Pipeline Freespan Evaluation: A New Methodology

Abstract

A methodology for the rigorous assessment of pipeline freespans is described, together with a description of its application to the Beryl Field network of pipelines. The methodology is in two parts, each with two stages, and comprise preliminary stress and vibration frequency checks followed by detailed strain and fatigue life checks where appropriate. Comprehensive software, automatically linked to the inspection database, has been written to allow efficient use of the methodology. The use of a new ROV based freespan rectification technique is also described. Both the assessment and rectification techniques were successfully used in Mobil's Beryl field and the SAGE pipeline in 1992.

Review of pipeline span analysis

“…It was claimed that the nonlinear behaviour of free spanning pipelines exposed to steady currents has a strong influence on the onset of hydroelastic synchronization due to vortex shedding; the mathematical model revealed the existence of a geometrical condition needed for the onset of synchronization for long free spans and can be used successfully for predictive purposes when applied to real free spans to assess several key factors, among other results. Kaye, et al (Kaye et al, 1993), described a stringent methodology for the assessment and rectification of pipeline free spans with respect to a certain field. This methodology comprised of two parts each with two stages, and consist of preliminary stress and vibration frequency checks succeeded by comprehensive strain and fatigue life checks where appropriate; also discussed was the use of an ROV based freespan rectification technique, among others.…”

Evaluating New Medicines for Use in Australian Hospitals: Lessons from North America

“…Most hospitals use a formulary (list of medicines and related information, evaluated and approved by a formal clinical process for use in the treatment of disease and promotion of health within a healthcare organisation) governed by the drug and therapeutics committees to promote rational, clinically appropriate, safe and cost-effective therapy. 1,2 Before new medicines are introduced to the formulary or existing indications extended, clinicians need to submit a request to the drug and therapeutics committee for consideration. 2 The information requested may differ across sites and the committees differ in the expertise of their members in assessing clinical and pharmacoeconomic data and in the tools they use to assist them in this process.…”

“…1,2 Before new medicines are introduced to the formulary or existing indications extended, clinicians need to submit a request to the drug and therapeutics committee for consideration. 2 The information requested may differ across sites and the committees differ in the expertise of their members in assessing clinical and pharmacoeconomic data and in the tools they use to assist them in this process. With no standard approach, there is the risk of inconsistent decisions by these committees, that these decisions may not represent best value for money, with the potential for inequities in access to medicines.…”

“…With no standard approach, there is the risk of inconsistent decisions by these committees, that these decisions may not represent best value for money, with the potential for inequities in access to medicines. [1][2][3] Australian hospitals' drug and therapeutics committees benefit greatly from the health technology assessments (objective, comprehensive, factual assessment of clinical and cost effectiveness, and broader impact of drugs, health technologies and health systems) that are undertaken by the Pharmaceutical Benefits Advisory Committee. However, there are medicines used in hospitals that will never be assessed by the Pharmaceutical Benefits Advisory Committee, e.g.…”

“…The economic analyses needed to assess the cost-effectiveness of these medicines are generally not available to the drug and therapeutics committees, and few committees have the resources to undertake or appraise such analyses. 2,3 In contrast, in the USA there are standard guidelines for formulary submissions to assist their institutional pharmacy and therapeutics committees to determine the total value that a drug brings to their population. [4][5][6] Canada has a centralised Common Drug Review process that includes the assessment of cost-effectiveness relative to accepted therapy.…”