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Innovative technology for enhancing oil recovery

08th August 2013

David Kaushanskiy, head of laboratory of biotechnology and computer simulation in oil and gas at the Russian Academy of Sciences (RAS) explains the features and benefits of Temposcreen-Luxe, a multi-functional technology that enhances oil recovery at the later stage of field development

Dr David Kaushanskiy
Dr David Kaushanskiy, head of laboratory of biotechnology and computer simulation in oil and gas at RAS

The current state of development of many long-exploited oilfields of Russia, Kazakhstan and other countries is characterised by a progressive increase in water cut (up to 70-98 per cent), a decrease in the oil recovery and high unit costs to obtain a tonne of produced oil.

 

The main objectives are:

 

• Obtaining additional oil;

• Cost reduction in oil production;

• Stabilisation or reduction of the water cut process;

• Increasing the oil recovery rate;

• Environmental protection.

 

The innovative technology for physical and chemical treatment using the Temposcreen-Luxe polymer-gel systems is designed to produce additional oil production and reduce water cut on fields of complex geological structure with heterogeneous sand and clay reservoirs exploited using water flooding methods at the later stage of development with a high percentage of water cut (from 40 to 98 per cent).

 

Temposcreen-Luxe selectively treats the highly permeable waterflooded formations, sharply reducing their permeability, aligns the well and formation injectivity profiles, changes the filtration flow, increasing the coverage of reservoir flooding, which leads to a reduction in water cut, an increase in oil production and enhanced oil recovery.

 

Temposcreen-Luxe technology is applicable to all oil fields with the following parameters:

 

• Reservoir thickness from 3 to 100 metres;

• Permeability of 80 to 5000 md;

• Porosity: 16-30 per cent;

• Reservoir temperature up to 95 °С;

• Water cut of 40 to 98 per cent;

• Dissection ratio: between 1-15;

• Reservoir pressure: up to 250 bar in the injection area;

• Minimum injectivity of injection wells: 80 m3/day;

• Maximum injectivity of injection wells: 1500 m3/day.

 

The Temposcreen-Luxe Polymer-gel System (PGS) is prepared at the well by mixing the single-component compound with water (fresh or mineralised) and injected by a conventional pump unit. From 0.8 to 1.2 tonnes of Temposcreen-Luxe reagent in powder form is required to treat one well.

 

The prepared compound is injected into the well for 20 - 30 hours and then the injection of water into the reservoir continues in normal operating conditions. The production wells begin to react in 1.5-2 months after injection of PGS into the reservoir. The duration of the effect of the Temposcreen-Luxe PGS is between 10-17 months. One tonne of Temposcreen-Luxe dry reagent makes it possible to obtain from 2,000 to 5,000 tonnes of additional oil depending on the geological structure of the reservoir and the size of its residual reserves.

 

The novelty of Temposcreen-Luxe PGS lies in its combination of two methods of inserting the gels into the reservoir:

 

• Method of gel synthesis in the reservoir;

• Method of direct injection of gels into the reservoir.

 

Due to the dispersed structure of the Temposcreen-Luxe gel, consisting of many small gel particles ranging from 0.2 to 4.0 mm, it has high mobility and penetrating ability with respect to cracks and large pores. When they get into the pore space, the gel particles in the mineralized water increase in volume and create additional resistance to water.

 

However, the gel does not penetrate into the low permeability and hydrophobic portions of the reservoir because the sizes of the gel particles are larger than the pore sizes of such rocks. The Temposcreen-Luxe Hydrogels exhibit selective properties with respect to oil and other hydrocarbons. Furthermore, the gel particles exhibit high iscoelastic and flocculating properties. The displacement ability of the fringes of Temposcreen-Luxe PGS in laboratory conditions on models of the reservoir reaches 85-95 per cent. During the Temposcreen-Luxe PGS injection process, there are two mechanisms for transporting gel particles into the depths of the reservoir:

 

• Transport of gel particles with fluid flow through the cracks and

high permeability streaks;

• Transport of gel particles with their simultaneous fragmentation in the rock formation.

 

The transport mechanism ratio is determined by the specific conditions on the oilfield and the PGS characteristics.

 

The Temposcreen-Luxe reagent compound does not contain chemical additives – salts of heavy metals and other harmful components, which makes its application environmentally safe. Temposcreen-Luxe is not very sensitive to the effects of salts, is resistant to degradation in reservoir conditions and can withstand reservoir temperatures up to 95°С.The high profitability of the Temposcreen-Luxe technology provides a quick return on the initial investment. Thus, the cost of one barrel of oil can reach around 2 USD, which is comparable to the cost of production of one barrel of oil in Saudi Arabia. Compared with traditional EOR technologies, the effectiveness of the application of the Temposcreen-Luxe technology is 3-4 times higher. It is possible to obtain an additional 2,000-5,000 tonnes of oil per tonne of Temposcreen-Luxe reagent. The technology is recommended for wide application in fields of complex geological structure, in the later stages of development with a high percentage of water cut. The Temposcreen-Luxe technology allows well operations to be carried out in any period of the year (temperature range from +50 to -40ºС). During the application of the technology, the operating costs are reduced not only for injection of the Temposcreen-Luxe PGS, but also for production of produced water.

 

High-tech production of the Temposcreen-Luxe reagent is currently underway. The annual production volume can range from 500 to 5,000 tonnes of reagent. A batch of Temposcreen-Luxe reagent is manufactured depending on the reservoir properties, the structure of the pore space and reservoir temperature. The reagent and technology are protected by RF patents and officially approved for use in the oil industry. Temposcreen-Luxe is manufactured in accordance with technical specifications, registered at the State Committee of RF standards (2216-004-05966919-2011), has a certificate of compliance № FEC RU.HP25.N04020), a certificate for the use of chemical products in the processes of production as well as transportation of oil (№ 153.39.RU.245810.04420.02.12).

 

In general, the use of Temposcreen-Luxe technology makes it possible to:

 

• Regulate the injectivity profile of the injection well and reservoir;

• Engage in the development of previously unworked reservoirs and interlayers;

• Increase the water flood sweep efficiency;

• Change the fluid filtration flow;

• Increase the displacement capacity of the injected system;

• Create conditions, using the flocculation properties, for the occurrence of additional

residual water resistance;

• Reduce water cut;

• Increase the oil recovery from highly flooded reservoirs at the late stage of their operation.

 

In December 2011, experimental work was conducted at the Komsomolsk field (reservoir PK-19) on 3 wells of the injection stock. The table below shows the results of additional production over 12 months. The technology has also developed with the use of Temposcreen-Luxe reagent for production wells. Temposcreen-Luxe PGS is injected in a specific pattern into the production wells to reduce water cut and obtain additional oil. The treatment time per well is 2-4 hours.

 

This technology requires a pilot work programme to be carried out on various fields with varying degrees of mineralization of the reservoir water. At the same time, after obtaining the results of the pilot work programme, systematic treatment of the oil well stock (injection and production) is proposed to significantly reduce water

cut and enhance oil recovery.

 

In addition to the above technologies, a water shutoff technology has been developed using DM. Temposcreen-Luxe PGS has a high water absorption capacity and is able to retain water in its structure even when exposed to high pressure. The volume of polymer-gel particles sharply increases, which enables the system to be used for various water shut-off purposes using DM.

 

Temposcreen-Luxe technology can significantly improve the performance of oil fields for enhancement of oil recovery. In 2011, Temposcreen-Luxe technology was awarded the exhibition’s gold medal at the 63rd International Exhibition «Ideas-Inventions- New Products» IENA-2011, which was held from 27 to 30 October 2011 in Nuremberg, Germany, and also received a certificate for its high environmental performance.

 

In 2012, Temposcreen-Luxe technology was awarded the gold medal at the 5th International Exhibition of Inventions in the Middle East IIFME-2012 (Kuwait City, Кuwait, November 2012).