There are already a number of Offshore field developments which fall into the ‘HP/HT’ category Considerable research has gone into the production of equipment which will operate reliably in the extreme conditions found with the well bore of such developments, and into the formulation of control fluids which will retain their performance characteristics under these same conditions However the critical nature of HP/HT operations requires that careful attention is given not just to the design phase, but also to the procedures used in qualifying equipment and during installation and maintenance Experience has proven that it is not valid to assume that procedures that have been found acceptable in "conventional" applications can be applied to HP/HT conditions. Castrol Offshore are providers of specialist hydraulic control fluids for many of these new fields This has required a high level of involvement with operators and manufacturers of well control equipment, and has included the development of new test procedures for evaluating component performance and control fluid compatibility with system materials of construction The test programme has also highlighted a number of issues which have important implications in terms of material selection and procedures used when assembling, testing and installing equipment. The paper seeks to inform by example some of the more important findings of Castrol Offshore's HPMT programme The emphasis is on areas which may not at first be generally felt to be subjected to HP/HT conditions by the pure industry definition (and therefore may well not be included in safety and reliability studies) but which can have serious implications if not considered. Key points will be:
the need for test and qualification regimes which simulate more closely the anticipated field conditions,
understanding the full meaning of materials compatibility, and
preventing actions which can compromise the integrity of the system.