Determinación de la condición de riesgo para el proceso de reinyección de recortes de perforación en pozos agotados en dos plataformas costa fuera en el suroeste de la Sonda de Campeche

Potential risks associated with the cuttings re-injection process as an alternative method for drilling wastes disposal were identi- fied and assessed in two offshore platforms located at the southwest of the Campeche Sonda in Mexico. Risks were evaluated using the HAZOP methodology, to identifying hazards in 11 nodes. In addition, deviations in the process were analyzed, and each risk analyzed was categorized as tolerable or non-tolerable and providing some recommendations. Consequences derived from accidental spills of slurry and/or cuttings were analyzed using the mathematical model YAXUM 3D to simulate the pollu- tants dispersion in seawater in three different climatic periods. The results of the consequences analysis shows that even the concentrations in the discharge point exceeded the recommended criteria for protection of the marine life and seawater quality, the spill is rapidly dispersed complying with permitted levels in 8 hr as a maximum.Los riesgos potenciales asociados al proceso de reinyección de recortes como un método alternativo para la disposición de los desechos de perforación fueron identificados y calculados en dos plataformas costa fuera situadas en el suroeste de la Sonda de Campeche en México. Los riesgos fueron evaluados usando la metodología Hazop, para identificar peligros en once nodos dentro del sistema de reinyección de recortes de perforación. Además, fueron analizadas las desviaciones en el proceso y cada riesgo analizado fue categorizado como tolerable o no-tolerable; asimismo, se propusieron algunas recomendaciones. Las consecuencias derivadas de derrames accidentales de lechada y/o recortes de perforación fueron analizados usando el modelo matemático YAXUM 3D para simular la dispersión de los agentes contaminantes en agua de mar en tres periodos climáticos. Los resultados del análisis de consecuencias demuestran que aun cuando las concentraciones en el punto de descarga excedieron los criterios recomendados para la protección de la vida de marina y de la calidad del agua de mar, el derrame es rápidamente dispersado cumpliendo con los niveles permitidos en ocho horas como máxim

An Application of Time Series Analysis for Forecasting and Control of Carbon Monoxide Concentrations

In large urban areas, where many activities occur due to a big number of citizens, physical polluting agents should be carefully assessed in order to protect human health. The monitoring and control of air pollution, acoustical noise, electromagnetic fields, etc., represent a relevant problem to be considered. Therefore, the development of mathematical models able to predict the air pollution behaviour is a very important field of research. In this paper, the authors will use a model based on Time Series (TS) analysis. A large set of field measurements is reconstructed by an appropriate functional form. The proposed model can evaluate the trend and the periodic pattern in the calibration dataset, and can forecast the slope in any future time range. The TS analysed in this work is composed by hourly CO concentrations observed in the urban site of San Nicolas de los Garza, Nuevo Leon, Mexico. To calibrate the model's parameters, a large set of one year field measurements will be analysed: this procedure will highlight a periodicity of 24 hours in the dataset and a substantial absence of any relevant trend. The authors will perform also a validation of the model on two different months, using data not adopted in the calibration phase. This procedure will show that the model is able to reproduce the overall trend and the periodic behaviour present in the large part of the dataset but, at the same time, it cannot predict isolated peaks or sudden fall of CO concentration. In addition, a Principal Component Analysis will be applied to a data set for one year period in order to investigate the relation among CO concentrations and other measured parameters (meteorological conditions and air criteria pollutants). Resulting principal components can be used in future multiple regression analysis in order to mitigate multicollinearity

Atmospheric Levels of BTEX and Criteria Pollutants (CO, NO2, O3 and PM2.5) in an Urban Site Located in North Baja California, Mexico: Source Implications and Health Risk

Atmospheric levels of BTEX (benzene, toluene, ethylbenzene, p-xylene) and criteria air pollutants (O3, NO2, CO, PM2.5) were measured in urban air of one site located in North Baja California, Mexico during winter 2017. Diurnal variation was studied collecting samples at 1.5 h time intervals in different sampling periods: 07:30-09:00 h, 12:00-13:30 h, 15:00-16:30 h, and 18:00-19:30 h and then analyzed by gas chromatography with flame ionization detection. The highest concentrations of BTEX occurred during the morning (07:30-09:00h) and afternoon (18:00-19:30h) sampling periods. Mean concentrations of BTEX were 32.40 μg/m3 for benzene; 13.28 μg/m3 for toluene; 17.16 μg/m3 for p-xylene; and 7.02 μg/m3 for ethylbenzene. BTEX concentration ratios and meteorological analysis indicated that these compounds were influenced by local and fresh emissions. Pearson correlation and Principal Component Analysis were performed in order to correlate BTEX concentrations with criteria air pollutants and meteorological parameters to infer their possible sources. A health risk assessment showed that local exposure to benzene exceeded 1 x 10-6 for integrated lifetime cancer risk. It suggests that people living in Tijuana, Baja California, Mexico may have a probable risk of suffering cancer in their lifetime. These results indicate that changes in the existing environmental policies should therefore be applied to improve air quality in this region