Page 67 - Environmental Control in Petroleum Engineering

Drilling and Production Operations 55

Table 2-9
Composition of Scrubber Wastewater

Constituent Concentration (ppm)
Aluminum 0,4
Bicarbonate 31,183
Boron 20.8
Calcium 11.2
Carbonate 0
Chloride 2,237
Copper 0.5
Fluoride 5.2
Iron 32
Magnesium 0.43
Manganese 0.63
Nitrate 0.5
Phosphate 0.6
Potassium 101
Sodium 53,000
Sulfate 79,013
Sulfur Dioxide 420
Zinc 5.3
Total Dissolved Solids 148,438
Source: from Sarathi, 1991.
Copyright SPE, with permission.

sources are sealed within the logging tools and are normally not
a problem.
Radioactive tracers are commonly used in injection wells to deter-
mine points of fluid entry into the formation (injection profile),
hydraulic fracture height, and/or fluid leaks in the cement behind
casing. The tracer is injected into the wellbore and a gamma ray detector
is then logged through the well to determine depths at which the radio-
activity is high. Commonly used radioactive tracers for liquid phase
measurements include antimony-124 (as antimony oxide), iridiurn-192 (as
potassium hexachloroiridate), scandium-46 (as scandium chloride), and
iodine-131 (as sodium iodide). Krypton-85 has been used as a vapor
phase tracer. Radioactive proppant is also used during hydraulic
fracturing to monitor the location of the fracture behind casing.
Radioactive proppants typically use the same isotopes that are used
for liquid phase tracers.