Distributed acoustic sensing (DAS) using fiber-optic cables as sensors has become a standard measurement technique in many industrialized settings. Geophysical applications have been mainly commercialized the borehole environment. When deployed on seabed (SB), horizontal analysis of DAS data poses new challenges due to particularity receiver response and characteristics data. Recent acquisition 2D towed-streamer (TS) survey following path communication cable (installed 1998), which is...

Distributed acoustic sensing (DAS) technology provides densely sampled vertical seismic profile (VSP) data. DAS strain measurement is shown to be axial scaled in the spatial frequency domain. A DAS-to-velocity transform introduced correct scaling effects and convert velocity. The DAS-transformed velocity preserves polarity attribute amplitude dependence with angle of traditional measurement. gain 40% at 45° 100% a 60° angle. Strain-Velocity summation methodology effectively perform wavefield...

The seismic quality factor, Q, is a critical parameter for data processing and interpretation. Distributed acoustic sensing (DAS) provides unique acquisition geometry that ideal estimating Q. We use simple twolayer model to generate synthetic DAS along vertical well using typical velocity values representative of the end points observed range. show Q estimation with spectral ratios method measurement, when performed without gauge length correction, results in significant errors. Properly...

The requirement for recording time to depth information dates back 1888, when August Schmidt proposed the first Checkshot technique measure rock velocities versus depth. For majority of last 100 years practice has essentially been unchanged, with a source at surface and downhole receiver located within wellbore. Distributed acoustic measurements on fiber optic cable can be acquired using various techniques such as hDVS (heterodyne distributed vibration sensing). With advancements in hDVS, we...

Abstract Distributed acoustic sensing (DAS) differs from particle velocity measurements in both amplitude and frequency response. DAS data are affected by the apparent of incident energy relative to fiber as well gauge-length at which is interrogated. We develop a generalized relationship for dependence response on elastic waves terms angle wave vector, polarization, phase velocity. Velocity sensor synthetic generated comprehensively evaluate conditioning methods needed prepare imaging....

Summary Surface distributed acoustic sensing (S-DAS) is a promising subsurface imaging, detection and monitoring technology. One of the main advantages S-DAS ability to have very dense spatial coverage along cable. However, DAS measurements are affected by gauge length (GL) parameter. Successful acquisition, processing modelling surveys call for clear understanding GL effect on data quality. We study using unique surface seismic field experiment, in which full optical were recorded with...

PreviousNext No AccessThird International Meeting for Applied Geoscience & Energy Expanded AbstractsSpecialized processing of a massive distributed acoustic sensing (DAS) 3D VSP in producing wellAuthors: Ali SayedFrancesca TwynamRan BachrachPhilippe CaprioliMarcus HollowayQingsong LiReetam BiswasDaniel TeboSam BuistAli SayedSLB, Francesca TwynamSLB, Ran BachrachSLB, Philippe CaprioliSLB, Marcus HollowaySLB, Qingsong LiBP, Reetam BiswasBP, Daniel TeboBP, and Sam...

A complete comparison is made between a rig-source vertical seismic profile (VSP) recorded in deviated well performed with conventional geophones data and distributed acoustic sensing (DAS) fiber optics. The DAS acquisition was using hybrid wireline cable during the logging descent of an ultrasonic tool for casing evaluation. This VSP project offers two rich sets which one-to-one most common quality indicators borehole can be made. objective to highlight commonalities, advantages, potential...

Distributed acoustic sensing technology enables high-density seismic acquisition at a fraction of the cost. When deployed on surface, surface distributed (S-DAS) provides cost-effective solution for dense high-resolution near-surface characterization through analysis and inversion waves. This is made possible by relatively low cost fiber spatial sampling realized data. The S-DAS data were collected during 3D land large-scale field test processed with focus recent advancements in use wave...

Shear energy observed on a multi‐offset VSP dataset from the West Texas Overthrust is analyzed. wave splitting in vertical vibrator data. Direct shear at zero‐offset used to compute velocity profile along well. PP and PS images of subsurface support surface seismic interpretation region through improved depth resolution complementary lateral coverage.

Vertical Seismic Profile (VSP) surveys are generally acquired using three-component geophones. Significant shear energy both direct and reflected, is often observed on near-offset VSP data. In this study, we observe shear-waves 3C Anisotropic rotations used to orient the horizontal components towards fast slow directions. The separated S1 S2 wavefields processed generate PS1, PS2, S1S1, S2S2 corridor stacks. Conventional PP stacks generated by processing vertical component. technique...

Summary Distributed acoustic sensing (DAS) technology offers a wide range of applications in geophysics. In the oil and gas industry, use DAS is well established borehole domain, but it only last few years that fiber optics as seismic sensor deployed on surface has been experimented. This novel advantages dense sampling at low cost; nevertheless, when surface, configurations pose specific challenges. Surface data have collected during acquisition 3D land large-scale field test, processed...

Summary Distributed acoustic sensing using fiber optics (FO) cables deployed horizontally on the surface or seabed (we define this as S-DAS configuration) is a novel technology with potential to become cost-effective alternative conventional towed streamer and ocean-bottom node seismic surveying. Robustness cost effectiveness of FO sensors generate an attractive value proposition for many monitoring applications. A relatively unexplored aspect ability use passive interferometry subsurface...

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Drilling horizontally within shale zones, in the presence of structural complexities, remains a major challenge. A multi-well walkaway-VSP survey was used to determine correct interpretation between two pilot boreholes having ∼500 ft depth mis-tie. Interpretation inter-well VSP image revealed an antithetic fault. Boreholes trajectories were revised successfully drill horizontal wells zone from both pilots.

PreviousNext No AccessThird International Meeting for Applied Geoscience & Energy Expanded AbstractsHigh-resolution imaging using least-squares migration in the image domain (LSMi) a marine distributed acoustic sensing (DAS) 3D-VSPAuthors: Ali SayedFrancesca TwynamRan BachrachMaud CavalcaLeo LeonMaria ShadrinaQingsong LiReetam BiswasDaniel TeboSam BuistAli SayedSLB, Francesca TwynamSLB, Ran BachrachSLB, Maud CavalcaSLB, Leo LeonSLB, Maria ShadrinaSLB, Qingsong LiBP, Reetam BiswasBP, Daniel...

An accurate earth-model is critical in correct depth imaging of a borehole seismic survey. Borehole survey generally provides excellent control on the vertical velocities at well location and can be used to estimate anisotropy lesser extent lateral heterogeneity, all essential components an earth model for imaging. In this study, direct- reflection-tomography construct precise anisotropic earth-model. Existing building workflows are adapted use P SH reflected-energy resolve complete VTI...

Summary We present results from a recent large-scale experiment using surface-distributed acoustic sensing (S-DAS) system. The objectives of the are to investigate seismic response S-DAS, its sensitivity and applicability S-DAS technology new energy challenges, specifically for geological storage CO2 monitoring, widely referred as carbon capture (CCS) windfarm technology. demonstrate that: has very high fidelity when compared velocity geophone. dynamic range broader band conventional...