A Modified Multiple-Mixing-Cell Method with Sub-Cells for MMP Determinations

Minimum miscible pressure (MMP) is an essential design parameter of gas flooding for enhanced oil recovery (EOR) applications. Researchers have developed a number of methods for MMP computations, including the analytical methods, the slim-tube simulation method, and the multiple-mixing-cell (MMC) method. Among these methods, the MMC method is widely accepted for its simplicity, robustness, and moderate computational cost An important version of the MMC method is the Jaubert et al. method which has a much lower computational cost than the slim-tube simulation method. However, the original Jaubert et al. method suffers several drawbacks. One notable drawback is that it cannot be applied to the scenario where the oil-gas MMP is lower than the saturation pressure of the crude oil. In this work, we present a modified MMC method that is more versatile and robust than the original version. Our method can handle the scenario where the oil-gas MMP is lower than the saturation pressure of the crude oil. Besides, we propose a modified MMC model that can reduce the computational cost of MMP estimations. This modified model, together with a newly proposed pressure search algorithm, increases the MMP estimation accuracy of the modified method. We demonstrate the good performance of the modified MMC method by testing it in multiple case studies. A good agreement is obtained between the MMPs calculated by the modified method and the tie-line-based ones from the literature.

Angular Distribution Studies for 65Zn Nuclei from 63Cu (α, pnγ) Reaction Using Constant Statistical Tensor, Least Square Fitting and σ/J Methods

Multiple mixing ratios (δ-values) have been calculated for high-spin states excited in 29𝐶𝑢 63 (α,pnγ) 𝑍𝑛 30 65 in present work using constant statistical tensor (CST), least square fitting (LSF) and σ/J methods together with experimental values reported for such γ-transition the good agreement for (δ-values) calculated in these three methods confirms its validity to calculate the (δ-values) for γ-transition.

Measurement and Modeling of Minimum Miscibility Pressure: A State-of-the-Art Review

Summary This paper gives a critical review of miscibility-measurement techniques published in the open literature along with recommendations and lessons learned. Many of these published methods violate the inherent assumptions for multicontact miscibility (MCM). The confusion often arises from a failure to distinguish between first-contact miscibility (FCM), in which two fluids can be mixed in all proportions without forming two phases, and MCM, in which fluid compositions that arise during the flow of two phases in a porous medium approach a specific critical point within the constraints of the MCM definition. There are many analytical, numerical, correlational, and experimental methods available to estimate the minimum miscibility pressure (MMP) for MCM flow. The numerous available methods, some of which are quite inexpensive, have caused significant misunderstandings in the literature and in practice regarding their ability to estimate MMP. Our experience has shown that the best methods are those that honor the multicontact process (MCM), in which flow interacts with phase behavior in a prescribed way. Good methods that achieve this are slimtube experiments, detailed slimtube simulations, multiple-mixing-cell calculation methods, and the method of characteristics (MOC). Techniques such as the rising-bubble-apparatus (RBA) and vanishing-interfacial-tension (IFT) (VIT) experiments are subject to significant uncertainties, although they can still provide useful information. Numerous MMP correlations have been developed. They should be used with caution for systems similar to those used to develop the correlation. Use for other fluid systems can lead to significant errors. We discuss the advantages and disadvantages of most current methods and show that various combinations of methods can reduce uncertainty.

Standard 3-point Micing Technique (Advanced)

How can you make a guitar sound full, large, and deep even if it was recorded in a bedroom? In this advanced lesson, I introduce the “standard 3-point micing technique,” which picks up the different personalities of an electric guitar and amplifier with a “bright” mic, a “dark” mic, and a “back” mic. This recording approach mirrors the “standard 3-point lighting technique” and its “key” light, “fill” light, and “back” light to form the basis of most lighting approaches for video, film, and still photography. The “standard 3-point micing technique” offers multiple mixing options based on different mic combinations, creative panning, and time delay.

CFD Modelling of Steam Turbine Last Stage Blades at Low Load Using Multiple Mixing Plane Approach

The continuous increase of variable renewable energy and fuel cost requires steam turbine power plants to operate with high flexibility. This situation leads to steam turbines running at very low volume flow (LVF) for an extended time. Ventilation power and temperature predictions have a significant impact on the thermo-economic optimization of the power plant and lifetime assessment of the ventilating stages. In the last decade with increasing capabilities of CFD and computational resources, significant steps have been made in assessing complex flow behavior. Full size or scaled experimental testing of different last stage blades for a wide range of low load operating conditions is expensive, therefore CFD provides new opportunities in low load assessment. However, prediction of the flow structure of the ventilating stages still represents a challenge for the current CFD tools in terms of calculation time and reliability of the results. There are many different approaches in assessing this phenomenon, which require different computer resources and may not be necessary for most industrial applications. This paper presents the validation of the multiple mixing plane approach (MMP) presented by [9] for low-pressure steam turbine running at low load. Through a comparison with measurements results and more sophisticated methods, it is shown that this approach is able to sufficiently accurately predict the flow field and hence the ventilation power and temperature at low volume flow.

Multiple-Mixing-Cell Model for Calculation of Minimum Miscibility Pressure Controlled by Tie-Line Length

A simple and robust algorithm has been developed to calculate the minimum miscibility pressure (MMP), which is considered one of the crucial and essential design parameters of miscible gas injection projects for enhanced oil recovery (EOR). This algorithm is to track all tie-line lengths through the cell-cell calculation by the minimum distance function for the prediction of MMP. The MMP is the pressure at which any one of all key tie-line lengths becomes zero. To verify the accuracy of the revised MMC algorithm for determining MMP, several examples taken from the published literature have been examined. The calculation results of our revised MMC algorithm show excellent agreement with those estimated by MOC, MMC, and slim-tube experiments, which are found to be reliable within acceptable accuracy (4.53%-0.50%).