Method for evaluating influence of tight reservoir micro-pore structure features on effects of displacement of oil by water

Abstract

The invention provides a method for evaluating the influence of tight reservoir micro-pore structure features on the effects of displacement of oil by water. The method comprises the following steps:1) establishing a tight reservoir micro-pore structure classification standard; 2) making micro models based on classified tight reservoirs; 3) performing an experiment of displacement of oil by wateron each micro model; 4) obtaining the effects of displacement of oil by water corresponding to different types of reservoirs. According to the method provided by the invention, a movable fluid parameter of a tight reservoir sample is measured by using the nuclear magnetic resonance technology, and the micro-pore structure of a tight sandstone reservoir is studied in combination with casting bodythin section analysis, scanning electron microscope, high pressure mercury injection and other experimental results, a micro-pore structure classification standard of the target reservoirs is established, the experiment of displacement of oil by water is performed on three types, and the relationship between the micro-pore structure features and the oil displacement efficiency has important guiding significance for the formulation and adjustment of development programs of the tight reservoirs.

Description

Technical field [0001] The invention belongs to the technical field of oil and gas field development, and relates to a method for evaluating the influence of the microscopic pore structure characteristics of a tight reservoir on the effect of water displacement based on nuclear magnetic resonance technology. Background technique [0002] In recent years, as conventional oil and gas resources have been declining, the world has increased the exploration and development of unconventional energy, especially tight oil and gas. Tight oil and gas occupies a large proportion of my country's oil and gas composition. Improving the development effect of tight oil and gas reservoirs is of great significance to safeguarding national energy security. [0003] The microscopic pore structure of tight sandstone reservoirs has a significant impact on the characteristics of water flooding. Tight sandstone reservoirs are characterized by small pore throats, high proportion of small primary and second...

AI Technical Summary

Problems solved by technology

[0004] At present, the division of tight reservoir microscopic pore structure classification standards is usually only based on reservoir characteristics (including reservoir genesis, petrological characteristics, and sedimentary microequalities), physical properties (porosity, permeability), pore-throat combination, and pore type. However, it is not perfect to evaluate the pore structure of tight reservoirs based on the above methods and related parameters.

In addition, there are great differences in water injection displacement types, oil displacement efficiency and residual oil distribution characteristics among different types of reservoirs. Therefore, the relationship between microscopic pore structure characteristics and oil displacement efficiency needs to be further studied.

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