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US 11,162,012 B2Granted
Well treatment fluid having biodegradable fluid loss control agent
AssigneeHalliburton Energy Services, Inc.
InventorsSandip Prabhakar Patil, Ganesh Shriniwas Pangu, Tamal Kumar Sen, Samuel Lewis
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Abstract
A method of treating a well that includes introducing a well treatment fluid into the well, and a well treatment fluid, are provided. The well treatment fluid comprises an aqueous base fluid, a bridging agent, a viscosifying agent, and a water soluble, biodegradable graft copolymer. In one embodiment, for example, the method is a method of cementing a casing in a well. In this embodiment, the well treatment fluid is a cement spacer fluid.
Claims18
A method of treating a well, comprising:
- introducing a well treatment fluid into the well, said well treatment fluid including:
- an aqueous base fluid;
- a bridging agent wherein said bridging agent is a nutshell;
- a viscosifying agent selected from the group consisting of one or more gums, one or more clays, and combinations thereof;
- and
- a water soluble, biodegradable, graft copolymer, said graft copolymer comprising:
- a grafting base selected from the group consisting of lignin, tannin, and humic acid;
- a first monomer component grafted onto said grafting base, said first monomer component being selected from the group consisting of acrylamido-2-methyl propane sulfonic acid, acrylic acid, acrylamide, vinyl acetic acid, methacrylic acid, dimethyl methacrylate, and combinations thereof;
- and
- a second monomer component grafted onto said grafting base, said second monomer component being an organic compound selected from the group consisting of gelatin, collagen, casein, soy protein, and combinations thereof;
- wherein the combination of aqueous base fluid, bridging agent, viscosifying agent, and graft copolymer is effective as a fluid loss control fluid within the well.
8 more elements
A method of cementing a casing in a well, comprising:
- a) placing a cylindrical casing into the wellbore, wherein said casing has an outside diameter that is less than the diameter of the wellbore such that an annulus is formed between the exterior of said casing and the wall of the wellbore;
- and
- b) after placing said casing into said wellbore, circulating a cement spacer fluid downwardly through the interior of said casing, out of an end of said casing, and upwardly through said annulus to the surface, said cement spacer fluid comprising:
- an aqueous base fluid;
- a bridging agent wherein said bridging agent is a nutshell;
- a viscosifying agent selected from the group consisting of one or more gums, one or more clays, and combinations thereof;
- and
- a water soluble, biodegradable, graft copolymer, said graft copolymer comprising:
- a grafting base selected from the group consisting of lignin, tannin, and humic acid;
- a first monomer component grafted onto said grafting base, said first polymer component being selected from the group consisting of acrylamido-2-methyl propane sulfonic acid, acrylic acid, acrylamide, vinyl acetic acid, methacrylic acid, dimethyl methacrylate, and combinations thereof;
- and
- a second monomer component grafted onto said grafting base, said second monomer component being an organic compound selected from the group consisting of gelatin, collagen, casein, soy protein, and combinations thereof;
- wherein the combination of aqueous base fluid, bridging agent viscosifying agent, and graft copolymer is effective as a fluid loss control fluid within the well;
- c) after circulating said cement spacer fluid downwardly through the interior of said casing, out an end of the casing, and upwardly through said annulus to the surface, circulating a hydraulic cement composition downwardly through the interior of said casing, out an end of the casing, and upwardly into said annulus;
- and
- d) allowing said hydraulic cement composition to set in said annulus thereby forming an annular sheath of hardened cement therein.
13 more elements
Dependencies are inferred from the claim text.