Quantitative Evaluation Method of Water-flooded Layer in Reservoir

Abstract

The invention provides a quantitative evaluation method of the water-flooded layer of the oil reservoir. The method comprises: measuring the oil-water relative permeability curve of the core sample; obtaining the irreducible water saturation S of the core sample wi and residual oil saturation S or , to calculate its movable oil index K o and movable water index K w ;Simulate and draw the K of the core sample ro —K o and K rw —K w Curve; take the core samples to be evaluated in the water-flooded layer of the target reservoir, and obtain the irreducible water saturation S wi , Residual oil saturation S or and water saturation S w , get its relative permeability index K rf , and then quantitatively evaluate the water-flooded layer of the target reservoir. Based on the seepage characteristics of the reservoir and the test data of the core relative permeability, the method analyzes the variation trend of the oil-water relative permeability curve with water saturation. Based on this, the oil-water relative permeability index is constructed to characterize the water-flooded degree of the reservoir, and its logging interpretation model is established, so that the evaluation of the water-flooded layer of the reservoir is more accurate.

Description

Quantitative Evaluation Method of Water-flooded Layer in Reservoir technical field [0001] The present invention relates to the field of oilfield development geology, in particular, to a quantitative evaluation method for water-flooded layers in oil reservoirs. Background technique The vast majority of oil fields in China are continental deposits, the reservoir heterogeneity is serious, and the natural energy is insufficient, and water injection is mainly used. The reserves of oilfields developed by water injection account for more than 85% of the total reserves. After decades of waterflooding development, most oil fields It has entered the stage of high water cut and high recovery, and one of the main problems faced in the middle and later stages of development is the evaluation of water-flooded layers. regardless Whether it is a sandstone reservoir or a conglomerate reservoir, the evaluation of the water-flooded layer is very difficult. The stronger the heterogeneit...

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Problems solved by technology

[0004] The main purpose of the present invention is to provide a quantitative evaluation method for water-flooded layers of oil reservoirs, to solve the problem of low evaluation accuracy for water-flooded layers of oil reservoirs in the prior art

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