Polymer-type acidic slickwater and preparation method thereof

Abstract

The invention relates to the technical field of reconstruction of reservoirs of oil and gas fields, particularly to polymer-type acidic slickwater and a preparation method thereof. The polymer-type acidic slickwater comprises the following raw materials by mass percent: 0.1% to 7.5% of acid, 0.05% to 0.2% of an acid resistant resistance-reducing agent, 0.05% to 0.5% of a discharge aiding agent and 0.05% to 0.5% of a clay stabilizer, and the balance being water, wherein the acid is at least one in hydrochloric acid, organic acid and hydrofluoric acid. According to the polymer-type acidic slickwater, low-concentration hydrochloric acid is adopted to dissolve parts of carbonate minerals on the surfaces of cracks, non-uniform etchings are formed on the wall surfaces of the cracks, and flow conductivity of the cracks is strengthened; slickwater has certain viscosity, so that a propping agent can be effectively conveyed to far ends of the cracks, flow conductivity of the cracks is further strengthened, and the fracturing transformation effect on the reservoirs is improved; and the preparation method is simple, the preparation cost is low, the harm of the prepared polymer-type acidic slickwater to the reservoirs of the carbonate minerals is small, the polymer-type acidic slickwater easily flows back, prop-carrying capacity is high, and mining and yield increase of the reservoirs of the oil and gas fields are effectively achieved.

Description

technical field [0001] The invention relates to the technical field of oil and gas field reservoir transformation, in particular to a polymer type acidic slick water and a preparation method thereof. Background technique [0002] my country's shale gas fracturing is still in the exploratory stage. The slick water fracturing fluid used in the early stage is mainly the technology provided by foreign oil service companies. There are few reports on the slick water fracturing fluid system with excellent performance in China, especially suitable for shale gas fracturing. The development and evaluation of additives such as drag reducers, clay stabilizers, and surfactants for rock gas fracturing have just started. [0003] However, the slick water system provided by foreign companies is mainly developed for the fracturing of shallow shale gas reservoirs in the United States, and the direct copying and application of shale gas reservoir fracturing in China has poor adaptability, first...

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Problems solved by technology

[0003] However, the slick water system provided by foreign companies is mainly developed for the fracturing of shallow shale gas reservoirs in the United States, and the direct copying and application of shale gas reservoir fracturing in China has poor adaptability, first of all, it is adaptable to domestic formations No matter what kind of additives are added, it can be used as soon as there is no damage to the formation; secondly, the shale gas in foreign countries is relatively shallow, and the fracturing equipment is advanced, so there is little concern about the friction loss of the pipe string, while the shale gas in my country is relatively shallow. Rock gas is deeply buried, the friction loss of the pipe string is very large, and the friction reducing performance of slick water has a greater impact on fracturing; in addition, the cost of foreign liquid materials is quite high, which increases the overall cost of fracturing, so it is necessary to target domestic shale Systematic research on slick water fracturing fluid system in key areas of gas reservoirs

[0004] At present, the slick water system used in the domestic field still has problems such as low resistance reduction rate, deviation of surface activity, low sand-carrying ratio, poor compatibility with the target reservoir, and large adsorption of polymer additives in the formation, which will cause great damage. The slick water system with good adaptability and compatibility to different shale gas reservoirs, under the premise of the same operation scale, the amount of drag reducing agent is reduced, and the on-site quick matching reduces the cost of slick water fracturing fluid

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