EurOCEAN 2000 - Vlaams Instituut voor de Zee

initially most important parameters. A new method and tool to better use and analyse the
autoclave core after retrieval onboard the research vessel by its pressurized transfer into a
laboratory autoclave was developed. Technical outlines and a pilot instrument for pressurized
core logging onboard and in the lab were established.
2. Technical scope and achievements of HYACE
On initiative of Fachgebiet Maritime Technik of Technische Universität Berlin, who took part
in the gas hydrate ODP Leg 164, a consortium of European research institutes and public and
private companies was formed in 1997. The goal of the group is to improve available but
insufficient ground truthing technology in the general framework of international marine gas
hydrate research with the financial aid of the EU Commission, which is acknowledged by all
partners with gratitude.
The scope of work was based on the following main tasks:
• Define in more technical detail geological and performance requirements for the set of
tools and methods to sample, measure in-situ and evaluate marine gas hydrates, the
emphasis being on the sampling and sample evaluation processes,
• A rotary autoclave corer with downhole drive and control, fitting into standard bottom
hole assemblies and wireline handling tools was developed for indurated sediments,
• Friable, hard and coarse grain size sediments associated with gas hydrates and/or free gas
from the hydrates - the most difficult area of coring - need a percussion autoclave sampler,
which was designed and offshore tested,
• Make available a push-in corer for soft sediments, including the essential autoclave
function to fit into standard bottom hole assemblies and wireline handling tools to be more
easily used worldwide and in Europe in particular,
• Transfer of autoclave cores under pressure, onboard ship, from the downhole to a
laboratory pressure vessel,
• An autoclave core logging unit was conceived to analyze hydrate samples under pressure,
in such a way that downhole conditions are preserved,
• Downhole measurements of those parameters which are needed for the systematic and
technically controlled research of gas hydrates, such as temperature and pressure, readout
onboard,
• Further studies are required to see whether existing techniques of downhole or in-situ
measurements (below the borehole) are adequate to map those ambient conditions which
cannot be inferred from the core,
• Establish the measurements to be made on the recovered samples and the method of such
monitoring under pressure to arrive at input data for computer modelling to predict what
happens with a change of pressure and/or temperature and what hydrate dissociation
processes could be expected.
With those tasks and achievements, particularly on the hardware side, the partners of Project
HYACE are accomplishing much more than what had been originally intended and
contractually agreed with the EU Commission. The challenging European marine science topic
"gas hydrates" is an incentive to do so. The partners hope that the EU Commission uses and
supports this volunteering scientific and innovative thrust to promote European contributions to
international geoscientific research and drilling in future years.
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