Incipient motion behavior of the settled particles in supercritical CO2

Hou, Lei; Bian, Xiaobing; Geng, Xueyu; Sun, Baojiang; Liu, Honglei; Jia, Wei

doi:10.1016/j.jngse.2019.102900

Cited by 11 publications

(5 citation statements)

References 20 publications

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“…Additionally, the slippage between the particles and the carrying CO 2 can be eliminated by increasing the flow rate of the slurry (Hou et al, 2017b). Restarting the movement of particles in CO 2 is even easier than in water due to the absence of interfacial tension and the generation of additional Magnus force through high-speed spinning, facilitating the restarting process (Hou et al, 2019).…”

Section: Frontiers In Energy Researchmentioning

confidence: 99%

“…Firstly, the proppant usually settles down rapidly in low-viscosity fluids (CO 2 and slickwater). The horizontal transport distance of the proppant before its settlement reduces under a low pump rate condition due to the lower horizontal dragging force (Hou et al, 2017b;Hou et al, 2019). This significantly constrains the proppant transport capability of supercritical CO 2 , and then the scale of proppant injection in fields (Table 3).…”

Section: Gap Between Theory and Practicementioning

confidence: 99%

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Promotion of CO2 fracturing for CCUS—the technical gap between theory and practice

Hou,

Luo,

Gong

et al. 2024

Front. Energy Res.

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CO2, used as an environmentally friendly fracturing fluid, has encountered a bottleneck in development in recent years. Despite great efforts in research work, limited progress has been made in field applications. In this study, an extensive literature review of research work and field cases was performed to summarize the technical issues and challenges of CO2 fracturing. The key issues of CO2 fracturing were analyzed to reveal the gap between fundamental research and field operations. The effects of CO2 properties on fracture creation and proppant transport were synthetically analyzed to extract new common research orientations, with the aim of improving the efficiency of CO2 injection. The hydraulic parameters of CO2 fracturing were compared with those of water-based fracturing fluids, which revealed a theory-practice gap. By studying the developing trends and successful experiences of conventional fluids, new strategies for CO2 fracturing were proposed. We identified that the major theory-practice gap in CO2 fracturing exists in pump rate and operation scale. Consequently, the friction reducer, effects of flow loss (due to leak-off) and distribution (within fracture networks), and shear viscosity of thickened CO2 are key factors in improving both fracture propagation and proppant transport. By increasing the scale of injected CO2, the CO2 fracturing technique can be enhanced, making it an essential option for carbon capture, utilization, and storage (CCUS) to reduce carbon emissions and mitigate climate change.

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Section: Frontiers In Energy Researchmentioning

confidence: 99%

Section: Gap Between Theory and Practicementioning

confidence: 99%

Promotion of CO2 fracturing for CCUS—the technical gap between theory and practice

Hou,

Luo,

Gong

et al. 2024

Front. Energy Res.

Self Cite

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“…1 a) and fracture level (Fig. 1 b), including the particle settling velocity (Gadde et al, 2004;Mack et al, 2014;McCabe et al, 1993;Richardson and Zaki, 1954;Yew and Weng, 2014), the critical velocity to restart the settled proppant (also used as the critical turning velocity in complex fractures) (Cao et al, 2006;Hou, Jiang, Li, Zeng andCheng, 2017a, 2017b;Hou, Jiang, Liu, et al, 2017a, 2017bRakshit Sahai, Miskimins, & Olson, 2014), the flowing layer height (H 1 ) (Hou et al, 2019a(Hou et al, , 2019bNovotny, 1977;Patankar et al, 2002;Jing Wang, Joseph, Patankar, Conway and Barree, 2003) and the equilibrium dune level (EDLthe dune height divided by fracture height) (Alotaibi and Miskimins, 2019). Based on the field pumping schedules, those features are further calculated by employing the Velocity, Settling, Bi-power, and EDL models to yield a group of independent variables, which is one of the inputs for ML models (Table 2).…”

Section: Features For Proppant Transportmentioning

confidence: 99%

“…The particle movements could reflect the proppant transporting by evaluating the ratio between particle and fluid velocities (Hou, Jiang, Li, et al, 2017a, 2017b. The Velocity model is defined as { The proppant is tending to form an equilibrium dune in low-viscosity fluids under constant injection conditions (Hou et al, 2019a(Hou et al, , 2019b, as shown in Fig. 1 (b).…”

Section: Appendix B Summary Of Feature Calculations 1 Velocity Modelmentioning

confidence: 99%

Evaluating essential features of proppant transport at engineering scales combining field measurements with machine learning algorithms

Hou¹,

Wang²,

Geng³

2022

Preprint

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The behaviours of the particle settlement, stratified flow and inception of settled particles are essential features that determine the proppant transport in low-viscosity fracturing fluids. Although great efforts have been made to characterize these features, limited research work is performed at field scales. To test the laboratory outcomes, we propose a machine-learning-based workflow to evaluate the essential features using the measurements obtained from shale gas fracturing wells. Over 430,000 groups of fracturing data (1 s time interval) are collected and pre-processed to extract the particle settlement, stratified flow and inception features during fracturing operations. The GRU and SVM algorithms, trained by these features, are applied to predict fracturing pressure. Error analysis (the root mean squared error, RMSE) is carried out to compare the contributions of different features to the pressure prediction, based on which the features and the corresponding calculations are evaluated. Our result shows that the stratified-flow feature (fracture-level) possesses better interpretations for the proppant transport, in which the Bi-power model helps to produce the best predictions. The settlement and inception features (particle-level) perform better in cases where the pressure fluctuates significantly. The features characterize the state of proppant transport, based on which the development of subsurface fracture is also analyzed. Moreover, our analyses of the remaining errors in the pressure-ascending cases suggest that (1) an introduction of the alternate-injection process, and (2) the improved calculation of proppant transport in highlyfilled fractures will be beneficial to both experimental observations and field applications.

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“…acting on the particle (Hou et al 2015, Liangchuan, Zaiming andZhengsong 2011). (II) The enhanced driving force (Magnus force generated by particle spin) and reduced resistance force (non-cohesive-force due to the non-interfacial-tension characteristic) results in easier restarting of the particles in Sc-CO 2 with an averaged Shields number of 0.0028 (Table 2)identifying a reduced drag force required to drive particle restarting in Sc-CO 2 (Hou et al 2019). (III) The measured particle velocity in the flowing direction reaches ~90% of the averaged fluid flow velocity under high flow-rate condition, demonstrating the high particle transport capability of Sc-CO 2 (Hou et al 2016, Hou et al 2017b).…”

Section: Particle Movements In Sc-co 2 Fracturingmentioning

confidence: 99%

Review of fundamental studies of CO2 fracturing: Fracture propagation, propping and permeating

Hou

Sheng

Elsworth

et al. 2021

Journal of Petroleum Science and Engineering

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This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

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Incipient motion behavior of the settled particles in supercritical CO2

Abstract: Please refer to published version for the most recent bibliographic citation information. If a published version is known of, the repository item page linked to above, will contain details on accessing it.

Cited by 11 publications

References 20 publications

Promotion of CO2 fracturing for CCUS—the technical gap between theory and practice

Promotion of CO2 fracturing for CCUS—the technical gap between theory and practice

Evaluating essential features of proppant transport at engineering scales combining field measurements with machine learning algorithms

Review of fundamental studies of CO2 fracturing: Fracture propagation, propping and permeating

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