Gravity Data Inversion with Method of Local Corrections for Finite Elements Models

Abstract

We present a new method for gravity data inversion for the linear problem (reconstruction of density distribution by given gravity field). This is an iteration algorithm based on the ideas of local minimization (also known as local corrections method). Unlike the gradient methods, it does not require a nonlinear minimization, is easier to implement and has better stability. The algorithm is based on the finite element method. The finite element approach in our study means that the medium (part of a lithosphere) is represented as a set of equal rectangular prisms, each with constant density. We also suggest a time-efficient optimization, which speeds up the inversion process. This optimization is applied on the gravity field calculation stage, which is a part of every inversion iteration. Its idea is to replace multiple calculations of the gravity field for all finite elements in all observation points with a pre-calculated set of uniform fields for all distances between finite element and observation point, which is possible for the current data set. Method is demonstrated on synthetic data and real-world cases. The case study area is located on the Timan-Pechora plate. This region is one of the promising oil- and gas-producing areas in Russia. Note that in this case we create a 3D density model using joint interpretation of seismic and gravity data.

Invers Modeling Gravity Data for Semi-Infinite Slab Using Matlab

“…Referring to the results obtained, the approach to solving the semi-finite slab gravity data inversion can be used with constraints. Constructions in the form of an acceptable range of values produce smooth recovered models (Martyshko et al, 2018).…”

“…(also called method) (method correction) (Martyshko, Ladovskii, Byzov, & Tsidaev, 2018). The slope filter is an interpretation method used to determine the source near the location based on the potential field data.…”

Parallel Algorithms for Solving Inverse Gravimetry Problems: Application for Earth’s Crust Density Models Creation

“…In order to separate the observed field anomalies by depth, we use the original method of elevated transformations [16,18] with the modification of the computational part, proposed by the authors of this paper, based on the method of local corrections [17,19,20]. We use this method for downward continuation and the density refinement.…”

“…Applying the same optimization technique for calculating the convolution of functions on a uniform grid, which was used in [20], for a fast algorithm for solving the forward gravity problem, we can write (7) in the form:…”

Evaluation of the parameters of the fault-like geologic structure from the gravity anomalies applying the particle swarm

“…Gravity data interpretation suffers from ill-pose and non-uniqueness like all potential data. To minimize these problems, we discovered the appropriate geometry for the subsurface structure with a recognized density followed by the inversion process (Asfahani and Tlas 2012;Martyshko et al 2018).…”