Detection method for heterogeneous degree of polymer flooding oil deposit

Abstract

The invention provides a detection method for the heterogeneous degree of a polymer flooding oil deposit. According to the detection method, the heterogeneous degree of the polymer flooding oil deposit is judged mainly according to a linear relationship between polymer output moments and injection and production well distance square. The detection method specifically includes: monitoring polymer concentration output data of each producing well, determining polymer output moments of the producing wells, and drawing a scatter diagram of the polymer output moments of the producing wells and the injection and production well distance square; calculating and standardizing a residual error, and eliminating singular points in data points according to the standardized residual error; performing linear regression on the data subjected to singular point elimination, and acquiring a straight line of the polymer output moments and the injection and production well distance square through fitting; calculating the standardized residual error again, dividing the heterogeneous degree of the polymer flooding oil deposit according to a numerical value of the standardized residual error and judging existence possibility of a large pore path. The method is high in operability, convenient to operate and capable of providing a good criterion for detection of the heterogeneous degree of the polymer flooding oil deposit.

Description

technical field [0001] The invention relates to a method for detecting the heterogeneity degree of polymer flooding oil reservoirs, in particular to a method for detecting the heterogeneity of oil reservoirs according to the relationship between the time of polymer production of production wells and the distance between injection and production wells. Background technique [0002] Polymer flooding is a method of flooding oil by injecting a polymer solution into the reservoir. Since the viscosity of the injected water is increased and the mobility ratio is improved, the swept volume can be effectively increased and the oil recovery rate can be enhanced. During the development of polymer flooding, the long-term scouring of the hyperpermeable zone by the injected fluid tends to aggravate the heterogeneity of the reservoir, causing the polymer solution to channel along the hyperpermeable zone or large pores, reducing the swept volume of the polymer solution. Seriously affect th...

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Problems solved by technology

[0003] At present, the detection of heterogeneity in polymer flooding reservoirs has attracted widespread attention. The main method used is tracer detection technology, but this technology requires special testing, which is expensive and affects production. It is necessary to establish A method for detecting the heterogeneity of polymer flooding reservoirs using only the production performance data of oil and water wells

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