Method for preparing fracturing fluid thickener with self-destruction effect

Abstract

The invention discloses a fracturing fluid thickener with a self-destruction effect. The fracturing fluid thickener comprises, by weight, 5-80% of monomer aqueous phase, 12-70% of oil-based solvents and 8-25% of emulsifiers. The usage of reducing agent solution in oxidation-reduction initiators accounts for 0.1-0.5% of the mass of emulsion. A method for preparing the fracturing fluid thickener mainly includes dissolving the emulsifiers in the oil-based solvents; adding the monomer aqueous phase with excessive oxidizing destruction agents into the oil-based solvents; carrying out stirring and deoxidizing, adding the reducing agent solution at the temperatures of 10-40 DEG C and initiating reaction for 0.5-4 hours to obtain inverse emulsion with the oxidizing destruction agents partially coated by micro-spheres; directly diluting the emulsion by the aid of water to prepare the fracturing fluid thickener with the self-destruction effect, or separating out the micro-spheres by sedimentation and then preparing the fracturing fluid thickener with the self-destruction effect. The fracturing fluid thickener and the method have the advantages that the fracturing fluid thickener and destruction agents can be produced by the aid of the method in an integrated manner, the destruction agents can be uniformly placed and can be released in a delayed manner, and accordingly the problems of difficulty in controlling the destruction time of directly mixed destruction agents for use in conventional processes or high cost and uneven destruction of capsule destruction agents can be solved.

Description

technical field [0001] The invention belongs to oil exploitation technology, in particular to a preparation method of a fracturing fluid thickener. Background technique [0002] Unconventional resources refer to resources that cannot be explored and developed by conventional methods and technical means. They mainly include shale gas, tight gas, coalbed methane, oil shale, tight oil and heavy oil, oil sand, etc. The total amount of resources is large. , high mining technology requirements, poor reservoir physical properties, generally air permeability is less than 0.1×10 -3 μm 2 , the porosity is less than 10wt% (Zou Cai, Petroleum Exploration and Development, 2013; Zou Cai, Acta Petroleum Sinica, 2012). The pore diameters of tight limestone oil, sandstone oil, and sandstone gas reservoirs are 40-500nm, 50-900nm, and 40-700nm, respectively. Such reservoirs are characterized by low porosity and very low permeability. Large-scale fracturing can produce large-scale, intercom...

AI Technical Summary

Problems solved by technology

[0004] For shale gas reservoirs with high clay content and strong plasticity, in the development of Barnett shale in the United States, slick water fracturing fluid is injected first, and then jelly fracturing fluid with high sand ratio is injected. It has achieved better results than conventional fracturing fluids, but the use of jelly fracturing fluid in horizontal wells is not ideal, and jelly will cause certain reservoir damage (Gerald R. Coulter, 2006, SPE-102063)

Images