Three-dimensional small surface element magnetotelluric continuous array data acquisition method

Abstract

The invention relates to a three-dimensional small surface element magnetotelluric continuous array data acquisition method for improving the acquisition quality in oil geophysical prospecting. The method comprises the steps: each acquisition station simultaneously begins to acquire and record time series data of a natural electromagnetic field when a small surface element grid is adopted to acquire and record for construction and electrode distribution, and a diagonal point and a center point respectively carry out addition and work out average value to the same weight of two adjacent points to all points of time domain electric filed data of all observation points by taking a recording point as a center; an angular point calculates the average value of the weights of the same electric field of two adjacent points and all measuring points towards the surface element; the calculated electric field weights of the maximum space are respectively used as new observation field values; new time series data for compressing noise and static displacement effect is obtained, and the apparent resistivity and the phase curve of each point can be obtained through processing by a conventional method. The invention compresses the noise and static displacement effect and obviously improves the MT data acquisition in areas with serious noise interference and static displacement.

Description

technical field [0001] The invention relates to geophysical exploration technology, and is a three-dimensional small bin magnetotelluric continuous array data acquisition method that effectively suppresses and eliminates noise by means of electric field closure and implements plane space filtering to eliminate static displacement in time series. Background technique [0002] At present, the magnetotelluric method has been widely used in the exploration of oil and gas, minerals and groundwater resources. However, the working method of single-point sounding (one-dimensional) or profile sounding (two-dimensional) has been used. One-dimensional working method, that is, laying out orthogonal electromagnetic field four-component receiving devices (Ex, Ey, Hx, Hy) or five-component receiving devices (Ex, Ey, Hx, Hy, Hz) at a measuring point, and continuously collecting time-domain electromagnetic fields, Fourier transform is performed on the time data in the room to obtain the pow...

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Problems solved by technology

[0003] This method can achieve better results when the underground structure is relatively simple, such as one-dimensional and two-dimensional geological conditions. There is a gap between the ability and accuracy of the method and the actual requirements. First, the static displacement is seriously affected, which is difficult to effectively suppress and eliminate, which affects the exploration effect, and even produces false structures. Second, the noise interference is difficult to effectively suppress, which affects the quality of the data; In addition, because a magnetic station is arranged on a relatively long array, the distance between the magnetic station and each measuring point is very different, and it is unreasonable in areas with large magnetic field changes. These problems are difficult to solve by the above methods