Asphaltene precipitation modeling in dead crude oils using scaling equations and non-scaling models: comparative study

This research study aims to conduct a comparative performance analysis of different scaling equations and non-scaling models used for modeling asphaltene precipitation. The experimental data used to carry out this study are taken from the published literature. Five scaling equations which include Rassamadana et al., Rassamdana and Sahimi, Hu and Gou, Ashoori et al., and log–log scaling equations were used and applied in two ways, i.e., on full dataset and partial datasets. Partial datasets are developed by splitting the full dataset in terms of Dilution ratio (R) between oil and precipitant. It was found that all scaling equations predict asphaltene weight percentage with reasonable accuracy (except Ashoori et al. scaling equation for full dataset) and their performance is further enhanced when applied on partial datasets. For the prediction of Critical dilution ratio (Rc) for different precipitants to detect asphaltene precipitation onset point, all scaling equations (except Ashoori et scaling equation when applied on partial datasets) are either unable to predict or produce results with significant error. Finally, results of scaling equations are compared with non-scaling model predictions which include PC-Saft, Flory–Huggins, and solid models. It was found that all scaling equations (except Ashoori et al. scaling equation for full dataset) either yield almost the same or improved results for asphaltene weight percentage when compared to best case (PC-Saft). However, for the prediction of Rc, Ashoori et al. scaling equation predicts more accurate results as compared to other non-scaling models.

Time Series Analysis and Modeling of Monthly Rainfall in Saudi Arabia

Managing of water resources is an important future issue. Modeling is fundamental in preparation and organization of water resource system. Forecasting of occasions request identify proper models to be used in this process. Water is the main living source on earth. The most common and fundamental source of water on earth supporting the survival of the majority of life forms is Rainfall. Time arrangement investigation which incorporates modeling and estimating constitutes a instrument of foremost significance with reference to a wide extend of logical purposes in meteorology (e.g. precipitation, stickiness, temperature, sun powered radiation, surges and drafts). The show work applies the Box-Jenkins approach, utilizing SARIMA (Regular Autoregressive Coordinates Moving Normal) demonstrate is utilized to perform brief term estimates of month to month time arrangement such as precipitation. Modeling the past watched precipitation time arrangement values which result in utilized to anticipate long run amounts in agreement to the past. The demonstrate is tried by confirming the past precipitation information. In turn, the research produces a solid future figure. This show is assessed by implies of the AIC-, BIC-, and SBC- demonstrate.