Global Oilfield Stimulation Market: Trends, Analysis, and Growth Opportunities

Global Oilfield Stimulation Market: Trends, Analysis, and Growth Opportunities

Oilfield Stimulation Chemicals: An Overview

Hydraulic Fracturing Process
Hydraulic fracturing, also known as fracking, is a process used to release petroleum, natural gas or other substances for extraction. It involves the high-pressure injection of 'fracking fluid' (primarily water, containing sand or other proppants suspended with the aid of added chemicals) into a wellbore to create cracks in the deep-rock formations through which natural gas, petroleum, and brine will flow more freely. However, for the hydraulic fracturing process to work effectively requires proper stimulation treatment involving various oilfield stimulation chemicals.

Gelling Agents
Gelling agents are chemicals added to the fracturing fluids to increase their viscosity. Viscosity is a measure of a fluid's resistance to flow. Higher viscosity fluids can carry more proppant grains deeper into the fractures. Common gelling agents used include guar gum, hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC), and copolymers. Guar gum is the most widely used due to its ability to produce clear, high-viscosity fracturing fluids that are thermally stable at high temperatures. However, other polymers are also used as they may offer better temperature stability or friction reduction.

Breakers
To allow production and flowback of the injected fluids after fracturing, the gel needs to be broken down over time to reduce viscosity. Breakers work to degrade the polymer gels after their work is done. Common breakers include oxidizers like sodium, ammonium, and potassium bromate or chlorate, as well as enzyme breakers derived from bacteria. Breakers ensure that the fracturing fluid's viscosity reductions to allow the fractures to reopen and hydrocarbons to flow after stimulation.

Surfactants and Acids
Surfactants are added to alter the wettability of formations and optimize fluid recovery. Surfactants reduce interfacial tension and allow for effective placement of aqueous fluids within hydrocarbon-bearing formations. Common surfactants used include ethoxylated alcohols and alkyl aryl sulfonates. Hydrochloric acid is often used in fracturing for reservoir acidizing and to solubilize carbonate rock formations to optimize production. It improves formation permeability and conductivity and increases the contact area between formation and proppant.

Biocides and Scale Inhibitors
Biocides such as glutaraldehyde and DBNPA are included to prevent bacterial degradation of fracturing fluids by microorganisms. They protect both the fluid and the formation from damage due to bacterial growth. Scale inhibitors like ethylenediaminetetraacetic acid (EDTA) are added to prevent minerals dissolved in formation water from precipitating as insoluble salt scale on pipewalls and within pore spaces. This keeps the formation permeable and productive.

Cross-linkers
Cross-linkers are used to further increase the viscosity of fracturing fluids and change their viscosity-shear response. Borate salts are commonly used cross-linkers with guar gum-based fluids to generate a stronger gel. This allows the transport of higher proppant concentrations deeper into fractures. However, cross-linkers make breaking fluid back down after fracturing more challenging.

Corrosion Inhibitors
Corrosion inhibitors protect equipment, casing and production tubing from damage by corrosion. Common types include oxygen scavengers, film-forming amine salts, benzoic acid or sulphide-based chemicals which form protective layers on metal surfaces. This prevents perforation materials washing out prematurely.

Proppants
Proppants are solid materials like sand, ceramic beads or sintered bauxite that are carried into fractures produced during hydraulic fracturing by the fracturing fluid. When the high-pressure pumping stops, the proppants remain in the fractures holding them open against closure stress due to in-situ rock and fluid pressure. This keeps the fractures conducting hydrocarbons long-term from the reservoir to the wellbore increasing production rates. Commonly used proppants include graded sand, resin-coated sand and high-strength ceramic proppants.

In conclusion, oilfield stimulation chemicals plays a key role in improving well productivity in low-permeability reservoirs. However, stimulation chemicals are crucial enablers for the fracturing process. They optimize fluid properties through viscosity control, break the fluids down after treatment to allow flowback and production. They also protect equipment integrity and keep the reservoir formation conductive long-term enhancing well economics. Selection of the right package of chemicals tailored to formation properties and conditions is important for fracture treatment success.