Cementing composition comprising within un-reacted cement

• US 8,236,879 B2
• Filed: 11/15/2006
• Issued: 08/07/2012
• Est. Priority Date: 09/20/2006
• Status: Expired due to Fees

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: Michaux, Michel, Le-Roy-Delage, Sylvaine
• Primary Examiner(s): Choi, Ling
• Assistant Examiner(s): USELDING, JOHN E
• Application Number:
  US12/441,240
• Publication Number:
  US 20100081733A1
• Time in Patent Office: 2,092 Days
• Field of Search: 524/2, 524/8
• US Class Current: 524/8
• CPC Class Codes: C04B 16/04 Macromolecular compounds C04B16/02 takes precedence
• CPC Class Codes: C04B 20/0076 characterised by the grain distribution
• CPC Class Codes: C04B 20/1018 with organic materials pigments or dyes C04B20/1096
• CPC Class Codes: C04B 2103/0049 Water-swellable polymers
• CPC Class Codes: C04B 2103/40 Surface-active agents, dispersants
• CPC Class Codes: C04B 2111/00068 Mortar or concrete mixtures with an unusual water/cement ratio
• CPC Class Codes: C04B 2111/50 Flexible or elastic materials
• CPC Class Codes: C04B 24/2676 Polystyrenes
• CPC Class Codes: C04B 24/36 Bituminous materials, e.g. tar, pitch C04B24/243 takes precedence
• CPC Class Codes: C04B 28/02 containing hydraulic cements other than calcium sulfates
• CPC Class Codes: C04B 40/0675 Mortars activated by rain, percolating or sucked-up water; Self-healing mortars or concrete
• CPC Class Codes: C04B 7/00 Hydraulic cements calcium sulfate cements C04B11/00
• CPC Class Codes: C09K 8/42 Compositions for cementing, e.g. for cementing casings into boreholes; Compositions for plugging, e.g. for killing wells compositions for plastering C09K8/50
• CPC Class Codes: C09K 8/428 for squeeze cementing, e.g. for repairing
• CPC Class Codes: C09K 8/467 containing additives for specific purposes

Abstract

Cementing compositions for use in oilfield applications are designed such that, after setting, a significant amount of cement remains unhydrated. After placement in a subterranean well, the unhydrated cement remains dormant. If the cement sheath becomes damaged, the unhydrated cement hydrates upon exposure to formation fluids, thereby restoring zonal isolation in the wellbore. The compositions comprise emulsions that allow a substantial reduction of the water-to-cement ratio, yet the rheological properties remain suitable for placement in the well.

Claims

1. A method for cementing a subterranean well, comprising:

(i) preparing a slurry comprising cement, water, and an emulsion; and

(ii) placing the slurry in the well,

wherein the water-to-cement ratio is between 0.04 and 0.29 by weight, and the emulsion comprises an aqueous suspension of latex particles, a suspension of nano organic solids, a suspension of nano inorganic solids, or a combination thereof.

2. The method of claim 1, wherein the latex particles comprise styrene-butadiene.

3. The method of claim 1, wherein the slurry further comprises flexible particles, fibers, particles that swell in the presence of a hydrocarbon, particles that swell in the presence of water, or a combination thereof.