Quantification of Methane-Induced Asphaltene Precipitation in a Multiple Contact Process

Area of Science:

• Petroleum Engineering
• Physical Chemistry

Background:

• Asphaltene precipitation during gas injection is a significant challenge in oil recovery.
• Understanding the mechanisms of asphaltene precipitation under reservoir conditions is crucial for mitigating formation damage.

Purpose of the Study:

• To investigate the asphaltene precipitation dynamics during multiple methane contact processes.
• To elucidate the primary mechanisms of asphaltene precipitation and subsequent formation damage.
• To evaluate the impact of asphaltene precipitation on reservoir permeability and conformance.

Main Methods:

• A unique experimental design was employed to quantify asphaltene precipitation over 20 methane contact steps.
• Light scattering setup was used to measure asphaltene precipitation under reservoir conditions.
• Core flooding tests were conducted on three different permeability cases to assess formation damage.

Main Results:

• Methane-induced asphaltene stability loss, rather than composition change, is the primary driver of precipitation.
• The size and structure of asphaltene particles evolve with repeated methane contacts.
• Permeability reduction mechanisms vary based on porous media pore throat size and asphaltene particle characteristics.

Conclusions:

• Asphaltene precipitation in multiple contact processes is governed by stability loss, not just composition alteration.
• Asphaltene precipitation can act as a conformance control method, influencing field development strategies.
• Findings provide critical insights for optimizing oil recovery operations and managing reservoir performance.