Nanomaterials for Unconventional Oil and Gas Reservoir Hydraulic Fracturing

A well-established practice is applying hydraulic fracturing stimulation technology to improve oil and gas recovery from unconventional reservoirs.

FREMONT, CA: Nanotechnology has been effectively introduced into the realm of hydraulic fracturing technology and has been extensively employed to improve many crucial features of this industry. This has contributed to the development of hydraulic fracturing technology, which is being investigated intensively by numerous oil service businesses and companies worldwide. This section provides a comprehensive review of the most recent research progress on nanotechnology in the hydraulic fracturing of unconventional oil and gas reservoirs, along with a discussion of the mechanism of action and application conditions of nanotechnology in the hydraulic fracturing unconventional oil and gas reservoirs.

NANOMATERIAL-ENHANCED FRACTURING FLUIDS

Hydrocarbon fluids are used in hydraulic fracturing to transport fracturing proppants into the formation and create artificial fractures. A fracturing operation's success or failure hinges on the fracturing fluid system. The fracturing fluid system must possess high-temperature resistance, good compatibility, minor reservoir damage, and excellent gel-breaking capability. Nanomaterials can be utilized in the fracturing fluid system because of their high surface activity and particular surface functionalization. Through cross-linking between nanomaterials and polymers, synergistic effects with surfactants, and the formation of reversible cross-linking structures with micelles, adding nanomaterials to the fracturing fluid system can improve the comprehensive performance of the system, which can effectively solve the problems of large displacement and high pump pressure in the fracturing of unconventional oil and gas reservoirs, reduce the risk in the fracturing operation, and iii.

POLYMER-BASED FRACTURING FLUIDS

Nanomaterials' Function in Polymer-Based Fracturing Fluids

The primary components of polymer-based fracturing fluids are a thickener, cross-linking agent, and gel breaker. This has long been a significant area of research for fracturing fluids due to their superior performance, low production costs, and ease of building. In hydraulic fracturing, guar gum polymer is the most widely utilized polymer. Guar gum is a biopolymer with a high molecular weight consisting of a main polysaccharide chain and a galactose side chain. However, the maximum temperature at which guar gum can be used is typically 82 degrees Celsius. The use of guar gum polymers and derivatives, such as hydroxypropyl guar gum (HPG), carboxymethyl guar gum (CMG), and carboxymethyl hydroxypropyl guar gum (CHPG), has improved its temperature resistance (CMHPG). Researchers have created synthetic polymers as alternatives for guar gum, such as polyacrylamide polymers (PAM) and their derivatives, which are also commonly employed in hydraulic fracturing.

Currently, polymer fracturing fluids have numerous drawbacks, including high residue after gel breakdown, weak temperature resistance, and shear resistance. Their application in various unconventional oil and gas reservoirs is rife with challenges. Consequently, it is vital to optimize the overall performance and build a polymer fracturing fluid system that causes less harm to the reservoir and has improved performance. The introduction of nanotechnology can resolve this issue. Adding nanoparticles to a polymer solution or cross-linked gel-fracturing fluid can enhance the spatial network structure of the fracturing fluid system, thereby improving the rheology of the fracturing fluid and its stability under high temperature and high pressure, thereby effectively reducing the required amount of polymer, the amount of gel-breaking residue, and the damage to the conductivity of reservoir and hydraulic fractures.