Standard framework-based method for quick three-dimensional gravity and magnetic inversion for physical properties

Abstract

The invention provides a standard framework-based method for quick three-dimensional gravity and magnetic inversion for physical properties in geophysical exploration. The method comprises: gridding gravity and magnetic data first and then converting the data grid into a square node grid; subdividing lower haft space and performing standard framework quick forward calculation and storage; solvingsquare roots of a framework coefficient of a calculation point of a framework central cylinder to obtain a bin inversion coefficient array; performing expansion calculation for quick extrapolation; obtaining a three-dimensional gravity and magnetic anomaly data volume after plane gravity and magnetic anomaly separation; performing inversion physical property numerical range constraint and field level constraint; and obtaining a high-accuracy inversion model by a forward process. The method can reflect the three-dimensional density and magnetic susceptibility distribution of an underground geologic body, solves actual geological problems of a complex region, and has high-efficiency, quick, reliable, effective and practical effects.

Description

technical field [0001] The invention relates to geophysical prospecting technology, in particular to a fast three-dimensional gravity and magnetic property inversion method based on a standard grid. Background technique [0002] The ground gravity and magnetic prospecting methods currently used, taking gravity and magnetic prospecting in the petroleum exploration industry as an example, the standards implemented are "Technical Regulations for Ground Gravity Prospecting (SY / T5819-2002)" and "Technical Regulations for Surface Magnetic Prospecting SY / T5771 -2004", the technical requirements for the processing and interpretation of gravity and magnetic data are based on plane processing, 2D\2.5D (two-degree\two-and-a-half degree) section inversion, single-interface gravity-magnetic interface inversion, and no requirements have been put forward 3D gravity and magnetic inversion process interpretation regulations and mature popularized technology. [0003] The existing gravity an...

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Problems solved by technology

[0003] The existing gravity and magnetic inversion technology generally adopts 2D\2.5D section inversion or single interface gravity and magnetic interface inversion, but the current simple three-dimensional gravity and magnetic inversion is only for simple standard geometric shapes (sphere, square cylinder, step ) for simple 3D inversion; these inversion methods can only achieve 2D inversion or 2D half-section inversion, inversion of a single simple geometry, or inversion of a single interface on a plane. Under the circumstances, there is a big difference from the actual geological body model, and even distortion occurs, which cannot simulate the complex three-dimensional structure and structure of the underground, and cannot meet the needs of oil exploration for complex three-dimensional inversion

However, the three-dimensional physical property inversion method of gravity and magnetic field has no practical or popularized application technology to compare with.

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