Estimation of elastic properties of sediments utilizing simulated annealing algorithm – a pseudo-wells generation approach

Abstract

The gas hydrate distribution model containing cement, or un-cement models, considerably affects elastic properties such as shear and bulk modulus. Thus, determining the distribution model in the hydrate-bearing sediments requires decreasing uncertainty in quantitative studies based on seismic velocities. Pre-stack seismic data include additional fluid information than post-stack seismic data, and the pre-stack inversion procedure has influential benefits such as stable outcomes, high resolution, and strong manageability. The amplitude-variation-with-angle (AVA) inversion along the bottom simulating reflector (BSR) utilizing compressional and Shear wave pre-stack analysis could be involved to evaluate hydrate and gas saturations at the pseudo well, especially in accretionary prism structures. It could change unconsolidated sediments' elastic properties and produce sharp bottom simulating. Pseudo-well generation is a title for estimating the elastic parameters of sediments in areas such as deep marine environments where drilled wells are absent (or sparse). This seismic angle-gather inversion problem has complex space and several local and global optimum solutions. In such cases, metaheuristic algorithms are a suitable tool for problem-solving. In this paper, the metaheuristic Simulated Annealing algorithm has been investigated, and the developed optimized algorithm has been presented. In order to analyze the performance of the algorithm, pre-stack seismic data is utilized as a benchmark. The conceptual model of this data includes the elastic parameter logs, which makes it an appropriate option for analyzing the performance and accuracy of the algorithm. According to the results, the generation of pseudo-wells with the algorithm mentioned earlier can be used to characterize hydrates-bearing sediments.