The Character And EOR Research Of ASP Flooding On The Second Type Oil Reservoir Of SaZhong Developing Area In Daqing Oilfield

The second oil reservoir is a kind of sandstone between the major and poor reservoir, compare to the major reservoir, its number of layers is more, its reserves is biger. But compared with the major reservoir, its permeability is lower and thickness is thiner, sand channel size is narrower, the continuity is worse. It is the succeden reservoir of productivity in daqing oil field. Asp is the abbreviation of alkali, polymer and surfactant. So ASP flooding is a kind of chemical displacement to according to certain formula proportion.This paper is based on the test of ASP flooding in the second type heterogeneous reservoirs SaZhong area. Fine description of reservoir characteristics and residual oil distribution study of the second oil reservoir were made, flood plain, distributary plain and the former front phase are the main sandstong reservoir in the second type reservoir of SaZhong area; studied the adaptability of compound flooding in this kind reservoirs according to the geological characteristics and reservoir properties, Resistance coefficient and residual resistance coefficien are positively in growth with the polymer molecular weight and its solutin’s concentration of the compound flooding, but oppsite to the core permeability. The unfiltered ASP system can make deeper core permeability damage than filtrable one. Adsorption of surfactants in oil is the largest in the three agents; a set of oil flooding comprehensive adjustment method was formed for different satage in the ASP flooding process. Injection in 2 or 3 section to reduce the permeability differential after 2.5, can effectively improve the using degree of the second type reservoir. The validity of fracture technology such as Multiple fracturing in the non-channel sand with A class connected is more than 400 days, and the fracture is made in the dropping and stable period of water cut, its validity can keep more than 11 months, the effect of the fracture can promote the ASP flooding effective. The profile technology is used in the injection well with high comprehensive parameter evaluation, higher than 0.6, can obviously increase the injection pressure and the used proportion of the reservoir. the water plugging technology is taken to the oil well,with deep submergence, high solution production and water cut, can effectively increase the oil production of single well in the water recovery period. According to the center oil wells’change rule of the water cut and oil product, prediction model with 4 point 3 phases is established, it’s fitting accuracy above 81%. The effect of asp flooding in the second reservoir was evaluated. For ASP flooding, its asp agent is producted later than its effect, and the ASP can enhance oil displacement efficiency, improve the use of thin layer section, its EOR is 28%, the effect is obvious. The technology expands the direction of EOR on second oil reserviors, and provide the gist for the asp flooding’s expand on scheme optimization design and development adjustment reference;it has very important significance to provides a more effective replacement technical safeguard measures for oilfield sustainable development.