Novel method for evaluating matching between initial radius of microsphere and reservoir pore throat structure

Abstract

The invention relates to a novel method for evaluating the matching between the initial radius of a microsphere and a reservoir pore throat structure, which comprises the following steps: (1) respectively measuring the reservoir core pore throat radius and the initial radius of the microsphere to obtain a reservoir core pore throat radius distribution curve, a microsphere radius distribution curve and a reservoir core pore throat radius and microsphere radius cumulative frequency distribution curve; (2) sequentially determining rmin, r25, r50, r75, rmax and Rmin, R25, R50, R75 and Rmax on the cumulative frequency distribution curve of the reservoir core pore throat radius and the microsphere radius; (3) fitting Q1 (R), Q2 (R), Q3 (R) and Q4 (R) on the reservoir core pore throat radius distribution curve; and fitting f1 (r), f2 (r), f3 (r) and f4 (r) on the microsphere radius distribution curve; and (4) evaluating the matching between the initial radius of the microsphere and the reservoir pore throat structure. According to the method provided by the invention, a long-period microsphere expansibility experiment is avoided, the method is simple, convenient, efficient and rapid, and a microsphere system meeting physical property conditions of a target reservoir can be rapidly screened out for the target reservoir.

Description

technical field [0001] The invention belongs to the technical field of petroleum exploitation, and relates to how to quantitatively and rapidly evaluate the matching between the initial radius of microspheres and the pore-throat structure of reservoirs. Background technique [0002] With the development of oilfields, water flooding has become the most widely used technical means at present. Since the Ordos Basin is mostly fractured and low-permeability reservoirs, natural micro-fractures and artificial fractures produced by fracturing are common in the reservoirs, and the heterogeneity of the reservoir itself is relatively serious. Long-term water injection development makes it easy to form advantages in the reservoirs. Channeling channel, once the channeling channel is formed, the water flooding sweep efficiency will decrease rapidly. [0003] The use of foam, microspheres and gel profile control plugging is the most commonly used technical method to control water channeli...

AI Technical Summary

Problems solved by technology

Carrying out the matching research between the radius of the microsphere and the pore-throat structure of the target reservoir is a necessary step before the field injection test of the microsphere, and it is also a key link that affects the later effect. However, at this stage, the matching of the microsphere and the pore-throat structure of the reservoir The performance evaluation is generally determined through long-term experiments to test the radius of the microsphere after the expansion is stable, and then simply compare the average diameters of the two to determine, and it is impossible to make a quick judgment directly through the initial radius parameter of the microsphere sample

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