A De-Noising Methodology for Multi-Component Seafloor Nodal Geophones
W. Jeong and C. Tsingas
Event name: 81st EAGE Conference and Exhibition 2019
Session: Poster: Noise Attenuation A
Publication date: 03 June 2019
Info: Extended abstract, PDF ( 759.79Kb )
Price: € 20
A key advantage of acquiring multi-component data using ocean bottom sensors is the ability to separate the full wavefield into up-going and down-going wavefields. To achieve clean up/down separation we need to eliminate the noise recorded by various components of the sensors. Unlike the hydrophone component, the geophone components recorded at the ocean floor are usually contaminated by a various noise modes, including Scholte waves, backscattering noise, converted shear waves and other various types of noise. In particular, converted shear waves cause a number of challenges during data processing and degrade the effectiveness of up/down separation. In this paper, a de-noising methodology is developed to obtain cleaner vertical geophone components. It uses all recorded components to suppress shear wave energy and comprises three steps: 1) design and apply a masking filter to decompose the vertical geophone traces into less sensitive and mutually dependent parts with the horizontal geophone traces; 2) adaptive subtraction of the horizontal geophone traces from the vertical geophone traces; and 3) matching the signal envelope between hydrophone and vertical geophone traces. This de-noising process serves as a pre-conditioning step before the subsequent critical seafloor data processing steps including PZ summation, up/down deconvolution, and multiple removal.