Redistribution of filtration streams
Description of injectivity equalization technology using polycar polymer material
Structure-forming methods for the selective isolation of aquifers, capable of forming structured systems under the influence of certain factors (crosslinker introduction, formation temperature, formation water salinity, etc.).
The most flexible and effective method is the use of cross-linked polymer systems (SPS), formed as a result of the interaction of water-soluble polyacrylamide PAA and a crosslinker. Salts of polyvalent metals act as a crosslinker
SPS Benefits
1. The initial compositions have a low viscosity, which allows injection at low injection pressures, and the structures formed in the reservoir have high shear gradients. (which is especially good at low permeability)
2. Possibly destruction.
3. The ability to adjust the rheological properties in a certain range
4. Gel-forming composition allows direct preparation and injection of gels into the formation at the wellhead
5. Applicability for terrigenous and carbonate reservoirs;
Structure-forming systems based on polycar polymeric material
Anionic polymers synthesized by free-radical polymerization of acrylic acid amides and anionic comonomers are used to prepare the basis of the composition.
Complex inorganic metal salts of potassium and chromium and sulfuric acid are used as a crosslinker to form a three-dimensional spatial-network structure.
Depending on the conditions of a particular object, chemical reagents can be additionally introduced into the composition of the polymer material - buffer systems, stabilizers, inhibitors, cationic surfactants, nonionic surfactants, etc.
When modeling the technology, factors that affect the kinetics of gelation and the filtration characteristics of gels are taken into account
Special Additives
- pH and the ability to structure formation are regulated by buffer systems (composite systems of alkali metals with anions of weak acids)
- Resistance to degradation is increased by introducing degradation inhibitors (organic compounds that form free radicals during oxidation)
- Metal ions are used to stabilize polyacrylamide from thermal degradation. The thermal stability of polyacrylamide increases in the presence of absorbed Ni (II) Co(II) Fe (II) Cu(II) Zn(II) ions
Destructor
Strong oxidizers are used to destroy the gel. Sodium bichromate (potassium) and various peroxide compounds are used as oxidizers. An effective reagent for the destruction of polymer chains in aqueous solutions is sodium hypochlorite - NaClO and special destructors
Injectivity profile alignment technology using polycar polymer material
For the work, a scheme for preparing a polymer composition and injecting it into the well is used, as well as our own equipment has been developed, which provides:
1. Preparation of a homogeneous base of the polymer composition, to reduce the dissolution time of the polymer and ensure high-quality crosslinking of the polymer composition. Due to the use of an ejector, the dissolution time is reduced by 1.5-2 times;
2. Controlled supply of the crosslinker and the possibility of crosslinking the polymer composition to the required rheological properties, depending on the "behavior" of the well;
3. Injection of a polymer composition into a well in a wide range of capacities and pressures
4. Continuous monitoring of the technological process of preparing a water-polymer mixture, as well as monitoring the flow rate and pressure during its injection into the well.
Used Equipment
To carry out work in NPO "ITIS", a scheme was developed for binding equipment, taking into account the special process of nand deposits.
Scheme includes:
- Standard pumping equipment for mixing and pumping polymer composition.
- Special devices for feeding, reducing the dissolution time and mixing of polymers (ejector, flow mixer).
- Special pumps and equipment for controlled supply of stapler and other components to the injection line during operation.
- A complete set of equipment and proprietary software for real-time monitoring of tubing and annulus pressure, injection rate of polymer solution and crosslinker, total volume of injected liquid and each component separately, concentration of crosslinker in the polymer composition.
Applicability and features of technology
1. Individual selection of effective formulations of proprietary process fluids corresponding to the necessary mining and geological conditions ensures operation in a wide temperature range (up to 100 0С and more) with high salinity and permeability from 2-800 mD.
2. The ability to control the rheological properties of the system without stopping the injection, which allows blocking the flushed zones to the required depth, as well as qualitatively blocking the flushed zones in their different areas.
3. Injection of a polymer composition into a well in a wide range of velocities and pressures, depending on reservoir characteristics
4. Continuous monitoring of the technological process of preparing a water-polymer composition, as well as monitoring the flow rate and pressure during its injection into the well, which allows you to quickly make decisions with the slightest changes in the course of the technological process
S&IA "INNOVATIVE TECHNOLOGIES AND SYSTEMS"
Kyiv, st. Zhmerinskaya, 1
+38 097 208-5939