Unsuccessful cementing operation can jeopardize the whole well construction process, resulting in further costly and time consuming repair operations. The quality of cementing job is dependent on the cement composition and its properties. Design of cement composition is based on the available geological condition, materials and technical situation at well location. The cement properties like flow-ability and strength properties are tested by laboratory methods before application in field conditions. Study of the slurry sedimentation stability is of great importance especially for construction of directional or horizontal wells. There is no convenient direct method to investigate the sedimentation stability of the cements. In this paper, a laboratory method is presented to assess the stability of the slurry by measuring its free fluid content. Laboratory investigations are expanded to study the effect of different additives (weighting agent, silica sand, silica flour and magnesium oxide) and well inclination angle on the sedimentation stability of the slurries. Results show that additive specific surface area plays a significant role in the stability of the cements and therefore should be measured for every additive precisely.

Wellbore stability is dominated by in-situ stress and geomechanical parameters of formation rocks, so estimating these parameters around the wellbore is important. The studied well is a suitable candidate for investigation of wellbore stability due to continuing directional drilling and planning for oriented perforation and hydraulic fracturing program from the wellbore and availability of dipole sonic, nuclear magnetic resonance (NMR), core image, and log data to optimize and estimate wellbore stability conditions. In this study, the rock permeability is derived from dipole sonic analysis to investigate the certainty of the model; these results are compared with NMR and special core analysis results. Then, based on these results, pore pressure, in-situ stress, rock mechanical properties, stress and fracture distributions, and anisotropy of formation are calculated and compared with Image log Results. Finally, the optimum mud weight to avoid wellbore failure can be estimated from all these data. As the final results, the maximum horizontal stress direction is N33E, and most open fractures are in this direction. The minimum horizontal stress direction is in N57W, and the safe and appropriate mud weight is between 6.5 and 7.5 ppg, which can be considered 7 ppg. This technique is based on dipole sonic analysis that can be applied to investigate wellbore stability in intervals with no core or image log analysis.

This study evaluated the nutritional and oxidative properties of blended Camelina oil (CO) and virgin olive oil (VOO) at different ratios (75: 25, 50: 50, and 25: 75 (w/w)). The physicochemical characteristics of the blends, including fatty acid profiles, antioxidant activity, smoke point, total phenolic compounds, tocopherol content, unsaponifiable matter, and oxidative stability, were analyzed. The results revealed that increasing the proportion of VOO led to a decrease in polyunsaturated fatty acids (PUFA) (48. 36%, 40. 55%, 31. 55%, 21. 89% and 13. 97%) and an increase in monounsaturated fatty acids (MUFA) (37. 47%, 44. 42%, 52. 10%, 60. 31%, and 66. 58%), improving thermal stability (2. 77h, 3. 9h, 4, 92h, 6. 7h, and 8. 94h). A 75%: 25% ratio of CO to VOO provided the best balance of fatty acid composition and optimal omega-6 to omega-3 ratio (0. 93) along with more nutritional benefits such as high levels of bioactive compounds (tocopherols 689. 11mg/kg). The study highlights the potential of blending oils to create healthier, more stable products with enhanced nutritional properties, leading to the development of new edible oil blends with improved nutritional quality and stability.

Background: The antioxidant activity of Bane (Pistacia atlantica) has been proved in different researches. This study evaluated the potential of Bane (Pistacia atlantica) essential oil (as a natural antioxidant) on the oxidative stability of sunflower oil. Methods: The essence of Bane was added to sunflower oil at concentrations of 200, 400, 600, 800, and 1, 000 ppm. Tertiary Butyl Hydroquinone (TBHQ) was applied as synthetic antioxidant. All samples with the control were stored at 65 ̊, C for 20 days. Gas Chromatography-Mass Spectrometry was used for the essence analysis. The 2, 2-diphenyl-1-picrylhydrazyl radical scavenging assay, rancimat, p-anisidine value (PAnVs), and peroxide value (PV) were determined to assess the efficacy of differecnt concentration of essence (200, 400, 600, 800, and 1, 000 ppm). Data were analyzed by Statistical Analysis System (SAS) version 9 Software. Results: The essential oil yield was 0. 1% v/w. The basic components of essence were monoterpene and sesquiterpene hydrocarbons. Synthetic antioxidant had the highest scavenging activity, followed by the mixture sample. PVs were in the range of 19. 56-20. 73 milliequivalents (meq)/kg for the treated samples after 20 days, while it was 38. 74 on the 20th day for the control. For all treatments, PV was increased with increasing storage time. P-AnVs were 8. 58-17. 14 for stabilized samples and 18. 02 for control sample on the 20th day of storage. In all stages, control sample had the highest P-AnV. For all samples, P-AnV increased as a subject of storage time. Conclusion: P. atlantica (Bane) essential oil had a stabilizing effect on sunflower oil and can be used as a natural antioxidant to stabilize edible oil during storage.