Sea is of low porosity and permeability, is unconsolidated, has poor cementation, and is easy to fragment in hydrate production. On the one hand, the condition of low porosity and permeability around the well would severely reduce the production effect; on the other hand, the hydrate decomposition would more easily bring wellbore instability caused by stratum stress change. Therefore, to achieve safe and efficient exploitation of NGH, proper reservoir reconstruct technology needs to be chosen for enhancing the reservoir’s permeability and stability. This paper chose the Shenhu area of South China Sea as the research area, constructed the three-dimensional heterogeneous geological model of hydrate-bearing sediments which can be approximated realistically to depict, then used high-pressure jet grouting (HPJG) technology to reconstruct the hydrate reservoir, optimized the grouting hole direction, location, and spacing, and assessed the productivity increasing effect. The research results show the following: (a) Because of the higher hydrate saturation (SH) and lower permeability (k) around the well, the HPJG in the vertical direction was profitable for reservoir productivity. (b) Considering the heterogeneous SH and k in the horizontal direction, the HPJG in the front of the horizontal well was profitable for the reservoir productivity. (c) The HPJG spacing needs to be properly designed in combination with the absolute standard (VP), the relative standard (RGM), and the specific production index (J). (d) Under the conditions of this paper setting, the optimal HPJG reconstruction scheme is as follows: the HPJG in the vertical direction was arranged at the front of the horizontal well, and the spacing between the holes was 10 m. The productivity after reconstruction ranged up to 55.69% compared with before.