Experimental evaluation of near wellbore stimulation – using electrical explosion shockwave on tight sand reservoir

He, Jianhua; Zhang, Rusheng; Zhang, Jingchen; Mei-juan, Liu; Osuji, Nicholas Izuchukwu

doi:10.2516/ogst/2018050

Cited by 6 publications

(1 citation statement)

References 33 publications

(30 reference statements)

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“…17 He et al carried out experiments to study the propagation of the explosion shock wave and the effective range of changes in permeability of the tight sand core samples caused by electrical explosion. 18 Maurel et al researched the facture characteristic of tight reservoirs and the permeability change under the effect of HVEP, and concluded that HVEP may replace the hydraulic fracturing in oil production. 19 The use of electrical pulses in enhancing the permeability of coal seam has attracted much attention.…”

Section: Introductionmentioning

confidence: 99%

Crack Propagation Characteristics of Coal Samples Utilizing High-Voltage Electrical Pulses

et al. 2021

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The technique of high-voltage electrical pulses (HVEP) is a new method to enhance the permeability of coal seams and improve the efficiency of coalbed methane (CBM) exploitation. This paper is aimed at investigating the crack propagation characteristics of samples of different strengths, proposing the improved procedure of HVEP in field application, and proving that the electrohydraulic effect has a wide use in field application of CBM extraction. In this paper, an experimental system utilizing HVEP in water condition is established, coal samples with different strengths are crushed, and the extended processes of cracks are analyzed. According to the research results, the electrohydraulic effect has a good breakage on the coal; the number of main cracks is 2–3 and the length of the main cracks is about 30 cm in the vertical direction of the hard samples; and the formation of cracks is relevant to the discharge voltage, discharge times, and mechanical parameters of the samples. The results of scanning electron microscopy (SEM) demonstrate that the cracks and pore connectivity of the coal samples are improved obviously, and the permeability results show that the permeability of crushed coal samples is 20% greater than that of the raw coal sample. Meanwhile, the generation process of cracks can be divided into four periods: namely, fatigue damage accumulation, slow development, rapid development, and failure; the rapid development stage is the optimal phase in field application. Moreover, the shock wave produced by HVEP via electrohydraulic effect can crush the samples mainly; furthermore, the energy produced by bubble rupture also has a great influence on the formation of cracks. This study can provide a foundation for the HVEP to improve CBM exploitation.

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Section: Introductionmentioning

confidence: 99%