Abstract: Temporary plugs are formed in process flowlines by injecting into the flowlines a plugging material having a freezing point only slightly below the ambient temperature. The plugging material is frozen in place, and a servicing operation is conducted on the flowline. The plugging material is then allowed to thaw or is thawed by applied heat. Linear primary alcohols and normal paraffinic hydrocarbons are preferred plugging materials.

Abstract: Low permeability formations are hydraulically fractured with a fracturing fluid which includes a material capable of (1) bonding fine formation particles to prevent movement of the particles into and within the formation and (2) forming a permeability-reducing skin at the formation/fluid interface to reduce fluid leak-off into the formation. The stabilizing and fluid leak-off reducing material is comprised of a water soluble polymer and an alkaline potassium salt.

Abstract: Oil field chemicals are incorporated in microcapsules of the condensation product of hydroxyacetic acid or the co-condensation product of hydroxyacetic acid and other compounds containing hydroxy-, carboxylic acid-, or hydroxycarboxylic acid moieties. The microcapsules are then introduced into an oil well bore and/or subterranean oil formation where the microcapsules dissolve over a period of time and release the oil field chemicals.

Abstract: A melted polymer of hydroxyacetic acid with itself or with other hydroxy-, carboxylic acid-, or hydroxycarboxylic acid-containing moieties is subjected to high shear and injected into an organic liquid which is inert to the polymer to form an organic liquid dispersion of very fine polymer particles. In one aspect the melted polymer is combined with the organic liquid and the combination is thereafter subjected to high shear to form the fine particle polymer dispersion. A dispersion agent may also be used to aid in dispersing the particles. The dispersion is used for fluid loss control and gel breaking in subterranean formations.

Abstract: Hydroxyacetic acid condensation product is used as a fluid loss material in a well completion or workover process in which a fluid comprising a hydrolyzable aqueous gel is used. The hydroxyacetic acid condensation product degrades at formation conditions to provide hydroxyacetic acid which breaks the aqueous gel, thereby restoring full formation permeability without the need for separate addition of gel breaker.

Abstract: Hydroxyacetic acid condensation product is used as a fluid loss material in a formation fracturing process in which a fracturing fluid comprising a hydrolyzable aqueous gel is used. The hydroxyacetic acid condensation product degrades at formation conditions to provide hydroxyacetic acid which breaks the aqueous gel, which provides restored formation permeability without the need for separate addition of gel breaker.

Abstract: Saline source water containing dissolved oxygen is deoxygenated to form injection quality water in the disclosed process and apparatus. In accordance with the invention, saline source water is electrolyzed in an electrolytic cell which produces hydrogen and chlorine. The hydrogen is reacted with the dissolved oxygen in a catalyst resin bed to reduce the dissolved oxygen to the desired level. Optionally, evolved chlorine may be used as a biocide in the system.