This paper studied the fracability of tight sandstone reservoirs by means of incorporating geomechanics properties and surrounding in situ stresses into a new model. The new fracability evaluation model consists of variables such as brittleness index...
The diagnostic fracture injection test (DFIT) is widely used to obtain the fracture closure pressure, reservoir permeability, and reservoir pressure. Conventional methods for analyzing DFIT are based on the assumption that a vertical well is drilled...
Hydraulic fracturing was the primary technology for shale oil and gas development. Creating a huge stimulated reservoir volume was essential to improving shale oil and gas production. Based on the CDEM, a 3D hydraulic fracturing numerical model was p...
Wellbore instability is a critical challenge in deep coalbed methane (CBM) development, especially for extended-reach horizontal wells subjected to pronounced horizontal in situ stress anisotropy. This study integrates uniaxial and triaxial laborator...
As the depth of coal mining increases, rockbursts become more severe, and multiple rockburst accidents have previously occurred, seriously affecting coal mine production safety. With the Hegang mining area as the research object and using field measu...
To investigate the characteristics of the in-situ stress field in the lower rock mass of underground gas storage caverns at the Zhumadian compressed air energy storage (CAES) power station, and to predict the risk level of rockburst in the caverns fo...
The distribution law of the ground stress field is of great significance in guiding the design of coal mine roadway alignment, determining the parameters of roadway support, and preventing and controlling the impact of ground pressure in coal mines....
Compared with conventional gas reservoirs, deep shale gas reservoirs are characterized by developed faults and fractures, strong heterogeneity, high stress sensitivity, and complex in situ stress distribution. To address traditional 3D static models&...
Minimum principal stress is a key factor governing the hydraulic fracturing behaviors in shale oil reservoirs. Due to the existence of stress heterogeneity, the hydraulic fracture growth and footprints can be affected, and the hydraulic fracturing ef...
Hydraulic fracture height growth in thin sandstone–mudstone interbeds is often limited by bedding interface failure and multi-cluster stress interference. In this study, a coupled fracture–matrix interface finite element model was develop...
In the study of borehole instability, the majority of input parameters often rely on the average values that are treated as fixed values. However, in practical engineering scenarios, these input parameters are often accompanied by a high degree of un...
Multi-stage, multi-cluster fracturing in horizontal wells is widely used as one of the most effective methods for unconventional reservoir transformation. This study is based on the extended finite element method and establishes a multi-hydraulic fra...
Mature thin oil reservoirs remain pivotal to maintaining reserves, sustaining production, and enhancing profitability due to their substantial annual output and untapped recovery potential. However, prolonged development leads to compromised fracturi...
Accurately predicting the breakdown pressure in horizontal sections is essential when designing and optimizing fracturing jobs for horizontal wells in tight gas reservoirs. Taking the Sulige block in the Ordos Basin as an example, for different compl...
Wellbore instability is one of the main problems of the oil industry, causing high costs in the drilling operation. Knowing about the mechanical properties of involved formations and in-situ stresses is a privilege gained by determining an appropriat...
Conventional drilling fluid density design based on the onset of yielding may not adequately balance wellbore stability against the available mud-weight window in deepwater sandstone–mudstone interbeds, where collapse and lost-circulation risks...
Wellbore instability remains a critical challenge over the entire service life of oil and gas wells, especially in deep carbonate reservoirs. This study integrates triaxial rock mechanics experiments and acoustic emission (AE) Kaiser effect tests to...
In karstic-fractured carbonate reservoirs, most of the oil resources are hosted in vugs. Connecting as many vugs as possible by hydraulic fracturing is the key to achieving effective development. However, the interaction mechanism between vugs and hy...
To address the limitations of traditional methods in modeling complex nonlinear relationships in horizontal in situ stress prediction for shale reservoirs, this study proposes an integrated framework that combines well logging interpretation with mac...
This study evaluated the effects of misfit type, magnitude, and location on the stress distribution in full-arch screw-retained implant frameworks. A maxillary finite element model with four implants was analyzed under 16 scenarios, characterized by...
Salt formations are commonly encountered during oil and gas drilling. Due to the rheological properties of salt rocks, casing collapse accidents happen frequently. Under action of nonuniform geostress, casing failure has become an important influenci...
The formation of a rich underground-seam network is the key problem in the development of low-permeability hot dry rock (HDR) resources. Considering the lack of macroscopic continuum theory to study hydraulic fracturing having preset fracture-interfa...
In this study, the static response of the preliminary pilot tunnels excavation to the ground, and the dynamic response of the group cavern system under seismic excitation under the use of the construction of a metro station based on the Pile-Beam-Arc...
An improved depleting sand fracture model was derived in this work using Finite Element Methods, taking into consideration the effect of pore pressure and production on in situ stresses. Sets of governing equations from the commercial finite element...
Deep Earth TK-1, China’s first 10,000 m scientific exploration well, encountered severe wellbore instability during sidetracking at a depth of approximately 9500 m under ultra-deep, high-stress conditions (maximum horizontal stress
In-situ stress estimation plays an important role on the success of an underground project. However, no method is error-free, and therefore a combination of methods is desirable. In this study, the in-situ stresses for a geothermal project have been...
In order to explore the distribution law of stress field under the mining mode of gob-side entry retaining by roof cutting without pillar (GERRCP) under goaf, based on the engineering background of 8102 and 9101 working faces in Xiashanmao coal mine,...
We investigated the relationship between stratigraphy, stress, and microseismicity at the Hydraulic Fracture Test Site-1. The site comprises two sets of horizontal wells in the Wolfcamp shale and a deviated well drilled after hydraulic fracturing. Re...
Based on the basic principle of thermodynamics, an elastoplastic damage constitutive model of concrete is constructed in this paper. The model is realized and verified in FLAC3D, which provides a solid foundation for the study of dynamic response and...
The G-function can obtain the formation ground stress information by identifying the fracture closure point after fracturing, but the main fracture closure period of the deep coal seam volume fracture network is long, and the on-site pump stop time i...
The characteristics and influencing factors of gas production in CBM wells are analyzed based on the field geological data and the productivity data of coalbed methane (CBM) wells in the Zhengbei block, and then the favorable areas are divided. The r...
Chongqing is a mountain city in western China with a complex geological environment, which brings many difficulties to the construction of large sections of underground projects. In order to avoid serious problems in the construction of Guobo Station...
The argillaceous surrounding rock of a horsehead roadway under high stress conditions is prone to deformation and failure, and the control of its long-term stability is difficult. Based on the engineering practices that control the argillaceous surro...
In the process of roadway excavation in thick and hard coal seams with a hard roof, the instantaneous release of a large amount of elastic energy accumulated in coal and rock mass causes disasters. Especially under the action of tectonic stress, dyna...
With the increase in mining depth, the risk of ground pressure disasters in yellow gold mines is becoming more and more serious. This paper carries out a borehole test for the pressure behavior in a non-coal mining area with a mining depth of more th...
To clarify the controlling effects of the well deviation angle and azimuth angle on the breakdown pressure, propagation morphology, and fracture-network complexity of hydraulic fractures in tight sandstone, true triaxial hydraulic fracturing physical...
Borehole instability problems are commonly encountered while drilling highly deviated and horizontal shale gas wells within the shale formations associated with high-dip bedding planes. An integrated rock mechanical study is described in this paper t...
This paper presents an integrated approach for mathematical statistics, theoretical analysis, and a field test to investigate the distribution law of in-situ stress and its engineering practice of rock burst control. The test site is located in the J...
Coal is inherently soft, characterized by well-developed cleat systems, low strength, and significant anisotropy. Existing models that treat coal as a continuous medium or consider only a single plane of weakness fail to capture the synergistic effec...
During drilling operations, drilling fluids undergo heat exchange with hydrate-bearing formations. The intrusion of drilling fluids affects hydrate stability, leading to variations in stress fields around a wellbore and complex scenarios such as bore...
This study presents an analytical model for estimating minimum horizontal stress in hydraulic fracturing stimulations. The conventional Diagnostic Fracture Injection Test (DFIT) is not practical in ultra-tight formations, leading to the need for pump...
This study focuses on the complex stress distribution in coal seams influenced by normal fault using the fault development zone of the LF-M1 oilfield in southern China as a case study. Based on 3D seismic and drilling data, a key research area was de...
In depleted offshore reservoirs, pore pressure declines and consequently horizontal in-situ stresses decrease as well. This causes a very limited well depth for extended-reach drilling targeting to offshore depleted reservoirs. In this paper, based o...
The fault fracture body, consisting of faults, fracture zones, cracks, and the matrix, plays a crucial role in controlling oil and gas accumulation. Understanding its spatial distribution and analyzing the in situ stress field are essential for optim...
Drilling is a key step in the exploitation of deep oil and gas resources. In order to clarify the stress state of the rocks and the mechanism of rock breakage in deep-well drilling, a thermal-hydro-mechanical coupling model for deep-well drilling was...
This study addresses the challenge of low working gas ratios in China’s underground gas storage (UGS) facilities by optimizing geomechanical evaluations to enable safe pressure increases and capacity expansion. Through mini-fracturing tests con...
Coal reservoirs exhibit strong heterogeneity and complex in situ stress conditions, and the initiation and propagation of hydraulic fractures are jointly controlled by reservoir geology and perforation design. A damage–seepage coupled numerical...
In the ocean, internal solitary waves (ISW) pose a serious threat to the safety of marine engineering structures such as floating production storage and offloading (FPSO) units and steel catenary risers (SCRs). In this work, a calculation method for...
Blasting is a prevalent technique in deep rock excavation, with the state of rock fragmentation under high in-situ stress conditions being distinct from that under low in-situ stress conditions. A new material point method framework utilizing the gen...
Permeability is the key factor controlling coalbed methane (CBM) production, and hydraulic fracturing is an essential technique for permeability enhancement in low-permeability coal reservoirs. In situ stress plays a dominant role in both coal reserv...
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