A carbon nanotube doped fracturing fluid system

Abstract

The invention discloses a carbon nano-tube doped fracturing fluid system which is prepared from the following components in percentage by mass: 0.2-0.8 percent of a thickening agent, 0.02-0.1 percent of a water-soluble carbon nano-tube, 0.3-0.6 percent of a crosslinking agent, 0.5-2 percent of a gel breaker, 0.1-0.8 percent of a discharge aiding agent and the balance of water, wherein the thickening agent is one or mixture of several components of hydroxypropyl guar gum, carboxylmethyl hydroxypropyl guar gum and cationic guar gum in an arbitrary proportion; the water-soluble carbon nano-tube is prepared from one or mixture of two of a hydroxylated multi-walled carbon nano-tube and an amino multi-walled carbon nano-tube in an arbitrary proportion; the crosslinking agent is prepared from one or mixture of several components of borax, boron triethanolamine and boron sorbitex in an arbitrary proportion; and the gel breaker is prepared from one or mixture of two of ammonium persulfate and potassium peroxodisulfate in an arbitrary proportion. According to the carbon nano-tube doped fracturing fluid system, carbon nano-tubes with high stability and similar sizes are introduced, so that the guar gum with strong flexibility has certain supporting performance, and the stability of an existing fracturing fluid system can be improved.

Description

Technical field [0001] The invention relates to a fracturing fluid system used for stimulation and transformation during oil and gas field development, in particular to a fracturing fluid system doped with carbon nanotubes. Background technique [0002] Due to the small natural channels and poor connectivity of low-permeability sandstone reservoirs, fracturing is an indispensable method for effective development. After nearly 70 years of development, fracturing technology has become increasingly mature. At present, the biggest obstacle is that various fracturing materials cannot keep up with the pace of the process, especially fracturing fluid materials. At the stage when the international oil price is hovering in a relatively low region, major oil fields are trying to reduce operating costs. Fracturing fluid accounts for nearly 40% of operating costs. Therefore, researchers are focusing on improving fracturing fluid performance and reducing costs. on. Conventional fracturing f...

AI Technical Summary

Problems solved by technology

However, the molecular chain of guar gum is connected by glycosidic bonds of mannose, and the bond energy of glycosidic bonds is low. Under high temperature conditions, it is easy to break, so that the molecular weight of guar gum is reduced, the cross-linking system is decomposed, and the solution system loses viscosity.

In order to solve this problem, researchers made guar gum small molecules and increased the amount of cross-linking agent (CN201110263461), which can alleviate the problem of guar gum fracturing fluid degradation at high temperature, but will increase the amount of cross-linking used, and The temperature resistance of the fracturing fluid system will not exceed 150 0 C; or use a large number of metal crosslinking agents (CN201210015247, CN201410807656), but the metal crosslinking agent will cause serious damage to the formation after entering the formation

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