Robust geophysical integration through structure-coupled joint inversion and multispectral fusion of seismic reflection, magnetotelluric, magnetic, and gravity images: Example from Santos Basin, offshore Brazil

Geophysics ◽  
2012 ◽  
Vol 77 (5) ◽  
pp. B237-B251 ◽  
Author(s):  
L. A. Gallardo ◽  
S. L. Fontes ◽  
M. A. Meju ◽  
M. P. Buonora ◽  
P. P. de Lugao
Keyword(s):  
Seismic Reflection ◽  
Joint Inversion ◽  
Crystalline Basement ◽  
Magnetic Data ◽  
Data Sets ◽  
Single Image ◽  
Gravity And Magnetic ◽  
Marine Seismic ◽  
Gravity And Magnetic Data ◽  
Magnetotelluric Imaging

We have applied a crossgradient joint inversion and geospectral visualization method to marine seismic reflection, magnetotelluric, gravity, and magnetic data sets acquired along a 162 km profile across a segment of Santos Basin oil province in the continental margin of southeast Brazil. The main exploration targets are the top of the fractured Precambrian crystalline basement and any concealed basement grabens, the overlying presalt and salt/carbonate deposits, and the postsalt cover deposits. The results of joint inversion clearly mapped the various units and are a significant improvement over previous models derived from separate 2D seismic reflection processing and 2D magnetotelluric imaging. Additionally, multispectral fusion of these models resulted in a single image that permits highly constrained geologic interpretations enabling a better understanding of basin architecture. We suggest that joint inversion and image fusion is the way forward for effective geophysical integration.

Integration of gravity, magnetic, and seismic data for subsalt modeling in the Northern Red Sea

2021 ◽  
Vol 9 (2) ◽  
pp. T507-T521
Author(s):  
Camille Le Magoarou ◽  
Katja Hirsch ◽  
Clement Fleury ◽  
Remy Martin ◽  
Johana Ramirez-Bernal ◽  
...  
Keyword(s):  
Red Sea ◽  
Seismic Reflection ◽  
Magnetic Data ◽  
Gravity Inversion ◽  
Gravity And Magnetic ◽  
3D Gravity ◽  
Thin Crust ◽  
Gravity And Magnetic Data ◽  
Refraction Data ◽  
Northern Red Sea

Rifts and rifted passive margins are often associated with thick evaporite layers, which challenge seismic reflection imaging in the subsalt domain. This makes understanding the basin evolution and crustal architecture difficult. An integrative, multidisciplinary workflow has been developed using the exploration well, gravity and magnetics data, together with seismic reflection and refraction data sets to build a comprehensive 3D subsurface model of the Egyptian Red Sea. Using a 2D iterative workflow first, we have constructed cross sections using the available well penetrations and seismic refraction data as preliminary constraints. The 2D forward model uses regional gravity and magnetic data to investigate the regional crustal structure. The final models are refined using enhanced gravity and magnetic data and geologic interpretations. This process reduces uncertainties in basement interpretation and magmatic body identification. Euler depth estimates are used to point out the edges of high-susceptibility bodies. We achieved further refinement by initiating a 3D gravity inversion. The resultant 3D gravity model increases precision in crustal geometries and lateral density variations within the crust and the presalt sediments. Along the Egyptian margin, where data inputs are more robust, basement lows are observed and interpreted as basins. Basement lows correspond with thin crust ([Formula: see text]), indicating that the evolution of these basins is closely related to the thinning or necking process. In fact, the Egyptian Northern Red Sea is typified by dramatic crustal thinning or necking that is occurring over very short distances of approximately 30 km, very proximal to the present-day coastline. The integrated 2D and 3D modeling reveals the presence of high-density magnetic bodies that are located along the margin. The location of the present-day Zabargad transform fault zone is very well delineated in the computed crustal thickness maps, suggesting that it is associated with thin crust and shallow mantle.

Regional transect across the western Caribbean Sea based on integration of geologic, seismic reflection, gravity, and magnetic data

AAPG Bulletin ◽  
2019 ◽  
Vol 103 (2) ◽  
pp. 303-343 ◽  
Author(s):  
Javier Sanchez ◽  
Paul Mann ◽  
Luis Carlos Carvajal-Arenas ◽  
Rocio Bernal-Olaya
Keyword(s):  
Seismic Reflection ◽  
Caribbean Sea ◽  
Magnetic Data ◽  
Gravity And Magnetic ◽  
Western Caribbean ◽  
Gravity And Magnetic Data

Focusing joint inversion of gravity and magnetic data using a clustering stabilizer in a space of weighted parameters

2020 ◽  
Vol 224 (2) ◽  
pp. 1344-1359
Author(s):  
Zhengwei Xu ◽  
Guangui Zou ◽  
Qianqian Wei ◽  
Junqi Tian ◽  
Hemin Yuan
Keyword(s):  
Joint Inversion ◽  
Model Space ◽  
Massive Sulfide ◽  
Realistic Model ◽  
Magnetic Data ◽  
Inversion Algorithm ◽  
Model Studies ◽  
Structural Correlation ◽  
Gravity And Magnetic ◽  
Gravity And Magnetic Data

SUMMARY This paper develops a minimum-support focusing stabilizer to perform a joint inversion of the vertical components of gravity and magnetic data using fuzzy c-means clustering (FCM) with the regularized Newton method in a space of weighted parameters. Not only does this joint inversion technology arrive at the conditionally well-posed traditional potential field inversion, but it also increases the structural correlation between multiple inverted models. The FCM and the focusing stabilizer make it possible to balance the convergence of the data space (D) and the model space (M), guiding multimodal geophysical parameters toward assigned petrophysical values, which makes the results more stable and realistic. Two model studies are presented to illustrate the method, a simple synthetic model with two rectangular bodies in a homogenous background and a realistic model of the Volcanogenic Massive Sulfide (VMS) deposits in northeastern New Brunswick, Canada. These models demonstrate that the new focusing joint inversion algorithm produces better images than traditional methods because the FCM function uses the structural correlation of density contrast and magnetic susceptibility as constraints.

Focusing Joint Inversion of Gravity and Magnetic Data using Weighted Fuzzy Clustering

2019 ◽  
Author(s):  
Zhengwei Xu* ◽  
Guangui Zou ◽  
Jiang Wang ◽  
Junqi Tian ◽  
Yue Mao ◽  
...  
Keyword(s):  
Fuzzy Clustering ◽  
Joint Inversion ◽  
Magnetic Data ◽  
Gravity And Magnetic ◽  
Gravity And Magnetic Data
Sign in / Sign up

Export Citation Format

Share Document