High temperature stratum self-generating foam composition and application thereof in viscous oil exploitation

Abstract

The present invention is foam-generating composition for high temperature stratum and its application in exploiting thick oil, and belongs to the field of surfactant technology. Chemicals capable of producing N2, CO2 and other gas are adopted to produce gases through the reaction of A+B+C-->N2+NH3+CO2+C, where A is reductant, B oxidant and C foaming agent. The reaction is controlled by temperature, and the foam-generating composition contains also surfactant with high heat resistance, high salt tolerance, high oil / water interface activity and high foam stability. After the chemicals are injected into the stratum at normal temperature, steam is injected to initiate reaction producing stable foam in the stratum, and the foam can plug to avoid steam fleeing, raise high temperature steam sweep efficiency, raise blotter efficiency, promote crude oil to disperse and raise the thick oil exploiting rate greatly.

Description

(1) Technical field [0001] The present invention proposes a high-temperature formation self-generated foam composition and its application in heavy oil recovery, which belongs to surfactant [0002] technology field. (2) Background technology [0003] In the production of heavy oil, steam injection thermal recovery is the main production method. High-temperature steam heats the oil layer, which greatly reduces the viscosity of crude oil, and at the same time eliminates the clogging of the oil layer near the wellbore, reduces the flow resistance of crude oil and increases the production. However, due to the ubiquitous interlayer and intralayer heterogeneity of oil reservoirs, and the low density and viscosity of steam, gravity overriding and viscous fingering seriously affect its effect. The former is because the density of the steam is lower than that of the oil, so that the steam surpasses the oil wall, and the latter is because the viscosity of the steam is lower than tha...

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Problems solved by technology

The cost of mechanical gas injection is high; the speed of gas introduction is fast and difficult to control; the diameter of the generated foam is large and uneven, which affects the stability of the foam; the injection process is easy to cause gas blockage at the injection end, and the injection pressure increases sharply, affecting the stability of the foam. construction

In addition, ordinary foaming agents cannot form stable foams at high temperatures, and cannot be used as high-temperature plugging and profile control systems

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