Electromagnetical method for dynamically monitoring oil reservoir injection-production

Abstract

The invention provides an electromagnetic method for dynamically monitoring the injection-production of oil pool in the geophysical exploration and the oilfield development technologies, particularly comprising the steps of: measuring transient electromagnetic for the first time in a work area, recording and handling the time variable data of horizontal components of Ex and Ey of electric field and a vertical component of the magnetic field Bz; obtaining the resistivity distribution of the measured area with the depth according to the reversion of an apparent resistivity value; measuring the transient electromagnetic for the second time in the work area on ground; calculating difference between the data obtained in two different times to obtain a plane distribution diagram of the field value of a reservoir bed or the difference value of the resistivity; according to the features of a facies zone of the reservoir in work area in water driving and steam driving, the plane distribution diagram of the resistivity and the difference value is used to reflect the porosity and permeability distribution in work area reservoir and determine the proliferation of the injection agent and the position of the remaining oil. The electromagnetic method improves the signal to noise ratio for observing data under a strong interference environment, enhances the capability of extracting weak signals, increases the accuracy and resolution of reversion and can realize dynamic monitoring of oil pool developing.

Description

technical field [0001] The invention relates to geophysical detection and oil field development technology, in particular to an electromagnetic method for dynamic monitoring of oil reservoir injection and production by using ground transient electromagnetic measurement inversion to obtain the change of resistivity of oil and gas reservoir water flooding or steam flooding development blocks. Background technique [0002] In oil reservoirs exploited by water injection or steam injection, due to the differences in the distribution of porosity, shale content, fractures, faults, etc. After the reservoir is displaced by injection, the seismic wave velocity parameters and electrical parameters of the reservoir will change. Therefore, it is very important to find out the advantageous channel of the injection body and delineate the position of residual oil for formulating a development adjustment plan and effectively realizing resource potential. [0003] The reflection seismic meth...

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Problems solved by technology

[0008] However, due to the strong interference environment of industrial power consumption in oil development areas and ground well networks, pipeline networks, and power grids, it is difficult for the above electromagnetic methods to obtain observation data with high signal-to-noise ratio in oil development areas, so it is even more difficult to be used for reservoir injection and production. Dynamic Monitoring

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