Intelligent layered nano foam stabilizer, preparation method thereof and application of intelligent layered nano foam stabilizer in foam flooding

Abstract

The invention discloses an intelligent layered nano foam stabilizer and a preparation method and application thereof in foam flooding, the formula comprises MXene, inorganic matter, an alkali source and a cross-linking agent, and the preparation method comprises the following steps: step 1, weighing raw materials; 2, preparing a mixed solution A; step 3, preparing a mixed solution B; and step 4, obtaining a finished product. The intelligent layered nano foam stabilizer is obtained by performing in-situ crosslinking on the surface and between layers of MXene, depositing magnetic nano particles and improving the hydrophilic and hydrophobic properties of the MXene, and the intelligent layered nano foam stabilizer has the characteristics of prolonging the service life of foam and improving the comprehensive performance of the foam, so that the acting time of the foam in a formation pore throat is prolonged, and the foam is prevented from being damaged. Temporary plugging of large hole channels of the stratum is achieved, and the crude oil recovery rate is increased; and after the foam is broken when meeting oil, the intelligent layered nano foam stabilizer can be quickly recycled and reused through an external magnetic field, and the intelligent layered nano foam stabilizer has important significance on improvement of the foam oil displacement effect and further popularization and application.

Description

technical field [0001] The invention relates to the technical field of tertiary oil recovery chemicals, in particular to an intelligent layered nano-foam stabilizer, a preparation method thereof and an application in foam flooding. Background technique [0002] With the sharp increase in demand for oil and gas resources in various countries around the world, deep oil and gas reservoir resources in high-temperature geothermal environments have gradually become the focus of exploration and development; foam has the advantages of small particle size, large specific surface area and good fluidity in the tertiary exploitation of oil and gas resources. It has shown great application value; foam can reduce the saturation of residual oil in rock through the advantages of low friction, low density and strong flowback ability, thereby enhancing oil recovery; but in the actual foam flooding process, foam The stability of the foam is poor, and there are defects that are easy to break in...

AI Technical Summary

Problems solved by technology

[0002] With the sharp increase in demand for oil and gas resources in various countries around the world, deep oil and gas reservoir resources in high-temperature geothermal environments have gradually become the focus of exploration and development; foam has the advantages of small particle size, large specific surface area and good fluidity in the tertiary exploitation of oil and gas resources. It has shown great application value; foam can reduce the saturation of residual oil in rock through the advantages of low friction, low density and strong flowback ability, thereby enhancing oil recovery; but in the actual foam flooding process, foam The stability of the foam is poor, and there are defects that are easy to break in the complex reservoir environment, and the swept volume cannot be expanded, which seriously restricts the efficiency of foam flooding;

[0003] The foaming systems used in traditional foam flooding mainly include single-component small molecule surfactants, single-component polymer surfactants and multi-component surfactant complex systems, although the foaming ability of these foaming systems Strong, but the life of the formed foam is short; as a new type of foam stabilizer, nanoparticles are compounded with small molecule surfactants to construct a nanoparticle / surfactant composite foaming system, which shows superiority in the process of foam formation. However, the currently used nanoparticle foam stabilizers are silica with spherical solid structure, aluminum hydroxide with irregular solid structure or bentonite with larger size and irregular solid structure. The oil displacement effect is poor; in addition, the recovery process of these nanoparticle foam stabilizers after oil displacement is cumbersome, and it is difficult to carry out large-scale popularization and application in oil fields;

[0004] Chinese patent document 201711382411.1 discloses a sulfonated residual oil modified bentonite foam stabilizer and its preparation method. The foam stabilizer is modified by adding bentonite and residual oil into an organic solvent, and then removing the organic solvent for sulfonation Processing the obtained; although the preparation method is simple, the synthesis process involves toxic organic solvents, which is difficult to popularize and apply on a large scale; in addition, the bentonite used in the foam stabilizer has a particle size of 38 μm-75 μm, which is easy to block the pore throat of the formation and cannot be recovered;

[0005] Chinese patent document 201810761015.8 discloses a preparation method of an intelligent nano-foam oil-displacing agent. The intelligent nano-foam oil-displacing agent is obtained by polymerizing and coating functional polymers on the surface of the core with solid nano-ferric iron tetroxide as the core; Although the total enhanced oil recovery of the intelligent nano-foam oil displacement agent can reach 18.2%, and it can be recovered and reused by applying an external magnetic field, but the polymer-coated nano-Fe3O4 is easy to agglomerate and block the formation pore throats. Problems with formation damage and low recovery rates;

[0006] Chinese patent document 202010174556.8 discloses a polymer-modified bentonite foam stabilizer and its preparation method. The foam stabilizer is first intercalated with a surfactant to expand the interlayer distance of bentonite, and then added functional monomers. It is prepared by copolymerization; although the foam stabilizer solves the problem of bentonite precipitation in the foam fluid, the synthesis steps are relatively cumbersome, and the half-life of the obtained foam is only about 5 minutes at most. To achieve enhanced oil recovery;

[0007] MXene is a new type of two-dimensional material similar to an accordion shape. It has a unique layered structure and a large specific surface area, and there are abundant active sites between layers; however, the surface of MXene contains abundant hydroxyl groups, which is a A two-dimensional material with good hydrophilicity cannot achieve a good foam stabilization effect; the modification of MXene has been widely used in the fields of flexible actuators and electromagnetic shielding, and the loading of smart nanoparticles and MXene Surface hydrophobic modification as a foam stabilizer for tertiary oil recovery has not been reported

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