Diguang Gong¹, Junbin Chen¹, Cheng Cheng², Yuanyuan Kou^2,*

Energy Engineering, Vol.121, No.2, pp. 425-437, 2024, DOI:10.32604/ee.2023.030196

Abstract Horizontal well-stimulation is the key to unconventional resource exploration and development. The development mode of the well plant helps increase the stimulated reservoir volume. Nevertheless, fracture interference between wells reduces the fracturing effect. Here, a 2D hydro-mechanical coupling model describing hydraulic fracture (HF) propagation is established with the extended finite element method, and the effects of several factors on HF propagation during multiple wells fracturing are analyzed. The results show that with an increase in elastic modulus, horizontal principal stress difference and injection fluid displacement, the total fracture area and the reservoir stimulation efficiency are both improved in all three… More >

Huaiyin He¹, Longqing Zou¹, Yanchao Li¹, Yixuan Wang¹, Junxiang Li¹, Huan Wen¹, Bei Chang¹, Lijun Liu^2,*

Energy Engineering, Vol.121, No.1, pp. 111-123, 2024, DOI:10.32604/ee.2023.041010

Abstract Multistage multi-cluster hydraulic fracturing has enabled the economic exploitation of shale reservoirs, but the interpretation of hydraulic fracture parameters is challenging. The pressure signals after pump shutdown are influenced by hydraulic fractures, which can reflect the geometric features of hydraulic fracture. The shutdown pressure can be used to interpret the hydraulic fracture parameters in a real-time and cost-effective manner. In this paper, a mathematical model for shutdown pressure evolution is developed considering the effects of wellbore friction, perforation friction and fluid loss in fractures. An efficient numerical simulation method is established by using the method of characteristics. Based on this… More >

Yu Gao¹, Zhenqiang Xu^2,3,*, Kaixiang Shen^2,3,*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.1, pp. 179-192, 2024, DOI:10.32604/fdmp.2023.030499

Abstract Hydraulic jetting is a form of fracturing that involves using a high-pressure jet of water to create fractures in the reservoir rock with a nozzle serving as the central component of the hydraulic sandblasting perforation tool. In this study, the flow behavior of the nozzle is simulated numerically in the framework of a SST k-ω turbulence model. The results show that the nozzle structure can significantly influence the jet performance and related cavitation effect. Through orthogonal experiments, the nozzle geometric parameters are optimized, and the following configuration is found accordingly: contraction angle 20°, contraction segment length 6 mm, cylindrical segment… More >

Sergey Galkin^1,*, Ian Savitckii¹, Denis Shustov¹, Artyom Kukhtinskii¹, Boris Osovetsky², Alexander Votinov³

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.2, pp. 273-284, 2023, DOI:10.32604/fdmp.2022.021697

Abstract Survey and novel research data are used in the present study to classify/identify the lithological type of Verey age reservoirs’ rocks. It is shown how the use of X-ray tomography can clarify the degree of heterogeneity, porosity and permeability of these rocks. These data are then used to elaborate a model of hydraulic fracturing. The resulting software can take into account the properties of proppant and breakdown fluid, thermal reservoir conditions, oil properties, well design data and even the filtration and elastic-mechanical properties of the rocks. Calculations of hydraulic fracturing crack formation are carried out and the results are compared… More > Graphic Abstract

Fang Shi^1,*, Daobing Wang², Xiaogang Chen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.2, pp. 575-598, 2021, DOI:10.32604/cmes.2021.015384

Abstract Field data suggests that carbonate reservoirs contain abundant natural fractures and cavities. The propagation mechanisms of hydraulic fractures in fracture-cavity reservoirs are different from conventional reservoirs on account of the stress concentration surrounding cavities. In this paper, we develop a fully coupled numerical model using the extended finite element method (XFEM) to investigate the behaviors and propagation mechanisms of hydraulic fractures in fracture-cavity reservoirs. Simulation results show that a higher lateral stress coefficient can enhance the influence of the natural cavity, causing a more curved fracture path. However, lower confining stress or smaller in-situ stress difference can reduce this influence,… More >

Daobing Wang¹, Fang Shi^2,*, Hao Qin^1,*, Dongliang Sun¹, Bo Yu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.3, pp. 891-914, 2021, DOI:10.32604/cmes.2021.014206

Abstract In this study, we use the extended finite element method (XFEM) with a consideration of junction enrichment functions to investigate the mechanics of hydraulic fractures related to naturally cemented fractures. In the proposed numerical model, the lubrication equation is adopted to describe the fluid flow within fractures. The fluid-solid coupling systems of the hydraulic fracturing problem are solved using the Newton-Raphson method. The energy release rate criterion is used to determine the cross/arrest behavior between a hydraulic fracture (HF) and a cemented natural fracture (NF). The failure patterns and mechanisms of crack propagation at the intersection of natural fractures are… More >

Yatin Suri¹, Sheikh Zahidul Islam^{1, *}, Mamdud Hossain¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.2, pp. 297-337, 2020, DOI:10.32604/fdmp.2020.08421

Abstract The distribution of proppant injected in hydraulic fractures significantly affects the fracture conductivity and well performance. The proppant transport in thin fracturing fluid used during hydraulic fracturing in the unconventional reservoirs is considerably different from fracturing fluids in the conventional reservoir due to the very low viscosity and quick deposition of the proppants. This paper presents the development of a threedimensional Computational Fluid Dynamics (CFD) modelling technique for the prediction of proppant-fluid multiphase flow in hydraulic fractures. The proposed model also simulates the fluid leak-off behaviour from the fracture wall. The Euler-Granular and CFD-Discrete Element Method (CFD-DEM) multiphase modelling approach… More >

Daobing Wang^{1, *}, Sergio Zlotnik^{2, *}, Pedro Díez², Hongkui Ge³, Fujian Zhou³, Bo Yu⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.2, pp. 703-720, 2020, DOI:10.32604/cmes.2020.08033

Abstract The hydraulic fracturing is a nonlinear, fluid-solid coupling and transient problem, in most cases it is always time-consuming to simulate this process numerically. In recent years, although many numerical methods were proposed to settle this problem, most of them still require a large amount of computer resources. Thus it is a high demand to develop more effificient numerical approaches to achieve the real-time monitoring of the fracture geometry during the hydraulic fracturing treatment. In this study, a reduced order modeling technique namely Proper Generalized Decomposition (PGD), is applied to accelerate the simulations of the transient, non-linear coupled system of hydraulic… More >

Duyen Le Hien Nguyen¹, Dieu Thi Thanh Do², Jaehong Lee², Timon Rabczuk³, Hung Nguyen-Xuan^1,4,*

CMC-Computers, Materials & Continua, Vol.61, No.3, pp. 951-977, 2019, DOI:10.32604/cmc.2019.08001

Abstract We in this paper exploit time series algorithm based deep learning in forecasting damage mechanics problems. The methodologies that are able to work accurately for less computational and resolving attempts are a significant demand nowadays. Relied on learning an amount of information from given data, the long short-term memory (LSTM) method and multi-layer neural networks (MNN) method are applied to predict solutions. Numerical examples are implemented for predicting fracture growth rates of L-shape concrete specimen under load ratio, single-edge-notched beam forced by 4-point shear and hydraulic fracturing in permeable porous media problems such as storage-toughness fracture regime and fracture-height growth… More >

Daobing Wang^1,2, Bo Yu^1,*, Dongliang Sun¹, Dongxu Han¹, Jingfa Li¹, Hao Qin¹, Peng Wang¹, Xufei Yang¹, Yajun Deng¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.3, pp. 147-148, 2019, DOI:10.32604/icces.2019.04786

Abstract Hot dry rock (HDR), which is usually buried depth in 3-10 km, contains abundant heat energy for heating the house and making the electricity. Hydraulic fracturing is an effective technology to develop the geothermal resources. In hydraulic fracturing, a large amount of cold water is injected to generate the artificial fractures in subsurface. However, in previous studies, the study on the mechanical properties of HDR under the combined action of triaxial stress and pore pressure is still in its infancy and an exhaustive investigation is lacking. In this study, we experimentally investigated the heat-treated HDR samples with the integrated consideration… More >