Major, minor element chemistry and oxygen and hydrogen isotopic compositions of Marun oil‐field brines, SW Iran: Source history and economic potential

Abstract

Cation and anion concentrations and oxygen and hydrogen isotopic ratios of brines in the Asmari Formation (Oligocene-early Miocene) from the Marun oil field of southwest Iran were measured to identify the origin of these brines (e.g. salt dissolution vs. seawater evaporation) as well as the involvement of water-rock reaction processes in their evolution. Marun brines are characterized by having higher concentrations of calcium (11 000-20 000 mg/L), chlorine (120 000-160 000 mg/L) and bromide (600-1000 mg/L) compared to modern seawater. Samples are also enriched in 18 O relative to seawater, fall to the right of the Global Meteoric Water Line and local rain water, and plot close to the halite brine trajectory on the dD versus d 18O diagram. Geochemical characteristics of Marun brines are inconsistent with a meteoric origin, but instead correspond to residual evaporated seawater modified by water-rock interaction, most significantly dolomitization. In addition, anhydrite precipitation or sulphate reduction appears to be important in chemical modification of the Marun brines, as indicated by lower sulphate contents relative to evaporated seawater. Extensive dolomitization, the presence of anhydrite nodules and high salinity fluid inclusions in the upper parts of the Asmari Formation fit a model whereby the Marun brines likely originated from the seepage reflux of concentrated seawater during the deposition of the overlying Gachsaran Formation evaporites in the Miocene.

Developing Meteoric Water Lines for Iran Based on Air Masses and Moisture Sources

“…As mentioned earlier, MWLs developed for the dominant Iran moisture sources can be used in the study of moisture source contribution rate in karstic springs and surface water resources recharge. Surface water resources isotope data were collected from three dominant zones in the north of Iran, west Zagros and south Zagros [17,18,20,43,54,57,62,67,68,[74][75][76][77][78][79][80][81][82][83][84][85] and presented in Supplementary Table S4. To study the role of the dominant moisture sources in surface water resources recharge, surface water samples were plotted on the Caspian Sea, the Persian Gulf and the Mediterranean Sea MWLs (Figure 7).…”

Güneydoğu Anadolu Havzasinda Petrol İle İyot İli̇şki̇si̇

“…In preliminary studies have been observed that formation waters of all oil and gas production basins in the world (including Southeastern Anatolia basin and Thrace basin) are contained >1 mg/L iodine (USGS Produced Water Database; Engle et al, 2016;Oppo et al, 2014;Oppo and Capozzi, 2015;Sudo, 1967;Kaiho, 2015;Kharaka et al, 1987;Dia et al, 1999;Dresel andRose, 2010, Rowan et al, 2015;Mirnejad et al, 2011;Xun et al, 1997;Fisher and Kreitler, 1987;Dickey et al, 1972;Land, 1995;Birkle et al, 2002;Birkle et al, 2009;Franks and Uchytil, 2016;Hitchton et al, 1971;Machperson, 1992;Kokh and Novikov, 2014;Novikov, 2013a, b;Novikov, 2012;Novikov and Shvartsev, 2009, Demir and Seyler, 1999, Kurchikov and Plavnik, 2009, Fu and Zhan, 2009, Kireeva, 2010, Bagheri et al, 2014. However, there are also production wells with formation waters containing iodine <1 mg/L in Southeastern Anatolia and Thrace basins (Appendix-1), Dörtyol (Hatay) gasfi eld, Cambay basin/India (Rebary et al, 2014) and in basins of other global oil and gas fi elds.…”