A tectonic physical simulation method for a thrust belt

Abstract

The invention provides a tectonic physical simulation method for a thrust belt. The method comprises the steps of (1) deformation analysis, (2) experimental modeling, (3) simulation experiment, and (4) loop optimization. In the first step, based on the tectonic setting of intra-continental deformation, deep deformation characteristics of a thrust belt are analyzed and a deformation field and a geologic model of segmented deformation are built. In the second step, a kinetic model is built in such a way that a first sand body and a second sand body are preset to form 70-degree angular contact, and an orogenic belt and a basin and an inclined compression and twisting process are simulated; the second sand body is inside provided with a silica gel layer to simulate the influence of a ductile bed on tectonic deformation; a single-side squeezing mode is employed as the acting force mode, so that the dive of the first sand body to the second sand body can be achieved. According to the method, the two block bodies with crosswise rheological difference are designed, so that the problem of thrust belt border deformation can be handled, the dive of an orogenic belt to a basin and the foldback thereof can be achieved, intra-continental thrust happening after splicing of ancient plates of different natures can be reflected and the method conforms to the unique rejuvenated foreland evolution and tectonic structure background of thrust belts.

Description

technical field [0001] The invention relates to an oil and gas field geological exploration simulation technology, in particular to a physical simulation method for a thrust belt structure. Background technique [0002] Structural physics simulation experiments can intuitively and effectively reproduce the deformation process of thrust belts, and then feed back the interpretation of geophysical data to reduce the risk of oil and gas exploration. [0003] The thrust belt refers to the transition zone between the orogenic belt and the basin, and is a thrust system formed by large-scale thrust and napping from the orogenic belt to the basin. Since the discovery of large oil and gas fields such as Kela 2 gas field and Qingxi oil field in 1998, the thrust belt has become one of the four major fields of oil and gas exploration, and has successively developed in Kuqa, Taxinan, Zhunxi, Tuha North Margin, Qaixi, Sichuan Significant progress has been made in piedmont thrust belts suc...

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Problems solved by technology

[0008] The purpose of the present invention is to address the above-mentioned defects in the prior art, and to provide a physical simulation method for the thrust zone structure. The model designs two blocks with transverse rheological differences, which can deal with the boundary deformation of the thrust zone and realize orogeny The subduction of the belt to the basin and its exhumation reflect the intracontinental thrust after the splicing of different ancient plates, which is consistent with the evolution of the unique regenerated foreland and the tectonic background of the thrust belt; in terms of research methods, after obtaining the two-dimensional section , it is proposed to use time-lapse photography to process model images to quickly recover the whole process of the experiment, present the deformation process that cannot be detected by the naked eye, and effectively track the evolution of each structural phenomenon

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