Asphaltene Precipitation and Deposition is a serious problem which can reduce the oil recovery by reducing reservoir permeability and altering the wettability. It can plug wells and flow lines through deposition and also cause separation difficulties at the separation facilities. Taking preventive measures are always a wise solution rather than attempting to resolve issues when they are occurred.
This study proposes a strategy and provides the comprehensive review of the methodology required to predict and prevent Asphaltene Precipitation.
Light crude oil samples were taken to be characterized for their thermodynamic properties. The saturation pressure and Asphaltene Onset Point (AOP) were measured at different pressures, temperatures and compositional changes using the Solid Detection System (SDS). Phase diagram and Asphaltene Precipitation Envelopes (APE) were developed. Cubic Plus Association (CPA) equation of state was used to develop the Asphaltene phase envelope using Multiflash (infochem). Titration technique was used to obtain the Asphaltene Floculation point (AFP) using the dead oil and n-Heptane as a precipitant. Effect of different inhibitors was then evaluated using the Solid Detection System (SDS) equipment using the titration technique. Rock-Inhibitor Compatibility was then checked in the reservoir core samples by performing the dynamic core flooding test in the laboratory.
Conclusively, this strategy helps to enhance the reservoir performance by minimizing the asphaltene precipitation and will save the cost associated with the consequences of high asphaltene precipitation.