Borehole Locations Research Articles

Improved seismic well tie by integrating variable-size window resampling with well-tie net

Accurate seismic well tie is essential for seismic inversion and reservoir characterization. The procedure of seismic well tie involves shifting, stretching and squeezing the synthetic seismogram computed from well logs to match the seismic traces at or near the borehole location. Numerous methods have been proposed for nonlinear alignment between synthetic and real seismograms. However, most well-tie methods are prone to over-stretching and the alignment result is sensitive to the chosen window size. To solve those problems, we propose a variable-size window resampling (VWR) algorithm and integrate with convolutional neural network (CNN) for automatic seismic well tie. Using VWR algorithm to reconstruct the waveforms in synthetic seismogram can simulate the variety of subsurface velocity. CNN can learn the characteristic of different waveforms and recognize the most correlated waveforms between synthetic and real seismograms for sequence alignment. We first use VWR algorithm to reconstruct a large number of synthetic seismograms for train set generation. We then build an CNN model that named well-tie net for training to learn the feature of different resampled synthetic seismograms. Finally, we use the well trained CNN model to segment the real seismogram and align with the synthetic seismogram for seismic well tie. We apply our method into the synthetic test and real seismic data with well logs and obtain high correlated seismic-well tie. We also compare with the conventional method dynamic time warping (DTW) to illustrate the effectiveness and robustness of our proposed method. Our proposed method can avoid the problem of over-stretching by using the variable-size window resampling algorithm and automatically tying the well to seismic trace using well-tie net. In addition, the train set for our method is generated automatically.

Application of analytical hierarchy process and integrated fuzzy-analytical hierarchy process for mapping potential groundwater recharge zone using GIS in the arid areas of Ewaso Ng'iro – Lagh Dera Basin, Kenya

The demand for freshwater has continuously increased in the arid areas of Ewaso Ng'iro – Lagh Dera basin, Kenya. This study aimed to and mapped areas of potential groundwater recharge in the basin by integrating factors that influence groundwater recharge using Analytical Hierarchical Process, and Fuzzy-Analytical Hierarchical Process in ArcGIS. The results of this study are presented in form of maps indicating the potential groundwater recharge zones. The zones are categorized as high, medium and low potential groundwater recharge zone, which were validated with the location of the fresh water boreholes. High groundwater recharge potential zones occur in the central part of the study area within the generally flat flood plains consisting of alluvium lithology. In contrast, low potential groundwater recharge zones occur in the southwestern part of the area within upland plains. The study can be helpful in the proper management of the groundwater resource.

Coal and Gas Comining in the High‐Gas Detong Mine, China: Analytical and Numerical Parameter Optimization of Gas Extraction Boreholes

The upper corner gas overrun caused by goaf gas gushing in the high‐gas mine can be mitigated by roof positioning of long boreholes in the goaf fracture zone, creating an artificial gas migration channel and achieving safe comining of coal and gas. This study numerically simulated the fracture evolution in the coal rock overlying goaf in workface #2‐104 of the Detong Mine, China. Using the O‐shaped circle theory and the FLAC3D commercial software package, the range parameters of goaf fracture zone gas‐concentrated areas were obtained by defining the pressure relief coefficient, which provided a basis for the arrangement of holes in the goaf located at 15 m from the workface goaf collapse zone to the workface floor and 15–60 m from the structure zone to the workface. According to the obtained goaf parameters, the distribution and migration law in the goaf under the conditions of initial state and extraction with different roof borehole parameters were simulated by the FLUENT software. The optimal borehole location was 30 m from the floor and 25 m from the return airway. The field experiment with three boreholes arranged in the optimal extraction position provided the extraction concentration in the borehole above 30%, the gas extraction volume of 12 m3·min−1, and the concentration at the upper corner below 1%, which ensured safe coal and gas comining.

How groundwater time series and aquifer property data explain heterogeneity in the Permo-Triassic sandstone aquifers of the Eden Valley, Cumbria, UK

A novel investigation of the impact of meteorological and geological heterogeneity within the Permo-Triassic Sandstone aquifers of the River Eden catchment, Cumbria (UK), is described. Quantifying the impact of heterogeneity on the water cycle is increasingly important to sustainably manage water resources and minimise flood risk. Traditional investigations on heterogeneity at the catchment scale require a considerable amount of data, and this has led to the analysis of available time series to interpret the impact of heterogeneity. The current research integrated groundwater-level and meteorological time series in conjunction with aquifer property data at 11 borehole locations to quantify the impact of heterogeneity and inform the hydrogeological conceptual understanding. The study visually categorised and used seasonal trend decomposition by LOESS (STL) on 11 groundwater and meteorological time series. Decomposition components of the different time series were compared using variance ratios. Though the Eden catchment exhibits highly heterogeneous rainfall distribution, comparative analysis at borehole locations showed that (1) meteorological drivers at borehole locations are broadly homogeneous and (2) the meteorological drivers are not sufficient to generate the variation observed in the groundwater-level time series. Three distinct hydrogeological regimes were identified and shown to coincide with heterogeneous features in the southern Brockram facies, which is the northern silicified region of the Penrith Sandstone and the St Bees Sandstone. The use of STL analysis in combination with detailed aquifer property data is a low-impact insightful investigative tool that helps guide the development of hydrogeological conceptual models.

Determination of borehole locations and saline-water intrusion for groundwater in Central Anatolia Region, Turkey using electrical tomography (ERT) method

Determination of borehole locations and saline-water intrusion for groundwater in Central Anatolia Region, Turkey using electrical tomography (ERT) method

Mine Water Inrush Risk Assessment Evaluation Based on the GIS and Combination Weight-Cloud Model: A Case Study.

With the increase in mining depth, the hydrogeological conditions of mines become more complex, which leads to higher possibility and harmfulness of water inrush accidents and brings great challenges to mine safety. It is particularly important to accurately evaluate the risk of mine water inrush. In order to study and prevent the floor water disaster of coal mines, it is necessary to correctly evaluate the risk of water inrush according to the limited borehole data. Based on the six main factors affecting water inrush, such as the seam dip angle, fault fractal dimension, key-strata thickness, water pressure, mining depth, and dip length, a comprehensive evaluation index system of floor water inrush risk is established in this paper. In the first step, we combine the combination weight method based on game theory with the cloud model to calculate the risk level of water inrush at each borehole location. In the second step, the risk level is displayed in a geographic information system, and the single index and comprehensive zoning map of water inrush risk in the study area are established to provide scientific guidance for mine water disaster prevention and control in this area. Through the case study of the Yangcheng Coal Mine, the whole process is further expounded. The results show that the five actual water inrush points in the Yangcheng Coal Mine are located in the dangerous area (grade IV) and the relatively dangerous area (grade III), which verifies the effectiveness of this method. At the same time, the evaluation results show that water pressure has great influence on floor water inrush.

3D Inversion of Airborne Magnetic Data and Validation of it by Using Sourk Mine Drilling Data

The airborne magnetic method is one of the most significantly applied approaches in mineral exploration. This magnetic method has been widely used in recent years due to its extensive coverage, lower cost than other methods and coverage of impassable areas and forests. For many years in Iran, the magnetic method has been utilized by authorities to survey ore deposits and to prepare structural and geological maps. This paper presents part of the Dehshir area exploration data of airborne surveys by helicopter with flight line spacing of 250 meters and flight height of 40 meters conducted by Geological Survey and Mineral Exploration of Iran. Furthermore, among the potential areas in the Dehshir area is the studied hereby area of Block C2 of Sourk mine. This region in Yazd province with a 4.1 km2 area is located at 95 km northwest of Yazd city. The purpose of this paper is to present a three-dimensional model of magnetic data and its validation using drilling data. The three-dimensional modeling of magnetic data has been processed by Inversion method. Next, the locations of boreholes were proposed for drilling. Then, the boreholes data is used to evaluate the geophysical method model by comparing the three-dimensional modeling of magnetic data and three-dimensional modeling of the proposed drilled boreholes data.

Effect of heterogeneity and injection borehole location on hydraulic fracture initiation and propagation in shale gas reservoirs

The breakdown pressure and fracture propagation are essential problems in hydraulic fracturing, but how they are affected by rock heterogeneity and injection borehole location has been unclear. In this study, a hydro-mechanical coupling model in micromechanics was established to investigate the mechanisms of fracture initiation and propagation in shale formations. The dependence of the breakdown pressure and fracture propagation on approach angle of bedding plane, particle heterogeneity and borehole location was numerically studied. First, a hydro-mechanical coupling model was developed with both parallel bond model (PBM) and smooth joint model (SJM) for heterogeneous shale formations. Then, this model was validated by theoretical analysis and experimental observations. Finally, the effects of rock heterogeneity and borehole location on the breakdown pressure, fracture modes, stress distribution were analyzed through numerical simulations. It is found that the approach angle of bedding has significant effects on breakdown pressure and fracture network, but has only limited impact on the stress distribution near borehole. The stress distribution near borehole is heavily affected by particle size distribution. The lowest breakdown pressure and hydraulic injection volume are observed at the borehole located at the bedding plane. These results can deepen our understanding on the micro-mechanisms in hydraulic fracture initiation and propagation.

Investigation of groundwater contamination in relation to septic systems in Kitwe West Township, Kitwe, Zambia.

This study investigated the quality of groundwater with respect to septic systems in Kitwe West township located in the western part of Zambia's Kitwe district. The study area was selected because most households in the township use boreholes and septic systems as sources of drinking water and wastewater disposal facilities respectively. The study showed the presence of total coliforms in 90% of the boreholes while only 30% of the boreholes were contaminated with fecal coliforms rendering the water unsafe for drinking. The study revealed that there was no distinct relationship between distance from borehole to septic tank system and the quality of borehole water. It was however observed that for boreholes within a 15 m proximity to individual home-owned dump sites the level of fecal contamination increased as the distance from the boreholes to the dump sites decreased. The study has vividly shown that the location of boreholes and septic tank systems in the same plot of land exacerbated by the presence of solid waste dump sites in a residential plot that depends on groundwater is not advisable. This is because the safety of groundwater cannot be guaranteed even if technical specifications are followed for boreholes and septic tank systems.

Estimation of near-surface temperature in Suwawa Geothermal Prospect, Gorontalo, Sulawesi, Indonesia, based on magnetotelluric and artificial neural network

A geophysical survey using broadband magnetotelluric (MT) technology was carried out in Suwawa Geothermal Prospect Area, Gorontalo Province, Sulawesi Island, Indonesia. The target of that research is to evaluate the geothermal potential hidden below the surface, based on underground resistivity distribution. However, the information about resistivity alone is not enough to get a proper understanding of the geothermal system in this area. Another important subsurface feature that could be useful for the evaluation is temperature. In this study, an attempt to predict the subsurface temperature using resistivity and limited information from a shallow borehole thermogram was carried out. Employing the dependency between resistivity and temperature an indirect temperature estimator was built, thanks to the applicability of artificial neural network (ANN) to learn the pattern connecting both parameters. Comparing some neural network training data shows that the predictive powers of the calibrated neural network highly influenced by the geological difference between the location of borehole and MT station. The best trained ANN was then used to predict the temperature below the other MT stations. The result shows that a proper ANN architecture is important to improve the deeper temperature estimation. The best ANN estimator was obtained from the BT01 and AMT39 data pair, which has the highest correlation as well. This preliminary study gives useful insight into how resistivity could be an alternative tool to delineate the near-surface temperature profile, in order to get a more comprehensive image of the subsurface geothermal system.

Contribution of remote sensing and geophysics to optimize the location of boreholes in the basement zone: The case of the city of Abeche (CHAD)

Contribution of remote sensing and geophysics to optimize the location of boreholes in the basement zone: The case of the city of Abeche (CHAD)

MATURITY OF POTENTIAL CRETACEOUS SOURCE ROCKS AT THE ISIS FIELD, OFFSHORE EASTERN TUNISIA: INFLUENCE OF HYDROTHERMAL FLUIDS

An increase in source rock thermal maturity is in general linked to burial‐related heating according to the regional geothermal gradient, but maturities may also locally be influenced by high‐temperature hydrothermal fluids or igneous intrusions. In the present study of the Isis field located in the Gulf of Gabes (offshore Tunisia), we combine an analysis of organic matter maturity indicators and clay mineral signatures to constrain possible fluid/rock interactions and to define controls on the maturity of potential source rocks. Cuttings samples were collected from source rock intervals in the Cretaceous Bahloul (Cenomanian – Turonian) and underlying Fahdene (Albian – Cenomanian) Formations at the PM borehole, and detailed organic geochemical and clay mineralogical analyses of source rock samples and extracts were carried out. Samples from the Bahloul Formation (2381 m to 2400 m) consist of black to dark grey claystones and globigerinid limestones. Those from the Fahdene Formation (2400 m to 2700 m) comprise alternating claystones and chalky limestones containing globigerinids including Ticinella primula. Both source rock intervals have similar mineralogical compositions consisting of calcite, quartz, albite, anorthite, minor anatase, pyroxene and pyrite. The clay mineralogy of the formations is composed of abundant smectite (two generations), subordinate kaolinite and minor illite and/or mica. The Fahdene source rock contains organic matter consisting of mixed kerogen Types II/III; Type II OM is present in the Bahloul Formation.At the borehole location, the source rock intervals in the Fahdene and Bahloul Formations have been affected by hydrothermal fluids which are derived from an unconformably overlying basalt succession which is >300 m thick. Based on bulk mineral assemblages, the Bahloul Formation has been modified by the hydrothermal fluids more significantly than the underlying Fahdene Formation. Analyses of the clay minerals compositions indicate that interactions between the hydrothermal fluids and the host rocks were very rapid and were localized within fractures and micropores. The Bahloul Formation source rocks have reached an advanced stage of thermal maturity (overmature or end‐ oil window) compared to the thermally immature source rocks in the Fahdene Formation.The results show that the main control on source rock maturation at the studied well was maximum palaeotemperature and this may locally have been influenced by short‐term hydrothermal and magmatic heating as well as by the regional geotherm. Clay minerals were less affected by hydrothermal heating compared to organic matter indices; this may be because mineral components are slower to react to short‐term higher temperature conditions than organic matter.Thus magmatic activity and hydrothermal fluids may locally accelerate the thermal maturation of source rocks even at shallow depths. The study also shows that a combination of clay mineral characterization and organic matter indicators can be useful for the assessment of thermal maturity in potential source rocks.

Geological and engineering geological characteristics of surface alluviums in the Gorgan city

Engineering properties of soils and the 3D modeling of geological formations are widely used in site investigations and the preparation of geological hazard maps. The present study was conducted to characterize the engineering geological properties of the young surface alluviums of the Gorgan city (Iran) to a depth of 25 m and 3D modeling of their geology using boreholes data. To this end, after determining the location of the available boreholes on the aerial map of Gorgan, four hypothetical cross-sections were considered in the North-South and East-West directions. Then, the borehole data were marked on each section and their 2D geological cross-sections were manually drawn using correlation of the similar layers. In the next step, by expanding the information of these sections, a 3D geological model of Gorgan city was prepared using a conceptual-observational method. According to the evidence from the boreholes and field observations, the depositional environment of Gorgan alluviums was an alluvial fan created by the Ziarat River. Additionally, in terms of engineering characteristics of alluviums, the Gorgan subsurface soils can be divided into four engineering units, including upper clay unit (UCU), middle gravel unit (MGU), lower clay unit (LCU), and sandy unit (SU), which share the same engineering characteristics. Finally, the results of tests performed on samples from different depths were employed to calculate the engineering geological characteristics of each unit, including Atterberg limits, compressibility, undrained shear strength, and drained shear strength parameters.

Determination of the Locations of Boreholes for Temperature Measurement during Artificial Ground Freezing

Determination of the Locations of Boreholes for Temperature Measurement during Artificial Ground Freezing

Optimisation of geotechnical surveys using a BIM-based geostatistical analysis

PurposeA principle prerequisite for designing and constructing an underground structure is to estimate the subsurface's properties and obtain a realistic picture of stratigraphy. Obtaining direct measure of these values in any location of the built environment is not affordable. Therefore, any evaluation is afflicted with uncertainty, and we need to combine all available measurements, observations and previous knowledge to achieve an informed estimate and quantify the involved uncertainties. This study aims to enhance the geotechnical surveys based on a spatial estimation of subsoil to customised data structures and integrating the ground models into digital design environments.Design/methodology/approachThe present study's objective is to enhance the geotechnical surveys based on a spatial estimation of subsoil to customised data structures and integrating the ground models into digital design environments. A ground model consisting of voxels is developed via Revit-Dynamo to represent spatial uncertainties employing the kriging interpolation method. The local arrangement of new surveys are evaluated to be optimised.FindingsThe visualisation model's computational performance is modified by using an octree structure. The results show that it adapts the structure to be modelled more efficiently. The proposed concept can identify the geological models' risky locations for further geological investigations and reveal an optimised experimental design. The modifications criteria are defined in global and local considerations.Originality/valueIt provides a transparent and repeatable approach to construct a spatial ground model for subsequent experimental or numerical analysis. In the first attempt, the ground model was discretised by a grid of voxels. In general, the required computing time primarily depends on the size of the voxels. This issue is addressed by implementing octree voxels to reduce the computational efforts. This applies especially to the cases that a higher resolution is required. The investigations using a synthetic soil model showed that the developed methodology fulfilled the kriging method's requirements. The effects of variogram parameters, such as the range and the covariance function, were investigated based on some parameter studies. Moreover, a synthetic model is used to demonstrate the optimal experimental design concept. Through the implementation, alternative locations for new boreholes are generated, and their uncertainties are quantified. The impact of the new borehole on the uncertainty measures are quantified based on local and global approaches. For further research to identify the geological models' risky spots, the development of this approach with additional criteria regarding the search neighbourhood and consideration of barriers and trends in real cases (by employing different interpolation methodologies) should be considered.

Evaluation of engineering site conditions in North Gyeongsang Province, South Korea, using a large database of borehole and standard penetration test data

In this study, the distributions of seismic response parameters and engineering site classes were quantified using a large database of borehole and standard penetration test (SPT) data for the North Gyeongsang Province, Korea. Empirical shear wave velocity (VS) profiles were constructed for 17,180 boreholes by applying a series of development methodologies based on combining the SPT–N value (blow count) and the boring log. N–VS relationship for each stratum was used and representative VS values were assigned for the lower rock layer without N value. If necessary, extrapolation and estimation were additionally applied to obtain the mean VS up to a depth of 30 m (VS,30). Seismic response parameters, such as VS,30 and the mean VS of soils above the engineering bedrock (VS,Soil), were derived and analyzed based on the empirical VS profile. Engineering site classification was performed using international and Korean seismic design codes. The validity of the empirical VS acquisition methodology and the related engineering bedrock depth determination were examined by comparing the derived bedrock depth to the appearance ratio and depth of the rock layer in the boring log. The effects of limiting the maximum converted N value, which is applied to the N–VS relationship, and of defining the engineering bedrock as a stratum with VS > 760 m/s were analyzed. Finally, the spatial bias of the borehole locations was reviewed by analyzing the distribution characteristics of the borehole elevations using a digital elevation model. The results may be used as basic data to assess the adequacy of site classification systems, to derive randomized input parameters, and as reference data for international geospatial zonation verification.

Astronomical dating of Quaternary strata in the South Yellow Sea and its indication for paleoclimatic evolution

The continental shelf has experienced high-frequency transgression-regression cycles during the Quaternary, and its sediments have stored significant information on sea-level changes, climate fluctuations and regional tectonic activities. Due to the lack of extended core records and high-resolution stratigraphic chronology, the strata correlation between continental and marine basin since the Quaternary still has considerable limitations. Here, we present a high-resolution grain size and geochemical study of core CSDP-1 (~3.5 Ma) recovered from the western South Yellow Sea (SYS), China. Two sensitive components were extracted from sediments, and their contents can be used to reflect the paleo-hydrodynamic intensity and reconstruct paleoclimate change. A comprehensive analysis including lithologic characteristics of sediments and seismic data interpretation, shows that the stratum deposition at the borehole's location is relatively continuous at the orbital time-scale. The results of spectral analysis, show that the fine sensitive component it records the periodic change information of the Earth's orbital parameters (~400-, 100-, 40-, and 20-kyr), and the astronomical chronology was established successfully. The variations of sensitive components in the sediments reveals that the SYS paleoclimate has undergone four periods since the Quaternary: cold conditions during 2.58–2.49 Ma and 1.88–0.83 Ma, warm and humid conditions during 2.49–1.88 Ma and 0.83–0 Ma. Moreover, the stratum in the SYS shelf records the Middle Pleistocene climate transition (MPT). It is inferred that the MPT in the SYS is mainly manifested by the enhancement of the 100-kyr period related to the synchronous forcing of the ~400-kyr eccentricity.

Assessment of antifungal potentials of violacein extract from Chromobacterium violaceum isolated from domestic and recreational water sources in Owerri, Imo State, Nigeria

Anti-Microbial Resistance (AMR) in superficial fungal infections are major worldwide public health problem that affects a large part of the human population globally. The antifungal potentials of violacein extracted from Chromobacterium violaceum isolated from domestic and recreational water sources in Owerri, Imo State, Nigeria, was assessed. Three water samples were collected from different locations of the Otamiri River, five from different swimming pools and three from different borehole locations in Owerri Metropolis. The samples were cultured on nutrient agar by pour plate method. The violet colonies of Chromobacterium violaceum were counted, characterized and identified. Water sample from Otamiri River station-1 had the highest bacteria count (20.00 × 101 CFU/Ml and 19.50 × 101 CFU/mL) respectively. Swimming pool 1 and 3 bacterial counts were (14.50 × 101 CFU/mL, 11.00 × 101 CFU/mL and 11.50 × 101 CFU/mL) respectively. For borehole 1, 2 and 3, swimming pool 2, 4 and 5 counts were (0.00 × 101 CFU/mL). The ethanolic extracts from the isolates (violacein) and the control drug (fluconazole 50µg/mL) both had inhibitory effects on the test organisms (Candida albicans and Aspergillus niger) at different concentrations. The MIC of Fluconazole on Candida albicans and A. niger were 25µg/ml and 50µg/Ml, respectively. Violacein from both swimming pools and Otamiri River isolates had MIC of 8.75mg/ml on A. niger and MIC of 4.375mg/ml on Candida albicans. Violacein which proved to have inhibitory effects on Candida albicans and Aspergillus niger can be harnessed for treatment of infections caused by these fungi.

Use of point scale models to improve conceptual understanding in complex aquifers: An example from a sandstone aquifer in the Eden valley, Cumbria, UK

AbstractUnderstanding catchment functioning is increasingly important to enable water resources to be quantified and used sustainably, flood risk to be minimized, as well as to protect the system from degradation by pollution. Developing conceptual understanding of groundwater systems and their encapsulation in models is an important part of this understanding, but they are resource intensive to create and calibrate. The relative lack of data or the particular complexity of a groundwater system can prevent the development of a satisfactory conceptual understanding of the hydrological behaviour, which can be used to construct an adequate distributed model. A time series of daily groundwater levels from the Permo‐Triassic sandstones situated in the River Eden Valley, Cumbria, UK have been analysed. These hydrographs show a range of behaviours and therefore have previously been studied using statistical and time series analysis techniques. This paper describes the application of AquiMOD, impulse response function (IRF) and combined AquiMOD‐IRF methods to characterize the daily groundwater hydrographs. The best approach for each characteristic type of response has been determined and related to the geological and hydrogeological framework found at each borehole location. It is clear that AquiMOD, IRF and a combination of AquiMOD with IRF can be deployed to reproduce hydrograph responses in a range of hydrogeological settings. Importantly the choice of different techniques demonstrates the influence of differing processes and hydrogeological settings. Further they can distinguish the influences of differing hydrogeological environments and the impacts these have on the groundwater flow processes. They can be used, as shown in this paper, in a staged approach to help develop reliable and comprehensive conceptual models of groundwater flow. This can then be used as a solid basis for the development of distributed models, particularly as the latter are resource expensive to build and to calibrate effectively. This approach of using simple models and techniques first identifies specific aspects of catchment functioning, for example influence of the river, that can be later tested in a distributed model.

Exploration and practice of stress-strain evolution law of hydraulic fracturing in coal mine

In order to explore the evolution law of stress and strain in the process of hydraulic fracturing, a hollow inclusions stress-strain gauge was used for monitoring. The results show that the influence range of high-pressure water spreads to the monitoring borehole at 47m after 2 hours of hydraulic fracturing, and its influence on the stress-strain monitoring point reaches the maximum, and the strain tends to be stable in the later stage. After 6 days of hydraulic fracturing, the strain returns to a stable state without any change, but it is still larger than the state before hydraulic fracturing. During hydraulic fracturing, the increment of principal stress increases, but the amplitude is different. Hydraulic fracturing mainly affects the increment of vertical stress, which is related to the stress-strain monitoring point and the space location of the hydraulic fracturing borehole. After hydraulic fracturing, the stress increment decreases gradually and tends to return to the original stable state due to the gradual pressure relief of fracturing fluid, but it is still larger than the state without hydraulic fracturing. Hydraulic fracturing has little effect on the azimuth and dip angle of coal and rock mass. The stress-strain law can provide reference for the exploration of the coal seam permeability increasing mechanism of hydraulic fracturing.