The investigation of the effect of free organic anions on scale inhibitors used to prevent nucleation occurring in oil rig wells, using dynamic test equipment.

When soluble salts in water come out of solution a precipitate forms. If this precipitate adheres to the walls of a pipe then scaling will occur. This big problem in the oil industry is solved by the use of scale inhibitors. The Gryphon oil field suffers from severe scaling problems. The oil from this field is very acidic. It is believed that these anions associate themselves with the scale inhibitors and so reduce the efficiency of the scale inhibitor. The identity and amount of the acids affecting the scale inhibitor needs to be found. This was preformed with extraction with a basic solution. Thirty different acids were found in the crude oil and formation water. Thirty acids in the crude oil and three in the formation water. Five acids were obtained and the concentration of four of them was found to be 0.14g/l of myristic acid, 0.076g/l of palmitic acid, 0.34g/l stearic acid and 3.21 g/l nondecanoic acid. The analysis of the acids was preformed by GC/MS using MTSBTFA as a derivatising agent. Derivatisation with MTSBTFA was necessary to reduce the volatility of low molecular weight carboxylic acids and to reduce the volatility of the higher molecular weight carboxylic acids. The organic anions effect on scale inhibitors was tested using a dynamic test rig called the P-MAC. The scaling ion solutions were ran through a heated coil and they scale up causing a restriction of the coil. The restriction caused a change in the differential pressure across the coil. In this way the scaling rate and effect of added chemical can be observed. Once suitable concentrations of scale inhibitor which prevented scale growth was found the effect of EDTA, gluconic, citric, propanoic acid, hexanoic acid and 2-hydroxyl hexanoic acid were tested. All the acids tested had no effect on the scale inhibitor. The organic anions especially the carboxylic acids were found to be scale dissolvers.

Grantor dc:publisher.institution

Robert Gordon University

Year dc:date.issued

1995

Author dc:creator

• Finegan, James T.

Advisor dc:contributor.advisor

• C. Johnson and B. McGraw

• Scale inhibitor
• Carboxylic acids
• Organic anions
• P-Mac test-rig
• Ion solutions
• Oil rig wells
• Nucleation

Language dc:language

en

Identifier

oai:rgu-repository.worktribe.com:2807381
https://doi.org/10.48526/rgu-wt-2807381

OAI identifier oai:identifier

oai:rgu-repository.worktribe.com:2807381