Earth boring – well treating – and oil field chemistry – Well treating – Contains inorganic component other than water or clay
Reexamination Certificate
2001-11-30
2004-09-14
Tucker, Philip C. (Department: 1712)
Earth boring, well treating, and oil field chemistry
Well treating
Contains inorganic component other than water or clay
C507S140000, C507S906000, C175S072000
Reexamination Certificate
active
06790812
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to lost circulation materials (LCM), and to spotting pills containing the LCM. More particularly, the invention relates to acid soluble LCM's, and to spotting pills containing the LCM, preferably to spotting pills having effective rheology and density.
BACKGROUND OF THE INVENTION
Drilling fluids serve various functions, such as promoting borehole stability, removing drilled cuttings from the wellbore, cooling and lubricating the bit and the drillstring, as well as controlling subsurface pressure. Certain subsurface permeable formations can cause, or lead to, “lost circulation,” or the loss of whole drilling fluid in quantity to the formation. In such a case, drilling of the well must be stopped and the condition corrected. Examples of such subsurface permeable formations include, but are not necessarily limited to: (1) natural or intrinsic fractures, (2) induced or created fractures; (3) cavernous formations (crevices and channels), and (4) unconsolidated or highly permeable formations (loose gravels).
Lost circulation materials (LCMs), or formation sealing agents, are used to minimize the loss of drilling fluids into subsurface permeable formations by sealing the formation. To prevent blow-out, or the uncontrolled flow of fluids from the formation into the well, a “pill” or slug of the LCM is needed which has a density that is similar to that of the drilling fluid used to treat the formation.
In some cases the formations desired to be sealed may be a potential producing zone for hydrocarbons. Unfortunately, if the sealed formation is a producing formation, it may be difficult to subsequently produce hydrocarbons from the damaged zone. LCM's are needed which permit removal of the seal and allow for full recovery of hydrocarbons from the loss zone.
SUMMARY OF THE INVENTION
The present application provides a high fluid loss spotting pill comprising: a carrier fluid; an LCM consisting essentially of an amount and form of acid soluble mineral particulate; said amount and said form being adapted to form a substantially impermeable, acid soluble filtercake upon injection of said composition with said carrier fluid into said wellbore and defluidization. In a preferred embodiment, the high fluid loss spotting pill preferably further comprises a weighting agent and a suspending agent effective to suspend said weighting agent. The quantity of weighting agent preferably is adapted to produce a density substantially the same as the density of a drilling fluid used to drill a formation being treated.
REFERENCES:
patent: 1984668 (1934-12-01), Weir et al.
patent: 3375888 (1968-04-01), Lummus et al.
patent: 3433740 (1969-03-01), Armentrout
patent: 3525397 (1970-08-01), Darley
patent: 4289632 (1981-09-01), Clear
patent: 4422948 (1983-12-01), Corley et al.
patent: 5353874 (1994-10-01), Manulik
patent: 5620947 (1997-04-01), Elward-Berry
patent: H1685 (1997-10-01), Lau et al.
patent: 5787332 (1998-07-01), Black et al.
patent: 5909774 (1999-06-01), Griffith et al.
patent: 6016879 (2000-01-01), Burts, Jr.
patent: 6131661 (2000-10-01), Conner et al.
patent: 6137006 (2000-10-01), Thieking et al.
patent: 6143698 (2000-11-01), Murphey et al.
patent: 6164380 (2000-12-01), Davis
patent: 6258757 (2001-07-01), Sweatman et al.
patent: 6561273 (2003-05-01), Brothers et al.
patent: 2003/0039616 (2003-02-01), Maberry et al.
Whistler, Roy L., et al., Starch: Chemistry and Technology, Chapter X, pp. 311-388, (1984).
Green, Method for Creating Dense Drilling Fluid Additive and Composition Therefor, U.S. Patent application Publication No. US2002/0147113A1, Published Oct. 10, 2002, pp. 1-6.
Carr Michelle
Clapper Dennis K.
Halliday William S.
Jarrett Michael
Baker Hughes Incorporated
The Morris Law Firm PC
Tucker Philip C.
LandOfFree
Acid soluble, high fluid loss pill for lost circulation does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Acid soluble, high fluid loss pill for lost circulation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Acid soluble, high fluid loss pill for lost circulation will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3224055