Method and device for determining true resistivity of horizontal well/highly-deviated well

Abstract

The invention discloses a method and a device for determining true resistivity of a horizontal well/highly-deviated well. The method comprises steps as follows: logging-while-drilling resistivity information, auxiliary logging curve information, logging information of an adjoining well or a pilot hole well and seismic data of the neighboring area of the well are acquired; a target stratum drilled at the horizontal well section/the highly-deviated well section is determined, the target stratum is layered, an initial ground layer model is established, and a resistivity initial value of the initial ground layer model is determined, and a while-drilling resistivity simulation response curve of a corresponding layer is generated; whether the while-drilling resistivity simulation response curve of the corresponding layer is identical to a while-drilling resistivity original response curve of the corresponding layer is judged, the resistivity initial value of the initial ground layer model is taken as the true resistivity value of the ground layer to be output if the while-drilling resistivity simulation response curve of the corresponding layer is identical to the while-drilling resistivity original response curve of the corresponding layer, and otherwise, the resistivity initial value is modified through interactive inversion. According to the method and the device, the recognition capability of an oil layer and the oil saturation estimation accuracy are improved greatly, and firmer foundation is provided for perforation oil testing.

Description

technical field [0001] The present invention relates to oil well logging technology, in particular to the technology for determining the true resistivity of formations, specifically a method and device for determining the true resistivity of formations in horizontal wells / highly deviated wells. Background technique [0002] For horizontal wells or highly deviated wells, due to the influence of mud invasion, wellbore, surrounding rock, well deviation and formation electrical anisotropy, the measured resistivity deviates from the true resistivity, especially in sand-shale interbeds and other fields. Anisotropic formations reduce the ability to identify oil layers through resistivity curves, and the calculated oil saturation has a large error. Therefore, it is necessary to use the inversion method to restore the real formation surface. [0003] However, the traditional inversion methods have been difficult to be practical because they are all purely mathematical methods, as lo...

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Problems solved by technology

[0003] However, the traditional inversion methods have been difficult to be practical because they are all purely mathematical methods, as long as the error between the simulated logging curve and the measured curve is less than a given ε, regardless of the rock physics, geology Whether the environmental and engineering conditions are reasonable, therefore, the results obtained by using traditional inversion methods are not reasonable enough

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