Use of a fluid composition with delayed cross-linking for holding a casing inside a drill hole and method for reinforcing a drill hole
AssigneesCray Valley S.A., Total Marketing Services
InventorsJérome Leleux, Nicolas Leblond, Hervé Cavalie, Philippe Thepot
Life of this patent
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Abstract
A cross-linkable composition with controlled cross-linking as a material is used for fixing and thermally insulating tubes used for casing in drill holes, especially oil drill holes, during exploitation operations, such as oil extraction, in the drill hole. The cross-linkable composition includes at least one diene polyol, at least one polyisocyanate, and at least one heat insulating liquid filler.
Claims16
A method for fixing at least one casing section of a drill hole well, said method comprising:
- a) introducing a tube in the drill hole well;
- b) pumping with a PUMP for a viscous product and injecting into the well a composition with controlled cross-linking, comprising the mixture of at least one diene polyol, at least one polyisocyanate having a functionality of at least 2, optionally a cross-linking retardant and at least one inert liquid filler;
- c) filling the whole or part of the annular space located between the ground and said tube with said composition, wherein at completion of cross-linking of said composition, said tube is fixed to the ground by the cross-linked composition;
- d) optionally before the end of the filling of the annular space, sending cement, for maintaining said composition before its complete cross-linking;
- and
- e) closing the lower space of the casing section.
Casing sections of a drill hole well, said casing sections comprising several concentric tubes of different heights and several annular spaces formed by the space between the ground and at least one tube, by the space between two tubes, or both;
- wherein at least one portion of the height of a casing section and at least one of the annular spaces is occupied by a composition with controlled cross-linking, said composition comprising:
- a) at least one diene polyol;
- b) at least one polyisocyanate with a functionality of at least 2,
- these components being the precursors of a cross-linked polyurethane formed in situ in said composition;
- and
- c) at least one heat insulating liquid filler, chemically inert towards said polyisocyanate and polyol,
- said composition being injectable into the well by a pump and having a dynamic viscosity of less than 3,000 mPaxs, and
- the pumpability of the said composition being maintained for 1 to 48 hours, in a temperature range from −20° C. to 200° C. and a pressure range from atmospheric pressure to a pressure of 300 bars,
- wherein a first tube is fixed to the ground by the composition when cross-linked, and a second tube is fixed to the first tube by the composition when cross-linked.
A method for fixing at least one casing section of a drill hole well, said method comprising:
- a) introducing a first tube in the drill hole well, thereby forming an annular space between ground and said first tube;
- b) pumping with a pump for a viscous product and injecting into the well a composition with controlled cross-linking, comprising the mixture of at least one diene polyol, at least one polyisocyanate having a functionality of at least 2, optionally a cross-linking retardant and at least one inert liquid filler;
- c) filling the whole or part of the annular space located between the ground and said first tube with said composition, wherein at completion of cross-linking of said composition, said tube is fixed to the ground by the cross-linked composition;
- d) introducing in the drill hole well a second tube concentric with the first tube and having a height different from the first tube;
- e) filling the whole or part of the annular space located between the two concentric tubes with said composition, wherein at completion of cross-linking of said composition, said second tube is fixed to the first tube by the cross-linked composition;
- f) optionally before the end of the filling of the annular space in step c) or e), sending cement, for maintaining said composition before its complete cross-linking;
- and
- g) closing the lower space of the casing section.
Dependencies are inferred from the claim text.