Method and device for correcting nuclear magnetic resonance logging porosity

Abstract

An embodiment of the invention provides a method and a device for correcting nuclear magnetic resonance logging porosity. The method includes: acquiring a well wall electric imaging logging image and nuclear magnetic resonance logging porosity corresponding to a target rock; establishing a nuclear magnetic resonance logging porosity correcting model according to size of the target rock, size of a gravel component, sizes of non-gravel components and porosity definitions; acquiring a proportion of the gravel component in the target rock according to the well wall electric imaging logging image; calculating a corrected nuclear magnetic resonance logging porosity according to the proportion of the gravel component in the target rock and the correcting model, wherein the corrected nuclear magnetic resonance logging porosity is a corrected value of the nuclear magnetic resonance logging porosity. Since the electric imaging logging image acquired according to an electric imaging logging technology is adopted for correcting the nuclear magnetic resonance logging porosity so as to obtain the corrected value of the nuclear magnetic resonance logging porosity, the situation that reservoir porosity determined by nuclear magnetic resonance logging is smaller than actual reservoir porosity of a stratum is avoided, and precision in evaluation of oil-gas reservoirs is improved.

Description

technical field [0001] Embodiments of the present invention relate to the field of petroleum exploration, and in particular to a method and device for correcting porosity in nuclear magnetic resonance logging. Background technique [0002] With the continuous development of petroleum exploration technology and the increasing complexity of exploration objects, NMR logging, as a new logging technology, has become one of the important logging methods to determine the porosity of reservoirs. Reservoir porosity refers to the ratio of the sum of the volume of all pore spaces in the rock sample to the volume of the rock sample. It is a parameter to measure the volume of pores contained in the reservoir rock and reflects the ability of the reservoir rock to store fluid. Therefore, the accurate calculation of reservoir porosity is of great significance to the fine evaluation of oil and gas reservoirs. [0003] The measurement object of nuclear magnetic resonance logging is the fluid...

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Problems solved by technology

[0004] However, when the reservoir lithology is sandy conglomerate, the reservoir porosity determined by nuclear magnetic resonance logging is smaller than the actual reservoir porosity of the formation, which makes fine evaluation of oil and gas reservoirs impossible

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