Seepage plugging agent for controlling peek-shaped water absorption in water injection well

Abstract

A seepage formation sealant for controlling peek-shaped water absorption in a water injection well is applied to the water injection process in an oil field or an oil well, is seepage formation sealing for controlling peek-shaped water absorption in the water injection well, and is characterized by comprising the following materials by weight percent: 10 to 20 percent of acrylamide monomer, 0.3 to 0.5 percent of sodium polymethacrylate, 0.2 to 0.5 percent of N-N methylene-bisacrylamide, 1.0 to 2.0 percent of ammonium persulfate, 5 to 15 percent of 50 to 70 mesh methylene-bisacrylamide for objective fracturing, 0.01 to 0.05 percent of foaming agent (alkyl glycoside), and water in balancing amount. The seepage formation sealant has the effects that filtration is carried out on the water absorption peek section of a reservoir bed, a high-seepage section is blocked effectively after polymerization reaction, a certain fluid permeability is reserved, and the permeability of a low seepage section is reduced slightly, so that the waste-absorbing capacities in the length wise direction of a thick oil pay are approximately the same to realize uniform water absorption.

Description

technical field [0001] The invention relates to the technical field of oil well water injection in oil fields, in particular to a chemical treatment agent for downhole oil reservoir protection, and is a permeation sealing agent suitable for controlling peak-shaped water absorption in water injection wells. Background technique [0002] At present, some ultra-low permeability reservoirs in Changqing have developed fractures. During the water injection development process, due to the serious heterogeneity of the reservoirs, there are differences in the permeability between layers (or layers) of water injection wells, so the starting pressure of water absorption in each layer and The amount of water absorption is different. The injected water flows along the high permeability zone, and the water absorption profile shows peak-like water absorption, and even finger-like water absorption in severe cases, resulting in poor sweeping effect of injected water and rapid rise of water cu...

AI Technical Summary

Problems solved by technology

[0002] At present, some ultra-low permeability reservoirs in Changqing have developed fractures. During the water injection development process, due to the serious heterogeneity of the reservoirs, there are differences in the permeability between layers (or layers) of water injection wells, so the starting pressure of water absorption in each layer and The amount of water absorption is different. The injected water flows along the high permeability zone, and the water absorption profile shows peak-like water absorption, and even finger-like water absorption in severe cases, resulting in poor sweeping effect of injected water and rapid rise of water cut in oil wells

The existing basic methods for adjusting the water absorption profile of water injection wells include injecting particles and suspended solids, using physical plugging methods to block high-permeability sections, and using chemical plugging agents. Commonly used are vegetable glue and polymer gel. The disadvantage of these chemical plugging agents is that they completely seal off the seepage channels of the oil layer, or only play a plugging role for a short time, and the validity period is very short