Abstract: Improved bonding in a well system between cement, well tubular members and the formation about the well/bore at a pay zone. Drilling fluid materials (mud, solids, filter cake, etc.) are displaced at turbulent flow conditions by a slug of concentrate consisting essentially of a water-free mixture of surfactant and alcohol. The aqueous fluid cement immediately follows the slug. Residual filter cake and tubular member are water-wetted. The cement on hardening has an improved bonding to both tubular members and formation at the pay zone.

Abstract: A process for removing contaminating insoluble solids (e.g., rust, sand, scale, barite and drilling mud) from an aqueous fluid such as produced in well systems during cleaning operations before placement of packer brines. A small effective amount of an alcohol, and a surface active chemical aid, are thoroughly intermixed into the aqueous fluid. The concentration and/or composition of the alcohol and/or surface active chemical aid is adjusted to control agglomeration of the insoluble solids and then to settle, float or suspend same in the aqueous fluid. After the solids agglomerate, the solids are separated in a quiescent separation zone from the fluid by decantation, flotation or filtration, respectively.

Abstract: A process for removing contaminating solids from high density, salt type aqueous drilling/completion/packer fluid prior to its introduction into a well bore. A small effective (e.g., 0.5% volume) of an aliphatic alcohol, 2-ethyl hexanol, and a surface active chemical aid, the amide reaction product of a fatty monobasic acid (oleic) with a secondary amine diethanolamine are thoroughly intermixed into the fluid. After the solids agglomerate, the solids are separated from the fluid before introduction in a solids-free condition into the well bore. The fluid may have a density as high as 19 pounds per gallon and be a brine formed of the sodium, calcium or zinc salts with chloride or bromide anions.

Abstract: A process for eliminating drilling fluid (mud, solids and oil) from a well system prior to introduction of solids-free completion and packer brine. Drilling fluid is displaced by circulating through well pipe and annulus of a treated water (surfactant and alcohol) to complete removal of drilling fluid. A plug of a gelled aqueous spacer may be used before or after the treated water. The plug spacer is displaced from the well system by the following treated water or circulating therein of the solids-free brine. The spacer isolates efficiently the treated water from the displaced drilling fluid or the displacing brine. If the drilling fluid is inverted, the spacer can be an inverted gel of bentone, water and diesel oil.

Abstract: A process for removing contaminating solids from high density, salt type aqueous drilling/completion/packer fluid prior to its introduction into a well bore. A small effective amount (e.g., 0.5% volume) of an aliphatic alcohol (e.g., n-hexanol) and a surface active chemical aid (e.g., bis hydroxy ethyl cetyl amine) are thoroughly intermixed into the fluid. After the solids agglomerate, the solids are separated from the fluid before introduction in a solids-free condition into the well bore. The fluid may have a density as high as 17 pounds per gallon and be a brine formed of the sodium, calcium or zinc salts with chloride or bromide anions.

Abstract: A liquid cleaning system for liquid that is substantially continuously circulated and which becomes contaminated with solid particulate and debris during circulation. The liquid cleaning system, which is particularly advantageous to cleaning liquid that is circulated within a petroleum well bore during completion and workover activities, incorporates a vibratory screen separator for accomplishing preliminary separation of large particulate and debris from the contaminated liquid and which also incorporates a filtration bank having a plurality of filters that are each interconnected with inlet discharge and drain headers. Filter bank incorporates a valving system having the capability of accomplishing backflushing by circulating clean fluid in reverse manner through selected ones of the filters to remove collected solid particulate therefrom and transport the removed particulate to the drain header.