- Antifoam Agents
- Anti-Sludge Agents
- Buffering Agents
- Clay Stabilizers
- Corrosion Inhibitors
- Corrosion Inhibitor Aids
- Foaming Agent
- Friction Reducers
- Gelling Agents
- H2S Inhibitor
- Iron Control Agents
- Mutual Solvent
- Oxygen Scavengers
- Scale Inhibitors
The oil and gas industries are continually seeking to increase the hydrocarbon ultimate recovery from mature or newly appraised reservoirs. Dutch Oilfield Supply and Services can provide you with advanced solutions to assist you in improving profitability in any stage of the well life cycle. We offer technical workflows and chemical technologies to optimize production and increase recovery. DOSAS is committed to the integrated production enhancement and reservoir management approach, covering both short-term production optimization and long-term reservoir engineering objectives. This results in optimum field development, improved hydrocarbon production and increased profitability for our clients.
Base fluid for acidizing treatments.
>> Hydrochloric Acid
– most commonly used type of acid for carbonate acidizing.
>> Hydrofluoric Acid
– in combination with HCl used for treating sandstone formations
>> Organic Acid
– used for treating high temperature carbonates as it has slower reaction rates compared to HCl.
For scenarios when foam occurs in aqueous based fluids in the blender or lines leading to the pumps, the antifoaming agents are added to fluid design.
These are additives to combat the formation of sludge. Sludge can be formed at contact of some crude oils and acid. Once formed, the sludge is difficult to re-dissolve.
Breakers are designed to reduce viscosity of water gels and to enhance fracture clean up after the treatment. Breakers reduce viscosity of the gel by disintegrating the polymer chains into small molecular weight fragments. Two most widely used types of breaker are oxidative breakers, based on free radical reaction, and enzyme breakers.
>> Low Temperature Oxidative Breaker
(125F to 200F)
>> Low Temperature Oxidative Breaker
(200F to 300F)
>> Enzyme Breaker
– has more advantage because of their catalytic nature, breaks the polymer into smaller fragments than oxidative breaker does.
Successful and predictable performance of stimulation fluids often requires certain pH environment. Buffering Agents are added to water-base fracturing fluids to achieve or maintain a desired pH value.
>> Low pH buffer
– acidic buffer for hydration of polymer in the pH range from 3 to 6
>> High pH buffer
– alkaline buffer for guar fracturing fluids in the pH range from 9 to 12
Clays can cause problems with oil and gas reservoir production. Two major clay problems are caused by clay migration and clay swelling, both of which result in a reduction of permeability. These problems can be caused by disturbing formation clays during drilling, completion or production. Clay Stabilisers aim to minimize dispersion and migration of clays in water-sensitive formations
>> Temporarily Clay Control
– provides clay control during stimulation treatment
>> Permanent Clay Stabiliser
– provides clay stabilisation after treatment during production phase
The most critical acid additives are corrosion inhibitors. The corrosion inhibitor is an additive that slows down the attack of acid corrosion on drill pipe, tubing or any other metal that the acid contacts during treatment. The type and concentration of corrosion inhibitor chosen will depend on the acid type, bottom hole temperature, type of steel contacted and expected treatment duration.
>> Mid temperature Corrosion Inhibitor for use with hydrochloric acid
>> High temperature Corrosion Inhibitor for use with hydrochloric acid
>> Corrosion Inhibitor for use with organic acids
>> Corrosion inhibitor for High Chrome Steel
Corrosion Inhibitor Aids
The addition of Corrosion Inhibitor Aids to existing organic inhibitor formulations greatly extends the range of their effectiveness, particularly in higher temperature applications.
Crosslinking agents are used to dramatically increase the viscosity of the polymer gel at relatively low polymer concentrations by binding polymer chains together. A number of metal ions can be used to crosslink water-soluble polymers.
– for high pH range 8-12
– for low pH environment
– for high temperature environment, up to 300F
Foaming agents are added to entrain gas in the treatment fluid. Presence of gas in the fluid enhances offloading the well after the treatment due to reduced hydrostatic pressure of foamy column. Applications include acid treatments or stimulation fluid energized with nitrogen or carbon dioxide
Friction reducing additives are used to reduce friction pressure by suppressing fluid turbulence when pumping acid treatments.
>> Acid friction reducer
– for use in acid treatments
>> Fresh-water/brine friction reducer
– for use in water-based fracturing fluids and brines
Gelling agent are used to viscosify the acid. This allows deeper penetration of acid in the reservoir and improved leak off control
>> Low temperature gelling agent
– for the reservoir temperature up to 125F
>> Mid temperature gelling agent
– for the reservoir temperature up to 200F
>> High temperature gelling agent
– for the reservoir temperature above 200F
>> Visco-Elastic Surfactants
– new generation of gelling agent thickens the acid by forming micelles associated in chain structures. Among the advantages of surfactant thickened acids are superior shear-stability and no residual damage to the formation, as system is polymer free
Hydrogen Sulphide (H2S) Inhibitor is designed to control the detrimental effects of H2S on acid corrosion inhibitors in sour environments
Iron Control Agents
When appreciable quantities of iron are dissolved by the acid in the form of ferric and ferrous ions, iron precipitation and permeability reduction may occur after acidizing as the acid spends. Sources of iron include corrosion products on the walls of the tubular, mill scale on newly manufactured tubing and iron-bearing minerals. Ferric ion is by far the most insoluble form. The three methods available to keep the iron in solution are pH control, chelating agents and reducing agents. These may be used individually or in combination, depending on the amount of iron dissolution expected.
>> pH Control Agents
– help to maintain low pH environment after the HCl acid is spent
>> Chelating Agents
– bond the iron and hold it in solution so that it cannot precipitate
>> Reducing Agents
– convert ferric to ferrous ion which does not precipitate until the pH is above 7.0. Returned spent acids typically have pH less than that.
Mutual solvents are multifunctional, nonionic agents that are soluble in oil, acid, freshwater and brines. They penetrate deeper than surfactants and increase miscibility by decreasing surface or interfacial tension. Mutual solvents are more effective than most surface-active agents in water wetting, preventing emulsions and minimizing particle plugging. The mutual solvents improve the clean-up of spent acid following the treatment
Emulsions sometimes develop as a result of an incompatibility of the stimulation fluid and oil from the reservoir. Non-emulsifiers are added to the treating fluid to prevent formation of emulsions with reservoir fluids.
>> Nonionic Non-emulsifier
>> Cationic Non-emulsifier
Oxygen Scavengers remove dissolved oxygen from the treating fluids. The scavengers prevent the oxidization of ferrous iron to ferric iron, thus the precipitation of ferric iron.
Scale is the deposit of inorganic minerals previously dissolved in water. It can be found in tubulars, but also in near wellbore area. Deposition of scale decreases production capacity by reducing near wellbore permeability, plugging perforations and restricting tubing diameter. Scale inhibitors are intended to prevent formation of scale.
>> Sulphate Scale Inhibitor
>> Carbonate Scale Inhibitor
>> Barium Sulphate Scale Inhibitor
Surfactants are commonly used in treating tight gas wells and in scale removal treatments. Their main function is to lower the surface and interfacial tension of the treating fluid. This aids in well clean up after the treatment