Abstract

The performance of coiled tubing pipe in real-world conditions is a topic of interest and frequent discussion within the industry. With pipe cost routinely exceeding $250,000 per string, service companies want to know if they are achieving the maximum return on their investment, and how their utilization compares with their competitors. However, industry-wide information is not readily available, especially for newer pipe grades, while published data tends to be specific to a particular company, region, or type of operation. As a result, policies regarding pipe life and criteria for retirement are largely set by each company, and industry practices can be slow to adapt as new products and procedures emerge.

An online system has been in place since 2010 where service companies upload, track and evaluate pipe and job data for the purposes of their own string management and operation planning. With records for over 5,200 strings and 146,550 jobs at the time of writing, this database has the potential to generate in-depth analysis of pipe performance. However, the data entered by each participant is confidential to that company, and is not usually available for general analysis. An initiative has therefore been developed whereby companies can choose to make certain data available, appropriately anonymized to protect commercial interests, which can be used to generate statistics of interest to the industry at large.

To illustrate the potential benefits, this paper will present a sample analysis of string performance based on cumulative running feet (or meters) at the time of pipe retirement. Since most coiled tubing operations are billed at least in part on running feet, this can be considered as a proxy for revenue. Total running feet will be compared with modeled pipe fatigue to see which metric better anticipates working life in real-world conditions. The paper will show how, when a large quantity of data is available, a statistically meaningful distribution of outcomes can be determined for each pipe diameter and grade, thus making it possible to compare grades, and quantify whether a given string has exceeded or fallen short of expectation, relative to the industry as a whole and not just the company concerned. The importance of taking into account all relevant factors, including the operating pressures and environment that the string has been exposed to during its working life, will be discussed.

In conclusion, an approach to increase the amount of available data, taking into account legitimate confidentiality concerns, will be proposed.

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