Magnetic resonance and transient electromagnetic spatial constraint joint inversion method

Abstract

The invention relates to a high-precision magnetic resonance and transient electromagnetic spatial constraint joint inversion method. The joint inversion method is based on a forward modeling method combining a continued fraction expansion numerical integration equivalent transformation method and a digital filtering method. The magnetic field calculation precision and speed are both taken into account, an original model and a simplest model are provided, a rotary coefficient matrix equation is designed, and exciting field distribution is simulated and detected when different slope dip angles appear and profile angles change. According to a forward modeling result obtained under the condition of changed dip angle parameters, the forward modeling result is combined with a hierarchical full collection data inversion method, a joint inversion objective function, an iterative equation and a three-dimensional ground model are constructed, a prior information constraint matrix, a roughness matrix, a layer thickness constraint matrix and other spatial constraint matrices are introduced to construct an inversion iterative equation set, based on a large scale matrix of a preconditioning conjugate gradient method, smooth and continuous constraint for the specific resistance, the layer thickness, the water content and the relaxation time is achieved, the problem of inversion non-uniqueness is solved, and the problem that optimization and calculation of a large-scale matrix for spatial constraint inversion involves mass data is solved.

Description

Technical field: [0001] The invention relates to a geophysical detection method and its data interpretation. Under the conditions of terrain undulations, stratum electrical properties and continuous changes of the earth model, the data inversion interpretation is performed by using the combined inversion method of magnetic resonance and transient electromagnetic space constraints. Background technique: [0002] The shortage of water resources seriously restricts the economic development of western my country, and the fissure water and karst water existing in the complex geological environment increase the difficulty of exploration. Seismic, electromagnetic, and high-density electrical methods used internationally can indirectly judge water sources based on spatial structure and resistivity information, but they do not have qualitative and quantitative analysis capabilities. [0003] Magnetic resonance sounding (MRS) is the only new geophysical method in the world that direct...

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Problems solved by technology

However, the above methods do not consider the correlation between adjacent survey lines and survey points in the spatial range, nor do they introduce factors such as the inclination angle of the survey profile into the inversion, resulting in error transmission, and extending the inversion to two-dimensional and three-dimensional also faces problems. Computational problems with overly large data matrices

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