Shell Oil Comapny

Dresser Industries, Inc.

James J Nahm

Kenneth M Cowan

Reece E Wyant

Arthur H Hale

Kazem Javanmardi

Harold J Vinegar

John Michael Karanikas

John H Pelletier

Leonard Michael Haberman

Earl H Doyle, Jr

Kris A Digre

Robert N Romero

David A Rowe

There is provided a method for insulating a wellbore comprising providing a wellbore, providing a casing within the wellbore, wherein an annulus is formed between the wellbore and the casing, filling the annulus with an emulsion of liquid sodium silicate and an acid forming agent, increasing a temperature in the annulus, and forming a silica gel in the annulus, the silica gel effective in insulating the wellbore. A steam injection tubing may be provided within the casing, wherein a second annulus is formed between the casing and the steam injection tubing and the second annulus is filled with the emulsion.

Method of thermally insulating a wellbore

An aqueous displacement fluid composition is used as a spacer fluid composition to change one type of drilling mud for another type of drilling mud or in cementing operations downhole, to clean downhole hardware in wellbores. The method comprises introducing into a wellbore an aqueous displacement fluid composition, such as a spacer fluid, to displace downhole wellbore fluids, having an improved rate of emulsification and a high capacity for emulsifying hydrocarbons, and aqueous fluid compositions. The aqueous displacement fluid composition introduced into wellbores contain mixtures of:

Aqueous displacement fluid compositions for use in wellbores

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.

Water-base mud conversion for high tempratice cementing

A high alumina wellbore cementing composition is provided, the composition comprising:

Alumina wellbore cement composition

A water-in-oil emulsion drilling fluid can be converted into an oil mud-cement slurry for use in oil well cementing procedures. Also, a universal fluid can be prepared using the water-in-oil emulsion drilling fluid by treating with an hydraulic material so that it will lay down a filter cake during drilling which can be triggered to set into a hard cement and bond to the formation after the above oil mud-cement slurry has been placed in the borehole at the conclusion of drilling.

Conversion of oil-base mud to oil mud-cement

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.

Universal fluids for drilling and cementing wells

A casing or liner in a wellbore penetrating a zone having high formation gas pressure is cemented with a cementitious slurry comprising blast furnace slag. In one embodiment the cementitious slurry is made by combining blast furnace slag and a drilling fluid. Also, a method for plugging or setting sidetracking plugs and other secondary cementing operations in a wellbore penetrating a zone having high gas formation pressure comprising placing a mass of blast furnace slag cementitious slurry at a preselected location and allowing the slurry to set.

Anti gas-migration cementing

A wellbore is drilled utilizing an oil-in-water emulsion drilling fluid, optionally containing blast furnace slag. A compatible cementitious slurry containing blast furnace slag and an activator system is then introduced into the borehole and displaced up into an annulus. Generally, the cementitious slurry is prepared by adding additional blast furnace slag and an activator such as a sodium hydroxide/sodium carbonate mixture to the used drilling fluid.

Conversion of emulsion mud to cement

A wellbore is drilled utilizing a conventional drilling fluid or a drilling fluid such as one containing a cementitious component selected from blast furnace slag, a metal oxide component of an ionomer or a metal oxide component of a phosphate salt. A compatible cementitious slurry such as one containing blast furnace slag and an activator system is then introduced into the borehole and displaced up into an annulus by direct contact with a displacement fluid. Generally, in the case of the slag-containing drilling fluid the cementitious slurry is prepared by adding additional blast furnace slag and an activator such as a sodium hydroxide/sodium carbonate mixture to the used drilling fluid. Similarly, in the case of the ionomers or phosphates, additional metal oxide component and the reactive second component can be added to the used drilling fluid to produce the cementitious slurry.

Slag-cement displacement by direct fluid contact

A spacer fluid containing blast furnace slag is utilized in a well drilling operation. In one embodiment an oil emulsion drilling fluid is displaced using spacer fluid comprising water, blast furnace slag and a surfactant. In another embodiment a spacer fluid comprising blast furnace slag and water is used in the cementing of an annulus surrounding a pipe with a blast furnace slag cementitious slurry.

Cementing with blast furnace slag using spacer

A method of cementing a casing in a wellbore is provided wherein a cement slurry is placed in the wellbore prior to inserting the casing into the wellbore. Voids in the resultant cement caused by poor centralization are eliminated by placement of the cement in the wellbore prior to insertion of the casing.

Process to cement a casing in a wellbore

A cementitious slurry containing blast furnace slag and a surfactant is utilized to displace an oil based drilling fluid without causing contamination by the blast furnace slag cement. In a specific embodiment, a cementitious slurry comprising blast furnace slag, a surfactant and water is used in the cementing of an annulus surrounding a casing or liner wherein a synthetic oil-containing drilling fluid is present.

Oil mud displacement with blast furnace slag/surfactant

Blast furnace slag spacer

A drilling fluid is diluted and a cementitious component added thereto. In a more specific embodiment the dilution is carried out by introducing liquid such as water to a flowing stream of the drilling fluid and thereafter a cementitious component is mixed therewith. Thus, the drilling fluid can be used in a conventional manner to drill a well and thereafter diluted and a cementitious component added to produce a cement for cementing operations such as setting a casing in the well and/or can be used for remedial cementing. In another embodiment of the invention, the drilling fluid itself contains a small amount of cementitious component and additional cementitious component is added after the dilution.

Growing community of inventors

Houston, TX, United States of America

James J Nahm