Research Article

Petrophysical Regression regarding Porosity, Permeability, and Water Saturation Driven by Logging-Based Ensemble and Transfer Learnings: A Case Study of Sandy-Mud Reservoirs

Table 6

Measured information of porosity, permeability, and water saturation gained by four validated predictors in three experiments.

Model 1RMSE results for porosity (%) evaluated by Equation (7) 2
1st experiment2nd experiment3rd experiment nontrans/trans 3
KNN-cored predictor1.20480.98820.8234/0.5543
SVR-cored predictor1.17510.92150.7436/0.5168
RF-cored predictor1.10240.85020.6466/0.4599
LightGBM-cored predictor0.89470.70910.6096/0.3934

RMSE results for permeability (mD) evaluated by Equation (8)
1st experiment2nd experiment3rd experiment nontrans/trans
KNN-cored predictor0.40270.34660.1375/0.1015
SVR-cored predictor0.39560.34400.1700/0.1189
RF-cored predictor0.36600.32010.1499/0.1070
LightGBM-cored predictor0.30240.25100.1115/0.0761

RMSE results for water saturation (%) evaluated by Equation (7)
1st experiment2nd experiment3rd experiment nontrans/trans
KNN-cored predictor4.55373.85766.5779/4.8992
SVR-cored predictor4.30163.78106.1735/4.6108
RF-cored predictor3.93483.49385.7748/4.3459
LightGBM-cored predictor3.66302.89414.8863/3.2708

1KNN = k-nearest neighbors; SVR = supper vector regression; FR = random forest; LightGBM = light gradient boosting machine; 2RMSE = root-mean-square error; 3“nontrans” means normal prediction, and “trans” stands for the prediction implemented under the support of transfer learning.