Abstract

Problems associated with Pipeline flow capacity reduction due to the presence of Scales, Asphaltenes and Parrafins have always been present and are well documented. Solutions to these problems are not however as well understood or discussed and, more often than not, complete replacement of the affected section is imminent because of the limited solutions available to the operator. Completely changing a section of Pipeline can have significant costs associated with it. Indeed, material & labor costs, environmental impact due to Pipeline construction and loss of flowing capacity represent the key reasons to avoid this type of operation if at all possible and give reason for ongoing investigations into possible alternatives.

This paper outlines a solution that was implemented several times in Ecuador whereby Coiled Tubing employing rotating & jetting technology was used to completely restore Pipeline flow capability without the need to replace any section of the affected tubular.

This solution involved the use of proprietary rotating/jetting technology introduced into the Pipeline at strategic locations, defined by computer simulations, to affect a successful cleanout operation. Selecting an efficient cleaning fluid was also very important for the success of these operations as there were significant economical and environmental limitations that had to be overcome.

Details about this solution, including defining the operational limitations of the Coiled Tubing material due to restrictions, orientation and curvature as well as fluid selection and other design limitations and considerations are included in this paper.

Introduction

An ongoing investigation to find technical & economical solutions for day to day problems such as pipeline plugging due to scale, and or asphaltene and paraffin presence allowed us to come up with both a cost effective and efficient solution: "Pipe Line Clean Up using Coiled Tubing, & Rotating Jetting Technology (RJT) Tool". At present, a total of five successful jobs in the Ecuadorian jungle have been performed that have helped a client restore complete flowing capacity to various pipelines/flowlines by cleaning and also avoid the excess costs involved for the replacement of said pipelines/flowlines; which, up until the introduction of this technology, represented the only viable alternative available.

By minimizing the amount of downtime (NPT) that is customary with complete pipeline/flowline replacement as well as avoiding excessive surface preparation and cleanup costs, it is no surprise that the savings that were achieved by the implementation of this technology were substantial.

Using advanced simulation software, engineers were able to properly define very difficult operational limits while at the same time logically programming job sequences, taking into account numerous conditions affecting the pipelines/flowlines.

The use of efficient but, at the same time, economical cleaning fluids, was mandatory due to the environmental & economical constrains of this project. Several laboratory tests with pipeline samples were conducted prior to each job to help identify the correct fluid to be used for an efficient pipe line clean up, while at the same time reducing the environmental risks of this project.

It should be noted that very valuable information was obtained from these operations and analyzed after every job. Said information allowed us to better understand the operations that were being performed and how we could utilize this information to improved subsequent operations.

Rotating Jetting Technology (RJT)

Rotating Jetting Technology (RJT) has been successfully utilized with Coiled Tubing since the early 1990's and is now considered commonplace to our industry. More than 3,500 wells in over 30 countries have used these tools on conventional cemented/cased hole and open hole (OH) completions to remove asphaltenes, paraffins, scales, cements, sand blockages and open hole near wellbore drilling mud damage. However, very little information exists pertaining to the use of RJT in pipeline/flowline cleanup operations.

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