Application of a new approach for modeling the oil field formation damage due to mineral scaling

International audienceMineral scaling has been considered a great concern for developing the oil production from the underground petroleum reservoirs. One of the main causes of this phenomenon is known as the chemical incompatibility of injected brine, frequently sea water, with the reservoir brine leading to the deposition of various supersaturated salts such as calcium carbonate, calcium sulfate and barium sulfate. In present communication, an evolutionary approach namely, Gene Expression Programming (GEP), was employed for rigorous modeling of formation damage by mineral scaling of mixed sulfate salt deposition. At first, a large databank of damaged permeability datapoints as a function of injected volume, injection flowrate, temperature, differential pressure and ionic concentrations of the existing chemical species in the porous media was employed. In this regard, a user-friendly correlation was extended for the first time by the aforementioned technique in the literature. Professional evaluation of the suggested GEP-based model was implemented by different statistical parameters and appealing visualization tools. Having proposed the GEP-based correlation, statistical parameters of the Average Absolute Relative Deviation Percent (AARD%) of 0.640% and determination coefficient (R2) of 0.984 was calculated. Accordingly, it is demonstrated that the proposed model has a superior performance and great potential for efficient prediction of damaged permeability due to the mixed sulfate salt scaling. Moreover, the implemented outlier diagnosis technique verified the validity of the databank used for modeling, as well as the high robustness of the suggested model was confirmed. In conclusion, the developed correlation in this work can be of enormous practical value for skillful engineers and scientists in any academic study and industrial applications dealing with mixed salt deposition

An Experimental Study of the Effect of Amines on Polymer Efficiency and Thermal Stability of Water-based Drilling Fluid

Amine compounds are believed to have acceptable results regarding their use as clay swelling inhibitor and corrosion inhibitor additives in drilling fluids. It is crucial to know the capability of amine compounds to enhance the thermal stability of drilling fluid; herein, a water-based fluid composed of biopolymer and other additives as the proper representatives of muds used in the pay zone section of a well is used. In order to enhance drilling fluid thermal stability to 250 °F (which is about 200 °F for starch in common drilling fluids), the compatibility of four amine compounds (mono ethanolamine, 1,6-diaminohexane, polyamine, and choline chloride) with three polymers (starch-green, poly-anionic cellulose, and starch-high temperature) is investigated; one of the named polymers is also chosen to examine its thermal stability performance along with the mentioned amine compounds at 250 °F. Two percent by volume concentration (2 Vol.%) of the mentioned amines were used. For these purposes, the rheological and filter loss properties were studied. The results showed that the starch-green is almost compatible with four amines. Moreover, mono ethanolamine and 1,6-diaminohexane acted better in terms of thermal stability at elevated temperatures

Effect of Slope Position on Soil Properties and Types Along an Elevation Gradient of Arasbaran Forest, Iran

Sustainable development by forest managing need to identify forest ecosystem elements. Forest soil is the most important element of forest ecosystem that has key roles in forest managing. Therefore, studying of soil properties and evolution under different environmental conditions is necessary for sustainable management of forest ecosystems. Spatial variation of soil properties is significantly influenced by some environmental factors that slope position is one of them. The aim of this study was evaluating effects of slope position on forest soil change which was carried out in Arasbaran forest, North-West of Iran. Nine soil profiles were dug, described and sampled in three different parts of an altitudinal transect with same environmental conditions and different slope positions. Then soil samples were analysed physicaly and chemicaly and so classified based on Soil Taxonomy 2014. Also according to obtained results One-way analysis of variance was used to test relations of soil properties and slope positions. This results revealed significant effect of slope positions on thickness of the soil profile and solum, clay, organic carbon and total nitrogen percentages and cation exchange capacity at 5% level of confidence which lead to change of type, depth and sequence of soil horizons along altitudinal transect. Finally, it has found that slope position not only has important role in soil properties changes and soil evolution but also it can't be refused the various role and influence of same forest stand in different slope positions. Therefore various soils such as Inceptisols, Alfisols and Molisols were observed under different slope positions. Then it can be achieved that, because of special forest vegetation, soil evolution along altitudinal transect of forest ecosystems are differing from other ecosystems. Thus, for forest soil management program it is necessary to consider both of topography and vegetation effect over the area, even if one of them is constant

Thermal and Rheological Properties Improvement of Oil-based Drilling Fluids Using Multi-walled Carbon Nanotubes (MWCNT)

In this paper, we detail our results for the impact of MWCNT on the thermal and rheological properties of oil-based drilling muds. Our analysis considers the effects of time, temperature, and MWCNT volume fraction. The scanning electron microscopy imaging technique was used to monitor the MWCNTsdispersion quality. The experimental results unveil a considerable enhancement in the thermal conductivity of the MWCNT-oil-based mud by 40.3% (and 43.1% in case of functionalized MWCNT) and 1% vol. MWCNT. The rheological properties results for the MWCNT-oil-based mud exhibit a similar (improvement) trend by reducing annular viscosity and increasing yield point and gel strength. The high-temperature high-pressure filtration tests conducted at 280°F and 500 psi show a  reduction of 16.67% for the filtrate amount in case of MWCNT-oil-based mud (with 1% vol. MWCNT). The effect of time on thermal conductivity reduction in both unfunctionalized and functionalized systems was observed to equalize (at 9.7%), after 100 hours of sample preparation. The performance results of MWCNT-oil-based mud are presented for an actual industrial drilling operation case.</span

The effect of cations on gelation of cross-linked polymers

The effects of different cation concentrations and types on rheological property and stability of Guar, Xanthan, and Partially Hydrolyzed Polyacrylamide (HPAM) cross-linked gels were analyzed through experiments. Also, a new approach was developed to reduce the negative effects of cation by application of multi-walled carbon nano-tubes (MWCNTs). The presence of cations in cross-linked gel system will reduce the viscosity of gel, the higher the cation concentration is, the lower the viscosity will be. The bivalent cation has a greater viscosity reduction effect on gel than monovalent cation. The stability of cross-linked gels is worse with cations, this situation becomes more serious under higher salinity. MWCNTs were added to HPAM gel, cross-linked by (3-Aminopropyl) triethoxysilane (APTES), they surrounded cations and removed them from polymers and reduced the reaction possibility. This method enhances the viscosity and breakdown pressure of cross-linked gels, improves the stability of HPAM cross-linked gel under different operating conditions, and can be applied to related drilling projects

Double-Layered Polyvinylpyrrolidone–Poly(Methyl Vinyl Ether-Alt-Maleic Acid) based Microneedles to Deliver Meloxicam:An In Vitro, In Vivo and Short-Term Stability Evaluation Study

This study aims to explore the use of polymeric microneedles (MNs) for the transdermal delivery of drugs, a non-invasive and convenient method that avoids first-pass metabolism and gastrointestinal complications. Specifically, we develop a double-layered MN formulation using polyvinylpyrrolidone and cross-linked poly(methyl vinyl ether-alt-maleic acid), comprising a dissolvable layer and a hydrogel-forming layer. Meloxicam serves as the model drug, and no organic solvents are employed in the manufacturing process to reduce toxicity. Coherent Anti-Stokes Raman Spectroscopy (CARS) is utilized to confirm that the manufacturing process does not alter the drug's physical properties. In vitro and ex vivo studies demonstrate that the double-layered MN formulation exhibits faster drug release in the first few hours, followed by a slower release. This results in extended bioavailability in vivo compared to the commercial oral formulation of meloxicam. Preliminary results indicate that the MN formulation is also effective in pain relief and inflammation reduction. The short-term stability of the MNs formulation is also confirmed, including its mechanical properties, sustained skin permeability, drug physical properties, and distribution within MNs using CARS microscopy. Overall, these results suggest that the double-layered MN formulation holds significant potential for transdermal drug delivery, offering a safer and more effective alternative to traditional oral administration

Global, regional, and national incidence, prevalence, and years lived with disability for 354 diseases and injuries for 195 countries and territories, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017.

The Global Burden of Diseases, Injuries and Risk Factors 2017 includes a comprehensive assessment of incidence, prevalence, and years lived with disability (YLDs) for 354 causes in 195 countries and territories from 1990 to 2017. Previous GBD studies have shown how the decline of mortality rates from 1990 to 2016 has led to an increase in life expectancy, an ageing global population, and an expansion of the non-fatal burden of disease and injury. These studies have also shown how a substantial portion of the world's population experiences non-fatal health loss with considerable heterogeneity among different causes, locations, ages, and sexes. Ongoing objectives of the GBD study include increasing the level of estimation detail, improving analytical strategies, and increasing the amount of high-quality data. METHODS: We estimated incidence and prevalence for 354 diseases and injuries and 3484 sequelae. We used an updated and extensive body of literature studies, survey data, surveillance data, inpatient admission records, outpatient visit records, and health insurance claims, and additionally used results from cause of death models to inform estimates using a total of 68 781 data sources. Newly available clinical data from India, Iran, Japan, Jordan, Nepal, China, Brazil, Norway, and Italy were incorporated, as well as updated claims data from the USA and new claims data from Taiwan (province of China) and Singapore. We used DisMod-MR 2.1, a Bayesian meta-regression tool, as the main method of estimation, ensuring consistency between rates of incidence, prevalence, remission, and cause of death for each condition. YLDs were estimated as the product of a prevalence estimate and a disability weight for health states of each mutually exclusive sequela, adjusted for comorbidity. We updated the Socio-demographic Index (SDI), a summary development indicator of income per capita, years of schooling, and total fertility rate. Additionally, we calculated differences between male and female YLDs to identify divergent trends across sexes. GBD 2017 complies with the Guidelines for Accurate and Transparent Health Estimates Reporting

Erratum: Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017

Interpretation: By quantifying levels and trends in exposures to risk factors and the resulting disease burden, this assessment offers insight into where past policy and programme efforts might have been successful and highlights current priorities for public health action. Decreases in behavioural, environmental, and occupational risks have largely offset the effects of population growth and ageing, in relation to trends in absolute burden. Conversely, the combination of increasing metabolic risks and population ageing will probably continue to drive the increasing trends in non-communicable diseases at the global level, which presents both a public health challenge and opportunity. We see considerable spatiotemporal heterogeneity in levels of risk exposure and risk-attributable burden. Although levels of development underlie some of this heterogeneity, O/E ratios show risks for which countries are overperforming or underperforming relative to their level of development. As such, these ratios provide a benchmarking tool to help to focus local decision making. Our findings reinforce the importance of both risk exposure monitoring and epidemiological research to assess causal connections between risks and health outcomes, and they highlight the usefulness of the GBD study in synthesising data to draw comprehensive and robust conclusions that help to inform good policy and strategic health planning