High-temperature-resistant and high-salt-resistant oil reservoir profile modifying water plugging agent and preparation method thereof

Abstract

The invention provides a high-temperature-resistant and high-salt-resistant oil reservoir profile modifying water plugging agent and a preparation method thereof. The high-temperature-resistant and high-salt-resistant oil reservoir profile modifying water plugging agent comprises a suspension and plugging agent particles, wherein the plugging agent particles take an inorganic silicon material as an inner core, a thermal-swelling crosslinked resin membrane as an inner layer covering membrane, and a rigid resin protective membrane as an outer layer covering membrane; the inner layer covering membrane covers the inner core, and the outer layer covering membrane covers the inner layer covering membrane; and the suspension comprises water, guanidine gum and sodium borate. The invention also provides the preparation method of the profile modifying water plugging agent, and the preparation method comprises the following steps: covering the inner layer covering membrane on the surface of an inner core raw material, and after a needed thickness is reached, covering the outer layer covering membrane on the surfaces of particles covered with the inner layer covering membrane to obtain plugging agent particles; dissolving the guanidine gum in water, then adding the plugging agent particles, and stirring; and adding the sodium borate to obtain the high-temperature-resistant and high-salt-resistant oil reservoir profile modifying water plugging agent. The high-temperature-resistant and high-salt-resistant oil reservoir profile modifying water plugging agent provided by the invention is good in plugging effect and causes small damages to a reservoir stratum.

Description

technical field [0001] The invention relates to a profile control water shutoff agent, in particular to a high temperature and high salt oil reservoir profile control water shutoff agent, which belongs to the technical field of oil reservoir exploitation. Background technique [0002] With the development of oilfields, after decades of water flooding, all major oilfields have entered the development stage of high water cut period or even super high water cut period. In order to continue in-depth exploration of follow-up resources and increase remaining recoverable reserves, unconventional reservoirs with low or ultra-low permeability, high temperature or ultra-high temperature have been paid more and more attention. Some oil fields with high temperature and high salinity reservoirs, such as some blocks in Tarim Oilfield, have produced a large number of high permeability strips after long-term water flooding, and the injected water rushes along the high permeability strips at...

AI Technical Summary

Problems solved by technology

[0007] However, under the background that the high-temperature and high-salt reservoirs that are in the later stage of development are getting more and more attention, the above-mentioned granular plugging agents have not yet achieved satisfactory results in the actual application of such mines

In particular, most solid-phase particle plugging agents only act on the near-wellbore zone, and the plugging of the formation is rigid and non-selective, which is likely to cause damage to the integrity of the reservoir

At the same time, due to the defects in injectability and operability, the application of granular plugging agents is limited.

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