Long-acting active sand-controlling oil washing agent and preparation method thereof

Abstract

The invention relates to a long-acting active sand-controlling oil washing agent and a preparation method thereof. The sand-controlling oil washing agent is composed of the following raw materials in percent by mass: 3-5 parts of a long-chain fatty acid ammonium salt, 0.3-0.6 part of a silane coupling agent, 3-5 parts of a poly-amino compound, 1-3 parts of formaldehyde, 2-5 parts of a water soluble surfactant, 0.1-0.3 part of a hydroxide, 0.2-0.5 part of hydrochloric acid and 5-10 parts of hexane. The sand-controlling oil washing agent is synthesized by employing a three-step method. The action principle comprises that the surfactant is absorbed on rock and displaces crude oil originally attaching to rock, so that crude oil falls off from the surface of rock, and the purpose of washing oil is realized; excess ammonium ions are absorbed on the surface of clay, so that the electrostatic repulsion force on the surface of clay is counteracted and clay is stabilized; and also through the consolidation effect of generated sand-controlling oil-washing resin macro-molecules on sandstone, gravels are stabilized and consolidated.

Description

technical field [0001] The invention relates to a sand control and oil washing agent used for sand producing oil wells in oil fields, which belongs to oil field chemical agents for oil field stratum transformation and improvement of development effect; in addition, the invention also relates to a preparation method of the oil washing agent. Background technique [0002] The reserves of unconsolidated sandstone reservoirs account for about one-third of all oilfields. This type of reservoir is mostly muddy and calcareous cemented, and the rock cementation strength is relatively weak. Especially in the middle and late stages of development, a part of the cement between the sand grains is dissolved during long-term water injection development, which reduces the cementation strength of the formation, and rocks are prone to Destruction of sand production; at the same time, the injection of oil displacement media such as polymers, lye, and surfactants currently used will intensify ...

AI Technical Summary

Problems solved by technology

This type of reservoir is mostly muddy and calcareous cemented, and the rock cementation strength is relatively weak. Especially in the middle and late stages of development, a part of the cement between the sand grains is dissolved during long-term water injection development, which reduces the cementation strength of the formation, and rocks are prone to Destruction of sand production; at the same time, the injection of oil displacement media such as polymers, lye, and surfactants currently used will intensify the migration of formation particles to varying degrees, and the formation of sand production will be more serious. The rock particles near the wellbore are partially static, affecting Subsequent modification and production development effect

Studies have shown that chemical sand-consolidating agents are affected by the adhesion of formation crude oil and the electrostatic adsorption of residual polymers in the formation, resulting in incomplete consolidation of the sand-consolidating agent on the surface of the formation sand grains, resulting in a short effective period of sand control. According to statistics, the current overall effective period of chemical sand control is less than one year. year