Rock Porosity Research Articles

Karst study of Jinfo Mountain based on image analysis

The KDR (karst development rate) of rocks and their PCR(porosity of carbonate rocks) are common research topics in Jinfo Mountain. The use of traditional carbonate research methods (TCRMs) for karst studies has been shown to be costly and time-consuming. Therefore, this study attempted to find a new, reliable, low-cost, and time-saving method for karst research. The Jinfo Mountain area is a typical carbonate rock area that is suitable for karst research. In this study, many images of rock samples from the Jinfo Mountain were obtained using rock-polarizing microscopes, which provided a good basis for the karst study of Jinfo Mountain. Furthermore, in this study, image analysis technology was used to find the karst development rate of rocks and their porosity. To ensure the accuracy of these research results, we compared the research results obtained using the image analysis techniques with those obtained using TCRM. The comparison showed that the image analysis technology is a feasible research techniques for studying karst in the Jinfo Mountain area. Furthermore, it has good reference significance for other karst study outside the Jinfo Mountain area.

Experimental insights into factors influencing Vp/Vs ratios at the Nevado del Ruiz Volcano, Colombia

Measurements of ultrasonic elastic waves were carried out at atmospheric and in-situ pressure conditions on rock samples from Nevado del Ruiz Volcano (NRV). The study focuses on Vp/Vs as a function of Vp as indicators of mineralogy, porosity, fluid-types and anisotropy. We find that Vp/Vs can separate the effect of microcracks vs. vesicles as a function of fluid type and effective pressures. Little-to-no pressure dependence in Vp/Vs suggest that the rock porosity is mainly comprised by vesicles, while largely varying Vp/Vs vs Vp is associated to cracks. This effect occurs under both, dry and fluid saturation conditions. When cracks close, the Vp/Vs values are representative of the rock mineralogy. Finally, as foliation results in a wide range of Vp/Vs, which could lead to misinterpretations. For instance, on NRV foliated rocks, Vp/Vs at dry conditions and parallel to the foliation plane ranges at values which are commonly associated to fluid saturation.

Relationship between Rock Porosity and Infrared Cooling Rate in Non-Standard Specimens of Tuffs Used in the Hungarian Cultural Heritage

This paper is focused on the application of Infrared Thermography to non-standard rock specimens, in terms of size and deterioration conditions, of Hungarian tuff to monitor their cooling process and to look for a relationship between the rock Cooling Rate Index and the porosity. Literature data agree on the potential of Infrared Thermography for the indirect estimation of rock porosity in fresh specimens through the IRTest, but this technique has never been tested on non-standard specimens. To this purpose, tests on three varieties of Hungarian tuffs were carried out. These materials were selected for their cultural importance linked to their usage as building stones and in other historical applications in Northern Hungary. Tuff specimens underwent a fixed number of salt crystallization cycles. The Cooling Rate Index (CRI) for each specimen was calculated according to the literature experience and correlated to their porosity estimated by water, helium, and mercury intrusion. The results show that the rock cooling process is related to porosity since more porous rocks are characterized by faster cooling. Positive linear trends were achieved for weathered specimens considering 20 min monitoring (CRI20), which is double the time suitable for untreated rocks. The reason should be searched in salt crystallization’s effects on the rock texture, paving the way to further studies on this pioneering branch of technological application.

Quartz types and origins of the Upper Permian Dalong Formation shale of the Sichuan Basin: Implications for pore preservation in deep shale reservoirs

Quartz is critical to reservoir properties (e.g., rock mechanical behavior and porosity) of organic mudstones, exerting an important effect on shale gas production. However, the types and origins of quartz in deeply-buried Upper Permian mudstones, a potential target of shale gas exploration in South China, remain poorly understood. A suite of deeply buried (5636–5645 m) mudstone samples of the Upper Permian Dalong Formation (DL) in the Sichuan Basin (South China) was selected to characterize quartz minerals using petrological and geochemical approaches, including SEM-CL observation. The studied mudstone samples are relatively enriched in organic matter (OM) (total organic carbon (TOC) = 1.88–18.46 wt%) and have been thermally over-matured. The DL organic mudstones accumulated in a failed rift basin, far removed from provenance areas, are chiefly composed of intrabasinal quartz and carbonate (mostly calcite). Quartz is represented by six major forms, including detrital quartz grains, siliceous skeletal fragments, silica nanospheres, microquartz aggregates, grain-replacive quartz, and matrix-dispersed microquartz, of which the latter five are of authigenic origin. Detrital quartz grains are not common in the DL mudstones. Silica reprecipitated as authigenic quartz was largely sourced from dissolved siliceous skeletal fragments (mostly radiolarians), and some silica appeared to have been released from the alteration of volcanic debris (mainly plagioclase) to form matrix-dispersed microquartz grains. Authigenic quartz influenced pore development and preservation of shale reservoirs in two ways. A rigid framework formed from numerous authigenic quartz grains (e.g., microquartz aggregates, silica nanospheres, and siliceous skeletal fragments) shields organic pores during mechanical compaction, whereas authigenic quartz precipitation (e.g., cavity-filling quartz, grain-replacive quartz) reduces porosity by filling voids. A moderate abundance of authigenic quartz (Sixs = ∼20%) is most favorable for development and preservation of pores (especially organic pores) in deep mudstone. Organic pores, widely developed in the studied DL deep mudstones, seem to be largely preserved in the samples with TOC values as much as 18.46 wt%. In summary, the DL mudstone deposits enriched in OM and contained moderate contents of authigenic quartz are especially favorable targets of deep shale gas exploration.

Influence of fracture pattern between Hot Sedimentary Aquifer (HSA) and Enhanced Geothermal Systems (EGS) on thermal production and permeability evolution

Thermal energy extraction relies on the fluid circulation and heat transfer between fluids and rock matrix. The conductive fracture channel provides effective conduits for fluid circulation, while absorbing heat energy from adjacent blocks depending on heat transfer length. The vertical depth variation not only leads to the quality of heat reservoir, but also brings substantial influence on fracture pattern due to stress state and chronological tectonic evolution. Consequently, it is vital to explore the influence of fracture pattern on the model of thermal energy production and subsequent permeability evolution. The induced thermal stress plays an important role in the stress state and fractures and therefore permeability development. It is hypothesized that the two-stage evolution of permeability and porosity: shrinkage effect from thermal cooling is strong sufficient with the highest drawdown gradient, which leads to significant minimum horizontal stress reduction and permeability enhancement. The second stage when rock temperature completely drained allows permeability and porosity reduce to the initial magnitude, with the thermal stress diminishes. The shallow geothermal extraction with less consolidation induces less thermal stress to change rock permeability and porosity. Therefore, the thermal stress needs to be taken into account in evaluating the formation properties evolution and stress state.

An empirical method to compensate the NMR calibrated porosity of the tight volcanic rocks based on comprehensive laboratory studies

The nuclear magnetic resonance (NMR) response is known to deviate from the true value for the volcanic reservoirs, particularly when the pore throat size is ultralow. Consequently, the related petrophysical parameters such as porosity, permeability, and pore size distribution from NMR measurements are greatly influenced. An empirical method to correct the NMR calibrated porosity for the tight volcanic rocks is proposed after comprehensive investigations of influential factors combined with mineralogical and petrophysical analyses. The laboratory result indicates that the relative porosity deviation is negatively correlated with the geometric mean of the transversal relaxation time (T2) but positively correlated with the clay content. Moreover, both the paramagnetic materials, such as the manganese (Mn) content, and the diamagnetic materials, such as the magnesium (Mg) content, contribute to the NMR relaxation intensity reduction but with different mechanisms. The NMR calibrated porosity can be compensated through multiple regressions with these controlling factors, which can be generalized to other tight volcanic reservoirs.

Geophysical characteristics of a fault system in the northern Central Range of Taiwan and its applications for geothermal energy exploration

The northern Central Range of Taiwan is a high-potential geothermal region. Since the formations are mainly tight metasandstone and slate, permeable structures associated with faults are commonly considered as conduits of geothermal fluids. This study determines the characteristics and orientations of the permeable fault zones by analyzing the geophysical logs and microresistivity formation image log (FMI) of the JT-4 well in Jentse, an important geothermal area in the northern Central Range. Between 720 and 1480 m measured depth (MD), the effective porosity of the intact host rock is mostly below 3% calculated by the geophysical log. Zones with porosity greater than 5% are only clustered within a few thin intervals. The FMI interpretations show these porous zones are in the interior of the fractured and faulted intervals. These porous fault zones comprise fault damage zones with a high density of open fracture planes and fault cores with porous fault breccias. There is a highly brecciated fault core in 1334–1339 m MD, which would be the most permeable interval of the well. Additionally, some healed fault zones with sealed fractures are observed. The picked drilling-induced tensile fractures signify that the direction of the present-day maximum horizontal principal stress is N40–50°E, and most of the open fractures also strike parallel to the NE–SW direction. The study results show that the open fractures are concentrated in the four fault zones belonging to one major normal fault system. After integrating the orientations and locations of the fault zones, we propose that the permeable normal fault system is about 200 m wide, trends N50–70°E, and dips 70–80° to the NW. The development of the open fractures and the permeable fault system in the northern Central Range may be controlled by the current rifting of the Okinawa Trough offshore northeastern Taiwan. The study exhibits the characteristics of fractured fluid conduits of the regional geothermal system, which will benefit future geothermal exploration in northeastern Taiwan.

Evaluation method of rock damage under uniaxial compression based on unit series-parallel electrical conductive model

The evaluation of rock damage behaviour is an important requirement for ensuring stability control and safety prediction in rock engineering. However, they have not been able to obtain sufficiently accurate and dynamic results due to the insufficient evaluation method. In this study, by means of fractals and unit series division, a unit series-parallel conductive model of damaged rock is derived, and a new evaluation method of rock damage under uniaxial compression was proposed. Rock was damaged by uniaxial compression, while electrical measurements and X-ray microscopy tests were performed to obtain the damaged rock resistivity, porosity, and fractal dimension variation. By establishing the relationship between defined meso-damage factor and resistivity, rock damage evolution law under axial compression was obtained. The results indicate that the growth trend was agree with the classical statistical damage model, which verified the accuracy of the results obtained by the proposed method. Moreover, as the strain increased, the damage factor determined by resistivity gradually decreased to −0.06 firstly and then increased rapidly to 0.79. Different from previous damage evolution law, brittle failure was observed and the cracks development in each stage was considered, including the closure (negative damage) and expansion (positive damage) of cracks.

Geological structure and oil-and-gas occurrence of Prorva group of the Southern deposits of the Caspian Depression in terms of geophysical information

Purpose. Purpose is to generalize and analyze the currently accumulated geological and physical as well as field data to study productive strata of Prorva group of oil-and-gas occurrence of the Southern deposits of the Caspian Depression in Kazakhstan. Methodology. Deep Triassic rock systems were studied thoroughly relying upon the explained new data by seismic data together with logging and field information using current processing and interpretative systems according to the newly drilled deep wells within the unexplored northwest part of the structure. Findings. The specified geological model of the field has been obtained. Twenty-one estimation targets have been singled out in the Jurassic-Trias structures; three new oil-and-gas-bearing formations have been identified as part of the Lower Cretaceous share of a productive stratum within the Valanginian level. According to geophysical analysis, Western Prorva and S. Nurzhanov deposits are the unified system with the oil-water contact level. Originality. Selection of the recommended location of the new wells is based upon specificity of the innovative scientific and technical approaches while studying regularities of facies substitution of reservoir rocks with enclosing systems of each productive stratum; and studying permeability and porosity of the reservoir rocks as well as fluids saturating them. Practical value. The obtained data have become the basis to assess the remaining carbohydrate reserves, and identify new opportunities increasing the reserves within the Western area of S. Nurzhanov deposit; moreover, they raise a question on the expediency to develop the Unified Project of the field mining.

Heterogeneity of reservoirs of the Qala suite (on the example of the Neft Dashlary field)

In order to study the heterogeneity of reservoir rocks based on core materials and well logging data, an analysis of the lithological-petrographic and reservoir properties of the rocks of the Qala suite of the PS of the Neft Dashlary field was carried out. For a more detailed study, an analysis of laboratory data on subformations (QaS1, QaS2, QaS3 and QaS4) has been carried out, the grainsize composition and reservoir properties (porosity, clay content, permeability and carbonate content) of reservoir rocks were studied. Based on the results of logging data interpretation and analysis of the constructed correlation schemes, heterogeneity, including the study of reservoirs thickness and the variability of their reservoir properties over the area have been studied. Keywords: Kalinskaya suite; Core; Logging; Heterogeneity.

Сomposition and structure features of the Vikulov productive deposits (Krasnoleninsky arch) and their influence on reservoir properties

Both sedimentological factors and secondary processes of lithogenesis influenced the formation of porosity and permeability properties of the reservoir rocks of the Vikulov suite of the Krasnoleninskoe field. The former includes the conditions of sedimentation of the deposits of the Vikulov suite, which at the initial stages of its formation were controlled by the development of a system of incised river valleys, the stages of filling of which, like their composition, have their own characteristics. Also, various genetic types of deposits were formed here. The formation of the upper part of the Vikulov suite took place in a shallow-marine setting, in conditions of storm and wave shallow water, which affected the thin-layered structure of the VK1-3 reservoir. On the other hand, in the sections of a number of wells, dense interlayers are noted, the formation of which is associated with both sedimentation and superimposed processes in lithogenesis, including the formation of hydrocarbon deposits. Therefore, the prediction of the distribution of productive reservoir rocks is the main task when creating a petrophysical model of the field, and to solve this problem, the methods of lithofacies and staged core analysis are used in the work.

Measured CO2 sorption isotherms with 25 Bakken Petroleum System rock samples from the Lower and Upper Shales, Middle Bakken, and Three Forks formations

Isotherms were measured with 25 Bakken Petroleum System (BPS) rock samples using a magnetic suspension balance at reservoir conditions of 110 °C and pressures up to 345 bar. Samples from four wells represented the Middle Bakken (MB) and Three Forks (TF) production zones, and the Upper Bakken Shale (UBS) and Lower Bakken Shale (LBS) source shales. UBS and LBS CO2 sorption capacities at 345 bar averaged 12–14 g/kg rock compared to 1.3 to 2.5 g/kg rock for MB and TF. Increasing pressure from 150 to 345 bar resulted in only small increases in CO2 sorption for all lithofacies. For the UBS and LBS source shales, the higher average total organic carbon (TOC) values (14.7 and 11.4 wt.%) and clay values (25 and 28 wt.%) corresponded to their higher CO2 sorption values while for the MB and TF samples, lower TOCs (0.3 and 0.5 wt.%) and clay values (8.2 and 18.2 wt.%) corresponded to lower CO2 sorption values. When all 25 samples (from all lithofacies) were evaluated as a group, sorption capacities were highly correlated with TOC (Spearman's rho values +0.84 to +0.85), with rock density (rho values -0.75 to -0.76), and clay content (rho values +0.66). However, correlations with porosity and thermal maturity (Tmax) were weak. Measured sorption capacities and rock porosities showed that sorption accounted for about 10-times as much CO2 storage as the available pore space for the UBS and LBS lithofacies. In contrast, the pore space dominated the storage resource of the TF and MB lithofacies.

Bayesian inversion for rapid multiwell interpretation of well logs and core data: Applications to unconventional organic-shale formations

Multimineral analysis is widely used to calculate in situ porosity, fluid saturation, and mineralogy of rocks penetrated by a well. It delivers weight/volumetric concentrations of rock solid/fluid constituents by combining multiple borehole geophysical measurements and often is referred to as petrophysical joint inversion. Recently, a probabilistic method was developed for improved petrophysical estimation of rock constituents and their uncertainty from well logs. This method mitigates borehole and instrument-related environmental effects present in the measurements and efficiently propagates the uncertainty from measurement noise and rock-physics models (RPMs) to compositional/petrophysical estimations. The probabilistic estimation method is extended to the challenging conditions of multiple neighboring wells penetrating similar rock formations where borehole/drilling environmental conditions, borehole instruments, and measurement noise may vary from well to well. A calibration step is performed in a few key wells with core data and/or advanced borehole measurements; it enables the same RPMs and prior models to be implemented in nearby wells but with limited measurements. In addition, a precomputed surrogate model constructed with radial basis function interpolation is implemented for accurate and efficient nuclear-property calculations. The multiwell interpretation method is verified using synthetic and field examples of organic-rich shale formations. Results find that the probabilistic method (1) improves rock petrophysical/compositional estimations by mitigating borehole environmental effects and incorporating a priori knowledge, (2) yields regionally consistent compositions among wells, and (3) quantifies the uncertainty of the estimations. As a result, the probabilistic approach is especially suitable for assessing petrophysical/compositional properties in multiwell settings with complex rock constituents and/or limited borehole measurements.

Influence of Rock Firing on the Wettability of Clay-Rich Sandstones

Rock firing is a conventional technique of core preparation to prevent clay swelling and fines migration in clay-rich rock; however, the influence of rock firing on the wetting behaviors and alterations of mineralogical compositions of clay-rich sandstones is not yet explicit. Thus, we assessed and compared the impacts of rock burning at two different temperatures (700 and 1100 °C) on the changes in wetting states of Bentheimer (BN) and clay-rich Bandera Gray (BG) sandstones through contact angle measurement, Amott wettability index determination, and thermogravimetric analysis (TGA). Results showed that rock firing makes the rocks more water-wet, but the clay-rich BG sandstone becomes significantly more water-wet than the quartz-dominated BN rock with increasing temperature. There was no change in rock porosity due to firing, but some clay remained, whereas some clays were transformed into other minerals after rock firing. Particularly, there were thermal transformations of clay to quartz and the disappearance of dolomite, chlorite, and clinochlore. Such transformation of these minerals into alkali metal oxide silicates dispersed on the rock matrix makes the surface more polar and enhances the interactions with water molecules, resulting in more water wettability for the BG sandstone. The study suggests that rock firing could change the clay-rich rock-wetting state into a more water-wet condition than the clay-poor or zero-clay sandstone samples; thus, the influence of rock burning on rock-wetting behavior should be considered to ensure an accurate prediction of the rock-wetting state due to rock burning. Moreover, burning at 1100 °C is recommended to achieve effective clay transformation and removal in clay-rich rock to prevent swelling, fines migration, and clay–fluid interactions.

Stacked ensemble machine learning for porosity and absolute permeability prediction of carbonate rock plugs

This study employs a stacked ensemble machine learning approach to predict carbonate rocks' porosity and absolute permeability with various pore-throat distributions and heterogeneity. Our dataset consists of 2D slices from 3D micro-CT images of four carbonate core samples. The stacking ensemble learning approach integrates predictions from several machine learning-based models into a single meta-learner model to accelerate the prediction and improve the model's generalizability. We used the randomized search algorithm to attain optimal hyperparameters for each model by scanning over a vast hyperparameter space. To extract features from the 2D image slices, we applied the watershed-scikit-image technique. We showed that the stacked model algorithm effectively predicts the rock's porosity and absolute permeability.

Distribution of silicification intervals throughout the Barra Velha and Itapema formations: Host rock controls and chronology of silica precipitation (Pre-Salt, Santos Basin, Brazil)

The Barra Velha and Itapema formations, Aptian, Santos Basin, constitute large hydrocarbon reservoirs, mainly in carbonate rocks. These rocks host up to centimeter-thick silica bodies with a variety of textures and geometries along different carbonate facies, suggesting syngenetic, diagenetic, and hydrothermal processes in their formation. The mineralogical and textural changes related to these processes can directly influence the porosity and permeability of the reservoir rocks, turning the study of the silicified intervals important in the exploration and production of these deposits. We present here a systematic macroscopic and microscopic description of the silica bodies and its distribution through the carbonate facies the of Barra Velha and Itapema formations from the Sapinhoá and Búzios fields. Data allow us to identify four geometric types of silica bodies: tabular, irregular, oval and disseminated, which are composed of chalcedony, microcrystalline and macrocrystalline quartz. Tabular, oval, and irregular silica bodies are cross-cutted by mechanical compaction structures such as vertical fractures, boudins and faults. In addition, these bodies include relicts of the host rock lamination, which in turn deflects around them. Thus, silica precipitation must have been penecontemporaneous or in the early stages of diagenesis, before the main mechanical compaction stage. These features were not observed in the disseminated silica type, in the contrary, this type involves and overlaps oval and irregular bodies, indicating that this silica precipitation probably occurred in latter stages in relation to other body types. The genesis of disseminated bodies can then be related to diagenetic or hydrothermal processes during diagenesis. Therefore, the geometry of silica bodies and their spatial distribution are influenced by the host carbonatic petrofabrics and the chronology of silica precipitation within the sedimentary to diagenetic evolution of the sedimentary package. Finally, we present a systematics that can be easily applied to recognize these silica types in other exploration fields of pre-salt interval. The results presented here have great potential to be applied in the research on pre-salt intervals from other Brazilian and African basins since the host carbonate rocks are very similar and favor the development of similar silicification processes and results.

Full scale, microscopically resolved tomographies of sandstone and carbonate rocks augmented by experimental porosity and permeability values

We report a dataset containing full-scale, 3D images of rock plugs augmented by petrophysical lab characterization data for application in digital rock and capillary network analysis. Specifically, we have acquired microscopically resolved tomography datasets of 18 cylindrical sandstone and carbonate rock samples having lengths of 25.4 mm and diameters of 9.5 mm. Based on the micro-tomography data, we have computed porosity-values for each imaged rock sample. For validating the computed porosity values with a complementary lab method, we have measured porosity for each rock sample by using standard petrophysical characterization techniques. Overall, the tomography-based porosity values agree with the measurement results obtained from the lab, with values ranging from 8% to 30%. In addition, we provide for each rock sample the experimental permeabilities, with values ranging from 0.4 mD to above 5D. This dataset will be essential for establishing, benchmarking, and referencing the relation between porosity and permeability of reservoir rock at pore scale.

Evolution of reservoir properties of oil shale rocks under hydro-thermal treatment: Investigations from micro- to macro-scale

Treatment with water at sub- and supercritical states which is considered as one of the most promising technologies for oil shale reservoirs development is still understudied. In particular, reliable correlations between most of the reservoir properties and temperature are absent. However, this data may significantly improve the quality of oil recovery predictions applying numerical simulations. This work is devoted to obtaining the dependency between porosity, permeability, organic matter content and temperature through physical modeling of hydrous pyrolysis. A unique experimental program design is proposed to investigate changes in reservoir properties at macro- and micro-scales and connect these changes with composition and pore structure evolution. A set of experiments on hydrous pyrolysis in a closed system was performed at temperatures 110, 250, 300,325, 350, 375, 400, and 450 °C, and the pressure of 23.4 MPa on rock samples of the Bazhenov formation.As a result, the relation between reservoir properties and the temperature was derived, characterized by a few specific temperature zones with particular behaviors of rock porosity and permeability. Effects on reservoir properties were analyzed in a complex way to highlight the mechanisms of void space transformation related both with pore space evolution and reduction. The observed effects include thermal expansion of organic matter with further transformation to synthetic hydrocarbons, formation of new mineral components, mineral matrix swelling and fracturing.

Study on the failure characteristics of overburden and the evolution law of seepage field in deep buried thick coal seam under aquifers

Water inrush at roof area seriously affects the safety of coal mines. The characteristics of aquifer and aquiclude at Wutongzhuang Mine are analyzed. Considering the effect of seepage field, a formula for calculating the height of water-conducting fractured zone (HWCFZ) in deep buried thick coal seam mining is derived. A damage-seepage coupling model with rock porosity and damage factor as independent variables is established. FLAC3D is re-developed by using FISH language, and the fluid–solid coupling calculation model of deep buried thick coal seam mining is established. The evolution law of the plastic zone, seepage field and water-conducting fractured zone (WCFZ)of the overburden in the gob with the advancement of the working face is analyzed, the main conclusions are as follows: With the continuous advancement of the working face, the distribution shape of the plastic zone and seepage field has changed from a trapezoidal to a saddle shape; when the working face reaches full mining, the maximum heights of the caving zone, fractured zone and HWCFZ are 24 m, 113 m, and 123 m, respectively; The 50 m-thick sandy shale aquifer is penetrated by the WCFZ, and the WCFZ on the side of the working face above the gob is the main water channel when the working face is advanced to 220 m. The on-site monitoring results showed that mine water inflow is not affected by surface rainfall and the 50 m-thick sandy shale is successively connected by the WCFZ. The results of comprehensive research showed that the HWCFZ cannot be calculated by traditional formulas when mining deep buried thick coal seams.

Numerical prediction of ground vibrations induced by LPG boiling liquid expansion vapour explosion (BLEVE) inside a road tunnel

Accidental boiling liquid expansion vapour explosions (BLEVEs) caused by the bursting of liquified petroleum gas (LPG) tank inside a tunnel can induce vibrations of its surrounding geological media and threaten the stability of adjacent tunnels and structures. Therefore, it is essential to understand the characteristics of vibrations induced by LPG BLEVEs inside the tunnel for the safety design of its adjacent structures. Owing to the difficulty in effectively predicting the LPG BLEVE loads, the current practice usually employs equivalent methods, e.g., the TNT-equivalency method, in LPG BLEVE load predictions for structural response analysis, which may lead to inaccurate response predictions. This study compares ground vibrations induced by a BLEVE inside an arched road tunnel with those induced by its equivalent TNT explosion via high-fidelity numerical simulations. The results demonstrate that the frequency of BLEVE-induced vibrations is lower than that induced by the TNT explosion at the same scaled distance. The intensity of LPG BLEVE-induced vibrations at relatively small-scaled distances is lower than that of TNT explosion-induced vibrations at the same scaled distance, but becomes higher after a certain scaled distance because of the relatively low attenuation rate. In addition, parametric analysis is conducted to evaluate the effects of various factors on the characteristics of LPG BLEVE-induced ground vibrations. It is found that the surrounding rock type, the rock porosity, and the cover depth of the tunnel have more significant influences than the concrete grade of the tunnel lining. The recommendation for the tunnel design is also given based on the intensity and frequency characteristics of BLEVE-induced vibrations.