Chemicals used in Petroleum Industry

Corrosion inhibitors slow metal corrosion by adsorbing to the surface and forming films, influencing anodic or cathodic reactions. They span organic and inorganic types, oil- or water-soluble, and volatile gas-phase inhibitors.

The lecture explains corrosion inhibition mechanisms for oil and gas systems across four environments, including acidic aqueous solutions, natural waters, primary/secondary production, and atmospheric or gaseous confined environments.

Corrosion inhibitors adsorb on metal surfaces in acidic solutions, forming a protective film that blocks both anodic and cathodic reactions and can create a diffusion barrier.

Learn to evaluate and select corrosion inhibitors through laboratory evaluations, compatibility tests, and field trials, using wheel, bubble, rotating disk electrode, jet impingement, and humidity chambers to simulate field conditions.

Evaluate corrosion inhibitors using destructive and non-destructive methods, including weight loss and electrochemical tests, to determine inhibition efficiency, guide field tests, and optimize passivation and dosage.

Place corrosion inhibitor injections at the wells and at strategic manifold locations (beginning, middle, or end) with monitoring at the end of the manifold and trunk line to protect pipelines.

Learn how scale inhibitors prevent insoluble salt deposits, including calcium carbonate, calcium sulfate, and barium sulfate, by managing supersaturation, nucleation, and crystal growth in oilfield water systems.

Explore major production scale types: calcium carbonate calcite, calcium sulfate gypsum, sulfides, iron scales, barium sulfate, and pyrite, and how temperature, pressure, pH, CO2, and ionic strength govern their formation.

Predict scale formation in produced water using saturation index, stability index, and empirical models, and validate with coban coupons and ICP analysis.

Learn three main scale prevention methods—ion-removing pretreatment, scale inhibitors, and post-formation removal—while analyzing ion exchange, low sulfate water, nanofiltration, and mechanism types: threshold, distortion, dispersion, shielding.

Learn about anti scaling types: organic phosphonates, organic polymers, and polyphosphates (phosphate esters); understand their shielding, threshold, and dispersion mechanisms, plus injection locations and squeeze job strategies in petroleum systems.

Discover how biocides curb microbial growth in oil and gas pipelines, preventing biofilms and microbiological influenced corrosion, and distinguish planktonic from sessile bacteria, including sulfate reducing and iron oxidizing bacteria.

Identify how microbiological influenced corrosion driven by SRB, SOB, and acid-producing bacteria forms biofilms in petroleum systems, and how biocide strategies, sampling, and serial-dilution monitoring detect and control it.

Explore microbiological monitoring techniques for petroleum samples, including culture media identifications, ATP photometry, hydrogenase enzyme tests, fluorescence microscopy, and antibody-based sulfate reducing bacteria detection.

Apply oxygen and hydrogen sulfide scavengers to remove corrosive species by reaction, choosing the phase and proper injection; consider pH, catalysts, and compatibility with biocides.

Explore hydrogen sulfide scavengers for petroleum systems, including solid and liquid non-regenerative and regenerative options, with triazine chemistry and direct injection or contact towers for offshore applicability.

Explain the seawater intake and treatment train for water flood, detailing pumps, strainer, clarifier, and sand filters, and how oxygen scavengers and sodium hypochlorite are dosed before injection.

Learn how demulsifiers destabilize crude oil emulsions by disrupting interfacial films to promote oil–water coalescence, and optimize factors like temperature, agitation, residence time, solids removal, and chemical compatibility for separation.

Explain demulsification mechanisms, focusing on flocculation and coalescence of water droplets and how temperature, water content, oil viscosity, and electrostatic fields affect separation, with chemical demulsifiers and adequate dose.

Select demulsifiers for breaking oil-water emulsions using solvents and surface-active agents. Understand how hydrophilic-lipophilic balance and interfacial film disruption drive coalescence, with field testing and bottle test guiding selection.

Explore thermal and mechanical demulsification techniques for oil-water separation, detailing heating, viscosity effects, coalescence, knockout drums, salt house, three-phase separators, and electrostatic grid methods.