Page 182 - Pipeline Pigging Technology

Gellypig technology for pipeline conversion

GELLYPIG TECHNOLOGY FOR
CONVERSION OF A CRUDE OIL PIPELINE

TO NATURAL GAS SERVICE:

ACASE HISTORY

INTRODUCTION

When pre-commissioning a natural gas pipeline, a thorough cleaning of
the pipeline's internal surface is necessary to provide trouble-free gas trans-
mission.
When the pipeline was originally in crude oil service, planned for conver-
sion to natural gas, the cleaning becomes even more involved and critical to
the pipeline's success. Pipelines generally contain various types of debris (e.g.
millscale, dirt, rust, construction debris, old products, etc.), whether con-
structed of new pipe or converted from existing pipelines. This debris can
result in an array of problems, such as frequent filter changes, reduced flow
capacity, higher operating expenses, instrumentation fouling, and concern
over valve seat erosion, just to name a few.
Dowell Schlumberger Inc (DS) has performed many successful cleaning
operations for both operational and pre-operational pipelines, utilizing the
gellypig technology developed in the early 1970s. The gellypig has been used
in the North Sea, Saudi Arabia, South America, the United States, and many
other regions of the world with excellent results. Pipelines have ranged from
4 to 36in diameter; from a few miles to hundreds of miles in length; and in a
wide variety of services (i.e. natural gas, crude oil, products, etc.).
Dowell Schlumberger was contracted by Missouri Pipeline Co in the USA
to perform gellypig services for its St. Charles project, a newly-acquired "loop"
line which would be converted to natural gas service, from a previously-
abandoned crude oil line.

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