This research work designed a novel mud-cake solidification method to improve the zonal isolation of oil and gas wells. The calculation methodology of mud-cake compressive strength was proposed. The optimal formula of activator and solid precursors, the proper activating time and the best activator concentration were determined by the compressive strength test. The effects of solid precursors on the properties of drilling fluid were evaluated. Test results show that the respective percentage of bentonite, metakaolin, slag and activator is 1 : 1 : 0.3 : 0.8, as well as the optimum ratio of NaSiO/NaOH is 40 : 1. The optimum concentration of activator is 0.21 and the activating time should be more than 10 min. The solid precursors did not show any bad influence on the rheological property of drilling fluids. Even though the compressive strength decreased when the solid precursors blended with barite, the strength values can still achieve 8 MPa. The reaction of metakaolin and activator formed cross-link structure in the mud-cake matrix, which enhanced the connection of the loose bentonite particles, lead to the significant enhancement of shear bonding strength and hydraulic bonding strength. This mud-cake solidification method provides a new approach to improve the quality of zonal isolation.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7062085 | PMC |
http://dx.doi.org/10.1098/rsos.191230 | DOI Listing |
Emergencias
December 2024
Servicio de Análisis Clínicos, Hospital Universitario Santa Lucía, Cartagena, Murcia, España.
Objective: To analyze the usefulness of mean mid-regional pro-adrenomedullin (MR-proADM) level to stratify risk in emergency department patients with solid tumors attended for febrile neutropenia after chemotherapy. To compare risk prediction with MR-proADM to that of conventional biomarkers and scores on the Multinational Association for Supportive Care in Cancer (MASCC) score.
Methods: Prospective observational cohort study enrolling patients with solid tumors who developed febrile neutropenia after chemotherapy.
Acc Chem Res
January 2025
State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory of Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, and Discipline of Intelligent Instrument and Equipment, Xiamen University, Xiamen 361005, P. R. China.
ConspectusMolecular photoelectrocatalysis, which combines the merits of photocatalysis and organic electrosynthesis, including their green attributes and capacity to offer novel reactivity and selectivity, represents an emerging field in organic chemistry that addresses the growing demands for environmental sustainability and synthetic efficiency. This synergistic approach permits access to a wider range of redox potentials, facilitates redox transformations under gentler electrode potentials, and decreases the use of external harsh redox reagents. Despite these potential advantages, this area did not receive significant attention until 2019, when we and others reported the first examples of modern molecular photoelectrocatalysis.
View Article and Find Full Text PDFSci Rep
January 2025
School of Civil Engineering and Communication, North China University of Water Resources and Electric Power, Zhengzhou, 450045, People's Republic of China.
As one of the bulk solid wastes in the Yellow River basin in China, fluorite tailings urgently need to be utilized as resources. In this paper, NaOH and NaCO were used for alkali thermal activation of ground fluorite tailings under different temperature conditions, and the reactivity was analyzed by XRD, SEM and compressive strength after hydration, so as to evaluate the feasibility of fluorite tailings as geopolymer precursor. The results show that the fluorite tailings can exhibit certain reactivity under alkaline heat excitation, and significant amorphous glass phase can be detected.
View Article and Find Full Text PDFJ Ethnopharmacol
January 2025
College of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, P.R. China; State Key Laboratory of Component-based Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, P.R. China.
Ethnopharmacological Relevance: Liver fibrosis, which is a precursor to cirrhosis in chronic liver diseases, is driven by various factors. The activation and proliferation of hepatic stellate cells (HSCs) are recognized as a crucial phase in the progression of liver fibrosis. Compared with western drug therapy, Traditional Chinese medicine (TCM) and herbal medicine not only have the advantages of multi-target and multi-pathways in the treatment of liver fibrosis, but also have high safety without toxic side effects.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!