Evaluation of Oxygen Corrosion in Waterflood And Disposal Water Systems
Authors: Conger H.C. 
Published: December 2007

American Institute of Mining, Metallurgical and Petroleum Engineers, Inc.

This paper was prepared for the SPE Rocky Mountain Regional Meeting to be held in Casper, Wyo., May 22–23, 1967. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copies. The abstract should contain conspicuous acknowledgement of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made.

Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

The case histories illustrate how specially polished pipe nipples have been used and examined in the field to evaluate the seriousness of an oxygen corrosion problem. The case histories also illustrate how these test pipe nipples have been used to evaluate actual, not relative, effectiveness of a chemical treatment program to control oxygen corrosion.

Data are presented and discussed showing the relationship between corrosion rates of test pipe nipples and actual in-service equipment. The case histories show how corrosion rates based on pipe test nipple data were used to project equipment life under no chemical treatment vs chemical treatment.

A comparative study of corrosion rates between the use of pipe nipples and coupons as a means of measuring oxygen corrosion is discussed. A further comparative study is made between coupon corrosion rates based on weight loss and pit depth penetration.

An explanation and illustration are presented on how the test nipples are optically examined to determine pit depth penetration. An explanation is given on how corrosion rates based on pit depth penetration are calculated. Data are outlined showing the necessary test nipple exposure time required to obtain valid results.

The case histories show that polished test pipe nipples are a valid, accurate and practical field method that can be used to evaluate the seriousness of an oxygen corrosion problem, and evaluate the actual, not relative, effectiveness of an oxygen corrosion treating program.

Introduction

As waterflooding activity increases each year, there is a need for more information and better methods to evaluate oxygen corrosion problems and treatment programs designed to control oxygen corrosion. There is an abundance of literature and information relative to overall corrosion rates of metals, but in the case of oxygen corrosion rates or pit penetration rate, there is very little information.

In general, the methods used today to evaluate oxygen corrosion provide relative data and information. It is difficult, if not impossible, to make a valid economic study based on relative information. It is necessary, in particular with oxygen corrosion, to develop techniques that will yield actual or true information and data. The following case histories provide a challenge to this problem.