阅读说明：本技术 可直接混配的海水基变黏压裂液及其制备方法 (Directly-mixed seawater-based viscosity-variable fracturing fluid and preparation method thereof ) 是由 陈紫薇 张胜传 李晓娟 贾云鹏 付大其 刘学伟 赵冬华 闫阳 于 2019-07-26 设计创作，主要内容包括：本发明属于压裂液领域,具体涉及一种可直接混配的海水基变黏压裂液及其制备方法。压裂液包括海水基滑溜水压裂液以及海水基高黏滑溜水压裂液；海水基滑溜水压裂液包括下述组分,以海水基滑溜水压裂液总量计,增稠剂占0.05％-0.15％,0.01％-0.03％增效剂,杀菌剂0.1％-0.2％,余量为海水；本发明解决了海上压裂由于储水空间有限,导致压裂规模小,压裂效果不理想的难题。海水资源丰富,压裂施工时现配现用,有效降低了压裂液用水及储运成本,大幅缩短施工周期。(The invention belongs to the field of fracturing fluids, and particularly relates to a seawater-based viscosity-variable fracturing fluid capable of being directly mixed and a preparation method thereof. The fracturing fluid comprises seawater-based slickwater fracturing fluid and seawater-based high-viscosity slickwater fracturing fluid; the seawater-based slickwater fracturing fluid comprises the following components, by weight, 0.05-0.15% of thickening agent, 0.01-0.03% of synergist, 0.1-0.2% of bactericide and the balance of seawater; the invention solves the problems of small fracturing scale and non-ideal fracturing effect caused by limited water storage space in offshore fracturing. The seawater resource is rich, the fracturing fluid can be prepared when in fracturing construction, the water consumption and storage and transportation cost of the fracturing fluid are effectively reduced, and the construction period is greatly shortened.)

1. A seawater-based viscosity-variable fracturing fluid capable of being directly mixed is characterized by comprising a seawater-based slickwater fracturing fluid and a seawater-based high-viscosity slickwater fracturing fluid;

the seawater-based slickwater fracturing fluid comprises the following components, by weight, 0.05-0.15% of a thickening agent, 0.01-0.03% of a synergist, 0.1-0.2% of a bactericide and the balance of seawater;

the seawater-based high-viscosity slickwater fracturing fluid comprises, by weight, 1% -2% of a thickening agent, 0.01% -0.03% of a synergist, 0.3% -0.5% of a cleanup additive, 0.1% -0.2% of a bactericide, 0.05% -0.1% of a gel breaker and the balance seawater.

2. The directly-mixable seawater-based viscosity-variable fracturing fluid as claimed in claim 1, wherein the viscosity of the seawater-based slickwater fracturing fluid is 1.5-3.0mpa.s, and the drag reduction rate is not less than 70%.

3. The directly-compoundable seawater-based viscous fracturing fluid of claim 1, wherein the viscosity of the water-based high-viscosity slickwater fracturing fluid is not less than 20mPa.s, and the resistivity reduction rate is not less than 70%.

4. The directly-compoundable seawater-based viscosifying fracturing fluid of claim 1, wherein the thickener is an inverse emulsion polyacrylamide.

5. The directly-compoundable seawater-based viscosifying fracturing fluid of claim 1, wherein the synergist is a biodegradable iminodisuccinic acid sodium salt.

6. The directly-compoundable seawater-based viscosifying fracturing fluid of claim 1, wherein the cleanup additive is an alkyl glycoside surfactant.

7. The directly-compoundable seawater-based viscosifying fracturing fluid of claim 1, wherein the biocide is dodecyl benzyl ammonium chloride.

8. The directly-compoundable seawater-based viscosifying fracturing fluid of claim 1, wherein the breaker is ammonium persulfate or potassium persulfate.

9. The directly-compoundable seawater-based viscosifying fracturing fluid of claim 1, wherein the seawater-based slickwater fracturing fluid and the water-based high-viscosity slickwater fracturing fluid are prepared by: adding the seawater with the component amount into a mixing and adjusting device, adjusting the voltage to be 50V-55V, simultaneously adding other component reagents, and stirring the mixture for 90-120s at a high speed by the mixing and adjusting device to obtain the composite.