Temporary plugging diverting agent used for reservoir reformation, and preparation method thereof

Abstract

The invention discloses a temporary plugging diverting agent used for reservoir reformation, and a preparation method thereof, and belongs to the technical field of petroleum and gas reservoir reformation. The temporary plugging diverting agent comprises, by mass, 30-45% of high-molecular polymer particles, 0-4% of a crosslinking agent, 5-12% of an expanding agent, 0.1-1% of a gel breaker, and the balance of oil, wherein the high-molecular polymer particles are at least one of polyvinyl alcohol particles, polyacrylamide particles and polyacrylamide derivative particles; the crosslinking agent is at least one of boric acid, water-soluble borate, water-soluble chromium salt, water-soluble aluminum salt, water-soluble titanium salt and water-soluble zirconium salt; the expanding agent is polyacrylamide crosslinked resin particles or acrylamide and acrylic acid copolymer crosslinked resin particles or a combination of the polyacrylamide crosslinked resin particles and the acrylamide and acrylic acid copolymer crosslinked resin particles; and the gel breaker is persulfate. The breakthrough pressure of the temporary plugging diverting agent can reach 60 MPa or above, the plugging rate can reach 99% or above, and the temporary plugging diverting agent is suitable for 80-140 DEG C reservoirs, and has good dissolving/degrading performance.

Description

technical field [0001] The invention relates to the technical field of petroleum and natural gas reservoir transformation, in particular to a temporary plugging diversion agent for reservoir transformation and a preparation method thereof. Background technique [0002] In the process of oil and gas exploitation, heterogeneous reservoirs and highly deviated well sections and horizontal well sections are usually modified to enhance oil and natural gas recovery. During the stimulation of heterogeneous reservoirs and highly deviated well sections and horizontal well sections, reservoir stimulation fluids (such as fracturing fluids, acid fluids, etc.) preferentially enter the high-permeability layers or fractures with the least resistance, and are difficult to enter Medium and low permeability layers with high resistance, so the stimulation degree of medium and low permeability layers is poor (or even not stimulated) or only part of the highly deviated well section and horizontal...

AI Technical Summary

Problems solved by technology

[0004] In the process of realizing the present invention, the inventors found that there are at least the following problems in the prior art: although the cross-linked gel type temporary plugging and diverting agent can meet the performance requirements of the reservoir reforming liquid and the construction environment requirements at the same time, its breakthrough pressure is generally If it is less than 5MPa, the plugging strength is small; although the breakthrough pressure can be increased to 30-50MPa by adding acid-soluble particles (such as calcium carbonate, magnesium carbonate) or introducing inorganic oxides as reinforcing agents for curing, it will cause temporary plugging and diversion. It is not easy to degrade or dissolve, so it needs to be unblocked with acid solution; and when the cross-linked gel temporary plugging and diverting agent is being constructed, it usually needs to inject two or more liquids separately and mix it underground for plugging, and the construction process is relatively complicated

Water-soluble granular temporary plugging and diverting agents are prone to "clustering" due to rapid hydration of the surface when they are injected with the reservoir reconstruction liquid during construction, resulting in increased construction pump pressure, and sand plugging in severe cases, or due to the dissolution rate Too fast, can not play a blocking role

In addition, the existing temporary blocking diversion agents have a narrow applicable temperature range and poor high temperature resistance