Boring or penetrating the earth – Processes – Boring with specific fluid
Reexamination Certificate
2001-10-16
2004-11-16
Tsay, Frank (Department: 3672)
Boring or penetrating the earth
Processes
Boring with specific fluid
C175S206000, C405S128350, C588S249000
Reexamination Certificate
active
06817426
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a method for treatment of drill cuttings to remove free hydrocarbons, including heavy crude oil and/or bitumen from the cuttings.
BACKGROUND OF THE INVENTION
During the drilling of oil and/or gas wells, a drill bit at the end of a rotating drill string, or at the end of a drill motor, is used to penetrate through geologic formations. During this operation, drilling mud is circulated through the drill string, out of the bit, and returned to the surface via the annular space between the drill pipe and the formation. Among other functions, the drilling mud provides a washing action to remove the formation cuttings from the wellbore. The mud returns to the surface along with entrained drill cuttings and typically flows through “shale shakers,” desanders, desilters, hydrocyclones, centrifuges, and/or other known devices to separate the cuttings from the mud. The shale shaker(s), which typically sit above the mud storage area, essentially are screens that are used to separate the drill cuttings from the drilling mud. The drilling mud falls through the screens by gravity and the cuttings pass over the end of the screens.
The disposal of the drill cuttings after separation from the drilling mud can present a problem. One way to dispose of the cuttings would be to discharge the cuttings directly at the drilling site. An even more economically efficient way to dispose of drill cuttings would be to “recycle” the cuttings as components of building materials, such as concrete. Unfortunately, the cuttings may contain environmentally undesirable “free hydrocarbons,” defined herein as hydrocarbons derived either from the drilling mud, from the rock formation, or both.
One approach that has been used to reduce potential environmental contamination by drill cuttings has been to minimize the toxicity of the oil-base fluids used to make drilling muds, and more recently, to use base fluids that are more biodegradable. Unfortunately, this approach does not eliminate contamination by the free hydrocarbons which originate in the rock formation rather than in the drilling fluid.
Methods are needed to treat cuttings, preferably in situ, to reduce the quantity of free hydrocarbons discharged into the environment upon subsequent use or disposal of the cuttings.
SUMMARY OF THE INVENTION
The invention provides a method comprising: providing cuttings produced during drilling operations comprising a first quantity of free hydrocarbons comprising bitumen; mixing with the cuttings a buffer solution comprising a buffer agent effective to activate at least one natural surfactant in the bitumen, thereby converting the solution into an emulsion comprising bitumen droplets having a mean average particle size of about 5 microns or less; and, thereafter adding to the emulsion an encapsulating material comprising an aqueous solution of a water soluble silicate under conditions effective to form silica shells around the droplets.
REFERENCES:
patent: 3210310 (1965-10-01), Holbert et al.
patent: 4040866 (1977-08-01), Mondshine
patent: 4209381 (1980-06-01), Kelly, Jr.
patent: 4395357 (1983-07-01), Kramer et al.
patent: 4425241 (1984-01-01), Swanson
patent: 4469603 (1984-09-01), Lepain et al.
patent: 4554081 (1985-11-01), Borchardt et al.
patent: 4597893 (1986-07-01), Byford et al.
patent: 4599117 (1986-07-01), Luxemburg
patent: 4600515 (1986-07-01), Gleason et al.
patent: 4645608 (1987-02-01), Rayborn
patent: 4649183 (1987-03-01), McCormick et al.
patent: 4812242 (1989-03-01), James et al.
patent: 4861499 (1989-08-01), Neff et al.
patent: 4892916 (1990-01-01), Hawe et al.
patent: 5005655 (1991-04-01), Stokke et al.
patent: 5076938 (1991-12-01), Noonan et al.
patent: 5156686 (1992-10-01), Van Slyke
patent: 5213625 (1993-05-01), Van Slyke
patent: 5402857 (1995-04-01), Dietzen
patent: 5564509 (1996-10-01), Dietzen
patent: 5570749 (1996-11-01), Reed
patent: 5622920 (1997-04-01), Rivas et al.
patent: 5792223 (1998-08-01), Rivas et al.
patent: 5839521 (1998-11-01), Dietzen
patent: 5882524 (1999-03-01), Storey et al.
patent: 6224534 (2001-05-01), Limia et al.
patent: 6267716 (2001-07-01), Quintero
patent: 2306523 (2001-04-01), None
patent: 0 554 377 (1993-06-01), None
patent: 0 728 826 (1996-08-01), None
Baker Hughes Incorporated
The Morris Law Firm, PC.
Tsay Frank
LandOfFree
Low shear treatment for the removal of free hydrocarbons,... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Low shear treatment for the removal of free hydrocarbons,..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Low shear treatment for the removal of free hydrocarbons,... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3360019