2011

SPE 147205 - Materials Selection: A Systems Engineering Approach

2011 Abstract, Eric Caldwell, Karthik Annadorai, Grant Gibson, Lee Jordan

Subsea and topsides materials selection is becoming a vital part in the development and long term sustainability of deepwater oil and gas production facilities. Increasing challenges associated with capital and operating cost constraints, schedule compression, remote locations, and the need to deploy materials ever closer to their known limits makes fit for purpose materials selection a complex and difficult issue that crosses many different discipline boundaries. Materials selection is primarily governed by corrosion engineering principles and applied chemical inhibition practices, and then by project specifics. However, there are two different practices that are generally followed that dictate how materials are ultimately selected. The first is by a standard materials selection process using guidance such as that provided in NORSOK M-001, and the second is by using a more informal system with limited guidance that involves individually selecting materials for a specific project.

 In actuality, the materials selection process is a combination of both. The selection process to identify which materials are considered appropriate is routine and straightforward and is dictated by various corrosion parameters and associated risks. Often this high-level assessment does not appropriately address project specifics, so causing the final material selections to be substantially different from those initially proposed.

One of the specific items that often drives this change in materials selection philosophy is the use of chemical inhibitors for corrosion inhibition and the perceived feasibility and level of risk associated with this. Use of a systems engineering approach to material selection can be used beneficially as a process that accelerates the determination and initial optimization of the materials, and the selection of chemicals and their injection locations, and associated monitoring methods and locations in a given topsides, subsea or water injection system design.

Source: SPE Annual Technical Conference and Exhibition, 30 October-2 November 2011, Denver, Colorado, USA

Copyright 2011. Society of Petroleum Engineers

Read More 

SPE 147552 - Integrated Field Optimization Strategy Applied to an Offshore Water Injection Project

2011 Abstract, F.R. Chaban, SPE, L.C. Jordan, SPE, and K.M. Annadorai, SPE, Gibson Applied Technology and Engineering; T.W. Wilkinson, SPE, and P. Myers, Energy XXI

 Some of the most significant challenges faced with respect to the management of offshore water injection projects are associated with maintaining injectivity into the reservoir and with handling H2S produced due to reservoir souring. This paper presents the process followed and findings generated by a comprehensive review of a mature water injection project performed with the goal of delivering a coordinated operating strategy that would maximize the life of field revenues associated with water injection.

An integrated and comprehensive field optimization approach to maximize the whole-life value of the total asset was undertaken. Aspects covered included water injection system operating practices, mechanical design and integrity management of the injection system, the chemical treatment program followed for both the injection and production streams, and reservoir modeling and production management.

Recommendations resulting from this review were prioritized based on their impact on the whole-life performance of the asset, rather than the more common practice of separating the injection and production system reviews or the assessments of reservoir management and facility operation. Areas of particular benefit were identified in association with implementation of an active souring control strategy to reduce future risks to the production system metallurgy by sulfide stress cracking (SSC), a focus on integrity management of the water injection system to maximize long-term system availability, and the implementation of an inter-well water tracer injection program to enable the validation of current reservoir models and support the placement of future injectors and producers.

Source: SPE Annual Technical Conference and Exhibition, 30 October-2 November 2011, Denver, Colorado, USA

Copyright 2011. Society of Petroleum Engineers

SPE 141982 - Stream-based HAZOP - A More Effective HAZOP Method

Abstract 2011, H.J. Duhon

The Hazard and Operability Study (HAZOP) is probably the most commonly applied process hazard analysis method. As such, HAZOPs are a very important tool for improvement of process safety. But HAZOPs are not as effective as they should be. Duhon and Sutton (SPE 120735, 2010) identified many reasons why we don’t learn all we should from HAZOPs. These insights suggest a path towards a more effective HAZOP process.

The process described here differs from the standard HAZOP process in several important ways. The most important difference is the definition of stream-based nodes rather than equipment-based nodes. In a stream-based node, a stream is followed from its inception to its logical conclusion. This is especially useful when considering flow deviations, because a flow disruption in any part of the stream affects all parts or at least all downstream parts of the stream. These stream-based nodes are much larger than typical equipment-based nodes and hence overcome the tendency of HAZOPs to create tunnel vision.

HAZOPs are supposed to evaluate operability, but that can’t be done effectively without reviewing the operating procedures or at least discussing how the system will be operated. There is no point in a typical HAZOP, because small nodes are selected, in which the procedures can be effectively introduced. Stream-based nodes provide a natural bridge to the procedures. High level operating procedures can be introduced during the stream-based node discussion providing an opportunity to do a Process HAZOP and a Procedure HAZOP simultaneously. A Procedure HAZOP often provides more insight than the Process HAZOP.

Source: SPE Americas E&P Health, Safety, Security, and Environmental Conference, 21-23 March 2011, Houston, Texas, USA

Copyright 2011. Society of Petroleum Engineers

NACE 11099 - Further Analysis On M13Cr-110 NACE TM0177 Method A Test Acceptability Prediction

2011 Abstract, Eric Caldwell, Grant Gibson, Lee Jordan

Martensitic stainless steels continue to be one of the most widely used corrosion resistant alloys in oil and gas developments. Determining if a martensitic stainless steel is acceptable in an unproven environment requires testing to confirm, but predicting the outcome of a given test environment is often initially based on personal experience rather than a qualitative and quantitative assessment. An empirical method for improving the predictability of NACE TM0177 Method A Tensile tests on modified 13Cr 110ksi grade martensitic stainless steels based on an H2S/Chloride/pH function has previously been developed based on published data in order to address this uncertainty. The environments considered by this function are only limited by the capabilities of the NACE TM0177 Method A test, and provide a method for rapidly estimating if a M13Cr 110ksi grade should pass or fail in multiple different environments. As a follow-on to the development of this empirical method, data points from new tests were used to check the general predictability of the H2S/Chloride/pH function. The general function was modified due to the addition of the new data, and subsequently checked again against a separate set of data. The nature and implications of these findings are discussed and conclusions drawn regarding the performance and value of the methodology for the evaluation of future materials applications.

Source: CORROSION 2011, March 13 - 17, 2011 , Houston, Texas

Copyright 2011. NACE International

Read More