Inaccuracy in Pipeline-Compressor-Station Construction-Cost Estimation
The intent of this paper is to investigate installed cost overruns of pipeline-compressor-station projects. A total of 220 pipeline-compressor-station projects constructed between 1992 and 2008 have been collected, including material, labor, and miscellaneous, land, and total installed costs; and compressor-station capacity; location; and year of completion. Statistical methods are applied to identify the distribution of cost overruns and overrun causes. Overall average overruns of pipeline-compressor-station material, labor, miscellaneous, land, and total costs are 3, 60, 2, –14, and 11%, respectively. Cost estimations of compressor-station construction components are biased except for the material cost. In addition, the cost-estimation errors of underestimated compressor-station-construction components are generally larger than those of overestimated components. Results of the analysis show that compressor-station project size, capacity, location, and year of completion have different impacts on individual construction component cost overruns.
Cost-estimating error is the tendency for actual costs to deviate from estimated cost. Bias is the tendency for that error to have a nonzero mean (Bertisen and Davis 2008). Project cost-estimation errors and bias are common and a global problem in cost estimating (Flyvbjerg et al. 2003). Project cost-estimation errors and bias have been mentioned and studied in numerous papers. Cost overruns of all Indiana department of transportation (INDOT) projects were 4.5%, while 55% of INDOT projects experienced cost overruns (Bordat et al. 2004). Jacoby (2001) found that 74 projects with a minimum cost of USD10 million had 25% cost overruns. Rui et al. (2011a, 2011b, 2012a, 2012b) investigated the cost overruns of 412 pipeline projects between 1992 and 2008, finding an average of 4.9% cost overrun for material, 22.4% for labor, -0.9% for miscellaneous, 9.1% for right of way (ROW), and 6.5% for total installed costs. In addition, literature reviewed also showed that cost overruns exist over time.
API Releases New Edition of Valve Standard
API released an updated valve standard for wellhead and tree equipment, which includes new automatic closure requirements.
Supervised Autonomy Bridges the Gap in ROV Inspections
ROVs dominate the world of subsea inspections, maintenance, and repair, but as operators work in a post-downturn economy, autonomous systems have become more in demand. Autonomous inspections are possible today, but how can they help with light and heavy intervention?
Condition-Based Maintenance Helps Develop a North Sea Low-Manned Platform
Remote condition monitoring of offshore platform equipment tracks performance data, watching for deviations from baseline benchmarks. Unexpected variances can be investigated and serviced by technicians dispatched to target the root causes—an approach called condition-based maintenance.
Don't miss out on the latest technology delivered to your email every two weeks. Sign up for the OGF newsletter. If you are not logged in, you will receive a confirmation email that you will need to click on to confirm you want to receive the newsletter.
24 October 2018
06 November 2018
24 October 2018
07 November 2018