Synthetic brine, composition

Procedures of these 40 C (104 F) experiments are described in the Experimental Section. Tests were performed at a representative west Texas formation temperature using a typical west Texas stock tank oil and a synthetic brine having a composition typical of west Texas injection waters. Results are summarized in Table III. The ratio of foam volume after 30 minutes at 40 C to that after 1 minute was used as an indication of foam stability. The surfactants which produced the greatest initial (1.0 minute) foam volumes also exhibited the greatest foam stability over the thirty minute test period. Because test temperature and salinity were different than used in earlier experiments, results in the presence of west Texas stock tank oil cannot be compared to results described above. However, trends in foam stability were consistent with those described above. Average stability of the foams produced by the AEGS and AES surfactant classes was greater than that of the AE foams. 

Xanthan samples from four commercial manufacturers were studied in synthetic reservoir brines and a dilute NaCl solution. The samples included broth and powdered xanthan products. The weight-average molecular weight, M, for each sample was measured in the different solvents by low angle light scattering. was not affected by the brine composition, and no... 

Preparation of the synthetic west Texas brine is described in reference 4. This brine had the following composition prior to filtration ... 

Akaganeite is formed in natiue under the same conditions used in laboratory synthesis, i. e. in the presence of chloride and at elevated temperatures (e. g. 60 °C). Examples are the hot brines of the Atlantis Deep of the Red Sea and the hot springs of similar composition of the White Island volcano. New Zealand. Natural and synthetic akaganeites frequently display similar crystal morphologies. 

Figure 10. Calculated salt effects on D/H fractionation in the system kaolinite-water from 0 to 150° C (modified after Horita et al. 1993b). Calculations are based on the empirical equations given in Table 4. The dashed lines are the calculated curves for 1 and 3 molal NaCl solutions, and a synthetic Salton Sea brine (3.003 molal NaCl + 0.502 molal KCl + 0.990 molal CaCb). The kaolinite-pure water curve (solid line) is from Liu and Epstein (1984). Note that neglect of the salt effect could result in large errors in calculated temperatures and/or fluid compositions when mineral-water fractionation data are applied to natural samples...

The xanthans were obtained from four commercial manufacturers. The products are denoted Xanthan A, B, C and D. Xanthans A, B and C were sup-plied as the gelatinous crude fermentation broths containing 3-8 wt% xanthan. Xanthan D was supplied as a powder. Six different production lots of Xanthan A were examined, and these polymers are labeled as A-l,...A-6. The compositions of the two test brines are presented in Table 1. Brine 1 was a moderate-salinity brine containing only NaCl and CaCl2. Brine 2 was the synthetic equivalent of the resident brine in one of Exxon s reservoirs. 

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