In the period 1990-92 John Downs and Eric van Oort of Shell Research developed the TAME clouding glycol system for drilling shales. The prototype TAME drilling fluid formulation was bought to the market by BW Mud and the first field trials were conducted by Shell UK Expro in the Uk North Sea. The info in this slide presentation was eventually presented to SPE in 1993 as SPE paper 26699

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KSEPL::KS082 8-MAV-1990 11 14:13.56
PROFS'SNIVM01(U27RS45)
STEWARTR,KS082
PATENT IDEA
Ton,
Thanks for sending me a copy of the SEM EP patent application.
On the subject of patents I have for some time been thinking of a new
drilling mud system that might address some of the current issues being
raised re. SEM and oil based muds
The problem with OBMs and to a certain extent SEM is that they
make use of a water immiscible phase ( emulsified with water) to coat
out onto borehole/cutting surfaces and reduce the unwanted shale/water
reactions that cause instability.Moves are underway to ensure that the
coating phase which ends up on the cuttings ( ego as a pile on the
sea-bed floor in offshore operations ), has minimal toxicity to free
living organisms - hence our move to put esters into SEM instead of oil
However even the least toxic components can still cause massive
damage to the ecosystem via their organic enrichment in for instance
a cuttings pi le.Through bacterial growth on the residual organic material
attached to the cuttings the whole environment can become anaerobic and
noxious under and around the cuttings dump.
My idea is to use a water soluble non-ionic compound ( eg like the
Shell Oxilubes which are alcohol alkoxylates or perhaps something
more biodegradable) which has a distinct cloud point at say 25 deg. C.
in place of the normal oil or ester phase. This product would then precipitate
out of solution at > 25 deg C. ( ie downhole ) and coat the borehole/cuttings
surface witha water impermeable layer.However, when the cuttings are brought
to the surface and cooled prior to dumping the non-ionic becomes water
soluble again and can be recovered from the water phase leaving uncontaminatedcuttings which can be easily dumped.If preferred
discharged straight into the cold sea-water and the nonionic would leach
out immediately into the water column thus avoiding organic enrichment
on the sea bed.
The concept seems ( to me at least emminently patentable. The question
is how much experimental evidence do I need to " prove" that the concept
could work in practice? Can we file a quick priority patent on the concept
alone? I think we will need to move fairly quiCkly on this one if we are
to avoid being pipped to the post
Kind regards,
John Downs
KSEPL LRP/12
the cu