Temporary plugging composition of oil layer and application method

Abstract

The invention discloses a temporary plugging composition of an oil layer and an application method of the temporary plugging composition. The temporary plugging composition comprises 2-20 parts by weight of cleaning diverter XT-25A and 10-20 parts by weight of sodium salicylate and also further comprises 2-10 parts by weight of acetic acid, 1-10 parts by weight of ammonium chloride and 80-97 parts by weight of water. According to the temporary plugging composition of the oil layer, disclosed by the invention, after being injected into a stratum, a temporary plugging solution made of the cleaning diverter XT-25A and the sodium salicylate preferentially enters high-permeability pores; after the temporary plugging solution is converged with stratum water, the viscosity of the temporary plugging solution is instantly increased, so that the purpose of limiting and preventing subsequent liquid from permeating and flowing along a water flow channel with a large hole channel is achieved; in the event of encountering an ultra-large hole channel or a cracked stratum, based on injection of the temporary plugging solution, acetic acid, ammonium chloride and water are made into cross-linked fluid and injected into the stratum; the cross-link fluid and the temporary plugging solution are converged to carry out cross-linking reaction, so that high-intensity gel is formed; large-hole, high-permeability or cracked stratums can be thoroughly plugged; filtration of transformed liquid is avoided; and the formed high-intensity gel can be automatically broken within a short time in the event of being encountered with hydrocarbon or ethylene glycol monobutyl ether.

Description

technical field [0001] The invention relates to an oil layer temporary plugging composition, which belongs to the technical field of petroleum exploitation. Background technique [0002] After the oilfield entered the ultra-high water-cut development period, the main oil layer was flooded in a large area, and the remaining oil in the formation was mainly distributed in the middle and low permeability intervals in the thick oil layer. Due to the small pore throats and tight lithology in the middle and low permeability intervals, the natural production capacity is extremely low. In order to increase the productivity of oil wells, it is necessary to carry out oil layer stimulation measures such as acidification of the reservoir. [0003] In conventional acidizing construction, the acid solution follows the principle of least resistance, and selectively preferentially enters the high-porosity and high-permeability reservoirs, while the low-permeability layers cannot receive pro...

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Problems solved by technology

[0003] In the conventional acidizing construction, the acid solution follows the principle of least resistance, selectively and preferentially enters the high-porosity and high-permeability reservoirs, and the low-permeability layer cannot receive proper treatment because of little or no acid inflow. In this way, the measures Afterwards, the liquid production rate of the reservoir often rises sharply, while the oil production rate drops sharply.

Therefore, for reservoirs in the ultra-high water-cut development period, if the conventional acidizing treatment measures are adopted, since the acid liquid cannot effectively enter the expected target interval, not only cannot effectively improve and improve the seepage capacity of the middle and low permeability layers, but further increase the thickness of the formation. Permeability difference between different sites, resulting in inefficient or ineffective acidizing construction

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