Foam combination flooding produced liquid demulsifier and preparation method thereof

Abstract

The invention discloses a foam flooding produced liquid demulsifier which is a non-ionic polyether demulsifier and is characterized in that the demulsifier is prepared by three steps: phenolic resin serving as an initiator firstly reacts with epoxypropane in the presence of an alkaline compound serving as a catalyst to obtain a propoxylated polyether compound; the propoxylated polyether compound performs addition reaction with ethylene oxide under the effect of an alkaline catalyst to form an intermediate; and the intermediate reacts with epoxypropane, wherein in the reaction formula of each step, the alkaline compound is sodium hydroxide, potassium hydroxide or sodium ethoxide; in the three steps of reaction for preparing the demulsifier, the mass ratio of the phenolic resin to alkaline compound to epoxypropane in the first step of reaction is (20-30):(0.05-0.15):(50-90); the mass ratio of the propoxylated polyether compound to alkaline compound to ethylene oxide in the second step of reaction is (20-35):(0.1-0.45):(70-160); and the mass ratio of the intermediate to alkaline compound to epoxypropane in the third step of reaction is (20-30):(0.05-0.15):(50-90).

Description

technical field [0001] The invention relates to an oilfield chemical treatment agent, in particular to a foam composite flooding production fluid demulsifier and a preparation method thereof. Background technique [0002] After the oilfield development entered the period of high water cut, the chemical flooding oil recovery technology has become the leading technology for the continuous and stable production of Shengli Oilfield. 4 m 3 / d, reaching 40% of the total fluid volume in the oilfield. Among many chemical flooding technologies, foam has the characteristics of high apparent viscosity and strong displacement ability, which can not only significantly improve sweep efficiency, but also improve oil displacement efficiency. Therefore, foam system has potential advantages in tertiary oil recovery. The foam agent in the foam flooding system is a strong surfactant, which interacts with the active components of crude oil under reservoir conditions, reduces the oil-water int...

AI Technical Summary

Problems solved by technology

The foam agent in the foam flooding system is a strong surfactant, which interacts with the active components of crude oil under reservoir conditions, reduces the oil-water interfacial tension, and has a strong oil washing ability, but it enhances the recovery of the milky state. The interfacial film strength of the liquid increases the degree of oil-water emulsification, which increases the difficulty in the treatment of the foam flooding produced fluid

[0003] Produced fluid from three foam wells in the foam flooding pilot block of Chengdong Oilfield entered Chengdonglian. The foam agent increased the emulsification tendency and stability of crude oil during crude oil exploitation and oil-water mixed transportation, which had a great impact on the dehydration of crude oil in the combined station. , after the produced fluid enters the combined station, it is difficult to dehydrate the crude oil, the dehydration temperature rises, and the water content of the exported oil increases, which affects the normal operation of the combined station

[0004] Currently, conventional demulsifiers are used to treat foam flooding production fluids, which have a good demulsification effect on the interfacial film formed by active substances such as crude oil acidic active components and asphaltene as the main film-forming substances; The interfacial film structure of the foam flooding produced by the interaction of active components is stable, and conventional chemicals have poor adaptability and cannot effectively break the emulsion. As a result, the combined station has taken technical measures such as dumping tanks and releasing water, but the water content of the crude oil exported is still seriously exceeding the standard