Test co 2 - Method and system for crude oil mmp

Abstract

The invention provides a method for testing CO based on a long narrow tube cementation model. 2 ‑Crude oil MMP method and system, the method is: obtain the relevant parameters of the low permeability oil layer, make a long narrow tube cementation model for indoor experiments, and obtain a sand-filled thin tube; Saturate the thin tube model with oil to obtain the formation crude oil saturation pressure; select multiple experimental pressures and conduct multiple narrow tube experiments to obtain the relationship between oil displacement efficiency and displacement pressure when injecting 1.2 times the pore volume in each narrow tube experiment. Relationship graph; the pressure value corresponding to the intersection of the immiscible segment and the miscible segment curve is the minimum miscible pressure value. The present invention adopts a long sand-filled capillary cementation model, which is a long capillary cementation model with micropores made under the condition of simulating the actual low-permeability reservoir, and the accuracy of the minimum miscible pressure measured by using the capillary model is higher , and is reasonable and scientific.

Description

technical field [0001] The invention relates to the technical field of laboratory experiments for oil field development, in particular to a method for making a cementation model of a long thin tube and a method for testing minimum miscible pressure. Background technique [0002] At present, there are two methods for obtaining the minimum miscibility pressure (MMP): theoretical calculation methods and experimental measurement methods. The theoretical calculation method is suitable for the situation where it is inconvenient to carry out experimental measurement, and the error is relatively large. Relatively speaking, the indoor experimental method is more accurate, and the CO measured in the narrow tube experimental method 2 It is currently the most widely used and most recognized method to involve crude oil in porous media in sand-packed capillaries. However, there are also relevant literatures that have raised some doubts about the problems in the narrow tube experiment: t...

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Problems solved by technology

The actual core test used by Liu Yuzhang and others corrected the test results of MMP, and confirmed that the reservoir structure has an influence on MMP, but the core used is relatively short compared with the thin tube test, only 1m

If we do not consider the period of the experiment, but only consider the academic accuracy and representativeness of the experiment, there is still a lack of research on the use of ultra-long core models with micropores

[0005] 2. The current minimum miscible pressure test does not take into account the influence of the permeability of low-permeability actual reservoirs, especially the permeability of low-permeability reservoirs

The fingering phenomenon of ultra-high permeability will inevitably be particularly obvious, and another point is not clear: that is, when the permeability changes greatly, whether the porosity also changes greatly, and how to eliminate the impact of porosity

[0006] Therefore, the defect in the prior art is that the existing CO 2 - In the research experiment of minimum miscibility pressure (MMP) of crude oil, the porosity of sand-packed capillaries and the permeability of low-permeability actual reservoirs will affect the test results of MMP. The limitation of its size, as well as the limitation of the actual reservoir permeability simulation, will also have an inevitable impact on the MMP test results

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