Method of analyzing a fluid comprising one or more phases in a sample of porous medium, comprising: - providing a device for analyzing a fluid in a sample of porous medium, the device comprising: * a measurement cell, containing a sample of porous medium containing a fluid comprising one or more phases; * a X-ray source, capable of illuminating the measurement cell with X-rays; * a detector, placed opposite the X-ray source with regards to the measurement cell, the measurement cell being interposed between the X-ray source on a one side and the detector on another side, the X-ray source being capable of illuminating the whole sample contained in the measurement cell without relative movement between the X-ray source and the sample; the detector being capable of receiving X-rays arising from the sample contained in the measurement cell and comprising a two-dimensional array of selective sensing areas capable of selectively detecting X-rays arising from different points spread on the surface of the sample, and outside of the sample; the device further comprising: * an analyzing unit able to determine a local property of the fluid at a plurality of positions of the sample, based on signals detected simultaneously by sensing areas at the given measurement time without relative movement between the X-ray source and the sample; the method comprising repeating the following steps, at several measurement times, without relative movement between the X-ray source and the sample: - illuminating at least a surface of the sample with the X-ray source, - selectively detecting X-rays arising from different points of the surface by a plurality of sensing areas of the detector; - determining a local property of the fluid at a plurality of positions of the sample, based on signals detected simultaneously by sensing areas, the determination step comprising calculating a fluid content in one or more phase at least at a plurality of positions of the sample, based on the signal detected by each sensing area. - providing a device for analyzing a fluid in a sample of porous medium, the device comprising: * a measurement cell, containing a sample of porous medium containing a fluid comprising one or more phases; * a X-ray source, capable of illuminating the measurement cell with X-rays; * a detector, placed opposite the X-ray source with regards to the measurement cell, the measurement cell being interposed between the X-ray source on a one side and the detector on another side, * a measurement cell, containing a sample of porous medium containing a fluid comprising one or more phases; * a X-ray source, capable of illuminating the measurement cell with X-rays; * a detector, placed opposite the X-ray source with regards to the measurement cell, the measurement cell being interposed between the X-ray source on a one side and the detector on another side, - illuminating at least a surface of the sample with the X-ray source, - selectively detecting X-rays arising from different points of the surface by a plurality of sensing areas of the detector; - determining a local property of the fluid at a plurality of positions of the sample, based on signals detected simultaneously by sensing areas, the determination step comprising calculating a fluid content in one or more phase at least at a plurality of positions of the sample, based on the signal detected by each sensing area.