Process fluids preparation
Oil and gas fields development and exploitation includes numerous operations, such as borehole drilling, oil recovery enhancement, maintenance, oil well conservation or abandonment.
Each of those operations requires various substances, their solutions, suspensions or emulsions.
Water-salt solutions and emulsions used as well kill fluids during repair works, clay or polymer fluids used for drilling or well conservation and abandonment, acid washes for near wellbore area — these and other substances are called process fluids and are used in oil production.
A well kill operation carried out during repairs requires a well killing fluid. Killing fluids can either be aqueous (fresh or produced water with additives, foam, stabilized with solid particles, water-salt solutions, gelated water-salt solutions) or non-aqueous (water-in-oil emulsion).
Fresh or produced water is the most common killing liquid used in well kill operations. These liquids’ density can be increased up to 2100 kg/m3 with various water-salt solutions with different mineral salts.
The right proportions of salts for killing fluids are calculated during laboratory studies and corrected after field tests.
Sodium, calcium or potassium chlorides and sodium and calcium nitrates are the most common components of the solutions. Bromine salts, or bromides as well as unique patented salt compositions are used in creating high-density liquids.
The main agents used in enhanced oil recovery are acids and gels. The makeup of acid agents for each operation is determined by an entire range of measurements and conditions, primarily determined by the type of the bridging agent used in any given reservoir. Depending on these conditions the bridging agent may include different acids, hydrocarbonic or mutual solvents along with various modifiers. Gels used in hydraulic fracturing are comprised of many components, such as thickeners, stabilizing elements, breakers, etc. All this requires strict adherence to the preparation specifications and technology.
All types of process fluids are produced at brine plants to ensure steady and homogeneous composition of the whole solution volume. Operating procedures and right proportions depend on the kind of the produced fluid.
To give process fluids the necessary characteristics they are modified by chemical agents — scale inhibitors, surface-active agents, oil wetting agents, hydrogen sulfide neutralizers, bactericides and other reagents.
The requirements towards process fluids are designed to ensure stable well productivity, technological effectiveness, work safety and borehole equipment preservation. Among the main controlled characteristics that vary depending on the type of fluid are: reservoir fluids compatibility, formation damage, amount of entrained solids, corrosion ratio and dissolution rate, time of gelation, draw-down and overbalance pressures, etc.
Process fluids characteristics are subject to strict control and are checked at both the place of production and the well site or well cluster. After the fluid characteristic control procedures are through, the liquids are delivered directly to consumers: a service company, for any particular type of work.
The Technotec International Company Group manages 11 large brine plants that produce the full range of process fluids. Our process fluids ensure maximum efficiency and performance in the field due to our strict compliance with production procedures and our advanced quality control procedures for both components and the final product. Our extensive experience and fine research capabilities allow our company to develop and constantly implement new solutions.
