Gross liquids

The aquifer response (or impact of the water injection wells) may maintain the reservoir pressure close to the initial pressure, providing a long plateau period and slow decline of oil production. The producing GOR may remain approximately at the solution GOR if the reservoir pressure is maintained above the bubble point. The outstanding feature of the production profile is the large increase in water cut over the life of the field, which is usually the main reason for abandonment. Water cut may exceed 90% in the final part of the field life. As water cut increases, so oil production typically declines a constant gross liquids (oil plus water) production may be maintained. 

Fixed opex is proportional to the capital cost of the items to be operated and is therefore based on a percentage of the cumulative capex. Variable opex is proportional to the throughput and is therefore related to the production rate (oil or gross liquids). Hence,... 

Entrainment can be estimated from the correlation given by Fair (1961), Figure 11.29, which gives the fractional entrainment tfr (kg/kg gross liquid flow) as a function of the liquid-vapour factor Fiv, with the percentage approach to flooding as a parameter. 

For decades, the Fair correlation [Pet/Chem. Eng., 33(10), 45 (September 1961)] has been used for entrainment prediction. In the spray regime the Kister and Haas correlation was shown to be more accurate [Koziol and Mackowiak, Chem. Eng. Process., 27, p. 145 (1990)]. In the froth regime, the Kister and Haas correlation does not apply, and Fair s correlation remains the standard of the industry. Fair s correlation (Fig. 14—34) predicts entrainment in terms of the flow parameter [Eq. (14-89)] and the ratio of gas velocity to entrainment flooding gas velocity. The ordinate values XF are fractions of gross liquid downflow, defined as follows ... 

M 10b] [P 9] In a round micro chamber with four bubbles held in four air pockets, notable gross liquid motion and orderly vortex-like patterns near the bubbles were seen (see Figure 1.28) [23]. Churning motion was also present. 

For distillations, it is often of more interest to ascertain the effect of entrainment on efficiency than to predict the quantitative amount of liquid entrained. For this purpose, the correlation shown in Fig. 14-26 is useful. The parametric curves in the figure represent approach to the entrainment flood point as measured or as predicted by Fig. 14-25 or some other flood correlation. The abscissa values are those of the flow parameter discussed earlier. The ordinate values / are fractions of gross liquid downflow, defined as follows ... 

The effects of gas velocity and pressure on liquid mixing can be explained based on the mixing mechanisms of gross liquid circulation and local turbulent fluctuations. The available theories in the literature describing liquid mixing under atmospheric pressure are based on liquid turbulence induced by rising bubbles (Baird and Rice, 1975), large-scale liquid internal circulation (Joshi, 1980), or a combination of these two... 

Figure 8.1.30. (a) Sieve trays in a distillation column (b) bubble-cap trays in a column (c) sieve plate structure (d) bubble-cap on a tray (e) gross liquid flow pattern in a plate from one downcomer to the next (f) desirable range of operating vapor and liquid flow rate conditions on a plate in a distillation column. 

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