ÇAĞRILI KONUŞMALAR / KEYNOTES Invited Speeches ... - TPJD

Tender Assist Drilling (TAD)
Alparslan Şahin
Turkish Petroleum Corporation, Drilling Department, Ankara
Platform rig is an immobile offshore structure from which development wells are drilled and
produced. The degree of a platform rig has an important effect in the field development cost. In
offshore, development wells can be drilled by a giant platform rig that can also has production
and processing facilities as well as living accommodations for the people. Alternatively, these
functions may be conducted on different platforms that are much smaller than a giant platform.
This can be achieved by using Tender Assist Drilling (TAD) which has a split drilling unit. The unit
that is immobile is a fixed platform and the other unit is mobile that provides logistic to fixed
platform. TAD system requires employing a Tender Support Vessel (TVS) during the drilling phase
of a well development to provide drilling utilities to the platform drilling equipment package. In
the first years of the TAD’s, barges mainly were used as tender to fixed platforms in shallow water
and good weather conditions but, it was seen that they easily became inoperable and unsafe
in deep water and rough weather. Alternatively, in 1980’s, the use of the tender assist barges
in harsh weather, existing mobile offshore drilling units (MODU), Semi-submersible platforms,
were converted to Semi-Submersible tender for fixed platform. This study aims to review tender
assist drilling (TAD) and its applications in the world. Besides, my goal particularly is to present
an application of tender assist drilling performed by Turkish Petroleum Corporation (TPAO) in
Turkey. TPAO constructed a fixed platform in Akçakoca Natural Gas Development Field, Düzce
and a tender assist barge was chosen for that fixed platform.
Keywords: Tender Assist Drilling, Platform Rig
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