Automatic optimization of oilfield scale inhibitor squeeze treatment designs

摘要

Squeeze treatments are one of the most common methods to prevent oilfield scale deposition, which in turn is one of the most significant flow assurance challenges in the oil industry. Squeeze treatments consist of the batch injection of a chemical scale inhibitor (SI), which above a certain concentration, commonly known as MIC (Minimum Inhibitor Concentration), prevents scale deposition. The most important factor in a squeeze treatment design is the squeeze lifetime, which is determined by the volume of water or days of production where the chemical return concentration is above MIC, which commonly is between 1 and 20 ppm. Typically, squeeze treatment designs include the following four stages: a preflush, acting as a buffer; the main slug, where the main chemical slug is injected; the overflush, which will displaced the chemical pill deeper into the formation and finally, a shut-in stage, which allows the chemical to be further retained in the formation.