Encapsulated water soluble chemicals for use in controlled time release applications, methods of encapsulating the chemicals and methods of using the encapsulated chemicals are provided. The methods of encapsulating the chemicals are basically comprised of forming a first coating of a dry hydrophobic film forming material or a sparingly soluble material which provides a dry shield on the chemical and then forming a second coating of a porous cross-linked hydrophilic polymer on the first coating which prevents the substantial dissolution of the resulting encapsulated chemical for a selected period of time.

Encapsulated chemicals for use in controlled time release applications and methods

Corrosion, scale-formation, or other deleterious processes are inhibited in an oil well by providing within the oil well (10) elements comprising an insoluble porous inorganic material in which is absorbed a well treatment chemical. The material may be in the form of particles or beads, for example porous ceramic spheres impregnated with an inhibitor material. Such particles may be injected as proppant particles into the formation through which the well extends, during a fracturing treatment. Alternatively such particles may be packed as a filter bed (26) in a filter (20) comprising two spaced tubular screens (24) between which the filter bed (26) is located. The inhibitor material gradually dissolves in the well fluids during operation, and may for example inhibit corrosion and/or scale-formation.

Oil well treatment

A material and a device for releasing chemicals in a fluid environment is disclosed, and a method for releasing substances into downhole fluid environments. The invention also relates to materials for sand control and hydraulic fracturing. The substance release device typically comprises a polymeric material for releasing a substance into a downhole fluid environment in a well, and in preferred embodiments the material comprises a spherical, plastic chemical release capsule which is hard, permeable and may encapsulate a range of solids and/or liquids for subsequent release. These solids or liquids can include inhibitors such as scale inhibitors and other oilfield production chemicals for release into the wellbore of an oil or gas producing well or a water injection well.

Microcapsule well treatment

A method of delivering chemicals to well such as an oil or gas well, the method comprising encapsulating the chemicals in or on a carrier particle such as starch, and delivering the carrier-encapsulated chemical to the well.

Method for delivering chemicals to an oil or gas well

The present invention relates to well bore operations, and more particularly, to contained micro-particles, and methods for using such contained micro­particles in cementing operations. An exemplary method of facilitating the use of micro­particles in a well bore fluid comprises the steps of providing contained micro-particles, and adding the contained micro-particles to the well bore fluid. In an exemplary embodiment, the well bore fluids of the present invention comprise encapsulated micro-particles. In another exemplary embodiment, the well bore fluids of the present invention comprise pelletized micro-particles.

Contained micro-particles for use in well bore operations

Gelatin capsules containing oil field chemicals, preferably weighted with a heavy metal compound, are made more stable under certain conditions by the incorporation of a strong chelating agent. The microcapsules can provide an extended treatment period since many materials that would damage the microcapsules are controlled by the chelating agent.

Kowalski Thomas Charles

Papers

Microencapsulated oil field chemicals

Microencapsulated oil field chemicals and process for their use

Micro-capsules of auxiliary substances for drilling fluid when recovering oil and method of their use

Mikrokapsel, blanding samt fremgangsmåte for deres anvendelse