Drilling and Completions operations optimization requires as starting point the building of an alive database that sustains the benchmark for a list of defined KPIs. The KPIs will represent main well construction activities conducted in different well types in a specific field. Once the data is captured and processed, the operations efficiency is obtained with the computation of the Invisible Lost Time (ILT). Computations are defined in different ways by different operators with different margins. The purpose of this paper is to probe that operational efficiency that can be tracked better when the percentiles lead the targets and not the Composite Best as a target. The continuous monitoring of the performance and the daily distribution of KPI's tracking dashboard has changed the mindset of the entire team, engaging the rig personnel in the identification of specific limiters that affect the performance and defining specific actions to take to revert the trend. The year to year comparisons showed a significant performance improvement in all the rigs but not at the same rate. The expected learning curve has deferred from one rig to another. A forecast tool has been created to generate an automatic AFE that delivers automatically TvD curves for the different percentiles and it is aligned to the latest rig's performance and the well architecture. This tool will help the drilling engineers to estimate, quick and more accurate, the well duration time, especially when the rig allocation is crucial for the yearly objectives of the project.
BackgroundWe aimed at evaluating liver biopsy and FibroScan (FS) to assess early histopathological changes among chronic hepatitis B virus (HBV) patients not candidates for treatment.MethodsOne hundred thirty-five chronic hepatitis B naive patients were followed up twice weekly at National Hepatology and Tropical Medicine Research Institute. All patients were not candidates for treatment according to both Egyptian and international guidelines. Pre-enrollment assessment was performed through biochemical, serological and quantitative HBV DNA testing. Liver biopsy was performed to 59 patients based on the guidelines while FS was performed to patients who were not candidates for liver biopsy (102 patients). Twenty-six patients performed both liver biopsy and FS (isolated liver biopsy 33 patients and isolated FS 76 patients).ResultsAt the end of study period, liver biopsy group showed that majority of subjects had grade F1 fibrosis (61.0%). Only 13.6% were F3. FS showed that almost half (47.1%) of subjects had a grade of F0 and 21.6% with grade F1. Only 4.9% of subjects had fibrosis grades of F3 or F4. In each test, nearly two-thirds of patients had evidence of F0/F1 fibrosis and the remaining one-third had more marked fibrosis. The degree of fibrosis as detected by both liver biopsy and FS was directly related to alanine aminotransferase (ALT), aspartate aminotransferase (AST), S. albumin and prothrombin. Patients with advanced fibrosis had significantly higher ALT and AST, while their S. albumin and prothrombin were significantly lower than those with minimal fibrosis.ConclusionFS study requires further validation in HBV but could be confidently used at the present time as a predictor for the degree of hepatic fibrosis in chronic HBV patients. Liver biopsy could be spared for cases that present with elevated liver functions and/or marked impairment of synthetic liver functions.
As the oil and gas industry expands into evermore challenging environments with more complicated processes and designs, minimizing well cost and ensuring the best use of resources has resulted in an increase in the engineering planning and field-execution requirements. Drilling optimization has changed from simply improving the rate of penetration (ROP) to analyzing all aspects of the drilling process by establishing an integrated workflow that enables different engineering departments to plan and execute the well. In this case history, the operator’s challenges included vibration in horizontal sections, hydraulics, and wellbore integrity concerns resulting from narrow mud weights available to minimize reservoir damage and to control pore pressure. Drilling optimization also includes measuring and improving operational efficiency and consistency. Many activities are required in a drilling operation, and the inefficiency of these activities increases well costs. This inefficiency can be described as invisible lost time (ILT), which has been shown to contribute to up to 15% of total well cost. It exposes open holes to longer elapsed times which causes hole problems, especially in reactive formations. This case study takes a holistic look at the drilling performance and efficiency improvements that can be made by planning, modeling, and introducing a collaborative drilling engineering team with a real-time field execution team to analyze drilling challenges and address those challenges for future developments.
Activated carbon (AC) has been prepared from rice husk (RH) as an agricultural by-product. Different analytical instruments characterized the prepared activated carbon. Fe 3+ and Mn 2+ were extracted from the aqueous solution. The effects of many different variables namely, pH effect, reaction time, adsorbent amount, starting concentration of metal ions, interfering ions and temperature on the adsorption of ions were evaluated. The optimal adsorption of Fe 3+ and Mn 2+ was 3 and 6, respectively. The optimal contact time was determined to be 2 hours for both Fe 3+ and Mn 2+ ions. The kinetic and thermodynamic of adsorption process was found to be a pseudo-second order for both Fe 3+ and Mn 2+ ions. The equilibrium data was applicable to Langmuir, and Freundlich isotherm. The correlation coefficient (R 2 ) of both isotherms were 0.99 & 0.89 for Fe 3+ , respectively and 0.99 & 0.77 for Mn 2+ , respectively. The obtained data predicted also that; the endothermic system governs the adsorption process. Furthermore, the maximum adsorption capacities for Fe 3+ and Mn 2+ were 72.2 & 49.6 mg/g, respectively and the removal of metal ions were 90.12 & 83.42 %, respectively. Finally, the results revealed that the adsorption process of the two metal ions is consistent with the pseudo-second-order kinetics.
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