Proceedings of the
Second International Energy 2030 Conference,
November 4-5, 2008, Abu Dhabi, U.A.E.
Benefits of Expandable Tubular in the Petroleum Industry
Dr. Abdennour C. Seibi
The Petroleum Institute, UAE
Abstract
Expandable Tubular Technology (ETT) is a downhole cold working process where a conical mandrel is
driven mechanically or hydraulically through a solid tubular to expand it to a specified diameter. This
technology is one of the interesting innovations for well construction and completion and one of its main
long term objectives is the achievement of mono-diameter wells. However, the already existing
applications are characterized by a considerable flexibility, wide range horizons, and cost effectiveness for
many long outstanding problems faced during well construction and operation. This technology has
gained momentum and attracted the attention of operators and researchers, and is rapidly expanding its
horizon for field applications. However, still a lot of research and laboratory experiments need to be done
before this technology is fully used for commercial applications.
The continual increased demand in deep, directional, horizontal, and extended-reach drilling may
create demand for more complex use of ETT. Thus, this technology is particularly an interesting field of
engineering research and development. Current research work mainly aims at addressing factors such as
reduction of power required to achieve certain expansion percentage, effect of friction and weight during
expansion, minimization of surplus deformation, optimization of mandrel shape, mandrel speed, pipe size
and grade, etc. Knowledge of post expansion mechanical properties is required for accurate service rating
of the tubular products under evaluation. Critical data such as hardness, chemical resistance, postexpansion
strength, ductility, impact toughness, burst and collapse strength are needed for selection of a
tubular for a given application. Therefore, the objective of this research work is to design an experimental
setup to investigate the mechanical expansion process for different expansion ratios. This allows the
measurements of the required drawing forces, tubular thickness variation, and stress concentration factors
in the neighborhood of induced circular holes. The experimental study will be supplemented by finite
element modeling of lab and field cases.
