@Article{sl.2013.009.131,
AUTHOR = {Duan Xiang-gang, Hou Ji-rui, Liu Hui, Yin Zhong-min, Tang
Yong-qiang, Su Wei},
TITLE = {The Influence of ASP Flooding on Reservoir Formation Sensitivity},
JOURNAL = {Structural Longevity},
VOLUME = {9},
YEAR = {2013},
NUMBER = {2},
PAGES = {131--142},
URL = {http://www.techscience.com/sl/v9n2/42909},
ISSN = {1944-6128},
ABSTRACT = {As an enhance oil recovery method, Alkali, surfactant and polymer
(ASP) flooding has been already widely used in Daqing oilfield. However, there
are many challenges to reservoir formation by using the ASP flooding, such as the
reaction between alkali and clay mineral, adsorption of surfactant and retention of
polymer, which may cause damage to oil and gas formation. In order to evaluate
the formation damage, reservoir sensitivity is researched.<br/>
Through the core flow testing, the sensitivity of velocity, water, alkali and acid of
core sample has been studied. The core samples are taken from the formation in
Daqing oilfield with or without ASP flooding. Moreover, the reason for the change
of reservoir sensitivity also has been studied by using scanning electron microscope
and X-ray diffraction method.<br/>
The experimental formation has the weak velocity sensitivity, strong to medium
water, acid sensitivity and weak to medium alkali sensitivity before ASP flooding.
However, when comparing the result with the reservoir sensitivity after ASP flooding, it is found that the velocity sensitivity disappears because of the decreasing
water sensitive minerals kaolinite, which has been corroded by alkali mostly. The
water sensitivity becomes more serious due to the increasing illite/smectite layer,
which has strong expansion ratio and cation exchange capacity, and can absorb a
large amount of polar water molecules. After the long time reaction between the
alkaline fluids and rocks after ASP flooding, both the acid and the alkali sensitivity
reduce relatively.<br/>
According to analyzing results, the components of reservoir stratum and clay mineral have been changed after the ASP flooding. Due to the Erosion of alkali on
formation Minerals, the content of kaolinite reduces, and some minerals increase,
such as illite/smectite layer, chlorite and plagioclase. In conclusion, alkali corrosion and scale-forming is considered to be the main reason for reservoir sensitivity
changing.},
DOI = {10.3970/sl.2013.009.131}
}