Method for preparing nano-micron autolysis temporary plugging diverter

Abstract

The invention discloses a method for preparing a nano-micron autolysis temporary plugging diverter. The method comprises the following steps: at the room temperature, weighing a certain quantity of water, adding an iron ion stabilizer, a clay stabilizer, a cleanup additive and a high-temperature corrosion inhibitor into the water, performing stirring to obtain a mixed liquid I; continuously addinga dispersant into the mixed liquid I, performing stirring, then adding a suspending agent and sodium chloride, and performing stirring for 3-10 min to obtain a mixed liquid II; and weighing concentrated hydrochloric acid, adding the weighed concentrated hydrochloric acid into the mixed liquid II, and performing continuous stirring for 10-30 min to obtain a suspension out of which sodium chlorideparticles are separated. The formed diverter is a sodium chloride particulate substance with the grain size smaller than 3 [mu]m, and can deeply enter a reservoir to temporarily plug a high-permeability layer and seams. Along with ending of acidizing construction, sodium chloride particles which play a temporary plugging role are dissolved into a residual acid liquid or formation water for unplugging. The method has the characteristics that an organic high-molecular compound is not contained, gluing linkage or gel breaking is not needed, self-unplugging is realized, little formation damage iscaused and the method is simple and is low in cost.

Description

technical field [0001] The invention relates to the field of oil and gas field development, in particular to a preparation method of a temporary plugging diversion self-dissolving diversion agent, in particular to an autodissolvable temporary plugging diversion agent containing nano-micron sodium chloride particles. Background technique [0002] Acidizing and acid fracturing is one of the commonly used stimulation measures for low-permeability reservoirs in the exploration and development of oil and gas fields. Through the contact reaction between the acid liquid and the formation rock, acid corrosion holes are generated, which makes the formation oil and gas flow out more easily, and achieves the purpose of increasing production capacity. However, the acid liquid follows the principle of natural selection during acidification, that is, it preferentially enters the high-permeability area of ​​the reservoir, and it is difficult to effectively transform the low-permeability of...

AI Technical Summary

Problems solved by technology

However, these two methods have certain limitations: chemical particle diversion technology, whether it is oil-soluble resin or water-soluble resin, although it can form a filter cake on the wall of the wellbore or fracture and then block the high-permeability area to achieve the purpose of diverting acid fluid. purpose, but the particles of this type of organic resin are very sensitive to natural fractures in the formation, which mainly form filter cakes on the fracture walls so that they cannot reach deeper layers

Second, most organic resin diverting agents are obtained through chemical cross-linking of high molecular polymers. If the flowback is not thorough, there will be residues, which will easily damage the formation, and even cause permanent blockage of the formation, causing irreversible damage to the permeability of the formation. Not reaching the purpose of acidification to increase production

Viscosification diversion diversion technology, the viscosifier, especially the polymer residue is serious, easy to cause secondary damage to the reservoir

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