Maximum Principal Compressive Stress Research Articles

Simulating spatial and temporal evolution of multiple wing cracks around faults in crystalline basement rocks

Fault zones are structurally highly spatially heterogeneous and hence extremely complex. Observations of fluid flow through fault zones over several scales show that this structural complexity is reflected in the hydrogeological properties of faults. Information on faults at depth is scarce, hence, it is highly valuable to understand the controls on spatial and temporal fault zone development. In this paper we increase our understanding of fault damage zone development in crystalline rocks by dynamically simulating the growth of single and multiple splay fractures produced from failure on a pre‐existing fault. We present a new simulation model, MOPEDZ (Modeling Of Permeability Evolution in the Damage Zone surrounding faults), that simulates fault evolution through solution of Navier's equation with a combined Mohr‐Coulomb and tensile failure criteria. Simulations suggest that location, frequency, mode of failure and orientation of splay fractures are significantly affected both by the orientation of the fault with respect to the maximum principal compressive stress and the conditions of differential stress. Model predictions compare well with published field outcrop data, confirming that this model produces realistic damage zone geometries.

Finite-element analysis on closing-opening correction osteotomy for angular kyphosis of osteoporotic vertebral fractures

BackgroundClosing-opening correction (COC) osteotomy is a useful procedure for severe angular kyphosis. However, there is no previous research on the reconstructed vertebrae with kyphotic malalignment in the presence of osteoporosis. Finite-element (FE) analysis was performed to estimate the biomechanical stress with both osteoporotic grades and corrective kyphotic angles during COC osteotomy for osteoporotic angular kyphosis. MethodsFE models of COC osteotomy were created by changing three major parameters: (1) grade of osteoporosis; (2) kyphotic angle; and (3) compensated posture when standing still. Osteoporosis was graded at four levels: A, normal (nonosteoporotic); B, low-grade osteoporosis; C, middle-grade osteoporosis; D, high-grade osteoporosis. The kyphotic angle ranged from 0° as normal to 15° and 30° as moderate and severe kyphosis, respectively. FE analyses were performed with and without assumed compensated posture in kyphotic models of 15° and 30°. Along each calculated axis of gravity, a 427.4-N load was applied to evaluate the maximum compressive principal stress (CPS) for each model. ResultsThe CPS values for the vertebral element were the highest at the anterior element of T10 in all FE models. The maximum CPS at T10 increased based on the increases in both the grade of osteoporosis and the kyphotic angle. Compensated posture made the maximum CPS value decrease in the 15° and 30° kyphotic models. The highest CPS value was 40.6MPa in the high-grade osteoporosis (group D) model with a kyphotic angle of 30°. With the normal (nonosteoporotic) group A, the maximum CPS at T10 was relatively low. With middle- and high-grade osteoporosis (groups C and D, respectively), the maximum CPS at T10 was relatively high with or without compensated posture, except for the 0° model. ConclusionsLack of correction in osteoporotic kyphosis leads to an increase in CPS. This biomechanical study proved the advantage of correcting the kyphotic angle to as close as possible to physiological alignment in the thoracolumbar spine, especially in patients with high-grade osteoporosis.

Upper mantle seismic velocities and anisotropy in China determined through Pn and Sn tomography

We have obtained velocity images of the uppermost mantle beneath China by performing tomographic inversion of both Pn and Sn traveltimes. From the Annual Bulletin of Chinese Earthquakes, 99,139 Pn arrivals and 43,646 Sn arrivals were selected. Pn anisotropy was also obtained simultaneously with Pn velocity. Average Pn and Sn velocities are 8.05 and 4.55 km/s, respectively, and maximum velocity perturbations are about 3–4%. The Pn and Sn velocities are low in eastern China and high in western China. Particularly high velocities are associated with old basins (for example, Tarim, Junggar, Turpan‐Hami, Qaidam, and Sichuan) and stable craton (for example, Ordos). Low Sn velocities are found mainly throughout North China. In addition, velocities are relatively low beneath the central Tibetan Plateau and the North‐South Seismic Zone (along 103°E). In Tarim and central China where we observe strong anisotropy, the fast Pn velocity directions are consistent with the directions of maximum principal compressive stress as well as directions of crustal movement determined from Global Positioning System. Beneath the India‐Eurasia collision zone, the Pn anisotropy direction is parallel to the collision arc and nearly perpendicular to both the direction of maximum compression and crustal movement resulting from pure shear deformation. Both the velocity variations and anisotropy indicate that the Tibetan Plateau was extruded, and the mantle material beneath the plateau has flowed around the East Himalaya Syntax, while the remaining material has diverted northwestward beneath the Tarim Basin.

Coupling characteristics of stress and strain at different layers of different sub-regions in Yunnan and its adjacent areas

In this paper, we collect 6 361 waveform data to calculate the shear wave splitting parameters from a regional seismic network of 22 digital stations in Yunnan and its adjacent area from July 1999 to June 2005. By using the cross-correlation method, 64 splitting events of 16 stations are processed. We also collect the splitting results of eight earthquake sequences to present the characteristics of shear wave splitting in Yunnan and its adjacent areas. The orientations of maximum principal compressive stress of three sub-regions in this area are derived from the CMT focal mechanism solutions of 43 moderate-strong earthquakes provided by Harvard University by the P axis azimuth-averaging method. The principal strain rate at each observatory is deduced from the observations of Crustal Movement Observation Network of China during the period from 1999 to 2004. In addition, the data of Pn aniso-tropy and SKS splitting of Yunnan and its adjacent areas are also collected. We have discovered from this study that the continental lithosphere, as a main seismogenic environment for strong earthquake, can be divided into blocks laterally; the mechanical behavior of lithosphere varies with depth and can be divided into different layers in the vertical orientation; the information of crustal deformation obtained from GPS might be affected by the type of blocks, since there are different types of active blocks in Yunnan and its adjacent areas; the shear wave splitting in this region might be affected mainly by the upper crust or even the surface tectonics.

Horizontal movement and strain characteristics in Tianshan and its adjacent region with GPS deformation data

Based on the multiple-term horizontal velocity solutions of 230 GPS monitoring sites in Tianshan and its adjacent region, the GPS site velocity fields and crustal horizontal strain fields in the area have been obtained. The results show that the crustal shortening rate of Tianshan, with the longitude (77°±1°)E as the boundary, gradually decreased towards two sides, from the south to the north, indicating that the pushing force of plate becomes weaker along with the fold deformation decreasing of the Tianshan. The direction of principal compressive strain of Tianshan and its adjacent area, nearly NNW, is basically perpendicular to the Tianshan cordillera trend, suggesting the distribution and variation of maximum principal compressive stress in Tianshan and its adjacent region resulted from collision and extrusion of Indian Plate. This paper indicates that the maximum shear strain field mainly concentrates on two areas, one is Isyk lake of North Tianshan, Kyrgyzstan, and the other is the juncture of Jiashi (South Tianshan) and Pamir arc faults. In the above areas, it can be shown from the epicentral distribution that the strong earthquakes mostly occurs at the high shearing strain accumulation field or its edge.

Seismic anisotropy of the crust in Yunnan, China: Polarizations of fast shear-waves

Using seismic data recorded by Yunnan Telemetry Seismic Network from January 1, 2000 to December 31, 2003, the dominant polarization directions of fast shear-waves are obtained at 10 digital seismic stations by SAM technique, a systematic analysis method on shear-wave splitting, in this study. The results show that dominant directions of polarizations of fast shear-waves at most stations are mainly at nearly N-S or NNW direction in Yunnan. The dominant polarization directions of fast shear-waves at stations located on the active faults are consistent with the strike of active faults, directions of regional principal compressive strains measured from GPS data, and basically consistent with regional principal compressive stress. Only a few of stations show complicated polarization pattern of fast shear-waves, or are not consistent with the strike of active faults and the directions of principal GPS compressive strains, which are always located at junction of several faults. The result reflects complicated fault distribution and stress field. The dominant polarization direction of fast shear-wave indicates the direction of the in-situ maximum principal compressive stress is controlled by multiple tectonic aspects such as the regional stress field and faults.

Deformation driven by subduction and microplate collision: Geodynamics of Cook Inlet basin, Alaska

Late Neogene and younger deformation in Cook Inlet basin is caused by dextral transpression in the plate margin of south-central Alaska. Collision and subduction of the Yakutat microplate at the northeastern end of the Aleutian subduction zone is driving the accretionary complex of the Chugach and Kenai Mountains toward the Alaska Range on the opposite side of the basin. This deformation creates belts of fault-cored anticlines that are prolific traps of hydrocarbons and are also potential sources for damaging earthquakes. The faults dip steeply, extend into the Mesozoic basement beneath the Tertiary basin fill, and form conjugate flower structures at some localities. Comparing the geometry of the natural faults and folds with analog models created in a sandbox deformation apparatus suggests that some of the faults accommodate significant dextral as well as reverse-slip motion. We develop a tectonic model in which dextral shearing and horizontal shortening of the basin is driven by microplate collision with an additional component of thrust-type strain caused by plate subduction. This model predicts temporally fluctuating stress fields that are coupled to the recurrence intervals of large-magnitude subduction zone earthquakes. The maximum principal compressive stress is oriented east-southeast to east-northeast with nearly vertical least compressive stress when the basin's lithosphere is mostly decoupled from the underlying subduction megathrust. This stress tensor is compatible with principal stresses inferred from focal mechanisms of earthquakes that occur within the crust beneath Cook Inlet basin. Locking of the megathrust between great magnitude earthquakes may cause the maximum principal compressive stress to rotate toward the northwest. Moderate dipping faults that strike north to northeast may be optimally oriented for rupture in the ambient stress field, but steeply dipping faults within the cores of some anticlines are unfavorably oriented with respect to both modeled and observed stress fields, suggesting that elevated fluid pressure may be required to trigger fault rupture.

Study on in-situ stress measurement around coastal marginal land in Fujian

The in-situ hydraulic fracturing stress measurements have been carried out around the coastal marginal land in Fujian Province. And the characteristics of magnitude, direction and distribution of tectonic stress have been obtained. Based on the observed stress data, the characteristics and activities of fault zones are analyzed and studied in the paper according to the Coulomb friction criteria. (1) The maximum horizontal principal compressive stress is in the NW-WNW direction from the north to the south along the coastline verge, which is parallel to the strike of the NW-trending fault zone, consistent with the direction of principal compressive stress obtained from geological structure and across-fault deformation data, and different from that reflected by focal mechanism solution by about 20°. (2) The horizontal principal stress increases with depth, the relation among three stresses is S H>S v>S h or S H≈S v>S h, and the stress state is liable to normal fault and strike-slip fault activities. (3) According to Coulomb friction criteria and taking the friction strength μ as 0.6–1.0 for analysis, the stress state reaching or exceeding the threshold for normal-fault frictional sliding near the fault implies that the current tectonic activity in the measuring area is mainly normal faulting. (4) The force source of current tectonic stress field comes mainly from the westward and northwestward horizontal extrusions from the Pacific and Philippine Plates respectively to the Eurasian Plate.

Effects of Mantle Flow on Generation and Distribution of Global Lithospheric Stress Field

We apply the kinematic simulation modeling method to study the effects of mantle flow on the generation of global lithospheric stress field. The internal density anomalies and surface plates' movements both drive the mantle circulation. Mantle flow causes normal stress and tangential stresses at the bottom of the lithosphere, and then the sublithospheric stress field induces the lithospheric deformation as surface force and results in the stress field within the lithosphere. The simulation shows that the agreement between predictions and observations is good in most regions. Most of subduction zones and continental collisions, such as the circumpacific subduction zone and the collision zone between the India and Eurasia plate, are under compression. While ocean ridges, such as the east Pacific ridge, the Atlantic ridge and the east African rift valley, are under tension. And most of the hotspots preferentially occur in regions where calculated stress is tensile. The calculated directions of maximum principal horizontal compressive stresses are largely in accord with that of the observation except for some regions such as the NW-Pacific subduction zone and Qinghai-Tibet Plateau, in which the directions of the maximum principal horizontal compressive stress are different. It shows that the mantle flow plays an important role in causing or affecting the large-scale stress field within the lithosphere.

Three-dimensional modeling of the mechanical property of linearly elastic open cell foams

Three-dimensional Voronoi models are developed to investigate the mechanical behavior of linearly elastic open cell foams. Dependence of the Young’s modulus, Poisson’s ratio and bulk modulus of the foams on the relative density is evaluated through finite element analysis. Obtained results show that in the low density regime the Young’s modulus and bulk modulus of random Voronoi foams can be well represented by those of Kelvin foams, and are sensitive to the geometric imperfections inherent in the microstructure of foams. In contrast, the compressive plateau stress of the foams is less sensitive to the imperfections. Failure surface of the foams subject to multi-axial compression is determined and is found to comply with the maximum compressive principal stress criterion, consistent with available experimental observations on polymer foams. Numerical results also show that elastic buckling of cell edges at microscopic level is the dominant mechanism responsible for the compressive failure of elastic open cell foams.

Hardness and yield strength of dentin from simulated nano-indentation tests

The finite element method (FEM) is applied for studying the hardness (H) and yield strength (Y) of dentin subjected to a nano-indentation process. The nano-indentation experiments were simulated with the ABAQUS finite element software package. This test, performed with a spherical indenter, was simulated by axisymmetric finite element analysis. The load versus displacement was calculated during loading-unloading sequence for different elastic modulus (E) and yield strength. Hardness and maximum principal compressive and tensile stresses were plotted for different elastic modulus depending on yield strength. The dentin was assumed to be isotropic, homogenous and elasto-plastic. The theoretical results outlined in this study were compared with the experimental works reported in the literature and then hardness and yield strength of dentin was estimated.

Study on the coalescence mechanism of splitting failure of crack-weakened rock subjected to compressive loads

It is of important significance to study the coalescence mechanism of splitting failure of crack-weakened rock masses under compressive loads. In this paper, a simplified mechanism of crack propagation, in which the crack grows along the direction of maximum principal compressive stress, is proposed. Thus, only mode I is taken into account in the formulation and solution. On the basis of the near crack line analysis method, the elastic–plastic stress field near the crack line is analyzed, and the law that the length of the plastic zone along the crack line is varied with an external loads have been established by the matching condition of the elastic- plastic fields on the boundary, the coalescence stress and the strength properties of rock masses have been determined. The solution is a function of the geometry of the crack array. The results show that the crack coalescence depends on the crack interface friction coefficient, the sliding crack spacing, orientation of the cracks, and the crack half-length. The conclusions are of important significance for rock mass engineering.

Hybrid fracture and the transition from extension fracture to shear fracture.

Fracture is a fundamental mechanism of material failure. Two basic types of brittle fractures are commonly observed in rock deformation experiments--extension (opening mode) fractures and shear fractures. For nearly half a century it has been hypothesized that extension and shear fractures represent end-members of a continuous spectrum of brittle fracture types. However, observations of transitional fractures that display both opening and shear modes (hybrids) in naturally deformed rock have often remained ambiguous, and a clear demonstration of hybrid fracture formation has not been provided by experiments. Here we present the results of triaxial extension experiments on Carrara marble that show a continuous transition from extension fracture to shear fracture with an increase in compressive stress. Hybrid fractures form under mixed tensile and compressive stress states at acute angles to the maximum principal compressive stress. Fracture angles are greater than those observed for extension fractures and less than those observed for shear fractures. Fracture surfaces also display a progressive change from an extension to shear fracture morphology.

Discussion on origin of Pn velocity variation in China and adjacent region

Pn velocity lateral variation and anisotropy images were reconstructed by adding about 50 000 travel times from the regional seismic networks to the datum set of near 40 000 travel times from National Seismic Network of China used by WANG,et al. We discussed the relation of Pn velocity variation to Moho depth, Earth’s heat flow, distribution of Cenozoic volcanic rock and the result of rock experiment under high pressure and high temperature. The result of quantitative analysis indicates that Pn velocity is positively correlated with the crust thickness and negatively correlated with the Earth’s heat flow. Two linear regression equations, one between Pn velocity and crust thickness, and the other between Pn velocity and heat flow, were obtained. The rate of variation of Pn velocityν p with pressureP, ∂ν p/∂P, estimated from the velocity variation with crust thickness, ∂ν p/∂H is close to the result obtained from the rock experiment under high pressure and high temperature. If the effect of crust thickness on Pn velocity is deducted from the velocity variation, then the low Pn velocity beneath Qinghai-Xizang plateau is more notable. The low Pn velocity regions well agree with the Cenozoic volcanic rock. In the several regions with significant anisotropy, the direction of fast Pn velocity is consistent with the orientation of maximum principal crustal compressive stress, and also with the direction of present-day crustal movement. It indicates that the fast Pn velocity direction may be related to the deformation or flow of top mantle material along the direction of maximum pressure.

Tectonic stress field and its effect on hydrocarbon migration and accumulation in Mesozoic and Cenozoic in Kuqa depression, Tarim basin

Through rock acoustic emission experiments and structural deformation analysis, the tectonic stages in Meso-Cenozoic in the Kuqa depression of the Tarim basin are firstly divided. Then, combining with rock magnetic fabric analysis and memory information, the distribution characteristics of tectonic stress field of every tectonic stage are quantificationally resumed. At the same time, according to the distribution relation of tectonic stress field of hydrocarbon formation stage by the finite element numerical simulation method and the known hydrocarbon reservoirs, the effects of tectonic stress field on hydrocarbon migration and accumulation are further analyzed. The Kuqa depression has mainly experienced six tectonic movements since Mesozoic. Except that the tectonic stress field of the Early Yanshan stage (208—135 Ma) showed northeast-southwest extensional stress field where the orientation of the maximum principal compressive stress (σ 1 ) was northwest-southeast, the others were compressive stress field where the orientations of the maximum principal compressive stress (σ 1 ) were near north-south. Along with the closure of the paleo-Tethys ocean, the Kuqa depression in the Indosinian stage (250—208 Ma) was in strong compressive circumstance with apparently big maximum principal stress (σ 1 ) magnitude. Due to the equilibrium adjustment of interior Eurasia, the Kuqa depression in the Early Yanshan stage (208—135 Ma) was in weak extensional circumstance with apparently small maximum principal stress (σ 1 ) magnitude. From the Late Yanshan stage (135—65 Ma) on, with a series of collision events occurring at the south edge of Eurasia, the Kuqa depression was in compressive circumstance again in which the maximum principal stress (σ 1 ) magnitude was from small to big in turn. The Late Himalayan stage (2.6—0.7 Ma) was the main tectonic deformation stage with the biggest principal compressive stress (σ 1 ) magnitude. Tectonic stress field plays a dominant role in hydrocarbon formation, it not only forms migration channels and trap structures for hydrocarbon accumulation, but also is the main drive power for hydrocarbon migration vertically along faults.

Computational Evaluations of Biomechanical Factors in Spondylolisthesis

This study is concerned with biomechanical evaluations of isthmic spondylolisthesis that causes slippage of a defected vertebra. Because the frequency of this disease depends on the site of spondylolysis, it is supposed that the mechanical boundary condition in lower lumbar spine has influence on isthmic spondylolisthesis. To clarify the mechanism of isthmic spondylolisthesis, the effects of isthmic defect on stress distribution in intervertebral disks were investigated by using a three-dimensional finite element model of a whole spine. The results of extension motion analyses show that the maximum compressive principal stress of L 4-L 5 disk in L 4 defect model is significantly increased in comparison with that of an intact model and the instability of the defect vertebra is also increased. Such a high compression on the disk may cause disk degeneration which leads to spondylolisthesis.

Microfracture analysis of fault growth and wear processes, Punchbowl Fault, San Andreas system, California

Fabric and timing relations of mode I microfractures are used to test current hypotheses for the origin of damage along large-displacement faults by the processes of fault growth and wear. Oriented samples 0.075 m to 1 km from the Punchbowl fault surface (i.e. ultracataclasite layer) document an increase in development of preferred orientation and increase in density of microfractures towards the ultracataclasite layer, defining a zone of fault-related microfracture damage about 100 m thick. A distinct microfracture set that is perpendicular to the slip direction of the fault is present throughout the damage zone. This implies that the average orientation of the maximum principal compressive stress within the damage zone was nearly normal to the fault surface. Two additional microfracture sets are present, one oriented at low angles to the fault within meters of the ultracataclasite layer, and another low-angle set that occurs in the outermost damage zone. The preferred orientations and timing relations are most consistent with local damage accumulation from stress cycling associated with slip on a geometrically irregular, relatively weak fault surface. Low-angle microfractures nearest the ultracataclasite layer also may record wear associated with the passage of earthquake ruptures, and those in the outermost damage zone may be consistent with Andersonian fault formation and subsequent fault weakening.

Numerical simulations of deformation and dynamics of horizontally lying slabs

SUMMARY Recent results of seismic tomography have revealed that configurations of subducted slabs are varied; some lie horizontally on the boundary between the upper and the lower mantle, and others penetrate into the lower mantle. In this study, to understand the physical mechanism of deformation and dynamics of subducted slabs in the mantle, a 2-D numerical model was constructed. For this purpose, the slabs were treated so as to move freely in an incompressible fluid model by removing a guide right after its bending at a depth of 660 km and at a depth of 400 km in the upper mantle. Incorporating density and viscosity jumps and a Clapeyron slope for a γ → Pv + Mw phase transformation of olivine obtained from high-pressure and hightemperature experiments at a depth of 660 km into the model, we investigate temperature and velocity distributions, state of stress and viscosity distribution in relation to the formation of horizontally lying slabs at a depth of 660 km. When the slabs are treated to move freely just after their bending at the 660 km phase boundary, the slabs temporarily appear to lie horizontally on the phase boundary. However, the slabs penetrate the phase boundary and eventually sink into the lower mantle. The length of the horizontally lying portion of the slab becomes longer as descending velocity increases; the lengths are about 1500 km, 1200 km, and 800 km for subducting velocities of 8 cm yr −1 , 4 cm yr −1 ,a nd 2c m yr −1 , respectively. When a viscosity jump of 10 to 100 times the viscosity for the upper mantle is given at the 660 km phase boundary, the length of the horizontally lying portion of the slab becomes shorter because of friction between the slab and the underlying lower mantle. For all the models in which the guide was removed at a depth of 400 km, the slabs penetrate into the lower mantle without lying horizontally on the phase boundary. These results indicate that it is difficult for the slabs to bend at the γ → Pv + Mw phase boundary, and to form the configuration of the horizontally lying slabs even if the slabs descend with a small dip angle. The calculated maximum principal compressive stress axes are oriented horizontally within the horizontally lying portion of the slabs, which is inconsistent with seismologically observed vertical directions of the P-axes there. In order to explain the observed configurations and state of stress within the horizontally lying slabs, it would be necessary to investigate the effects of a complicated viscosity and composition structure in the mantle in more detail.

Conditions for compaction and shear bands in a transversely isotropic material

This paper derives conditions for localized deformation for a transversely isotropic constitutive relation intended to model the response of geological materials in the axisymmetric compression test. The analysis considers the possibility of shear bands, with dilation or compaction, and pure compaction bands. The latter are planar zones of localized pure compressive deformation (without shear) that form perpendicular to the direction of the maximum principal compressive stress. Compaction bands have been observed in porous rock in the field and in the laboratory. They are predicted to occur when the incremental tangent modulus for uniaxial deformation vanishes. The critical value of the tangent modulus E for constant lateral stress is −9 Kνr/2, where ν is the negative of the ratio of increments of lateral to axial deformation (at constant lateral stress), r is the ratio of axial to lateral stress increments causing zero axial deformation, and K is the modulus relating increments of lateral stress and deformation. The expression for the critical tangent modulus for shear band formation is more complex and depends, in addition to r, ν, and K, on the shear moduli G l and G t, governing increments of shear in planes parallel and perpendicular to the axis of symmetry, respectively. Uncertainty about material parameters prevents a detailed comparison with observations but the results are consistent with observations of low angle shear bands (with normals less than 45° from the symmetry axis) for compressive volumetric strain ( ν<1/2). In addition, the critical tangent modulus for such bands may be positive if G l and G t are small relative to K and r is around unity.

An approach to the present-day three-dimensional (3D) stress field and its application in hydrocarbon migration and accumulation in the Zhangqiang depression, Liaohe field, China

From the measurements of bore-hole breakout, hydrofracturing, and rock acoustic emission in the Zhangqiamg depression, Liaohe field, China, we have determined that the orientation of the maximum principal compressive stress is nearly east–west with a small angle of pitch (no more than 10°), and the regression equations of stress gradient with depth are σ 1=8.359+0.0142 H ( r=0.96) and σ 3=5.801+0.00437 H ( r=0.94). The present-day three-dimensional (3D) stress field of the Zhangqiang depression is approached using measured data and by 3D modeling. The approach shows that a full 3D crustal stress field analysis of an oil basin is consistent with the actual measurements. And then we use fluid potential or gradient to discuss the quantitative correlation between crustal stress and hydrocarbon migration and accumulation. The results show that low fluid potential areas surrounded by high regions are eligible for hydrocarbon accumulation and have been tested at the Keerkang oil field. The results also show that the distribution of favorable areas for hydrocarbon accumulation varies in different layers in space and is used in hydrocarbon exploration in the Zhangqiang depression. Therefore, the understanding of the 3D crustal stress field of a basin is essential for evaluating hydrocarbon migration and accumulation, and the technology and methodology developed here can be applied to other petroliferous basins.