The Correlation of "Tube Wave" Events With Open Fractures in Fluid-filled Boreholes

Huang, Chaoyang; Hunter, J A

doi:10.4095/109558

Cited by 15 publications

(4 citation statements)

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“…A conversion of downward propagating P-waves into downward and upward propagating Stoneley waves was observed at the level of the karstic bodies. This phenomenon occurs in highly permeable formations [15,24,26] and would indicate the presence of flow to be confirmed by Production Logging Tool (PLT) data [24,25]. We can notice, for example, the conversion from P-to Stoneley waves at 55 m depth (Fig.…”

Section: Example Of a Near Surface Karstic Reservoirsupporting

confidence: 59%

Characterizing flow in the first hundred-meter depth of a fractured aquifer using hybrid seismic methods, acoustic logging, and flow-log measurements

Mari

Delay

Porel

et al. 2021

Oil Gas Sci. Technol. – Rev. IFP Energies nouvelles

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Understanding subsurface flow, especially in fractured rocks only housing water through a few preferential pathways, is still challenging. The point is mainly associated with the poor accessibility of the subsurface and the lack of accurate representations for both heterogeneity and spatial distribution of water bearing bodies. This notwithstanding, highly-resolved geophysical investigations bring new images of the subsurface. This is exemplified over a fractured limestone aquifer at the site scale (for example, that of the radius of influence of an extraction well). On an experimental site, situated in the Cher region (France), two boreholes have been drilled for field experiments. Full Waveform Acoustic Logging (FWAL) and seismic experiments were conducted. Hybrid seismic imaging, which consists in combining refraction and reflection seismic results, has been carried out. Based on a four-step procedure, the processing of refracted and reflected waves provided two sections. After assemblage, these sections produced in a first step an extended time reflectivity section starting from the surface and, in a second step, a section over depth after calibration with Vertical Seismic Profile (VSP) and acoustic data. However, even the Very High Resolution (VHR) seismic methods do not have a sufficient vertical resolution to describe accurately the geological formation. The acoustic sections were processed to separate the different wave fields, to extract the criss-cross events and to build a criss-cross index log. A log of fracturation index, based on both criss-cross index and P-wave velocity measurements, was computed to detect the presence of fractures. After calibration, and under the assumption that the slower the P-wave velocity, the higher the permeability – porosity, a 3D seismic block of reflection can inform on preferential areas where flow should occur. At the scale of an open wellbore, acoustic loggings that measure wave velocities over a short distance within the well also inform on open features crosscut by the well. Finally, flow log measurements confirm the occurrence of flowing horizons that were previously marked by both seismic and acoustic data. Seismic and acoustic data are therefore suited to image contrasted hydraulic properties over fractured subsurface systems usually poorly documented.

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Section: Example Of a Near Surface Karstic Reservoirsupporting

confidence: 59%

Characterizing flow in the first hundred-meter depth of a fractured aquifer using hybrid seismic methods, acoustic logging, and flow-log measurements

Mari

Delay

Porel

et al. 2021

Oil Gas Sci. Technol. – Rev. IFP Energies nouvelles

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“…Ce sont les ondes de tube créées in situ dans les zones à forte perméabilité par l'intermédiaire des ondes de compression qui traversent la zone perméable et donnent naissance à deux ondes de tube, l'une montante, l'autre descendante comme le montre la figure 2.6. L'amplitude de ces deux ondes de tube est directement proportionnelle à la perméabilité de la zone où elles ont été créées et la valeur de la perméabilité ainsi trouvée est significative par rapport au puits sur une distance égale à la demi-longueur dominante de l'onde de compression incidente (Huang et Hunter, 1981). Un exemple réel d'analyse d'onde de tube dans une zone réservoir est présenté par J.L.…”

Section: Ondes Sismiquesunclassified

Sismique en forage et diagraphies acoustiques

Mari¹,

Vergniault²

2020

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“…These are the tube waves created in situ in areas of high permeability via compression waves that cross the permeable zone and give rise to two tube waves, one upgoing, the other downgoing as shown in Figure 2.6. The amplitude of these two tube waves is directly proportional to the permeability of the area where they were created and the value of the permeability thus found is significant compared to the well over a distance equal to the dominant half-length of the incident compression wave (Huang and Hunter, 1981). An example of tube wave analysis in a reservoir zone is presented by J.L.…”

Section: Seismic Wavesmentioning

confidence: 99%