Kaituo Jiao¹, Dongxu Han^2,*, Bo Yu²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.4, pp. 1-5, 2023, DOI:10.32604/icces.2023.09168

Abstract Acid fracturing is critical to improving the connectivity inside underground reservoirs, which involves a complex thermal-hydro-mechanical-chemical (THMC) coupling process, especially deep underground. Heat conduction anisotropy is one of the intrinsic properties of rock. It determines the heat response distribution inside the rock and alters the temperature evolution on the reactive surface of fractures and pores. In another way, the rock dissolution rate is closely related to the reactive surface temperature. Predictably, heat conduction anisotropy leads to different rock dissolution morphologies from that of the heat conduction isotropy situation, then the cracks distribution and permeability of… More >

Decheng Li¹, Yan Zhang², Dongdong Ma², Haozhe Geng¹, Yu Wu^1,2,*

Energy Engineering, Vol.120, No.11, pp. 2503-2516, 2023, DOI:10.32604/ee.2023.041803 - 31 October 2023

Abstract The fracturing process of sandstone is inherently complex due to its loose internal structure and deformation adaptability. Liquid nitrogen pre-injection has emerged as a promising approach to damage reservoir rocks, effectively reducing fracture pressure and establishing intricate fracture networks, thus offering a potential solution for reservoir reconstruction. To unravel the fundamental mechanisms governing sandstone fracturing behaviors following liquid nitrogen pre-injection, sandstone fracturing experiments were conducted under varying durations of liquid nitrogen injection, rock temperature, and in-situ stress conditions. The experiments showcased the evolution of injection pressure and fracture characteristics under different testing conditions, complemented by… More >

Daobing Wang^1,*, Cheng Zheng¹, Bo Yu¹, Dongliang Sun¹, Dingwei Weng², Chunming He², Meng Wang²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.4, pp. 1-2, 2023, DOI:10.32604/icces.2023.09205

Abstract Refracturing has become an important technique for increasing hydrocarbon production due to the low oil prices. During refracturing, the granular diverter materials are injected to temporarily seal old fractures in subsurface. These diverter materials are usually carried by the fracturing fluid, which is a typical solid-fluid flow in the fracture [1-3]. Therefore, we need to thoroughly understand the flow mechanism of diverter materials in hydraulic fractures, which is the key to the success of refracturing treatment.
Using the Euler-Lagrange method, this paper presents a multiphase model to numerically simulate the flow process of diverter materials in… More >

Xiaojun Zhang¹, Jun Li^1,2,*, Wei Lian², Gonghui Liu¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.1, pp. 1-1, 2023, DOI:10.32604/icces.2023.010343

Abstract In recent years, shale gas development in Fengnan 4 well area of Xinjiang Oilfield is dominated by platform wells. In contrast to conventional fracturing development, the zipper fracturing is primarily used in this block. In this paper, the finite element model of platform well fracturing is established by establishing the mathematical model of multi-cluster fractures interacting with each other, considering the condition of multi-well and multi-fracture. The sequential fracturing of platform wells and the zipper fracturing (well alternating fracturing, fracturing stage alternating fracturing) are simulated in this paper, and the variation law of induced stress… More >

Zhiyuan Yao^1,2,3, Jing Sun^1,2,3,*, Dehua Liu^1,2,3

Energy Engineering, Vol.120, No.8, pp. 1853-1866, 2023, DOI:10.32604/ee.2023.025846 - 05 June 2023

Abstract Shale gas reservoirs have poor physical properties and a large number of micro-nano pores have been developed. Shale gas wells have no natural productivity and need fracturing reconstruction measures to put into production. However, the fracturing fluid will enter the reservoir space of shale matrix after fracturing and affect the production of shale gas. At present, there is no consensus on the influence of fracturing fluid retention on gas well production. Based on this, the paper adopts gas molecular transport analyzer to carry out experimental research on the influence of fracturing fluid on shale gas… 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 - 29 August 2022

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… More > Graphic Abstract

Lingyun Zhao^1,2, Heng Yang^3,4,*, Yuanlong Wei^1,2,*, Yuhuan Bu^3,4, Shaorui Jing^3,4, Peiming Zhou^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.2, pp. 329-344, 2023, DOI:10.32604/fdmp.2022.020216 - 29 August 2022

Abstract Perforation and fracturing are typically associated with the development of coalbed methane wells. As the cement sheath is prone to failure during this process, in this work, the effects of the casing pressure, elastic modulus of the cement, elastic modulus of the formation, and casing eccentricity on the resulting stresses are analyzed in the frame of a finite element method. Subsequently, sensitivity response curves of the cement sheath stress are plotted by normalizing all factors. The results show that the maximum circumferential stress and Mises stress of the cement sheath increase with the casing internal More > Graphic Abstract

Qixing Zhang^1,2, Bing Hou^1,2,*, Huiwen Pang^1,2, Shan Liu^1,2, Yue Zeng^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.133, No.3, pp. 471-507, 2022, DOI:10.32604/cmes.2022.020831 - 03 August 2022

Abstract China began to build its national shale gas demonstration area in 2012. The central exploration, drilling, and development technologies for medium and shallow marine shale reservoirs with less than 3,500 m of buried depth in Changning-Weiyuan, Zhaotong, and other regions had matured. In this study, we macroscopically investigated the development history of shale gas in the United States and China and compared the physical and mechanical conditions of deep and shallow reservoirs. The comparative results revealed that the main reasons for the order-ofmagnitude difference between China’s annual shale gas output and the United States could… More >

Zhenfeng Zhao¹, Bin Li¹, Zubo Su¹, Lijing Chang¹, Hongzheng Zhu¹, Ming Liu¹, Jialing Ma^2,*, Fan Wang¹, Qianwan Li¹

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.6, pp. 1781-1794, 2022, DOI:10.32604/fdmp.2022.019998 - 27 June 2022

Abstract Often oilfield fractured horizontal wells produce water flowing in multiple directions. In this study, a method to identify such channeling paths is developed. The dual-medium model is based on the principle of inter-well connectivity and considers the flow characteristics and related channeling terms. The Lorentz curve is drawn to qualitatively discern the geological type of the low-permeability fractured reservoir and determine the channeling direction and size. The practical application of such an approach to a sample oilfield shows that it can accurately identify the channeling paths of the considered low-permeability fractured reservoir and predict production More >

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 - 19 April 2021

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… More >