Thermal, compositional, and salinity effects on wettability and oil recovery in a dolomite reservoir

Low salinity and composition effects in improving oil recovery in sandstone reservoirs are known. However, these effects have not been thoroughly studied for the carbonate reservoirs. Because of the lack of the clay minerals in the carbonate rocks, the mechanisms for the improved oil recovery with low salinity, brine composition, and temperature may not be the same as those for sandstones. This experimental study attempts to investigate the effects of low salinity, brine composition, and temperature on wettability and oil recovery in a dolomite reservoir. Also, it is attempted to confirm that wettability alteration is the main mechanism for improvement of oil recovery. The experiments for this study were performed at both ambient and reservoir conditions as well as at a temperature of 250°F using two different techniques, Dual-Drop Dual-Crystal (DDDC) and coreflooding. Water-advancing contact angle was measured using the DDDC technique to characterize reservoir wettability with different salinities including twice, 10, 50 and 100 times diluted brines. Also, the effect of brine composition on wettability was investigated with Yates synthetic brine, Yates synthetic brine without sulfate, and brines containing sulfate in different concentrations. In addition, the effect of temperature on wettability was investigated using DDDC technique. Coreflood experiments were carried out using a dolomite core to determine aging time, to measure the oil recovery, and to confirm whether an optimal salinity brine and an optimal composition of brine obtained contact angle measurments improve the oil recovery compared with Yates synthetic brine. Oil-water relative permeabilities were generated by history matching the oil recovery and pressure drop data obtained from the coreflood experiments. The experimental results showed that the wettability was altered from strongly oil-wet to intermediate-wet by diluting the Yates synthetic brine by about 50 times and increasing the amount of sulfate in Yates synthetic brine from 2.2 g/l to 4.4 g/l. Also, increasing the temperature to 250°F had a significant effect on wettability and changed the wettability from oil-wet to intermediate-wet. Coreflood results confirmed the wettability alteration to intermediate-wet and also demonstrated improvements in oil recovery induced by the optimal salinity and optimal brine composition

Effectiveness of the Concurrent Intravenous Injection of Dexamethasone and Metoclopramide for Pain Management in Patients with Primary Headaches Presenting to Emergency Department

Introduction: Headache is a common reason for visiting emergency departments, and pain control is a major therapeutic goal in patients with headaches. Objective: The present study was conducted to examine the effectiveness of the concurrent intravenous administration of dexamethasone and metoclopramide in pain control in patients presenting to emergency departments with complaints of primary headache. Methods: This quasi-experimental study examined patients with moderate to severe headache attacks presenting to emergency departments. An 8-mg dose of dexamethasone and a 10-mg dose of metoclopramide were intravenously administered to the patients. The degree of headache was measured and recorded using the Numeric Rating Scale (NRS) upon admission and one hour and two hours after the injection. Results: A total of 51 patients with a mean age of 38.3±10.5 years participated in the study. The patients’ mean pain score was 8.4±1.3 upon admission and reduced to 6.2±2.3 one hour after the administration of the medication and to 3.1±2.9 two hours after the administration, suggesting significant reductions on both occasions (P<0.05). The therapeutic success was 39.2% one hour after the administration of the medication and 84.3% two hours after the administration. Conclusion: Based on these findings, the concurrent administration of dexamethasone and metoclopramide appears to affect the control of headache intensity in patients with primary headaches presenting to emergency departments

A 33-year-old woman with severe postpartum headache

 Patient was a 33-year-old woman underwent her first time cesarean section combined with spinal epidural anesthesia 5 days before and discharged the day after with good condition. She got severe headache with pain score about 8-9, 2 days after discharge from hospital. Her headache was severe, bilateral, pulsatile and almost likely sudden onset accompanied with nausea that mildly progressed after starting. She went to the hospital which her delivery was taken; with impression of Post Dural Puncture Headache (PDPH) 10mg IV morphine sulfate was administered totally and subsequently discharged home with relative decreased headache. The day after first headache attack, when she admitted in our Hospital, claimed that could not hold her baby for breast feeding. In minimental status examination, time disorientation was obvious but orientation to place and person was intact. In motor examination we found right side hemiparesis and also decreased right upper and lower limbs tone. Brain CT Scan and then MRI was performed and reveal massive cortico-subcortical hemorrhagic infarction on left parieto-occipital lobes. With attention due to significant nonhomogene occupying lesion, brain MRI with gadolinium and also MRV was per-formed.What is your doagnosis