Materials & Corrosion

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

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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

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NACE 10401 - Prevention Of Corrosion In Carbon Steel Pipelines Containing Hydrotest Water - An Overview

2010 Abstract, Adam Darwin, Karthik Annadorai, Gibson Applied Technology and Engineering, LLC; Krista Heidersbach, Chevron Energy Technology Center

A critical step in proving a pipeline is fit for operational use is the hydrostatic test, in which it is filled with water and pressurized to 125% of its Maximum Allowable Operating Pressure (MAOP). The water that is used in this testing can cause corrosion of the pipe, potentially leading to failure early in its operating life. Failures have occasionally been reported even before a pipeline enters service.

The most common mechanisms by which carbon steel pipelines may undergo corrosion on exposure to hydrotest water are Microbially Induced Corrosion (MIC), oxygen-related corrosion, galvanic corrosion and under-deposit corrosion. An overview of these mechanisms is presented, along with a discussion of the influence of different environmental factors on them. Factors considered include water source, degree of filtration, exposure period and temperature, air pockets, presence of internal pipe coatings and future pipeline service conditions.

Maintaining the risk of pipe corrosion from hydrotest water within acceptable limits is discussed. Factors considered are:

How long the untreated water may be allowed to be present in the pipeline.

Should water treatment be required, what must be used?

Disposal requirements for the treated water, including chemical treatments.

Source: CORROSION 2010, March 14 - 18, 2010 , San Antonio, TX

Copyright 2010. NACE International

NACE 05633 - The Impact of Reservoir Souring upon Decision Processes Made During the Design of New Deepwater Developments

2005 Abstract, Lee C. Jordan, Justin P. Landry, Howard Duhon, and Grant T. Gibson, GATE LLC

This paper presents an overview of the impact of potential future reservoir souring and associated H2S production on the design decisions that must be made during the development of a deepwater production asset. The problem is inherently one of decision making under uncertainty, as determination of the likely magnitude of reservoir souring is a process requiring review of a large number of variables and the application of predictive techniques of limited accuracy. This paper reviews some of the practical uncertainties involved in predicting souring and identifies how these subsequently impact design and operability issues. By exhaustively identifying design objectives in the form of an objectives map it is possible to assess the impact of souring on all aspects of the design. Best practice approaches to risk management and mitigation are also presented in relation to the design of both water injection and production facilities.

Source: CORROSION 2005, April 3 - 7, 2005 , Houston, Tx

Copyright 2005. NACE International

NACE 04104 - Hydrogen Embrittlement Of Corrosion Resistant Alloys Under Cathodic Protection Conditions

2004 Abstract, Jonathan Marsh, Gibson Applied Technology; Grant T. Gibson and Michael Walsh, GATE LLC

This publication examines the issue of hydrogen embrittlement of CRA materials under the cathodic protection conditions often found in the up stream oil and gas industry. The environment in question is thus oxygenated seawater. The different possible mechanisms of hydrogen embrittlement for CRA materials under these conditions are discussed, as are the different factors affecting susceptibility and mitigation of susceptibility. The susceptibility of the different classes of materials is examined, and susceptible materials highlighted. The importance of undertaking a materials/CP review at different stages of a given project is proposed, and two case studies are described. Finally, a flow plan is put forward indicating the procedures that can be followed.

Source: CORROSION 2004, March 28 - April 1, 2004 , New Orleans, La

Copyright 2004. NACE International

NACE 02064 - Laboratory Investigation of Corrosion and Corrosion Protection of a Candidate Umbilical Material for Subsea Production Service

2002 Abstract, Lianfang Li and William H. Hartt, Florida Atlantic University; Grant T. Gibson, GATE LLC; Steve L. Wolfson, Shell E&P

Umbilical functionality is critical to proper operation of subsea production systems, and for this reason it is important to properly select materials and corrosion protection options for this service. In this regard, specimens of a chromium-manganese-nickel duplex stainless steel (UNS S32001) in the normal, welded, and crevice conditions were exposed freely corroding and cathodically polarized for up to 413 days in natural sea water environments that were intended to simulate umbilical service. The results of these exposures are presented, and projections are made regarding appropriateness of this material for umbilical service.

Source: CORROSION 2002, April 7 - 11, 2002 , Denver, Co

Copyright 2002. NACE International