Abstract
Many of Kazakhstan’s major oil fields are now entering a phase of declining production, marking a new stage in the country’s oil and gas industry development. The development of heavy-oil reservoirs presents several well-recognized challenges for oil producers. These include equipment performance issues, shorter operating life of surface and downhole systems, higher failure rates under increased loads, low well productivity, and persistent difficulties in utilizing associated gas. Collectively, these factors severely undermine the overall profitability of field development and production. A wide range of studies has explored the mechanisms of emulsification and demulsification. Stable emulsions create both technical and economic challenges for the industry, particularly in treatment, refining, and transportation operations. Addressing them effectively is crucial for maintaining efficient hydrocarbon production. This paper discusses the formation of crude-oil emulsions, approaches to their demulsification, properties of suitable demulsifiers, and the mechanisms governing emulsion formation. Crude oil contains natural surface-active compounds that readily promote the formation of stable emulsions. To meet industrial standards, these emulsions must undergo thorough treatment. Understanding the role of natural surfactants that enhance emulsion stability is therefore key to achieving effective oil–water separation. The review also considers various published mechanisms of emulsification and identifies the formulations most effective for demulsification.