A composite plugging removal agent and a composite plugging removal method for fracturing and putting into production horizontal wells in tight sandstone reservoirs

Abstract

The invention discloses a composite blocking remover and a method for removing blockage of a compact sandstone reservoir pressing crack commissioning horizontal well in a composite manner. The composite blocking remover comprises a preposition liquid, a main treating fluid, an active blocking remover and a subsequent fluid. The preposition liquid is composed of organic acid, inorganic acid, a stabilizer, an oxidizing agent, a chelating agent, a corrosion inhibitor, polyol ether and water. The main treating fluid is composed of organic acid, inorganic acid, the stabilizer, the oxidizing agent, a fluorine carbon surfactant and water. The active blocking remover is composed of a zwitterionic surfactant, the stabilizer and water. The subsequent fluid is water. The composite blocking remover can remove the blockage of routine colloid, asphalt mass and inorganic solid phase particles, and can remove the damage of water blocking and crude oil emulsification by pertinency, and has the advantages of good slow performance, effectively preventing secondary deposition pollution such as the iron ion deposition and acid sludge generation, the horizontal well near-well and deep reservoir pollution can be effectively released, the oil well production power is recovered, and the recovery efficiency can be greatly increased.

Description

technical field

[0001] The invention belongs to the technical field of oilfield exploitation, and in particular relates to a composite plugging-removing agent, and also relates to a composite plugging-removing method for fracturing and putting into production horizontal wells in tight sandstone reservoirs. Background technique

[0002] Tight sandstone reservoirs are characterized by low permeability, narrow pore throats, and well-developed micro-fractures, and the drilling fluid is prone to leakage during drilling; when horizontal wells are put into production by staged fracturing, a large amount of liquid will inevitably enter the formation; , the reservoir is extremely vulnerable to damage from external incompatible fluids, and at the same time, due to the influence of temperature, pressure and other factors, it is easy to cause wax, colloid, and asphaltene to deposit near the wellbore, forming organic plugging; the well fluid contains a large amount of inorganic or Organi...