Oil-gas fracture four-dimensional electromagnetic multi-component real-time monitoring system and method

Abstract

The invention provides an oil-gas fracture four-dimensional electromagnetic multi-component real-time monitoring system and method. The system is composed of an electromagnetic wave excitation sourceand an electric field or magnetic field signal monitoring device. The electromagnetic wave excitation source includes an electric dipole for transmitting electromagnetic wave excitation signals with different frequencies to a fracturing target layer beyond a set distance in a direction parallel or perpendicular to a horizontal well direction. The electric field or magnetic field signal monitoringdevice is used for acquiring electric field signals and / or magnetic field signals before fracturing of monitoring points in a fracturing monitoring range and electric field signals and / or magnetic field signals during the fracturing process. The electric field signals and / or magnetic field signals include horizontal components of electric field signals and / or magnetic field signals parallel to andperpendicular to the electromagnetic wave excitation signal emitting source when the electric dipole is perpendicular or parallel to the horizontal well of the electric dipole.

Description

technical field [0001] The invention relates to the technical field of oil and gas development in the field of exploration geophysics, and more specifically, to a four-dimensional electromagnetic multi-component real-time monitoring method and system for oil and gas fracturing. Background technique [0002] In the field of petroleum, fracturing refers to a method that uses hydraulic action to form cracks in oil and gas layers during the process of oil or gas recovery, also known as hydraulic fracturing. Fracturing is to artificially create fractures in the formation, improve the flow environment of oil underground, increase the production of oil wells, and play an important role in improving the flow conditions at the bottom of oil wells, slowing down interlayers and improving the production status of oil layers. There are two types of fracturing methods: hydraulic fracturing and high-energy gas fracturing. Hydraulic fracturing is to inject fluid into the well at high speed ...

AI Technical Summary

Problems solved by technology

Compared with the traditional Controlled Source Audio-Frequency Magneto Tellurics (CSAMT) and ground electromagnetic method Melos, this electromagnetic monitoring method has subversive advantages; Magneto-telluric (MT) field source has the disadvantages of randomness and weak signal, but it uses a pair of orthogonal electric components and magnetic components measured in the far zone, and calculates the apparent resistivity according to the approximate formula of the far zone. The scope of its application is limited; the signal measured in the far zone is weak, which deviates from the original intention of using an artificial source to make the signal strong; if it is measured in a closer place, the signal strength can indeed be increased, but the approximate formula for the far zone is difficult to establish, and a New contradiction; the Melos method breaks through the limitation of the "far zone" and greatly expands the observation range of the frequency-domain electromagnetic method; compared with the CSAMT method, it could have gained certain advantages, but it puts the measurement results of the non-far zone " "Correction" to the remote area, paid the price of increasing the workload in the field and indoors, the gain outweighs the gain

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