Chemical waterflooding technology
As a result of the long-term operation of oil fields, uneven heading of productive formations occurs due to the multiphase environment of the oil reservoir. Of particular importance are issues related to the influence of rock-geometric, zonal and tectonic heterogeneities of formations on the performance of wells. Ensuring an increase in oil production or maintaining it at the same level is possible provided that effective methods of increasing oil recovery are widely implemented, allowing for the involvement of hard-to-recover and residual oil reserves in development.
Physical and chemical methods of increasing oil recovery, providing an increase in the displacement coefficient and reservoir coverage by flooding, are widely used in domestic and foreign practice.
Applied when:
- The mobility of the injected agent (water) is higher than the mobility of the displaced oil
- At low efficiency of water injection
- At premature water breakouts
- At high values of residual oil saturation
Polymer flooding (polyacrylamides SNPH-PM) is a technology for increasing oil recovery. It is achieved by increasing the reservoir coverage coefficient, that is, a more uniform distribution of the displacing agent over the reservoir and reducing the residual oil saturation in the washed zone. This allows you to increase the amount of oil that can be extracted from the reservoir.
(SP/ASP) Surfactant polymer flooding (SNPC-PM polyacrylamides and SNPC-CM reagents) is an additional method of increasing the oil displacement coefficient. It allows to reduce the residual oil saturation even in those areas of the reservoir that have already been washed with water. This is achieved by reducing the amount of residual oil saturation.
Flooding using foaming compounds (SNPH-CM reagents) is a method of increasing oil recovery based on the sequential introduction of foaming compositions into the reservoir and the production of foam under reservoir conditions, which significantly increases the reservoir coverage coefficient and displacement coefficient. As a result of the generation of stable foam with high multiplicity, the flow of reservoir fluids is redistributed directly in reservoir conditions. The liquid pushing through the foam system will involve low-permeability oil-saturated zones in the development.
Description
Polymer / Surfactant and polymer flooding
SNPH JSC offers formulations for chemical flooding with preset parameters based on the SNPH-PM polymer range and surfactant compositions of the SNPH-CM range /micellar composition of SNPH-96. The compositions are selected individually for the field conditions of each customer based on the results of laboratory studies and design of the chemical flooding process.The main purpose of injection of a surfactant polymer solution is to achieve a maximum ORF( oil recovery factor) of up to 85%. Applicable at any stage of field development. Optimization of the chemical composition during the project implementation, ensuring maximum coverage due to runway and increasing the viscosity of the injected agent.
Polymers
Various types of polyacrylamides are used in polymer flooding projects. The choice of chemical reagents depends on the geological as well as physical and chemical conditions of the target formations of the oil field. Modern developments in the field of chemistry make it possible to select polymers for deposits with different characteristics.
The range of SNPH-PM polymers for chemical flooding includes more than 15 grades with a wide range of characteristics for various reservoir conditions:
- Medium-temperature polymers are suitable for use in reservoirs with temperatures up to 70°C and water mineralization up to 300 g/l
- High-temperature polymers are suitable for use in formations with temperatures up to 95°C and mineralization up to 300 g/l
Compositions of surfactants
The reagents of the SNPH-CM line and the micellar composition of SNPH-96 represent a composition of surfactants in solvents and are pumped into the reservoir when dosed into a stream of mineralized water. They are used in conjunction with polymer solutions.
The main mechanisms of influence of surfactant compositions on the productive reservoir are:
- Reduction of interfacial tension at the water — oil and oil-rock boundary, increase in oil mobility.
- Change in the wettability of the reservoir rock surface.
The reagents of the SNPH-SM line and the micellar composition of SNPH-96 have a number of advantages:
- Suitable for injected and reservoir waters of various mineralization (stable over a wide range of reservoir temperatures)
- Compatible with applicable water-soluble polymers;
- Wide range of solidification temperatures (including formulations with temperatures below minus 50 °C)
Turnkey polymer flooding services:
- Feasibility study and design of the chemical flooding process
- Detailed modeling and calculation of the effect
- Selection and supply of polymers and other necessary chemical products
- Installation and maintenance of equipment for pumping polymer solution
- Implementation of the polymer flooding project at the field by own engineering and field staff
Polymer flooding equipment
SNPH JSC has its own engineering and production base, which allows us to design equipment to meet customer requirements.
SNPH JSC develops equipment for polymer and surfactant polymer flooding to meet the needs of each customer.
SNPH JSC cooperates with Russian and foreign manufacturers to manufacture the basic elements of polymer and surfactant-polymer flooding equipment. The basic equipment includes tank equipment, pumping units, flow meters, gas analyzers, frames, pipes and other components.
Polymer flooding. After-sales service
SNPH JSC provides comprehensive on-site service. A highly qualified team of engineers ensures the continuous operation of polymer flooding equipment, controls injection parameters, eliminates complications, and monitors the viscosity of the polymer solution.
The mobile laboratory allows for quality control, monitoring of the state of chemical reagents and process water in the field in real time mode, which allows you to quickly change and/or respond to any changes in the properties of the polymer solution during the injection of formulations.
In 2019, pilot field tests were conducted on chemical treatment technology in conjunction with ultrasound exposure (acid injection and ultrasound treatment) at 2 wells of the Vereiskiy horizon (C2ver).
| Well No. 5213 of the Staro-Kadeevskoye field | Well No. 5273 of the Staro-Kadeevskoye field |
|---|---|
| Mastering the transition to C2ver. | Intensification of inflow. |
| The planned flow rate of 100% has been reached. Reduction of work time during well development from 2-3 days to 10 hours. | Increase of the initial flow rate of the well by 80-100%. |