The use of sulfate reducing bacteria (SRBs) in laboratory studies is a common approach for investigating microbially influenced corrosion (MIC). The characteristic formation of black iron sulfide precipitates during SRB growth, however, preclude the use of traditional spectrophotometric approaches for capturing growth data instead necessitating labour-intensive or technically specialized approaches. As such, an understanding of SRB growth responses to experimental conditions is often missing from MIC studies. Bernardez and de Andrade Lima (2015) have outlined a spectrophotometric approach for estimating SRB cell mass via the addition of HCl. This method has potential for the study SRB growth however its applicability is currently limited by the use of large aliquot volumes (45 mL), which restrict the number of timepoints that can sampled from one culture, and the extensive time devoted to cell preparation prior to OD readings. •We demonstrate an improved method for capturing SRB growth data via spectrophotometry following acidification. We incorporate lower sample volumes and adapt the method described in Bernardez and de Andrade Lima (2015) to a high throughput microtiter plate approach that increases the efficiency of this method and its applicability to growth rate studies.•Our results allay theoretical concerns that acidification may distort growth rate analysis by impacting cells differently depending on their metabolic state.•We further demonstrate that this method (acid-amended OD measurements) is more accurate and far more cost efficient than traditional methods (dilution spread-plate counting) and popular molecular methods (quantitative PCR) currently in use in SRB growth research.

Acoustic emission (AE) is a phenomenon where transient waves of stress are generated during deformed material, which is applied to detect and monitor the cracks and cracks propagation. The majority of related literature studied simulated wave sources, which were utilized for a single point of a pipe and have been strictly controlled by temporal characteristics. Therefore, the realistic wave sources which do not have known temporal characteristics are studied in the present work. The realistic source is quasi-static crack propagation under three-point bending. The distortions of AE signals are experimentally evaluated by testing the AE signals of crack propagation using simulated sources. A variety of stress intensities are applied on a steel pipe to determine the effect of stress type and intensity on the characteristics of the source using time and frequency domains. Machines are mounted on the steel pipe to locate and reconstitute the features of time and frequency domain of the AE sources. It is concluded that the AE energy was sensitive to the crack size which was concerning to the transition of plane-stress to plane-strain. The potential of AE technique for identifying the nature, intensity and location of crack propagation is demonstrated.

Interstate pipelines are the most efficient and feasible mean of transport for crude oil and gas within boarders. Assessing the risks of these pipelines is challenging despite the evolution of computational fuzzy inference systems (FIS). The computational intricacy increases with the dimensions of the system variables especially in the typical Takagi–Sugeno (T–S) fuzzy-model. Typically, the number of rules rises exponentially as the number of system variables increases and hence, it is unfeasible to specify the rules entirely for pipeline risk assessments. This work proposes the significance of indexing pipeline risk assessment approach that is integrated with subtractive clustering fuzzy logic to address the uncertainty of the real-world circumstances. Hypothetical data is used to setup the subtractive clustering fuzzy-model using the fundamental rules and scores of the pipeline risk assessment indexing method. An interstate crude-oil pipeline in Egypt is used as a case study to demonstrate the proposed approach.

Summary: Drilling fluids consist of colloidal suspensions that are made up of solid particles suspended in liquid. The aqueous component of the drilling mud invades a permeable formation due to differential pressure, leaving solid deposits on the drilled formation walls, forming a filter cake. Typical drilling fluids should create a thin, slick filter cake and fluid loss control to seal permeable zones as swiftly as possible. Tight holes, elevated levels of rotational resistance and friction, wellbore obstruction, fluid loss into formations, suboptimal well-log data, and reservoir formation impairment result from thick filter cakes and excessive filtration. Controlling infiltration of fluids to establish a minimal, low-porosity filter cake is frequently required to avoid drilling and production issues. In this study, we used computational fluid dynamics (CFD) to model the development of filter cakes induced by pipe rotation in vertical and inclined wellbore walls under elevated temperature and pressure during deep drilling. Multiple tests validate the basic model for application in both shallow and deep drilling operations. By use of an Eulerian-Eulerian approach to describe drilling fluids as a binary-phase system, including particles in suspension in the non-Newtonian fluid, our research investigates the power-law and Herschel-Bulkley rheological models. These models successfully predict the flow pattern of drilling fluid at the bottom region of deep drilling operations. The study further explores filter-cake formation by examining the influence of overbalanced pressure on filter-cake thickness at various pressures. Drilling simulations, incorporating pipe rotation and eccentricity effects under realistic operating parameters, accurately project filter-cake thickness, aligning closely with experimental measurements and existing CFD literature in this domain.