Long-acting sealing agent for blocking high-angle cracks and preparation method

Abstract

The invention discloses a long-acting sealing agent for blocking high-angle cracks and a preparation method. The sealing agent is composed of hydrogenated butadiene-acrylonitrile rubber, phenolic resin, polyvinyl chloride resin, a plasticizer, an enhancer, a density regulator, a reinforcing agent, a vulcanizing agent, a scorch retarder and an anti-aging agent. The material comprises the followingcomponents in percentage by weight: 33-42% of the hydrogenated butadiene-acrylonitrile rubber, 24-35% of the phenolic resin, 13-22% of the polyvinyl chloride resin, 3-8% of the plasticizer, 2-6% of the enhancer, 1-5% of the density regulator, 1-3% of the reinforcing agent, 1-3% of the vulcanizing agent, 0.2-1% of the scorch retarder and 0.2-0.8% of the anti-aging agent. The method is used for thewestern marginal thrust zone fault block oil reservoir of the Erdos basin; according to the long-acting sealing agent for sealing the high-angle cracks, the long-acting sealing agent can be used for solidifying the high-angle cracks or faults with different opening degrees in a stratum, and the problems of fracturing fluid filtration loss and out-of-control crack height caused by natural crack orfault penetration which cannot be solved by a conventional method are solved.

Description

technical field [0001] The invention belongs to the technical field of chemicals used in the petroleum industry, and in particular relates to a long-acting sealing agent for sealing high-angle cracks and a preparation method thereof. Background technique [0002] Fault-block reservoirs represented by the thrust belt at the western margin of the Ordos Basin require hydraulic fracturing to obtain industrial production capacity due to their tight physical properties; During the process, the developed natural fractures and faults will lead to a large amount of fracturing fluid fluid loss and out-of-control fracture height, which will make the fracturing effect poor or even lead to the failure of fracturing construction. Currently, there are no effective plugging agents and plugging methods for reservoirs with high-angle fractures. At present, for reservoirs with natural fractures, the commonly used method is to add fluid loss reducer to reduce the influence of natural fractures...

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Problems solved by technology

[0003] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art, to provide a long-acting sealant for sealing high-angle fractures and its preparation method, which overcomes 1 in the prior art: adding fluid loss control agents to reduce the influence of natural fractures , the disadvantage is that it cannot overcome the problem of out-of-control fracture height caused by the existence of natural fractures or faults; 2: Inject temporary plugging agents in the front of the fractures to seal natural fractures. The disadvantage is that the performance of plugging agents on the market varies, and most of them are temporary plugging pressure 3: Even if the fractures are blocked during fracturing, the formation water will rush into the oil layer after the plugging agent fails after fracturing and a large amount of water will come out, and the stimulation effect is poor, etc.

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