A kind of high temperature diverting acid composition and preparation method thereof

Abstract

The invention provides a high temperature diverting acid composition and a preparation method thereof. The high temperature steering acid composition comprises the following components in mass percentage: hydrochloric acid 10-25%, corrosion inhibitor 1-4.5%, iron ion stabilizer 1.5-3%, corrosion inhibitor 0.5-2.5%, iron ion stabilizer auxiliary 0.5-3% of high temperature stabilizer, 5-10% of retarder, 3-8% of diverting agent and the balance of water. The diverting acid composition of the present invention can be applied at 180° C., the iron ion content reaches 5000 ppm, and the high content of hydrogen sulfide (H 2 Acidizing stimulation of high-temperature reservoirs with S content reaching 10%), the system is injected into the formation, and the viscosity of the acid liquid increases after reacting with the reservoir, and the turning pressure of plugging is greater than 6MPa, the high-permeability reservoir is temporarily blocked, and the acid liquid flows to the low-permeability reservoir. In addition, the system has good resistance reduction performance (resistance reduction rate>60%), good retardation performance, and achieves the purpose of uniform acid distribution and deep acidification in cores with extremely poor permeability of 60 times.

Description

technical field [0001] The invention belongs to the field of reservoir reconstruction in the process of oil and gas development. More specifically, it relates to a high temperature diverting acid composition and a preparation method thereof. Background technique [0002] Acidizing is an effective technology for oil and gas well production and injection well injection. Actual oil and gas reservoirs have serious heterogeneity. Conventional acidifying liquids enter along high-permeability layers, and it is difficult to effectively acidify low-permeability reservoirs, which seriously affects the effect of acidizing operations. In order to achieve the transformation of heterogeneous oil and gas reservoirs, acid liquid systems that can block diversion, that is, diversion acid, are commonly used at home and abroad for acidification. Steering acid usually adds viscoelastic surfactant to conventional acidification solution, so that acid solution has special steering performance. D...

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Problems solved by technology

[0011] CN 201210219382.8 discloses a steering agent that mixes butanol, ethyl bromide, and N-alkyl-N-dioctadecane and reacts at 70-75°C for 6-6.5 hours. The prepared steering acid has a temperature resistance of 150°C. However, no test data for temperature resistance

[0012] The existing diverting acid can achieve good diversion of heterogeneous reservoirs, but the temperature resistance is within 160°C, and the acid liquid system used in the field is within 150°C. The resistance reduction rate of the existing diverting acid in field application has been publicly reported All of them are lower than 60%, and the literature reporting the temperature resistance, steering performance, corrosion performance and iron stabilizing ability of the temperature-resistant 180°C steering acid does not involve

With the development of exploration and development to deep reservoirs, there are more and more reservoirs with a formation temperature of 180°C, and the formation components are complex, such as sulfuric acid gas wells with rich pyrite formations, and secondary precipitation after acidification is difficult to control , the existing system is difficult to meet the needs of this type of reservoir transformation, it is necessary to develop a new type of steering acid with good temperature resistance, good retarding effect, low friction, and less secondary damage to the reservoir

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