Slickwater fracturing fluid

Abstract

The invention provides a slickwater fracturing fluid. The slickwater fracturing fluid is composed of the following components, in parts by weight: 0.03-0.18 part of a biopolymer resistance reducing agent, 0.12-0.28 part of a clay stabilizing agent, 0.03-0.18 part of a discharge aiding agent, 0.00003-0.00018 part of a gel breaker and 99-100 parts of water. Preferably, the slickwater fracturing fluid is composed of the following components, in parts by weight: 0.05-0.15 part of the biopolymer resistance reducing agent, 0.15-0.25 part of the clay stabilizing agent, 0.05-0.15 part of the dischargeaiding agent, 0.00005-0.00015 part of the gel breaker and 99-100 parts of the water. The slickwater fracturing liquid provided by the invention has a high flowback rate, the flowback substance has high biodegradability, and the flowback fluid has a low mineralization degree, a low fluorine content, low damage to a reservoir, and high environmental friendliness.

Description

technical field [0001] The invention belongs to the field of fracturing fluids for petroleum exploitation, and in particular relates to a slick water fracturing fluid. Background technique [0002] Shale gas refers to unconventional natural gas that occurs in organic-rich shale-dominated reservoir rock series. It is continuously generated biochemical gas, thermogenic gas or a mixture of both, and can exist in natural fractures in a free state. It exists in the surface of kerogen and clay particles in an adsorbed state, and a very small amount is stored in kerogen and asphaltene in a dissolved state. The proportion of free gas is generally 20% to 85%. The large-scale volumetric fracturing technology represented by multi-stage horizontal wells and slick water fracturing fluids has achieved great commercial success in shale gas development in China, the United States and some other countries and regions. [0003] In the process of using fracturing fluid for shale gas developme...

AI Technical Summary

Problems solved by technology

[0003] In the process of using fracturing fluid for shale gas development, in order to improve the performance of slick water fracturing fluid, it is usually necessary to add a certain amount of additives, such as drag reducers, clay stabilizers, etc. When the fracture network system is established, it also causes serious reservoir damage to the formation. For example, polyacrylamide and its derivatives are used as fracturing drag-reducing agents, because they are easily adsorbed on the surface of clay minerals in the reservoir and form a filter. On the other hand, the huge scale of water used in the transformation of shale gas reservoirs has been criticized by environmentalists. The chemical additives contained in a large amount of flowback fluid have a huge impact on the environment, as shown in: 1 ) The polyacrylamide in the flowback liquid can change the soil structure, affect the survival of protists and microorganisms, and change the plant growth by changing the microenvironment of the plant root system; 2) The residual acrylamide monomer mainly causes severe neurological, reproductive and developmental Toxicity; 3) The use of a large amount of potassium chloride in the clay stabilizer leads to a significant increase in the salinity of the flowback fluid, which affects the salinity of the surface water and causes land salinization; 4) The use of fluorine-containing surfactants in the drainage aid , causing the abnormal increase of fluorine in the soil and water environment, causing systemic chronic damage mainly to human teeth and bones through bioaccumulation

Therefore, the slick water fracturing fluid in the prior art usually causes great damage to the shale gas reservoir and the surrounding environment

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