Due to the unique nature of each oilfield, polymer chemistry must be optimized for field conditions. Injectivity, sweep efficiency, retention, and compatibility with water and other chemicals have to be studied. In some cases, the formulation of polymer with protective additives is necessary to maintain viscosity and to ensure its performance.
SNF has conducted more than 50 field specific studies for customers over the past few years. These include studies of polymer molecular weight, physical form, concentration, inversion systems, as well as functional monomers and polymers with protective additives against iron, oxygen, and H2S. These studies require close cooperation between SNF and the operator, and involve medium to long term evaluation of polymer behavior under reservoir conditions. In some cases this includes SNF expertise in polymer synthesis.
SNF can help in the screening and qualification process in the following areas:
- Polymer synthesis and characterization
- Monomer selection & integration
- Polymer selection
- Filter ratio
- Long-term thermal stability
- Core flooding (for qualification purposes only)
- Mixing and inversion
- Compatibility with production chemicals
Oil Sands Tailings
Due to the unique nature of each tailings stream, polymer chemistry must be optimized for field conditions. Ionicity, molecular weight, macromolecular structure, and chemistry have to be studied. In some cases, the use of dual polymers treatment may be required for sake of high clarity released water and strong solid deposits.
SNF has conducted many MFT treatment operations during the past 10 years. These studies require close cooperation between SNF and the operator and involve medium to long term evaluation of polymer behavior against changing field conditions. (water salinity, MFT mineralogy, etc.)
Primary and Secondary Bitumen Extraction
Addition of caustic is a cheap and common way to improve bitumen recovery by forming natural surfactants, thus facilitating the liberation of bitumen from sand grains and increasing bitumen buoyancy. However, high a high pH is known to disperse the clays and fines in the resulting tailings, thus making it more difficult to settle.
SNF is developing new chemistries allowing improvement of both the bitumen recovery and the froth quality, which has resulted in a series of patent pending new technologies. These additives can be added at different stages of the process and can selectively target components responsible of performances loss: divalents, fines, etc.
With two research centers dedicated to Oil Sands applications (Andrézieux, France, and Edmonton, Canada), SNF can help in the screening and qualification processes in the following areas:
- Polymer synthesis and characterization
- Monomer selection & integration
- Polymer selection
- Quality control (HPLC, GC, viscosity, etc)
- Flocculation tests
- In-line flocculation test rig
- Cake deposit mechanical characterization
- Capillary Suction Time
- Batch Extraction Unit flotation tests
- Denver Extraction Cell
- Dean-Stark toluene extraction
SNF has a large scale facilities yard to test parameters related to polymer processing in realistic field conditions. Typical tests include polymer dissolution and emulsion inversion units, flow loops, inline viscometers, portable injection units, static mixers, and shear analysis of wellhead equipment. All systems required for polymer processing or handling can be quickly tested at SNF with the help of skilled technicians that know how to handle all aspects of polymer.
SNF provides a complete range of services and equipment through our FLOQUIP™ engineering and fabrication group. FLOQUIP fabrication centers are located near our polymer plants in Andrézieux (France) and Midway, GA (USA). From pilot projects to complete turn-key systems, SNF designs, fabricates, and installs all standard and custom equipment.
Conceptual studies evaluating technical feasibility, CAPEX, facility requirements, and logistics during the planning phase are available. Various options for polymer storage, dissolution, and injection are considered and a process description is provided. Logistics options, basic costs, and high-level planning are also available.
The following are provided in a conceptual study:
- Process description
- Process flow diagram for polymer storage, preparation, and injection
- Mass balance
- Equipment list
- Estimated power consumption
- General layout and space requirement
- Operating and control philosophy
- Material selection report
- Schedule for fabrication of polymer facilities
- Identification of long lead items
- Supply chain description
- SNF vendor list
- Cost estimation of facilities (±30%)
- Comparison of various options and SNF recommendations
SNF provides engineers with a high level of experience in polymer flooding, project management, process and mechanical engineering, piping, instrumentation, automation, and chemistry. For specialized disciplines such as civil engineering and pipelines, SNF works with consultants familiar with local field regulations. Attention is focused on Health, Safety, and Environmental issues, ergonomic reviews, and local regulations in accordance with the customer’s policies and requirements.
SNF can provide equipment, polymer, and field service for injectivity tests. The response to a range of polymer viscosities and injection rates is reviewed to confirm the target viscosity and the polymer product selection. The following are provided for an injectivity test:
- Stand-alone polymer mixing and injection units
- SNF personnel to operate the equipment and run basic viscosity measurements
- Supply of polymer and other chemicals
Pilot and Full-Field Equipment
As soon as polymer selection and injection parameters have been validated, the next step of the project is either continuous pilot injection, or full-field installation. This is the core business of the SNF FLOQUIP engineering department, which offers either skid-mounted units (for pilot or small full-field projects), or field-erected plants (for large pilot or full-field projects) where equipment is sent and assembled on site.
Based on experience in polymer flooding, SNF defines, selects, and implements equipment with proven efficiency and durability.
Due to polymer shear sensitivity, specific attention must be given to all equipment handling polymer solutions, such as low pressure transfer pumps, tanks agitators, high pressure injection pumps, and static mixers. Facilities should also be engineered to minimize oxygen ingress. This can lead to polymer degradation in the presence of contaminants such as iron or hydrogen sulfide.
In the past, when hydrating powder-grade polymers with conventional systems such as eductors, many challenges and shortcomings were encountered. In response, SNF designed and patented the FLOQUIP PSU™ dissolution equipment. This equipment is now a standard for FLOQUIP in EOR applications in the United States and Canada.
Manufacturing and Fabrication
To limit costly activities in the field, SNF develops units that are stand-alone structures, either closed or open design. These structures are then shipped and installed at the customers’ sites.
Manufacturing and fabrication, like welding, are performed in compliance with required construction standards such as ASME, API, and DIN.
Customer Site Construction
If construction and installation activities are included in the overall scope of the project, SNF subcontracts local construction companies that are knowledgeable of specific, local requirements.
Commissioning, Training, Quality Control, and Operations
Following installation of facilities at the field site, SNF engineers and technicians perform start-up and commissioning in accordance with customer specifications. In addition to the facilities start-up, polymer solution samples are analyzed for viscosity, filter ratio, hydration, and polymer concentration in order to optimize the system.
Theoretical and practical training is provided for facility operation and maintenance, as well as laboratory and quality control procedures. Upon completion of the start-up and commissioning, the system is handed over to the customer. SNF can also provide ongoing supervision of the operations or full operation and maintenance of the facilities.
Designing an onshore polymer flooding project is often easier than offshore. In the latter, it is compulsory to optimize the equipment footprint to fit the space available and load limits of the FPSO (Floating Production Storage Offloading) or platform. Furthermore, logistics are important when transporting large volumes of products, either in powder or liquid form. Emulsion-grade polymer is easier to handle offshore when the local weather conditions are particularly unfavorable, such as in the North Sea. Inversion is made on site and the solution is readily injected into the reservoir. When the conditions are more favorable, powder-grade polymers may offer a more cost-effective option for the customer.
SNF is dedicated to optimizing supply chain and our polymer packaging to ensure economical and efficient delivery of products used in the Oil & Gas market. Some examples are shown below:
Emulsion packaging and logistics
Powder packaging and logistics