Method for constructing reservoir oil-water property identification chart

Abstract

The invention discloses a method for constructing a reservoir oil-water property identification chart. The method comprises the following steps of respectively carrying out D-T2 two-dimensional nuclear magnetic resonance measurement on saline water with different masses to correspondingly obtain water signal centroids of the saline water with different masses; respectively carrying out D-T2 two-dimensional nuclear magnetic resonance measurement on the oil with different masses to correspondingly obtain oil signal centroids of the oil with different masses; and respectively projecting the watersignal centroids and the oil signal centroids into a preset coordinate system, determining distribution areas of the water signal centroids and the oil signal centroids, and constructing a reservoiroil-water property identification chart. According to the method, the defects that T2 one-dimensional nuclear magnetic resonance cannot distinguish oil-water signals and an existing D-T2 chart is notapplicable to unconventional reservoirs are overcome, identification of the oil-water signals can be achieved without clearing various influence factors and influence degrees thereof in advance, and the method is easy and rapid to operate, accurate and visual in identification and quite wide in application prospect in the unconventional reservoirs.

Description

technical field [0001] The invention relates to the technical field of oil and gas exploration and development, in particular to a method for constructing a reservoir oil-water property identification chart and a reservoir oil-water property identification method. Background technique [0002] NMR is a non-destructive and rapid identification and evaluation method for formation pore fluid. Existing T 2 The one-dimensional spectrum method needs to measure fresh samples and saturated samples first, and then soak the rock samples in relaxation reagents (such as manganese chloride) for a certain period of time, so that the water signal can be suppressed. However, for ultra-low porosity and ultra-low permeability unconventional reservoirs with nano-scale pore-throat scale, it is difficult for relaxation reagents to diffuse into tiny pores, and the degree of suppression of water signals and the time required cannot be measured, so oil-water signals cannot be accurately distinguis...

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Problems solved by technology

However, for ultra-low porosity and ultra-low permeability unconventional reservoirs with nanoscale pore-throat scale, it is difficult for relaxation reagents to diffuse into tiny pores, and the degree of suppression of water signals and the required time cannot be measured, so oil-water signals cannot be accurately distinguished

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