Browsing by Autor "Clara Paz"

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An Effective Scale Inhibitor and a Tailored Acid Cleanout Successfully Maintains Well Productivity After Severe Scale Formation in a Mature Gas Producing Field: Case History in a Sub-Andean South Field
(2025) Álvaro Guzmán; Soraida Alvarado; C. A. Barbery; M. J. Morón; Hugo E. Antelo; Carla Miranda; Luís T. Antelo; Clara Paz
Abstract This paper presents a successful study case of restoration and prolongation of a naturally fractured reservoir gas well deliverability in a Sub-Andean South field in Bolivia, using a suited chemical treatment applied with Coiled Tubing. In addition, with an integrated scale model the optimum operational production condition was determined. The project outlines the methodology followed, execution and results. Tubing restriction by scale in the latest drilled well "W#8" was confirmed for the first time in the field after 15 production years. To identify the scale, coiled tubing (CT) with a junk basket was run in hole (RIH) to bring a bottomhole sample to the surface for analysis. In an in-situ mobile laboratory, the scale samples were summited to an organic acid (13% acetic/9% formic) blend to compare the dissolving capacity with HCl acid. Approximately 90% dissolution of the scale sample was achieved using the organic acid mixture. Due to HCl sensitive formation mineralogy, reservoir temperature (+280°F) and to minimize corrosion exposure to the Super 13 Chrome completion, organic acid formulation was selected. CT was then RIH with a scale removal rotating jet to clean out the well, circulating and reciprocating through the affected area, and opened flow to surface to maintain a flowing gas column. Well gas productivity recovered but only for a 3-month period. Afterwards, a second organic acid pickling was repeated, but production recovered for less than 2 months. A technical study was conducted to identify well conditions and to select the appropriate treatment for scale removal and inhibition in following CT interventions, aiming to reestablish and maintain gas deliverability. Complementary, a scale assessment permitted to identify the origin and tendency of the scale and to determine the optimum production condition. Then, for the next performed intervention the pickling acid was repeated, the middle zone was isolated, a near wellbore acid in the upper zone was performed and a polyacrylate scale inhibitor was pumped. As a result, the well not only exhibited an immediate deliverability recovery to 75 Mscfd but also kept producing at a stable recommended rate of 66 Mscfd for more than 12 months. This paper offers tailored methodologies and solutions to existing well conditions that resulted in a well remediation that increased the time between clean-up interventions to +300%. These customized solutions can be applied in similar or neighboring mature fields as corrective and preventive techniques.
Impact of Mobile Phone Usage on Sleep Quality Among Medical Students Across Latin America: A Multicenter Cross-Sectional Study (Preprint)
(2024) Juan S. Izquierdo‐Condoy; Clara Paz; Humberto Alejandro Nati-Castillo; Ricardo Gollini-Mihalopoulos; Telmo Raul Aveiro‐Róbalo; Jhino Renson Valeriano Paucar; Sandra Erika Laura Mamami; Juan Felipe Caicedo; Valentina Loaiza-Guevara; Diana Mejı́a
<sec> <title>BACKGROUND</title> The ubiquitous use of mobile phones among medical students has been linked to potential health consequences, including poor sleep quality. </sec> <sec> <title>OBJECTIVE</title> This study investigates the prevalence of mobile phone addiction and its association with sleep quality among medical students across six Latin American countries. </sec> <sec> <title>METHODS</title> A descriptive, cross-sectional, multicenter study was conducted from December 2023 to March 2024 using a self-administered online survey. The survey included the Mobile Phone Addiction Scale and the Pittsburgh Sleep Quality Index (PSQI) to assess addiction rates and sleep quality among 1,677 medical students from Bolivia, Colombia, Ecuador, Panama, Paraguay, and Peru. </sec> <sec> <title>RESULTS</title> Approximately 32.5% of participants exhibited mobile phone addiction, with significant variations between countries. The overall mean PSQI score was 7.26, indicating poor sleep quality. Higher addiction rates were associated with worse sleep quality across all PSQI components (p < 0.05). Regression analysis highlighted a strong association between mobile phone addiction and poorer sleep, controlled for demographic variables (Beta=1.40; (95%CI: 1.05 - 1.74).This study underscores a significant prevalence of mobile phone addiction among medical students and its detrimental association with sleep quality in Latin America. The findings advocate for the need to address mobile phone usage to mitigate its negative implications on student health and academic performance. Strategies to enhance digital literacy and promote healthier usage habits could benefit medical education and student well-being. </sec> <sec> <title>CONCLUSIONS</title> This study underscores a significant prevalence of mobile phone addiction among medical students and its detrimental association with sleep quality in Latin America. The findings advocate for the need to address mobile phone usage to mitigate its negative implications on student health and academic performance. Strategies to enhance digital literacy and promote healthier usage habits could benefit medical education and student well-being. </sec>