Waterproof locking agent and preparation method thereof

Abstract

The invention provides a waterproof locking agent which is suitable for the technical fields of oil field oil gas drilling and oil-gas field development. According to the scheme, surface tension and oil-water interfacial tension in rock capillary pores are effectively reduced, and the surfaces of the rock capillary pores are converted into neutral lubrication, so that the water locking effect is relieved, and the oil and gas recovery efficiency is improved. The waterproof locking agent comprises the following components: 3%-10% of a nonionic surfactant, 10%-15% of an anionic surfactant, 5%-10% of a zwitterionic surfactant, 5%-10% of low-carbon alcohol and the balance of water. The waterproof locking agent is simple in preparation method, can reduce surface tension and oil-water interfacial tension, converts rock capillary pore surfaces into neutral wetting, and has good waterproof locking effect performance.

Description

technical field [0001] The waterproof locking agent prepared by the invention is suitable for oil and gas drilling in oil fields and the technical fields of oil and gas field development. Background technique [0002] The water lock effect refers to a phenomenon in which foreign fluids enter the reservoir during the drilling, completion and development of gas reservoirs, resulting in an increase in water saturation and a decrease in gas phase permeability. [0003] Low-permeability reservoirs generally have the characteristics of high capillary pressure, strong water sensitivity, small pore throats, poor permeability, and severe heterogeneity. In the process of oil production, the well fluid is prone to capillary self-absorption in the water phase, causing a large amount of well fluid to enter the reservoir. The poor permeability of low-permeability reservoirs leads to the flowback of the well fluid that invades the reservoirs, resulting in water lock damage. [0004] At p...

AI Technical Summary

Problems solved by technology

In addition, the rocks in the reservoir are mostly water-wetted, and the self-absorption effect of water also occurs. The water phase in the wellbore working fluid is sucked into the oil-gas seepage channel of the rock in the reservoir, and the oil and gas in the reservoir are pushed to the deep bottom, changing the well The distribution of oil, gas and water around the eye will cause the relative permeability of oil and gas to decrease, and finally lead to the decrease of oil and gas recovery