Nano-micron self-soluble temporary plugging steering agent for acidification

Abstract

The invention discloses a nano-micron self-soluble temporary plugging steering agent for acidification; the steering agent comprises the following components in parts: 0.5-1.5 parts by mass of an ironion stabilizer, 0.5-1.5 parts by mass of a clay stabilizer, 0.5-1.5 parts by mass of a discharge assisting agent, 0.5-1.5 parts by mass of a high temperature corrosion inhibitor, 0.05-0.15 part by mass of a dispersant, 0.1-0.3 part by mass of a suspending agent, 30-50 parts by volume of concentrated hydrochloric acid, 7-20 parts by mass of sodium chloride and 25-30 parts by mass of water. The formed steering agent is a sodium chloride particle substance with the particle size of less than 3 [mu]m, can enter a deep part of a reservoir and temporarily plug a high-permeability layer and net seams; along with the end of acidification construction, the sodium chloride particles playing the temporary plugging effect are dissolved in less than 10% of an acid residual liquid or formation water and plugging is removed. The steering agent does not contain organic polymer compounds, has the characteristics of no need of glue crosslinking, no need of glue breaking, self plugging removal, little damage to formation, simple preparation method, low cost and the like.

Description

technical field [0001] The invention relates to the field of oil and gas field development, in particular to 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 the reservoir, which af...

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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