Lignosulfonates are water-soluble anionic polyelectrolyte polymers. In the oil industry, lignosulfonates are used as a reagent to control the basic parameters of drilling fluids and as deflocculants to prevent the coagulation of solids. Lignosulfonate is ideal for oil drilling use because it is stable at high temperatures.
More specifically, the use of lignosulfonate mud is employed when oil drilling into formations containing a lot of Bentonite. Clay materials in drilling mud like bentonite are prone to coagulation. Using lignosulfonates, coagulation can be halted and results in extended use of bentonite.
There are many different systems of drilling fluid in the oil industry, including freshwater, saltwater, and synthetic-based pneumatic fluid systems. The terms drilling fluid and drilling mud are used interchangeably to mean the same thing: they’re used to aid tools during the drilling of wells. It is sometimes referred to as drilling mud because of the fluids’ thick consistency.
Drilling fluids are used for the following purposes in the oil industry:
- Carry cuttings from a hole
- Cool & clean the drill bit
- Reduce friction
- To avoid damage to formations
- Maintain bore stability
- Set retarder in oil well cementing
Drilling Fluid Additives
Additives are chemicals that are added into drilling fluids for a particular purpose: either to adjust pH and kill bacteria or to control viscosity. They are formulated in storage tanks or an excavated sump at the drill site.
Using lignosulfonates, coagulation can be halted and results in extended use of bentonite. Lignosulfonates have been successfully used in lime-based and brine-based drilling fluids or drilling muds.
- Chemical stabilizer
- Cement softener
- Dispersing agent
Lignosulfonates are also a component of gelling systems. Gelling systems are low viscosity solutions containing a pH between 2.5-3. Gel formation redistributes and better manages filtration flows, alignment profile pick-injection wells, and restriction of water.
All of this leads to the recovery of oil. Lignosulfonates work in this process by absorbing properties of surface-active additives.
Due to environmental concerns, chrome-free lignosulfonates are being used more frequently in oil drilling as a response to the effects chromium versions have on the climate. Chromium-based lignosulfonates have been incredibly popular for the past 30 years.
It was discovered that adding metal ions to lignosulfonates made them useful in many different drilling environments and temperatures. However, due to environmental effects, chromium lignosulfonates have been banned in certain regions of the world.
Drilling mud is a water-based mixture used to carry rock cuttings to the surface while lubricating and cooling the drill bit. Lignosulfonates are some of the most commonly used in this industry due to their stable nature and characteristics.
They stabilize emulsions because the molecule is absorbed in the oil-water interface. For more information on lignosulfonates and their other uses, contact us at Bisley International.