Fiber steering acid

Abstract

The invention relates to a fiber steering acid. The fiber steering acid comprises the following components in percentage by weight: 12 to 30 percent of hydrochloric acid, 1 to 3 percent of a corrosion inhibitor, 1 to 2 percent of a surface active agent, 1 to 2 percent of an iron ion stabilizing agent, 0.1 to 2 percent of fibers and the balance of water. The fibers are hydroxypropyl methyl cellulose, hydroxypropyl cellulose, hydroxyethyl cellulose or polyester fibers, and the used length of the fibers is 5 to 30mm; the corrosion inhibitor is methyl sulfate heptadecenyl imidazoline ammonium, methyl sulfate heptadecyl-dihydroxyethyl imidazoline methyl ammonium, chloro-1-N-ethoxyl-2-alkyl imidazoline ammonium or a mixture thereof; the surface active agent is dodecyl sodium sulfate, cetyl sodium sulfate or a mixture thereof; and the iron ion stabilizing agent is sodium citrate, sodium isoascorbate or a mixture thereof. According to the fiber steering acid, the fibers are injected into a stratum and wound with one another to block cracks and holes with larger apertures and guide acid liquor to change directions, so that uniform acid distribution and deep part acidification are achieved, and the fibers are completely degraded and pollution-free to the stratum.

Description

technical field [0001] The invention relates to a diverting acid used in acidizing construction of oil and gas wells in the field of oil and gas field development and production increase. technical background [0002] The main purpose of reservoir matrix acidizing is to decontaminate the near-wellbore zone or create new flow channels (wormholes) to bypass the polluted zone, increase the connectivity between the reservoir and the wellbore, and improve the productivity of oil and gas wells or the injection capacity of water injection wells. In order to achieve the desired purpose of acidification treatment, the problem of uniform acid distribution must be solved first. According to the principle of the least fluid flow resistance, the acid liquid enters the layer with the highest permeability or the least damage first, and for the low-permeability zone or serious damage layer that needs to be unplugged, little or no acid may enter. For extremely thick reservoirs with large di...

AI Technical Summary

Problems solved by technology

[0006] When there are natural fractures in the reservoir or there is a huge difference in permeability, whether it is mechanical diversion or chemical diversion, its diversion effect is not ideal

For many small and thin reservoirs, the packer cannot seal well, and for the reservoirs with developed fractures, the packer cannot effectively control the flow direction of the acid liquid; the chemical diverting agent currently used is some polymer compounds, Rely on these polymer compounds to adhere to the walls of cracks or pores, block the cracks and pores, and divert the acid liquid, but when the cracks and pores are large, these polymer compounds cannot effectively play a blocking role