Obesity is well known to be a contributory risk factor for several disease states, including diabetes mellitus. Further, obese women are more prone to have babies born with congenital abnormalities. Paucity of data on maternal-fetal disposition of essential trace elements in obese pregnancies prompted us to undertake this study. Maternal venous and umbilical arterial and venous samples were collected from obese patients (body mass index >30) and control pregnant women (body mass index <25) at time of spontaneous delivery or cesarean sections and concentrations of essential trace elements such as Cu, Fe, Mo, Se, and Zn determined in various samples by atomic absorption spectrophotometry. Activities of antioxidant enzymes, superoxide dismutase, glutathione peroxidase, and total antioxidant activity in maternal and umbilical blood were assessed using appropriate reagent kits. Maternal-fetal disposition and exchange parameters of elements studied were assessed using established criteria. Concentrations of Cu, Fe, Mo, Se, and Zn in the serum of control pregnant women at time of delivery averaged 2232.6, 2398.1, 10.9, 108.9, and 661.9 microg/L respectively, whereas in the obese group, the values of the above elements averaged 2150.3, 2446.8, 12.6, 96.8, and 838.9 microg/L respectively. Umbilical vein/maternal vein ratios of Cu, Fe, Mo, Se, and Zn in the control group averaged 0.29, 1.93, 1.06, 0.76, and 1.12, respectively, whereas in the obese group, their fetal-maternal ratios averaged 0.32, 2.23, 1.06, 0.78, and 1.53, respectively. The Cu : Zn ratio in the maternal vein of the obese group (3.60 +/- 0.20) was significantly lower (Student's t-test; p < 0.05) than that of the controls (2.50 +/- 0.19); however, Cu : Fe ratio (1.04 +/- 0.08 vs 1.02 +/- 0.09) was not significantly different (Student's t-test; p > 0.05) in the two groups. Varying differences were noted in the case of antioxidant enzyme activities between the control and study groups. We conclude that obesity is associated with alterations in maternal-fetal disposition of some essential trace elements and antioxidant enzyme status and that these alterations could pose a potential health risk for the mother as well as the fetus.

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The Kuwait Oil Company currently pumps about 10 Mm 3 /yr from one of its well fields in central Kuwait (Eocene Aquifer) and plans to increase this rate to 30 Mm 3 /yr to meet its water demand. The objective of this study is to investigate the sustainability of brackish groundwater resources for oil operations in the mentioned well field in a way to identify the consequences of increasing the pumping rates on groundwater levels and groundwater salinity. A suitable methodology to assess the sustainability of brackish groundwater utilization has been developed based on pumping tests in addition to flow and salinity numerical modeling. Extensive hydrogeological and salinity field investigations were also conducted. The results show that pumping rate should not be increased above 20 Mm 3 /yr in the aquifer of the study, otherwise a sharp decline in groundwater levels and a significant increase in groundwater salinity will occur. The results of the pumping tests show that the hydraulic properties of the Eocene Aquifer can support regional utilization of the aquifer, but any additional pumping wells should be located within a wider area than the current well field. The salinity variation analysis shows that a mixing process between brackish and saline water is taking place.

Enhanced oil recovery methods are appealing to increase oil recovery from reservoirs due to market pressures in times of lower oil price. Chemical enhanced oil recovery (cEOR) methods such as ASP involve the use of alkali, surfactant, and polymer, to create an ultralow interfacial tension (IFT) between microemulsion and oil phases. These chemicals have the potential to interact with asphaltenes in crude oil and may cause either a decrease or an increase in asphaltene deposition. This paper presents an investigation into the effects of ASP chemicals on asphaltene precipitation. Crude oil, from a cEOR-nominated Kuwaiti reservoir, was analyzed with an ASP formulation that was determined through microemulsion phase behavior experiments. Crude oil, chemical components, and incompatible solvent were added together, and light transmission was measured over a 15-minute period to determine asphaltene precipitation over time. A blank graph of the crude in incompatible solvent showed a light transmission increase of 36.2% over the test duration indicating asphaltene precipitation. If asphaltenes remain suspended in oil, light transmission remains low and stable from the beginning to the end of the test. Addition of asphaltene inhibitor (AI) to the crude oil prevented asphaltene flocculation which was evidenced by a maximum light transmission of 3.0%, an efficiency of 91.7% dispersability relative to the blank sample. With addition of the ASP formulation, light transmission increased which indicates interaction between (1) chemical species of the ASP formulation with asphaltenes or (2) the alkali in the chemical package altering the pH and causing more asphaltene precipitation from suspension in the crude. Maximum light transmission of oil dosed with the chemical additives is 41.3% which is a decrease in asphaltene inhibition efficiency of 14.1% relative to the blank. With the addition of AI to the crude containing the chemical additives, the maximum light transmission is 6.5% indicating an efficiency of 82% asphaltene dispersability. Results indicate a clear relationship between addition of ASP chemicals and asphaltene precipitation. Conditions will differ for other crude oils and cEOR formulations, but asphaltene scaling issues should be considered for cEOR projects.

The Mauddud Formation in the Greater Burgan field is a thin carbonate reservoir with very low permeability but with moderate to good porosity and variable fracture density. The formation could be divided into three distinctive layers, based on the structural and digenetic complexities. Production in Mauddud wells show rapid decline due to tight rock matrix (low permeability). This decline is associated with an increase in Gas-Oil Ratio (GOR) as reservoir pressure falls below the bubble point pressure near the wellbore. Horizontal wells were drilled in an attempt to develop the Mauddud Formation targeting sweet zone. Most of the wells were located in a relative structural high on the up-thrown blocks of the North and Eastern flank of the Greater Burgan field that had the highest likelihood of intersecting fractures. They are mostly adjoining the major faults. There are now around 40 wells drilled in Mauddud including horizontal and multilaterals, most of which became non-producers due to above reasons. A study has been carried out to evaluate opportunities to revive these wells through available and new technologies in the industry. A detailed geological study incorporating all the available data was carried out initially. Wells were screened for stimulation by using various proven new technologies. Acid Frac, Stage Frac, near well bore SurgiFrac and Matrix Acid techniques have been applied with varying results. Advanced placement technique like distributed temperature profiling was used in some of the jobs. This paper presents the details of the application of the above mentioned technologies, to the candidate wells and discusses the results. The success of some of these technologies opened up new opportunities for a new beginning to revive the closed wells completed in Mauddud Formation.