Oil & Gas
SNF provides advanced polymer technologies to help improve the performance and profitability of oil and gas extraction operations. Our global presence can lend our expertise to support your business – wherever that might be.
Backed by world-class equipment and engineering support, highly qualified applications specialists, quality and efficient manufacturing, and supply chain management, SNF is a recognized leader in the development of high-performance chemical solutions designed to meet or exceed the needs of our customers.
SNF offers a broad range of products formulated to provide cutting-edge solutions for Hydraulic Fracturing, Enhanced Oil Recovery (EOR), Oil Sands, Drilling, Cementing, Well Stimulation, and Production. Our wide range of products includes:
- Drag/Friction Reducers
- Guar Alternatives
- Drilling Fluids
- Completion Fluids
- Scale Inhibitors
- Fluid-Loss Control Additives
- Low Viscosity Fluids
- Rheology Control Additives
- Hydration and Dosing Systems
The Journal of Petroleum Technology highlights SNF Dry Friction Reducers in the Frac Industry
ENHANCED OIL RECOVERY (EOR)
Among Chemical Enhanced Oil Recovery (CEOR) methods, polymer flooding is a straightforward technique with a long commercial history and proven results. This consists of injecting polymer-augmented water into a subterranean formation in order to improve, thanks to the viscosity increase, the sweep efficiency in the reservoir and provide mobility control between water and hydrocarbons. However, implementing a successful polymer flood in the field requires specific knowledge and expertise to avoid polymer degradation and associated viscosity loss.
Polymer flooding can yield a significant increase in oil recovery compared to conventional water flooding techniques. A typical polymer flood project involves mixing and injecting polymer over an extended period of time until about one-third to one-half of the reservoir pore volume has been injected. This polymer “slug” is then followed by continued long-term water flooding to drive the polymer slug and the oil bank ahead of it toward the production wells.
Polymers will increase water viscosity and thus the mobility ratio and the displacement efficiency in the reservoir. Recovery of trapped oil can be achieved by adding other chemicals to the injection brine; these can be surfactants (to decrease the interfacial tension between oil and water) or alkali (to generate in-situ surfactants and also avoid surfactant adsorption on the rock). These processes are described below.
Most floods will fail without mobility control, and polymer addition is a prerequisite. Moreover, the dosage of each chemical can fluctuate and large amounts of surfactants are often required to accommodate the high level of adsorption within the reservoir. The dosage of alkali could also be an issue, because it requires a costly water softening system.
CHEMICAL ENHANCED OIL RECOVERY (CEOR)
In CEOR, recovery of residual oil is achieved by adding surfactants and alkali to the injection water. Surfactants decrease the interfacial tension between oil and water and alkali agents can be added to generate in-situ surfactants and help to reduce the high level of surfactant adsorption to the reservoir rock. Due to the high pH brought about by the addition of alkali a water softening system is needed to eliminate precipitation of hardness ions.
Selecting the right polymer
SNF has developed a wide range of polymers, both in powder and emulsion forms, to cover the vast majority of existing reservoir conditions. Polymers for flooding are anionic in nature and the selection depends on 3 primary parameters which are: temperature, water composition (salts, contaminants), and permeability. SNF has a specific knowledge base and guidelines to fine-tune the chemistry in order to limit chemical, mechanical, and thermal degradations. The SNF portfolio of polymers includes:
- Anionic co-polymers for temperatures below 85°C (185°F)
- Sulfonated co- and ter-polymers for temperatures below 100°C (212°F) and/or salty brines
- N-Vinyl Pyrrolidone based ter-polymers for temperatures up to 140°C (284°F)
- Associative polymers
- Thermo-associative polymers
- Iron and H2S resistant polymers
- Salt resistant polymers
- Protective packages
SNF has long a history of supplying the Oil & Gas industry with chemicals used during Well Completion and Hydraulic Fracturing phases. Listed below are some of our products and their associated services:
Since its discovery as a drag reduction agent (DRA) in 1948, many applications for drag reducers have been developed. DRAs have been used in irrigation networks and municipal sewer systems to improve flowrates and power loads on equipment, as well as in firefighting applications to extend the range of water exiting fire hoses.
Several publications and field results reported the benefits realized by DRA injection, in addition to decreasing the pressure drop in the injection systems. These benefits include:
- Reduction in corrosion by up to 30%
- Increased injection rates, and consequently, increased production rates
- Energy and cost savings
Drag reducing agents are widely used in the Oil & Gas industry when extracting gas from shale plays using hydraulic fracturing technology. Whatever the stage of injection, synthetic polyacrylamides help to drastically reduce the amount of pressure in the pipes when large volumes of water are injected into the ground to open fractures and place the proppants. The dosages of polyacrylamides used in these cases range from 150 to 300 ppm active polymer, depending upon water and field characteristics, as well as injection rates.
Selecting the right polymer
SNF has developed a wide range of polymers, both in powder and emulsion forms, to cover the majority of existing conditions within the Oil & Gas industries. Our polymers range from cationic to non-ionic and anionic in nature, and the selection of the best product depends on several parameters such as temperature and water composition (salts, contaminants).
To ensure proper dissolution of friction reducers provided in powder form, SNF has designed, engineered and manufactured its unique mobile powder polymer dissolution unit called PowderFrac™.
PowderFrac is a unique, mobile, self-contained, and automated Friction Reducer (FR) hydrating and dosing system designed to rapidly hydrate dry friction reducers. It offers enhanced performance and cost-savings for a product/system having a greener footprint compared to traditional liquid, emulsion friction reducers.
Hydraulically fracturing shale rock allows an increase in permeability by opening, connecting. and keeping open preexisting or new fractures in the formation. The design of the fracturing fluid is therefore critical to the success of the treatment. Its main functions are to open the fractures and to transport and keep the proppant in place along the length of the fracture.
Guar gum was one of the first polymers used to viscosify water for such applications. This substance, better known for its ability to thicken ice cream, experiences significant price variations and has become more expensive as global supplies have diminished.
SNF has developed a new range of synthetic polymers that can be considered as a guar alternative for this type of application. The “one-stop-shop” approach (one product is used as FR, in linear and crosslinked applications) developed by SNF can bring tremendous benefits to the industry by reducing the number of chemicals handled and associated logistics.
The primary advantages of these products include:
- Viscosity performance comparable or superior to guar, both in linear and crosslinked systems
- Products can be fine-tuned to resist high temperatures
- Viscosity can be broken with conventional oxidizers
- Crosslinking with zirconium over a wide range of salinities and pH
- The developed products are cleaner than guar, as shown by regain conductivity tests
- All polymers provide improved friction reduction properties
- No need for biocide addition to protect from polymer degradation
Friction Reducer Polymer
Friction Reducer Polymer – Guar Alternative
SNF’s portfolio also includes a wide range of scale inhibitors developed to mitigate the damages caused by mineral precipitations during the completion or exploitation phases of oil and gas wells. The products can be tagged or non-tagged and supplied in powder or liquid form.
SNF, the largest manufacturer of polyacrylamide polymers has been committed to delivering cost-effective, high performance products and systems to the Canadian Oil Sands since 2002. SNF is dedicated to delivering class-leading chemistries for non-conventional crude production in the Canadian Oil Sands.
We understand the critical issues facing today’s tailings management. SNF has provided consultation and servicing throughout the CAPEX and OPEX stages of tailings management including:
- Development of mechanical, operational, and chemical management strategies to help maximize efficiencies from the ground up
- Implementation of solutions to enhance productivity and maximize environmental sustainability
Being the world leader in water-soluble polymers, SNF experts help operators solve problems unique to Oil Sands applications. Our water and process expertise is inherently beneficial due to the continuous treatment required for the reuse and recycle of water needed for separation.
Tailings are made up of natural materials including water, fine silts, residual bitumen, salts, and soluble organic compounds. They also include solvents that are added to bitumen during the separation process.
- Bitumen is derived from the Oil Sands deposits by open-pit mining and water-based extraction techniques
- Recovered bitumen is upgraded into marketable low-sulphur synthetic crude oil (SCO)
Tailings management seeks to improve the speed and efficiency with which tailings, including MFT (mature fine tailings) can be settled, consolidated, and used for reclamation purposes – all while reducing the need for larger and larger land areas for ponds.
SNF Energy Services personnel work with our customers to help them improve their tailings management operations, and to comply with current regulatory directives.
SNF OIL SANDS PRODUCT INFORMATION
SNF understands the challenges Oil Sands operators face. Primary and secondary extraction require increasingly efficient separations, and therefore, SNF offers a portfolio of products that handle:
- Primary Extraction
- Flotation improvement
- Tailings management
- Secondary Extraction
- Polymers and Dispersants
Look to SNF for effective and efficient solutions to:
- Mitigate technical risk by testing process technologies on a pilot scale
- Offer a safe, flexible, and cost-effective method to demonstrate and optimize production aspects
- Give operators the ability to test the commercial viability of new technologies before capital investment
Successfully completing an oil well at reasonable costs depends considerably on the properties of the drilling fluids. Many specific requirements are placed on the fluid to achieve several purposes which include:
- Carrying cuttings from down-hole to the surface and permit their separation
- Keeping the drill bit clean and cool
- Reducing friction between the drill string and sides of the wellbore
- Preventing inflow of formation fluids such as gas, oil, or water
- Maintaining stability of the uncased sections of the borehole
- Forming a thin, permeable layer that seals formation openings and prevents fluid losses
SNF has developed a wide range of polymers for water-based drilling mud systems. Each range of SNF polymers covers one or several drilling fluid requirements such as fluid loss control, viscosity improvement, or scale inhibition.
Our synthetic polymers are produced in a variety of forms, molecular weights and compositions for specific drilling applications. For instance, the same Partially Hydrolyzed Polyacrylamide (PHPA) can provide fluid loss properties, viscosity or thixotropic behavior, or drag reduction effect to the fluid.
SNF’s portfolio of products includes:
- Shale Inhibitors (clay stabilizers)
- Bentonite Extenders
- Fluid-loss control agents for mud and cement
- Scale Inhibitors
Water shut-off treatments refer to a treatment that is applied to an oil or gas producing well to either reduce or totally shut off water production. Chemicals such as gelling agents can be used to complete this task.
Conformance treatments are applied to increase the sweep efficiency in a reservoir and, as such, can be compared to polymer flooding in Ehanced Oil Recovery applications.
SNF offers a wide range of products and solutions covering both applications:
- Polymers reactive with organic or inorganic crosslinkers (Chromium, Aluminum, Zirconium, Titanium)
- Crosslinked microgels
- Micro-particles with delayed uncoiling
At the pilot stage (with only a small percentage of injecting wells under polymer flooding), there is generally no need to assess in detail the effect of the back-produced polymer since the dilution effect in the reservoir will lead to negligible concentration of polymer within the water treatment facilities.
When dealing with a full-field project, two different aspects have to be considered in the treatment processes. The first is related to the separation of the crude and produced water. The second deals with the treatment of produced water once it has been separated from the crude, in order to be re-used or disposed of. Both aspects are discussed in the following:
IMPACT ON THE SEPARATION OF OIL AND WATER
Influence on the separation process
On the production side, depending on the design of the production facilities and the type of injected fluid (presence of surfactant or alkali, or both) an emulsified fluid is created. De-emulsifiers or “breakers” are needed to break this emulsion. The presence of polymer can interact with the breaker and it may result in altered separation. Skilled service companies generally do the selection of the most appropriate and compatible breaker through bottle tests. Since polyacrylamide polymers are water-soluble, they are considered absent from the oil phase.
Presence of suspended solids
Anionic polyacrylamides are efficient flocculating agents of mineral suspended solids. Thus, if the TSS (Total Suspended Solids) is high in the produced fluid, some agglomerates should appear in the water phase in the presence of polymer. These precipitates can deposit on the surface of specific equipment such as the heat treater used for the separation of oil and water, which contributes to the creation of hot points, which can lead to accelerated corrosion issues. These deposits have to be removed on a regular basis.
Treatment of produced water
Once the main part of the oil has been recovered from the produced fluid, a low amount of oil and TSS still remain in the produced water. Devices for produced water treatment are usually sized to operate with water viscosities below 4 mPa.s. Polymer breakthrough at the production side will contribute to an increase of viscosity and will reduce the efficiency of the treating devices to separate the oil and suspended materials wetted by it. For example, if produced water viscosity is increased to 10 mPa.s, the residence time required will be five times longer and treatment device sizing requirement becomes five times larger.
Different methods can be applied to decrease the viscosity of the fluid containing polymer in order to improve water treatment efficiency. The principle is to decrease drastically its molecular weight, and thus, the associated viscosity of the fluid by means of mechanical and/or chemical degradations.
Mechanical degradation of the polymer
Mechanical degradation can be performed to decrease the molecular weight of the polymer and thus decrease the viscosity of the solution. A shearing pump or a choke valve can be used to achieve the degradation and decrease the viscosity of the polymer solution
Chemical degradation of the polymer
Polyacrylamides are chemicals that can experience chemical degradation in the presence of oxidizers. Oxidizers generate radicals that react with the backbone chain of the polymers, resulting in a decrease of the molecular weight and viscosity drop. An example of a preferred oxidizer is sodium hypochlorite (NaClO).