An effective scheme of joint migration inversion in the pseudo‐time domain

Traditional full-waveform inversion is a non-linear and ill-posed problem. To reduce the non-linearity of it, joint migration (joint inversion) was proposed as an alternative. Joint tries to minimize mismatch between measured modelled reflection data. One key feature its parameterization: two separate parameters, reflectivity (for amplitudes reflected events) propagation velocity phase effects). This separation helps inversion. During inversion, with being updated, reflectors in updated image are also shifting depth accordingly, this phenomenon called depth–velocity ambiguity. interaction parameters during desired keep time consistent data but may lead non-robustness due presence local minima. Therefore, we propose more robust scheme, which parameterizes models vertical time, termed pseudo-time In pseudo-time, updates will not result associated location changes estimated image. Instead, mainly getting focused. limitation that depth-pseudo-time conversion process assumes simple linear relationship might cause some artefacts converted when there exist strong lateral variations. subsequent round recommended resolve issue. We demonstrate effectiveness our method two-dimensional synthetic example extreme scenario, where initial model homogeneous, realistic offshore example, field from Vøring basin Norway three-dimensional example. all examples, manages recover reasonable inverted invert focused image, compared