Coiled tubing drilling with supercritical carbon dioxide

Patent · Tue Jan 01 00:00:00 EST 2002

OSTI ID:874240

Kolle, Jack J ^[1]

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1. Seattle, WA

A method for increasing the efficiency of drilling operations by using a drilling fluid material that exists as supercritical fluid or a dense gas at temperature and pressure conditions existing at a drill site. The material can be used to reduce mechanical drilling forces, to remove cuttings, or to jet erode a substrate. In one embodiment, carbon dioxide (CO.sub.2) is used as the material for drilling within wells in the earth, where the normal temperature and pressure conditions cause CO.sub.2 to exist as a supercritical fluid. Supercritical carbon dioxide (SC--CO.sub.2) is preferably used with coiled tube (CT) drilling equipment. The very low viscosity SC--CO.sub.2 provides efficient cooling of the drill head, and efficient cuttings removal. Further, the diffusivity of SC--CO.sub.2 within the pores of petroleum formations is significantly higher than that of water, making jet erosion using SC--CO.sub.2 much more effective than water jet erosion. SC--CO.sub.2 jets can be used to assist mechanical drilling, for erosion drilling, or for scale removal. A choke manifold at the well head or mud cap drilling equipment can be used to control the pressure within the borehole, to ensure that the temperature and pressure conditions necessary for CO.sub.2 to exist as either a supercritical fluid or a dense gas occur at the drill site. Spent CO.sub.2 can be vented to the atmosphere, collected for reuse, or directed into the formation to aid in the recovery of petroleum.

• Research Organization: Tempress Technologies, Inc., Kent, WA
• DOE Contract Number: FG03-98ER82696
• Assignee: Tempress Technologies, Inc., Kent, WA
• Patent Number(s): US 6347675
• OSTI ID: 874240
• Country of Publication: United States
• Language: English

Related Subjects

coiled
tubing
drilling
supercritical
carbon
dioxide
method
increasing
efficiency
operations
fluid
material
exists
dense
gas
temperature
pressure
conditions
existing
drill
site
reduce
mechanical
forces
remove
cuttings
jet
erode
substrate
embodiment
cosub2
earth
normal
exist
sc-cosub2
tube
equipment
viscosity
provides
efficient
cooling
head
removal
diffusivity
pores
petroleum
formations
significantly
water
erosion
effective
jets
assist
scale
choke
manifold
mud
cap
control
borehole
ensure
occur
spent
vented
atmosphere
collected
reuse
directed
formation
recovery
carbon dioxide
supercritical fluid
water jet
fluid material
dense gas
drilling operation
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