In-situ reagents injection system and method

An in-situ reagents injection system, comprising:

• a compressed air conveying pipeline providing compressed air to a first side of an injection well;
• a remediation reagents conveying pipeline providing remediation reagents to a second side of the injection well;
• an injection adjusting valve;
• an injection pipe;
• a first sealing unit;
• and
• a second sealing unit,
• wherein the compressed air conveying pipeline and the remediation reagents conveying pipeline are connected with the injection pipe at a same intersection in a Y connection located inside the injection well, the intersection is provided with the injection adjusting valve at the Y connection inside the injection well, and the injection adjusting valve is configured for switching off the remediation reagents conveying pipeline when the compressed air is injected or switching off the compressed air conveying pipeline when the remediation reagents are injected to the injection well,
• wherein the second sealing unit is arranged outside pipe walls at an end of the injection pipe, the first sealing unit is arranged outside the pipe walls at a position 0.5 m-0.75 m, away from a port at the end, from the second sealing unit, and the first sealing unit and the second sealing unit are configured for forming a seal with walls of the injection well when operated with the in-situ reagents injection system, and
• wherein a plurality of openings are formed in walls of the injection pipe between the first sealing unit and the second sealing unit.