Jianchao Shi^1,2, Yanan Zhang³, Wantao Liu^1,2, Yuliang Su^3,*, Jian Shi^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.5, pp. 1147-1163, 2024, DOI:10.32604/fdmp.2023.044500

Abstract Class III tight oil reservoirs have low porosity and permeability, which are often responsible for low production rates and limited recovery. Extensive repeated fracturing is a well-known technique to fix some of these issues. With such methods, existing fractures are refractured, and/or new fractures are created to facilitate communication with natural fractures. This study explored how different refracturing methods affect horizontal well fracture networks, with a special focus on morphology and related fluid flow changes. In particular, the study relied on the unconventional fracture model (UFM). The evolution of fracture morphology and flow field after More >

Fang Li^1,*, Juan Wu¹, Haiyong Yi², Lihong Wu², Lingyun Du¹, Yuan Zeng¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.5, pp. 1015-1030, 2024, DOI:10.32604/fdmp.2023.043256

Abstract Methods for horizontal well spacing calculation in tight gas reservoirs are still adversely affected by the complexity of related control factors, such as strong reservoir heterogeneity and seepage mechanisms. In this study, the stress sensitivity and threshold pressure gradient of various types of reservoirs are quantitatively evaluated through reservoir seepage experiments. On the basis of these experiments, a numerical simulation model (based on the special seepage mechanism) and an inverse dynamic reserve algorithm (with different equivalent drainage areas) were developed. The well spacing ranges of Classes I, II, and III wells in the Q gas More > Graphic Abstract

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 More >

Xin Ai^1,2,*, Mian Chen¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.3, pp. 661-670, 2024, DOI:10.32604/fdmp.2023.026819

Abstract

The efficient development and exploitation of shale oil depends on long-distance horizontal wells. As the degree of cleaning of the wellbore plays a key role in these processes, in this study, this problem is investigated experimentally by focusing on the dimensionless cuttings bed height. A method is proposed to calculate the horizontal-well hydraulic extension taking into account the influence of the wellbore cleaning degree on the wellbore pressure distribution and assess the effect of a variety of factors such as the bottom hole pressure, the circulating pressure drop, the drilling pump performance and the formation

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Xinyu Zhao^1,2,*, Mofeng Li², Kai Yan², Li Yin³

Energy Engineering, Vol.120, No.12, pp. 2933-2949, 2023, DOI:10.32604/ee.2023.041580

Abstract This study presents an avant-garde approach for predicting and optimizing production in tight reservoirs, employing a dual-medium unsteady seepage model specifically fashioned for volumetrically fractured horizontal wells. Traditional models often fail to fully capture the complex dynamics associated with these unconventional reservoirs. In a significant departure from these models, our approach incorporates an initiation pressure gradient and a discrete fracture seepage network, providing a more realistic representation of the seepage process. The model also integrates an enhanced fluid-solid interaction, which allows for a more comprehensive understanding of the fluid-structure interactions in the reservoir. This is… More >

Linjuan Zeng¹, Daogang Cai¹, Yunhai Zhao^1,*, Changqing Ye¹, Chengcheng Luo²

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.11, pp. 2813-2825, 2023, DOI:10.32604/fdmp.2023.026190

Abstract The flow behavior of shale gas horizontal wells is relatively complex, and this should be regarded as the main reason for which conventional pipe flow models are not suitable to describe the related dynamics. In this study, numerical simulations have been conducted to determine the gas-liquid distribution in these wells. In particular, using the measured flow pressure data related to 97 groups of shale gas wells as a basis, 9 distinct pipe flow models have been assessed, and the models displaying a high calculation accuracy for different water-gas ratio (WGR) ranges have been identified. The More >

Yudong Tian^1,2, Gonghui Liu¹, Yue Qi^1,2,*, Jun Li^1,3, Yan Xi^1,4, Wei Lian^1,3, Xiaojie Bai², Penglin Liu¹, Xiaoguang Geng²

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.11, pp. 2837-2845, 2023, DOI:10.32604/fdmp.2023.028805

Abstract Organic rich dark shale of Q Formation can be found in many areas (e.g., in the North of S Basin). The shale target stratum is easy to hydrate and often undergoes spallation. Therefore, centering the casing in the horizontal section of the irregular borehole is relatively difficult. Similarly, achieving a good cement flushing efficiency under complex borehole conditions is a complex task. Through technologies such as centralizer, efficient preflushing, multi-stage flushing and ductile cement slurry, better performances can be achieved. In this study, it is shown that the cementing rate in the DY2H horizontal section More >

Zhen Zhong^*, Yadong Li, Yuxuan Zhao, Pengfei Ju

Sound & Vibration, Vol.57, pp. 15-27, 2023, DOI:10.32604/sv.2023.041954

Abstract Bent-housing motor is the most widely used directional drilling tool, but it often encounters the problem of high friction when sliding drilling in horizontal wells. In this paper, a mathematical model is proposed to simulate slide drilling with a friction reduction tool of axial vibration. A term called dynamic effective tractoring force (DETF) is defined and used to evaluate friction reduction effectiveness. The factors influencing the DETF are studied, and the tool placement optimization problem is investigated. The study finds that the drilling rate of penetration (ROP) can lower the DETF but does not change… More >

Bin Li^*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.10, pp. 2729-2748, 2023, DOI:10.32604/fdmp.2023.029649

Abstract In order to overcome the deficiencies of current methods for the prediction of the productivity of shale gas horizontal wells after fracturing, a new sophisticated approach is proposed in this study. This new model stems from the combination several techniques, namely, artificial neural network (ANN), particle swarm optimization (PSO), Imperialist Competitive Algorithms (ICA), and Ant Clony Optimization (ACO). These are properly implemented by using the geological and engineering parameters collected from 317 wells. The results show that the optimum PSO-ANN model has a high accuracy, obtaining a R² of 0.847 on the testing. The partial dependence More >

Hongsha Xiao¹, Ruihan Zhang^2,*, Man Chen¹, Cui Jing¹, Shangjun Gao¹, Chao Chen¹, Huiyan Zhao¹, Xin Huang^2,*, Bo Kang³

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.7, pp. 1803-1815, 2023, DOI:10.32604/fdmp.2023.026143

Abstract The production performances of a well with a shale gas reservoir displaying a complex fracture network are simulated. In particular, a micro-seismic cloud diagram is used to describe the fracture network, and accordingly, a production model is introduced based on a multi-scale flow mechanism. A finite volume method is then exploited for the integration of the model equations. The effects of apparent permeability, conductivity, Langmuir volume, and bottom hole pressure on gas well production are studied accordingly. The simulation results show that ignoring the micro-scale flow mechanism of the shale gas leads to underestimating the More > Graphic Abstract