Silicate plugging agent for oil-well water plugging and application method thereof

Abstract

The invention discloses a silicate plugging agent for oil-well water plugging and an application method thereof, wherein the silicate plugging agent comprises the following components by weight percentage: 8-12% of general purpose portland cement, 1-3% of silica fume, 0.3-0.7% of water glass, 0.01-0.03% of sodium lignin sulfonate and the balance of water. The application method of the silicate plugging agent for oil-well water plugging comprises the following steps: in the stirring process, orderly adding the water glass, the sodium lignin sulfonate and the silica fume in a stirring pot with water proportionally, and stirring evenly to obtain a mixed solution; next, adding the general purpose portland cement to the mixed solution while stirring to form the base solution of the silicate plugging agent; and pouring the base solution of the silicate plugging agent into formation fractures. The silicate plugging agent provided by the invention has the advantages of high water cement ratio, good pumping performance, long initial setting time, high after-final-setting strength, good water scouring resistance, all of which are similar to the own physical properties of the formation; the silicate plugging agent is capable of achieving the construction requirements of oil-well water plugging; and the properties of the silicate plugging agent are suitable for nonhomogeneous fractured reservoirs.

Description

technical field [0001] The invention relates to the field of oilfield chemicals, in particular to a silicate plugging agent for oil well water plugging and a use method thereof. Background technique [0002] In the process of oil field development, due to formation heterogeneity, natural fractures in the original formation or artificial fractures generated during the development process, as well as strong production and injection, the sand production in the formation, the loss of a large amount of cement, and the destruction of the cemented structure are caused. The characteristics of high permeability, large pores, and fractures will appear in the formation, which will lead to a sharp increase in water cut in the oil well, a rapid decline in production, an increase in the workload of water treatment, low recovery of the oil reservoir, and even water-flooded wells. The plugging of this type of formation Technology has always been an intractable problem. [0003] In the prio...

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Problems solved by technology

[0004] In the process of realizing the present invention, the inventors found that the prior art has at least the following problems: organic plugging agents have low plugging strength or short plugging validity period, conventional cement plugging agents have low water-cement ratio, are prone to settlement, and have poor pumpability , The initial setting time is short, and the construction pipe string is easy to be blocked, which brings certain limitations to the on-site construction