Abstract: Described herein are methods of cementing at least a portion of a well comprising feeding a magnetorheological cementitious slurry to a well and applying a magnetic field to the magnetorheological cementitious slurry concurrent with at least a portion of said feeding step to cause a mechanical response in said magnetorheological cementitious slurry in the well. Also disclosed herein are methods of temporarily blocking at least a portion of a well comprising providing a magnetorheological fluid in a well, applying a magnetic field to cause a mechanical response in said magnetorheological fluid thereby blocking at least a portion of the well, and removing the magnetic field to unblock the portion of the well. Also disclosed herein is a magnetorheological cement.

Abstract: A method of cementing an annular space between a pipe string and a well bore, the method comprising the steps of (a) providing a cement composition including a calcium-deficient calcium silicate; (b) mixing the cement composition with water to form a cement slurry; (c) mixing the cement slurry composition with carbon dioxide form a foamed cement; and (d) placing the foamed cement in the annular space between the pipe string and the wellbore.

Abstract: Described herein are methods of cementing at least a portion of a well comprising feeding a magnetorheological cementitious slurry to a well and applying a magnetic field to the magnetorheological cementitious slurry concurrent with at least a portion of said feeding step to cause a mechanical response in said magnetorheological cementitious slurry in the well. Also disclosed herein are methods of temporarily blocking at least a portion of a well comprising providing a magnetorheological fluid in a well, applying a magnetic field to cause a mechanical response in said magnetorheological fluid thereby blocking at least a portion of the well, and removing the magnetic field to unblock the portion of the well. Also disclosed herein is a magnetorheological cement.

Abstract: Described herein are methods of cementing at least a portion of a well comprising feeding a magnetorheological cementitious slurry to a well and applying a magnetic field to the magnetorheological cementitious slurry concurrent with at least a portion of said feeding step to cause a mechanical response in said magnetorheological cementitious slurry in the well. Also disclosed herein are methods of temporarily blocking at least a portion of a well comprising providing a magnetorheological fluid in a well, applying a magnetic field to cause a mechanical response in said magnetorheological fluid thereby blocking at least a portion of the well, and removing the magnetic field to unblock the portion of the well. Also disclosed herein is a magnetorheological cement.

Abstract: Described herein are methods of cementing at least a portion of a well comprising feeding a magnetorheological cementitious slurry to a well and applying a magnetic field to the magnetorheological cementitious slurry concurrent with at least a portion of said feeding step to cause a mechanical response in said magnetorheological cementitious slurry in the well. Also disclosed herein are methods of temporarily blocking at least a portion of a well comprising providing a magnetorheological fluid in a well, applying a magnetic field to cause a mechanical response in said magnetorheological fluid thereby blocking at least a portion of the well, and removing the magnetic field to unblock the portion of the well. Also disclosed herein is a magnetorheological cement.

Abstract: A cementitious slurry is prepared from drilling fluid, blast furnace slag and an emulsion comprising an oil external phase and an aqueous internal phase having therein a additive for said cementitious slurry. In a preferred embodiment the additive is an accelerator for the blast furnace slag such as sodium hydroxide. This allows mixing the additive with the drilling fluid and blast furnace slag without immediate contact between the additive and the other ingredients. After the cementitious slurry has been mixed and pumped into position in a wellbore, the emulsion breaks and the additives are released.

Abstract: A method and composition for cementing a well by combining water, blast furnace slag and a phosphate ion-containing compound to form a cement slurry, displacing the cement slurry into the well, and allowing the cement slurry to set.

Abstract: The thermal stability of hardened drilling mud-concrete is improved by incorporating blast furnace slag, microfine slag or fine ground glass into the mud-concrete prior to hardening.

Abstract: A cementitious slurry is prepared from drilling fluid, blast furnace slag and an emulsion comprising an oil external phase and an aqueous internal phase having therein a additive for said cementitious slurry. In a preferred embodiment the additive is an accelerator for the blast furnace slag such as sodium hydroxide. This allows mixing the additive with the drilling fluid and blast furnace slag without immediate contact between the additive and the other ingredients. After the cementitious slurry has been mixed and pumped into position in a wellbore, the emulsion breaks and the additives are released.

Abstract: A high alumina wellbore cementing composition is provided, the composition comprising:a) high alumina cement; andb) a polyacrylic acid phosphinate having a molecular weight of about 3800 in an amount effective to prevent gelation of the cementing composition for a time period of at least three hours.This composition can remain pumpable for a time period sufficiently long to place the cement in a wellbore using conventional wellbore cementing procedures, and, after the composition is cured, is capable of withstanding elevated wellbore temperatures.

Abstract: A defective cemented annulus in a wellbore is repaired by injecting a water-soluble monomeric composition having polymerizable unsaturated groups. This allows repair of leaking cement jobs where the leakage occurs through very small imperfections. In accordance with the invention, a section of the casing above the area where formation fluid pressure may be entering is sealed off with packer devices, perforated or mill cut and a monomer solution is injected into the cemented annulus.

Abstract: A universal fluid which includes a water-based drilling mud and a hydraulic material is used to drill a borehole and lay down settable filter cake. After drilling is completed, the filter cake and universal fluid are caused to solidify in selected parts of the borehole by admixing the universal fluid with an activator.

Abstract: Drilling fluid is solidified by the incorporation therein of coal slag. In a preferred embodiment lime is also incorporated into said drilling fluid and/or said drilling fluid is a lime drilling fluid. Thus, there is provided a cementitious composition comprising drilling fluid, coal slag and, generally, lime.

Abstract: A drilling mud is converted in-situ to a cement by addition of blast furnace slag.

Abstract: A method and composition for cementing a well by combining water, blast furnace slag and trisodium phosphate to form a cement slurry, displacing the cement slurry into the well and allowing the cement slurry to set.

Abstract: A method and composition for cementing a well by combining water, blast furnace slag and sodium tripolyphosphate to form a cement slurry, displacing the cement slurry into a well and allowing the cement slurry to set.

Abstract: A method and composition for cementing a well by combining water, blast furnace slag and sodium pyrophosphate to form a cement slurry, displacing the cement slurry into a well and allowing the cement slurry to set.

Abstract: Drilling fluid is solidified by the incorporation therein of low grade blast furnace slag. In a preferred embodiment lime is also incorporated into said drilling fluid and/or said drilling fluid is a lime drilling fluid. Thus, there is provided a cementitious composition comprising drilling fluid, low grade blast furnace slag and, generally, lime. Also provided is a drilling and cementing process wherein a cementitious slurry comprising low grade blast furnace slag is introduced into a wellbore to cement a casing or liner.

Abstract: Method for altering the trajectory of a borehole by use of a sidetracking plug.

Abstract: A cementitious slurry is produced by combining an aqueous drilling fluid with a slurry of Portland cement in oil. Generally the drilling fluid is an aqueous drilling fluid containing clay such as prehydrated bentonite. The resulting composition has a particular utility in primary cementing operations for oil wells.