A New Approach to Decommissioning Cost Estimation Using Settled Liability Data
Cost data in the oil and gas industry are proprietary and obtaining them is challenging; in addition, unless collected across a large and diverse sample, summary statistics are unlikely to be representative of the activity or process it is trying to inform. The purpose of this article is to apply settled liability data to infer private information on the cost of decommissioning in the Gulf of Mexico. The procedure avoids most of the traditional problems associated with cost studies but requires careful normalization and a clear understanding of the limitations of analysis. Using settled liability data from 17 public companies with operations primarily in the Gulf of Mexico, decommissioning cost is evaluated on a regional basis and by operator from 2008 to 2012. The average cost to decommission a structure between 2008 and 2012 is estimated to be $6.4 million in water depth less than 200 ft and $15.6 million in water depth greater than 200 ft. Average cost statistics are suggested as a market index for Gulf of Mexico decommissioning activity.
Rigless well abandonment remediation in the shallow water U.S. Gulf of Mexico
Abstract From 2004–2015, over 11,000 wells were plugged and abandoned in the federal waters of the Gulf of Mexico, but no studies have ever been conducted on the reliability of operations and the frequency of remediation activity. The purpose of this paper is to estimate the probability that a dry tree well abandoned using rigless methods, the most common approach in the shallow water Gulf of Mexico, requires remediation after initial operations are completed. A random sample of 502 platform wells abandoned in 2010 in water depth less than 400 ft were tracked for five years to identify bubbling/leaking events. Nine wells were identified that required remediation after operations were performed leading to a remediation probability estimate of 1.8% and a 95% confidence interval ranging between 0.6 and 3.0%. The limitations of the analysis and directions for future work are described.
A Critical Assessment on Functional Attributes and Degradation Mechanism of Membrane Electrode Assembly Components in Direct Methanol Fuel Cells
Direct methanol fuel cells (DMFC) are typically a subset of polymer electrolyte membrane fuel cells (PEMFC) that possess benefits such as fuel flexibility, reduction in plant balance, and benign operation. Due to their benefits, DMFCs could play a substantial role in the future, specifically in replacing Li-ion batteries for portable and military applications. However, the critical concern with DMFCs is the degradation and inadequate reliability that affect the overall value chain and can potentially impede the commercialization of DMFCs. As a consequence, a reliability assessment can provide more insight into a DMFC component’s attributes. The membrane electrode assembly (MEA) is the integral component of the DMFC stack. A comprehensive understanding of its functional attributes and degradation mechanism plays a significant role in its commercialization. The methanol crossover through the membrane, carbon monoxide poisoning, high anode polarization by methanol oxidation, and operating parameters such as temperature, humidity, and others are significant contributions to MEA degradation. In addition, inadequate reliability of the MEA impacts the failure mechanism of DMFC, resulting in poor efficiency. Consequently, this paper provides a comprehensive assessment of several factors leading to the MEA degradation mechanism in order to develop a holistic understanding.