Development of the Minami Kuwayama Oil Field: Battle against Asphaltene

Abstract

1. Takaaki UetaniAbstract The Minami Kuwayama eld, one of the largest oil elds in Japan, began production in 2003. Severe asphaltene problems have been experienced in all wells, in both the reservoir and production tubing, and at the surface facilities. We have been operating this eld for over 10 years and learned that we could sustain the productivity through the use of chemicals and the control of production rates. This article provides our experience and major ndings.

Evaluation of Asphaltene Adsorption Free Energy at the Oil–Water Interface: Effect of Oil Solvents

“…In combination with our previous work, the study highlights the significance of heteroatoms in asphaltenes. In an oil field, which suffers from serious emulsion problems, we show that the asphaltene is nitrogen rich, and the asphaltene molecule contains pyridine-type structures like As01-s. , In previous work, it was also shown that the addition of toluene has no significant effect on solving the oil–water emulsion problem from this oil field. This experimental result can be explained by our MD simulation result.…”

“…This result implies that solely adding solvent (such as toluene) may not be enough for solving the emulsion problems induced by pyridine-type nitrogen-containing asphaltenes. 14 This is also in line with the previous notion that the emulsifying capacity can be reduced but not eliminated in good solvents. 26 For the asphaltene without heteroatoms, the asphaltene is found to be solvated in the oil phase, and there is no well-defined adsorption state when the heptane volume fraction is equal to or less than 50%.…”

“…It is noteworthy that the adsorption Gibbs free energy of this nitrogen-containing asphaltene is high enough to adsorb on the toluene–water interface. This result implies that solely adding solvent (such as toluene) may not be enough for solving the emulsion problems induced by pyridine-type nitrogen-containing asphaltenes . This is also in line with the previous notion that the emulsifying capacity can be reduced but not eliminated in good solvents .…”

“…It is known that asphaltenes are the major components responsible for the formation and stabilization of water-in-oil emulsions by acting as emulsifying agents. Asphaltenes adsorb at the oil–water interface and form mechanically strong interfacial films, which prevent coalescence between water droplets. − …”

Evaluation of Asphaltene Hildebrand and Hansen Solubility Parameters Using Digital Oil Models with Molecular Dynamics Simulation

“…1 Their propensity to form flocculation and dense deposits within reservoirs, wellbores, and transportation pipelines gives rise to significant operational and production challenges. 1,2 Consequently, asphaltenes demand increased attention to address such issues effectively. However, owing to the high complexity of the mixing system, the explicit structure of asphaltenes remains largely unknown.…”