HYDRATES PROBLEM WITHIN THE FRAMEWORK OF MULTIPHASE PRODUCTION AND TRANSPORT OF CRUDE OILS AND NATURAL GASES .2. POSSIBLE SOLUTIONS TO EXPLOITATION DIFFICULTIES GENERATED BY HYDRATES

Offshore exploitation of fossil fluid fuels has emphasized the need of improving our knowledge on hydrates which can plug production, treatm ent and transport facilities. The first part() recalled the molecular structure of I, II and H hydrates, then the physical-chemistry of the ir formation was briefly reviewed from both the thermodynamic and the kinetic points of view. In this second part, the possible remedies to the problems met by operating companies are described, mainly classica l thermodynamic inhibitors such as alcohols or salts which decrease th e hydrates formation temperature, and dispersant additives which avoid crystals growth and/or agglomeration. At last an original circulation loop at pilot scale is presented, its characteristics which allow the testing of dispersant additives under representative hydrodynamic and physico-chemical conditions being outlined.