On the problem of increasing oil recovery - the methods of ultrasonic intensification, hydrodynamic studies, the purpose of application of ultrasonic technology
The problem of increasing oil recovery is quite acute in the continuous deterioration of the resource base and small increments of oil reserves by new discoveries in the most heavy-heavy oil and low-permeability reservoirs.
Most oil fields has entered a stage of development characterized by reduced reservoir pressure, oil production and an increase in water production, resulting in many fields the vast majority of wells converted for mechanized and repeatable operation.
Accordingly, all newly introduced in the development of the field are usually hard-to-stock.Therefore, production in many oil fields are now becoming ineffective and requires changes in the earlier development of the system design.
The high rate of selection of stocks in initial period of development is usually carried out with insufficient knowledge of the geological object. As a result of various-making supplies are not involved in the development of a low-permeability regions, and highly permeable given to premature flooding. Thus, an active form hard-to-stock.
Oil remaining in the washed out areas and the substratum due to anthropogenic influences transformed. In addition, the remaining oil in the reservoir have a negative impact of hydrophobic interactions.
The heterogeneity of the reservoir properties, as in the section and along strike, resulting in uneven oil recovery and reduce the rate of oil recovery by reservoir as a whole.
In the process of long-term operation of the well borehole is colmatation space reservoir, which reduces the productivity of the well and working capacity of the perforation interval, which requires periodic cleaning of the near-well zone (BFZ).
In the later stages of field development, we are dealing with a virtually new reservoir properties, new hydrologic, hydrodynamic, thermal and physico-chemical regimes, with a changed composition of the reservoir fluids.
Scientific studies show that the later will be the adjustment of the system, the lower will be the results of fishing. In this case irreversibly deteriorate not only the general technical and economic parameters, but also reduces the value of economically viable extraction ratio compared with the potentially achievable with the use of new technologies. Possible loss of oil may reach 10% or more.
Under these conditions, more than ever urgent problem of increasing the efficiency of existing fields by providing the potential of each well, regardless of life.
The solution to this problem without significant material costs, in principle, possible.
For example, the methods of ultrasonic intensification.
In order to make the choice of optimal parameters of boreholes and on the effects on near-wellbore reservoir zone to hold in the complex hydrodynamic study of one of the main objectives of which is to determine not only the seepage of reservoir parameters, and parameters and the state of the well bottom zone, significantly influence the intensity of the flow reservoir fluid.
It is well known that the decrease in the permeability of the near-well zone of the reservoir due to a number of fundamental factors:
1.Reduction constant bottomhole zone of the reservoir, due to the tangential annular compressive stresses that occur during drilling as a result of overburden pressure;
2.Deposition in the near-well reservoir area of the solid phase process liquids (killing, cleaning, drilling fluids, etc.) and other solid residues.
3.Forming plugs in the holes punched through the removal of rock particles from the formation, deposition of reaction products as a result of widely used treatments bottomhole formation zone of chemical reagents and paraffin deposition.
4.Mudding capillary system of the reservoir due to blockage of pore channels colloidally disperse system, which forms the spatial grid.
Physico-chemical characteristics of the impact of these factors on the formation are different in nature.
If the first factor leads to a decrease in pore size in the bottom hole well and, consequently, to reduce the permeability, the second factor causing clogging of pores foreign body, a third factor causes blockage of perforations, the fourth factor also leads to a decrease in pore size.
These factors reduce the production of oil and injectivity of wells.
Obviously, for maximum effect in the choice of technology of oil production must take into account these factors and to look for, respectively, the ways to eliminate their negative effects.
The use of ultrasound technology to effectively solve most of these problems.
Ultrasound exposure arises a set of complex, interrelated processes that lead to the fact that the compression wave, cyclic loading the porous medium, reflected many times, the waves are transformed into stress-strain, creating conditions for development of a network of cracks and microcracks, as in the walls of the perforation, and in the adjacent reservoir rock.
The interaction of the acoustic field with the phases of the rock is reached:
- An increase of permeability due to changes in the structure of the porous space;
- The destruction of the mineral salt deposits in the capillaries;
- Acoustic degassing and reduction of oil viscosity;
Ultrasound-modulated frequency, passing through the reservoir can be included in the work as individual and low-permeability streaks zakolmatirovannye and productive part of the whole reservoir ...
- High power ultrasonic vibrations can provide effective cleaning of bottomhole formation zone regardless of the nature colmatant.
- Ultrasonic vibrations effectively clean the capillaries near the reservoir area
- Ultrasonic vibrations reduce the surface tension in the capillaries
- Ultrasonic vibrations effectively destroy the salt formation in the capillaries
- Ultrasonic vibrations effectively destroy the colloid formation
Reconstruction of the potential productivity of production and injection wells is achieved by breaking down kalloidno-dispersed systems, the near-well clogging of the sewer ...
The technology maintains the integrity of the production casing and cement sheath behind it and the low costs of production work.
It uses a small-sized mobile devices, the impact of the process is technically and physiologically safe and environmentally friendly
The ultimate goal of the application of ultrasonic technology in the oil industry - increasing the profitability of exploitation of oil fields.
The technology allows, without prejudice to oil-bearing reservoir effectively to achieve the restoration of productive layers of filtration properties with minimal time and material costs.
In a separate direction can be identified using ultrasound technology as preventive measures carried out on a regular basis in order to maintain an optimal state of the filtration properties of the reservoir and bottomhole formation zone.
Progress Industrial Systems SA (Switzerland), is a world leader in the design and manufacture of sonar systems for the intensification of oil production.
Using the experience gained in the field of ultrasound technology and expertise to develop sonar systems for different operating conditions, the company has achieved great success in the creation of powerful ultrasonic systems capable of operating at great depths and high temperatures.
At the moment, we have created unparalleled in the world of sonar system for the intensification of oil consisting of a powerful ultrasound generator in robust, tamper, and performance of the two ultrasonic emitters of different diameter, powered by a standard logging cable. All equipment is implementing the technology of ultrasound exposure, consistent with the standard equipment of geophysical parties, which does not cause difficulties in mastering the technology staff personnel.
Technical specifications of:
Generator power from 4500 to 12000 W
Operating Frequency: 20000 Hz
Power emitters: from 500 to 1200W.
Type of signal: sine, modulated, pulse.
Terms of use:
Maximum cable length: 5000m maximum temperature in the reservoir: 95 ° C maximum pressure in the bottom hole 350 bar.
The effectiveness of the equipment proved by tests conducted in 2006-2008 in Russia in the north-Iraelskom deposit, deposit Sotchemyusskom
in Romania, nizkodebitnye field Vata, Tazlau, Baltani.
Tests were carried out in Russia under the auspices of the Department "Well logging," Ukhta State Technical University, and in Romania for the oil company PETROM (OMV Österreich) with the assistance of Geophysical Company ATLAS GIP (Weatherford USA).
The positive effect of the filters obtained at the four (4) wells in the 30-80% increase in flow of fluid from the reservoir, which indicates an increase in the filtration properties, and allowed not to stop the oil filter to clean the traditional way.
Conclusion:
Restoration of oil wells is recommended for 20 to 350%. The effectiveness of the method after professional analysis and selection of wells up to 90%.
Progress Industrial Systems SA is ready to offer you the most modern equipment for carrying out the work on ultrasonic stimulation of oil production.
The equipment provides Reagent-free, environmentally friendly, mobile way of increasing the productivity of the wells, and help save the material and human resources, reduce the cost of oil. Particularly effective method of note in the extraction of heavy oil.
Company Progress Industrial Systems SA is continually upgrading equipment and tries to take into account the wishes of the customer.
