Vector-acoustic reverse time migration of Volve ocean-bottom cable data set without up/down decomposed wavefields

Abstract

Methods for wavefield injection are commonly used to extrapolate seismic data in reverse time migration (RTM). Injecting a single component of the acoustic field, for example, pressure, leads to ambiguity in the direction of propagation. Each recorded wavefront is propagated both upward and downward, and spurious (or ghost) reflectors are created alongside real reflectors in the subsurface image. Thus, wavefield separation based on the combination of pressure and particle velocity data is generally performed prior to imaging to extract only the upgoing field from multicomponent seabed or towed marine seismic recordings. By instead combining vector-acoustic (VA) data with monopoleand dipole-type propagators in the extrapolation of shot or receiver gathers, we show that wavefield separation (or deghosting) can instead be performed "on-the-fly" at limited additional cost. This strategy was successfully applied to a line of a North Sea ocean-bottom cable data set, acquired over the Volve field. We then evaluate additional advantages over standard RTM with decomposed fields such as improved handling of the directivity information contained in the acquired VA data for clearer shallow sections and better focused space-lag common image gathers, and imaging of the downgoing component without the need for additional finite-difference modeling via mirror migration. Finally, we prove the robustness of our method with respect to sparse and irregular receiver sampling.

Intelligent Drilling of Oil and Gas Wells Using Response Surface Methodology and Artificial Bee Colony

“…The ABC algorithm has been utilized for solving various engineering problems such as ROP optimization [29], oil and gas well placement optimization [30], over break prediction in the tunnel [31], etc. A detailed description of ABC optimization can be found in other references [31][32][33][34]. Figure 4 depicts the flowchart of the Artificial Bee Colony paradigm that was originally proposed by Karaboga [28].…”

Porosity and permeability prediction through forward stratigraphic simulations using GPM™ and Petrel™: application in shallow marine depositional settings

“…Grain size, sediment matrix, and the degree of sorting will typically drive the volume of the void created and therefore the porosity and permeability attributes. Wireline-log attributes such as gamma ray (GR), sonic (DT), density (RHOB), and neutron porosity (NPHI) distinguish lithofacies units, stratigraphic Ravasi et al, 2015).…”

Inversion of vector-acoustic data in a local domain

“…both vector and scalar components, gives an opportunity for a more accurate understanding the subsurface. Specifically, using all the components of the wavefield improves reverse-time migration (RTM) by reducing artifacts and improving illumination (Ravasi et al, 2015), and full waveform inversion (FWI) by providing constraints on the subsurface parameters (Fleury and Vasconcelos, 2013;Zhong and Liu, 2019). In order to take advantage of the full pressure and particle velocity wavefield, we need to model the wavefields using the first-order vector-acoustic wave equation.…”