An experimental method to discriminate the swept state of chemical flooding front

Abstract

The invention relates to an experimental method for judging the swept state of chemical flooding front. In the physical simulation flooding experiment, resistance probes are arranged in different positions of the core model in advance. After the flooding experiment starts, the resistance probes can detect the same position of the core. The resistance values ​​at different times are collected by the resistance measuring device and transmitted to the computer for analysis, and the curve of resistivity changes with time is drawn according to different time sequences. Based on this series of changes in the resistivity curve, the abrupt region can be found, and then the swept position of the displacement front can be obtained. Sampling is carried out at the position of the displacement front to minimize the waste of the sample. After the obtained sample is allowed to stand for clarification, the supernatant liquid is taken and analyzed in relevant equipment for its concentration and composition. The invention is simple to operate, and can more accurately determine the sweep state of the chemical flooding front.

Description

technical field [0001] The invention relates to the field of petroleum engineering, in particular to an experimental method for judging the sweep state of a chemical flooding front. Background technique [0002] When conventional oil fields enter the late stage of water flooding development, due to the heterogeneity of the reservoir, the oil recovery rate is low, and some crude oil in the low permeability layer cannot be produced. At this time, chemical flooding can often achieve ideal results. Chemical flooding can improve the efficiency of oil washing and expand the scope of exposure. Since the 1990s, chemical flooding has become an important method for enhancing oil recovery in the later stage of oilfield development by water injection in my country. In order to further improve the oil displacement effect of chemical flooding and improve the mechanism of chemical flooding, it is necessary to conduct in-depth and systematic research on the seepage law during chemical flood...

AI Technical Summary

Problems solved by technology

Sampling is commonly used in experiments to detect the concentration of chemical agents. However, it is difficult to characterize the front of the chemical flooding process. It is not known whether the sampling position has been affected by the chemical agent. Frequent sampling is often required to obtain the concentration change of the chemical flooding front.

Therefore, it often results in the waste of samples and the change of the flow field in the core during the experiment, which is easy to displace the formation of the dominant channel, and even directly affects the accuracy of the experimental results.

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