Akademik Veri Yönetim Sistemi
İPETGAS 2023, Ankara, Türkiye, 27 - 29 Eylül 2023, ss.699-701
Well tests are conducted to estimate essential reservoir parameters like
permeability and skin factor. Pressure data is recorded at regular intervals
during these tests, which are crucial for predicting the production potential
of oil or gas. Analyzing pressure changes provides insights into the
reservoir's characteristics and its ability to produce hydrocarbons over time.
Three different cases of drawdown tests are examined, and derivative
curves are plotted using data points separated by specific intervals, ranging
from 0.10 to 0.50 of a log cycle. This interval selection is vital to avoid
excessively noisy derivative values during differentiation. A novel method is
developed to determine the log cycle interval that minimizes noise while
maintaining the integrity of the derivative curve. Additionally, second and
third derivatives are calculated for each log cycle interval to identify the
most suitable one.
The log cycle interval helps identify early, middle, and late-time
regions, representing different flow regimes in both cases. The data from the
middle time region is selected for the estimation process, as it offers the
best estimates of permeability. These results are then compared with those
obtained from KAPPA's Saphir Module, an industry-standard PTA (pressure
transient analysis) module. The Python code used for estimation is found to
provide more accurate estimations of permeability and skin factor and can
handle noises up to ±2.5%.