Preparation method and application process of oil washing agent

Abstract

The invention discloses a preparation method and an application process of an oil washing agent. A base solution is prepared from the following components by weight percent: 10-15% of A, 5-10% of B, 15-20% of C, 5-10% of D, 5-10% of E, 5-10% of F, 5-10% of G, 5-10% of H and 10-20% of water. A preparation method of the base solution of the oil washing agent comprises the following steps: adding F and G into a stirring tank with a heating function according to the proportion; sequentially adding A, B, C, D and E into the stirring tank while stirring, and heating for complete dissolution; and finally, adding H, controlling the temperature at 80+/-5 DEG C, and performing heat preservation for 1 hour to obtain the base solution. The oil washing agent is obtained by preparing the base solution into 1% of aqueous solution with 4% of NaCl and 0.1% of CaCl2 solution, and curing the aqueous solution in water bath at 90 DEG C for 24 hours. The application process of the oil washing agent adopts an oil recovery method of combining the oil washing agent with the CO2 huff-puff technology; the oil washing efficiency of the oil washing agent reaches 97% and above, and the purpose that the single round of huff-puff can increase the oil recovery rate by 1% is further achieved.

Description

technical field [0001] The invention belongs to the technical field of tertiary oil recovery, is mainly used for the exploitation of old oilfields with high water content, and relates to a [0002] A preparation method of an oil washing agent and a process method for increasing the recovery rate of residual oil. Specifically relate to a kind of preparation method of oil washing agent [0003] method and its application. Background technique [0004] After more than ten to several decades of water injection development, the old oil fields in various countries in the world have generally entered the stage of high water cut and high recovery degree, and most of the old oil fields in my country have also entered the late stage of high water cut or high water cut. In the ultra-high water-cut stage, the comprehensive water cut is as high as 80% or more. A large amount of data shows that the high water-cut exploitation stage is the most difficult period for oilfield development....

AI Technical Summary

Problems solved by technology

[0006] Existing oil washing agents are sensitive to salinity, and their performance drops significantly when the salinity is high, especially in the presence of high-valent metal ions such as calcium and magnesium, which greatly restricts their application. Therefore, it is necessary to develop a system suitable for actual oilfield systems. Detergent for formation properties