Rock wetting heterogeneity characterization method and device based on imbibition wetting angle distribution

Abstract

The invention provides a rock wetting heterogeneity characterization method and device based on imbibition wetting angle distribution. The method comprises the following steps: soaking a rock saturated by a first fluid in a second fluid; measuring the wetting angle of the first fluid on the rock surface under the imbibition effect; soaking the rock saturated by the second fluid in the first fluid; the wetting angle of the second fluid at the rock surface under imbibition is measured, wherein the first fluid is immiscible with the second fluid. According to the rock wetting heterogeneity characterization method and device based on imbibition wetting angle distribution, provided by the invention, errors caused by insufficient contact between liquid drops and the surface of a rock core to wetting angle measurement are eliminated; a new thought is provided for measuring and representing wetting heterogeneity; and according to the probability distribution of the wetting angle, a basis is provided for porous medium two-phase fluid displacement mechanism research and numerical simulation research.

Description

technical field [0001] The invention relates to the field of petroleum exploration and development, in particular to a core parameter measurement technology, in particular to a method and device for characterizing the heterogeneity of rock wetting based on the distribution of the wetting angle of imbibition. Background technique [0002] Wettability is an important parameter to describe the physical properties of oil and gas reservoirs, and it has a significant impact on multiphase seepage in reservoir rocks. Therefore, whether it is migration and accumulation research or development mechanism research, the wettability of reservoir rocks is very much concerned. sex. The commonly used methods for determining wettability in the prior art include three methods: the Amott method, the USBM method and the wetting angle. The Amott method and the USBM method derive the wettability index on the basis of two-phase displacement, and use the wettability index. To characterize rock wett...

AI Technical Summary

Problems solved by technology

The commonly used methods for determining wettability in the prior art include the Amott method, the USBM method and the wetting angle method. Among them, the Amott method and the USBM method derive the wettability index on the basis of two-phase displacement, and use the wettability index To characterize rock wettability, the wettability measurement process of these two methods is cumbersome and time-consuming, and the obtained wettability index cannot be directly related to the capillary force concerned in oil and gas exploration and development; for the wettability angle method, its When measuring the wetting angle of reservoir rocks, a droplet is usually dropped on the surface of the core, and the shape of the droplet is photographed by a camera, and the wetting angle is measured after analyzing the shape of the droplet. The defect of this method is that the surface of the core is microscopically Rough, with many microscopic pits distributed, so the droplet is not in direct contact with the rock surface at the pits, but is in contact with another phase fluid retained in the pits, which is bound to give the measurement of the wetting angle bring large error

[0003] In addition, due to the influence of factors such as the electrical properties of rock particles and the distribution of oil and water in rock pores, the wettability of reservoir rocks presents a characteristic of non-uniform distribution. Some explorations have been made in the aspect of homogeneity, but these methods are often limited to the ratio of the surface area of ​​oil-wetted and water-wetted particles, and the degree of oil-wetted and water-wetted cannot be measured

Images