Marlim R3D - A Realistic Model For Mcsem Simulation

The marine Controlled-Source Electromagnetic (mCSEM) method provides complementary information to seismic imaging in the exploration of sedimentary basins. The mCSEM can be used to help in subsalt structural imaging, but mainly for reservoir scanning and appraisal as EM methods are especially sensible to the fluid content within the rocks. The mCSEM interpretation workflow is heavily based on inversion and forward--modeling for hypothesis testing. Until the recent past, the effectiveness of a given interpretation workflow was achieved after the drilling results, as there wasn't any geological complex model available to serve as a benchmark. The Society of Exploration Geophysics (SEG) recognized that gap and launched the SEAM (SEG Advanced Modeling)-Phase I project aiming to advance the geophysical science through the construction of a multi-physics subsurface model and generation of an associated dataset. SEAM Phase-I, a representation of the deepwater Gulf of Mexico salt domain, was designed to take as much realism and geological complexity as possible. Following the success of that first model, SEG launched SEAM Phase-II focused on the solution of land seismic challenges like near-surface complexities and fractured reservoirs. In the present publication, we will also describe the workflow to build Marlim--R3D, a realistic and complex geoelectric model. Marlim-R3D aims to be a reference model for mcSEM modeling and inversion studies of turbidite reservoirs of the Brazilian continental margin. Our model is based on previous seismic interpretation and constrained by the input of available well-log information. The workflow used is composed of seven sequential steps: seismic and well-log dataset loading, well-tie, Vp (P-wave velocity) cube construction, Vp-resistivity calibration, time-depth conversion, resistivity cube construction, Quality-control check. As a result, we obtained an interpreted dataset composed by main stratigraphic horizons, pseudo-well logs, and the resistivity cubes. These elements will be freely available for research or commercial use, under the Creative Common License. <strong>Files Description : </strong> <strong>Depth horizons: *xyz extension (Upper Oligocene, Upper Miocene, Sea Bottom, Top of Marlim Reservoir, Top and Base of the Salt)</strong> <strong>Pseudo Wells: *.LAS extension (extrated properties from modelling) ------- *.track extensions (well track)</strong> <strong>3D Cubes: *sgy </strong> <strong>Horizontal &amp; Vertical Resistivity (Calculated resistivity from modelling - horizontal and vertical anisotropy) </strong> <strong>Log(RESH) &amp; Log(RESV) files are the resistivity cubes but in common logarithmic scale </strong>海洋可控源电磁法（marine Controlled-Source Electromagnetic, mCSEM）在沉积盆地勘探中可为地震成像提供补充信息。该方法可辅助盐下构造成像，而其核心应用场景为储层识别与评价，这是因为电磁方法对岩石内部的流体含量尤为敏感。 mCSEM解释工作流高度依赖用于假设检验的反演与正演建模。直至近期，此类解释工作流的有效性仍需通过钻井结果验证，彼时尚无可用的复杂地质模型作为基准参照。 国际勘探地球物理学家学会（Society of Exploration Geophysics, SEG）注意到这一空白，发起了SEAM（SEG Advanced Modeling）一期项目，旨在通过构建多物理场地下模型并生成配套数据集来推动地球物理科学发展。 SEAM一期项目复刻了墨西哥湾深水盐构造域，设计时尽可能融入真实地质场景与复杂构造特征。得益于该初始模型的成功，SEG随后推出SEAM二期项目，聚焦解决陆地地震勘探的诸多挑战，例如近地表复杂性与裂缝性储层问题。 在本研究中，我们还将阐述Marlim-R3D模型的构建工作流——这是一款兼具真实性与复杂性的地电模型。Marlim-R3D旨在作为巴西大陆边缘浊积岩储层mCSEM建模与反演研究的参考模型。本模型基于已有的地震解释成果，并结合现有测井资料进行约束。 所采用的构建流程包含七个连续步骤：地震与测井数据集加载、井震标定（well-tie）、纵波速度（P-wave velocity, Vp）立方体构建、Vp-电阻率校准、时深转换、电阻率立方体构建以及质量控制检查。 最终我们得到了一套包含主要层序地层界面、伪测井曲线与电阻率立方体的解释数据集。这些数据将按照知识共享许可协议（Creative Common License）免费开放，可用于科研或商业用途。 <strong>文件说明：</strong> <strong>深度层位：*.xyz 格式（包括渐新统上部、中新统上部、海底、Marlim储层顶界、盐层顶界与底界）</strong> <strong>伪测井：*.LAS 格式（提取自建模的物性参数）—— *.track 格式（测井轨迹）</strong> <strong>三维立方体：*.sgy 格式</strong> <strong>水平与垂直电阻率（建模计算得到的电阻率，考虑水平与垂向各向异性）</strong> <strong>Log(RESH) 与 Log(RESV) 文件为转换至常用对数尺度的电阻率立方体</strong>