Preparation method and application of autogeneration gas foam composite oil-displacing agent under shaft

Abstract

The invention discloses an autogeneration gas foam composite oil-displacing agent under a shaft. The autogeneration foam composite oil-displacing agent under the shaft is characterized by being formed by an agent A and an agent B, wherein the agent A comprises the following components in percentage by mass: 45 percent-65 percent of urea, 20 percent-35 percent of ammonium nitrate, 5 percent-10 percent of sodium azide, and 8 percent-15 percent of acetylsalicylic acid; the agent B comprises the following components in percentage by mass: 35 percent-65 percent of sodium nitrite, 15 percent-35 percent of glycine betaine, and 10 percent-30 percent of polyacrylamide. When entering into a stratum or the shaft, the foam composite oil-displacing agent provided by the invention generates gas through chemical reaction under the stratum conditions; the gas is reacted with the glycine betaine and the polyacrylamide in the oil-displacing agent, so that mass of foam is formed in the stratum; the generated foam is stable, is distributed evenly, and has long duration time without additional gas; the operation process and the operation equipment are simple; and according to a method, the yield can be improved, and the cost is reduced.

Description

technical field [0001] The invention relates to oil field tertiary oil recovery technology, in particular to a preparation method of an underground self-generating foam composite oil displacement agent and an oil displacement method using the underground self-generating foam composite oil displacement agent. Background technique [0002] At present, with the later stage of exploitation of most oilfields in China, many oilfields are in the stage of high water cut and high recovery degree, the comprehensive recovery rate is relatively low, and many wells have low production. In the 1980s, my country developed chemical flooding tertiary oil recovery technology. Tertiary oil recovery is compared with primary oil recovery and secondary oil recovery. In the early stage of oil exploitation, the oil recovery is only using the natural energy of the formation as primary oil recovery, and the recovery rate is only about 10%. Reaching about 25% to 40%; tertiary oil recovery is to use p...

AI Technical Summary

Problems solved by technology

Steam foam flooding is affected by the heterogeneity of the reservoir, the steam absorption of each single layer is uneven, the steam rushes along the high permeability zone, and the phenomenon of overburden and steam channeling occurs, and the volume of steam sweep decreases. , the throughput effect becomes worse

Since nitrogen, carbon dioxide and other gases can not only improve the effect of steam injection huff and puff, but also serve as the origin of foaming, nitrogen is injected at the same time as steam in the oil production process to reduce the heat loss of the wellbore and adjust the gas suction of the thermal recovery well profile, expand the volume and range of steam sweeping, and improve the utilization rate of steam. Due to the complex construction, long time and high cost of nitrogen foam profile control technology, and a nitrogen truck cannot meet the current production needs