Prediction of Fines Migration through Core Testing

Karazincir, Oya (Chevron) | Williams, Wade (Chevron) | Rijken, Peggy (Chevron)



Fines migration is a commonly observed phenomenon in oil and gas wells, but often difficult to duplicate in the laboratory. A suite of labs tests was conducted to gauge the effect that different test conditions have on fines migration and to improve fines migration prediction through updated test strategies. Core tests were conducted on core samples collected from a field in West Africa. Field B shows evidence of fines migration through increased PI and reduced skin after a diesel pump-in, and significant increase in production rates after hydrofluoric (HF) acid treatments. Some of the earlier conventional core tests conducted with cores from the same field failed to predict a potential for fines migration. Hence, a study to optimize current fines migration test methods was initiated. With the new tests, the effect of injected fluid volumes, injected fluid type, test temperature, surge conditions and depletion on fines was investigated. Results from these new tests showed evidence of fines migration as observed in the field, in contrast to the earlier tests conducted using conventional test methods. While the tests confirmed the presence of non-Darcy flow at high injection rates, strategies to exclude the contribution of non-Darcy flow from fines-related formation damage were developed and will be discussed.