CC BY
18
Section 5. Mechanics
DOI: http://dx.doi.org/10.20534/AJT-17-3.4-20-22
Akramov Bahshillo Shafievich, Tashkent State Technical University, Professor of «Development and exploitation of oil and gas fields»,
Candidate of Technical Sciences, Professor.
Khaitov Odiljon Gafurovich, Tashkent State Technical University, Associate Professor of «<Development and exploitation of oil and gas fields»,
Candidate of Geological-mineralogical Sciences. Nuriddinov Jamoliddin Fazliddin charcoal, Tashkent State Technical University, master-student of the department «<Development and exploitation of oil and gas fields»
E-mail: joha-79@yandex.ru
Oil displacement by water in an electric field
Abstract: The paper deals with the efficiency of the electric field effect on oil recovery process. Also shows the possibility of electro-osmotic effects on oil displacement by water. Keywords: condition, water, electric, electrolyte.
The current stage of development of the oil industry in Kazakhstan is characterized by complicated conditions of field development, increased share of hard and decreased the proportion of active oil reserves, a sharp increase in water cut, the deterioration of the technical condition of wells, etc.
In general, the conditions for fields that are in late stage development, alternative constraint falling oil production and increase oil leak may be the impact on hard-and residual oil through increased use of complex geological and technical measures, modern methods of enhanced oil recovery and processing of bottom zones of wells.
During the last decade there is a continuous deterioration of the quality status of the raw material base of the oil industry due to the significant development of reserves of highly productive fields that are in continuous operation. A significant part of the oil fields in Western Kazakhstan is in the late stages of development, which is characterized by a constant decline in oil production, while increasing its water content.
Improving the efficiency of extraction of hydrocarbons from subsurface largely depends on the creation of new process control near the wellbore. Bottom hole zone,
this area belonging to both the reservoir and the well itself. It not only focus but also enhanced many complications that accompany the process of extracting hydrocarbons from oil and gas reservoirs. Their diversity and complexity caused the appearance of a significant number ofdifferent techniques and technologies intensification of oil.
Despite the theoretical bases of many different methods to increase well productivity impact on bottom zone and technology of their conduct, yet the success of many methods remains low at 40-60%. This is due to the fact that the methods used have some disadvantages: the awkwardness of technology; insufficiently developed theoretical principles of design processes; insufficiently informed choices wells for various methods of influence and their priority; insufficient account of the properties and structure of a particular well bottom zone.
At present, for various reasons in Western Kazakhstan idle large number of wells. For enhanced oil and gas recovery oil gas increase at different stages of development of hydrocarbon deposits are widely used for more than 70 different efficiency technologies and methods ofaction.
Thus, injection of large amounts of water leads to the precipitation of inorganic salts in the formation and the well
Oil displacement by water in an electric field
bore itself zone. Application ofacidizing, the use ofsurface-active agents (surfactants), particularly hydrocarbons or organic additives or their products, environmentally safe and leads to the destruction of oilfield equipment. The use of thermal methods, and particularly in-situ burning, accompanied by increased destruction of productive reservoirs and sand production, increasing aggressiveness produced products due to combustion products, education in the formation of persistent oil-water emulsions, etc.
Quite effective was the use of hydraulic fracturing (HF) to create additional channels deep in the reservoir. Through this action changes the characteristics of not only effective drainage area, but also the formation itself; at the expense of neighboring wells intensify its operation. However fracturing technology is costly, complex technological equipment, and under the influence in areas near the oil-water contact (OWC), often as a result of hydraulic fracturing of oil instead of receiving water.
Studies show that one of the effective methods of intensification of oil may be the electrical action on the producing formation.
In issue [1] describes the use of an additional factor contributing to the movement of water in the reservoir effect of the electric field at the bottom of the well.
The electric field can change the configuration of the hydrodynamic field, which in essence is the basis of the electroosmotic effects and the filtering process.
Detailed theory of electro, considered in issue [2; 3] It should be noted that electroosmotic is widely used in hydraulic industry when grouting.
In 1936 at the First International Conference on Soil Mechanics L. Kazagrande, proposed a method of processing clay soils DC whereby the bearing capacity of soils is increased five to ten times. In this method the liquid through a clay soil texture (moisture content 80%) is passed direct current voltage of300-500V and 8-14A, as long as the soil does not solidify.
The successful use of the method ofwork contributed to Casagrande K. Endelya and E. Gofman [5]. They confirmed the improvement of the physical and mechanical properties of the clay after treatment with direct current.
More research to improve the properties of clay soils under the influence ofDC were conducted laboratory drilling oil and gas wells Oil Institute of the USSR Academy [6]. These studies showed that the determining factor in consolidating the clay when exposed to an electric current, is the exchange reaction between the caution uptake.
Electricity costs are determined by the specific conductivity of soil near and depend on the location of the electrodes. In the wild, according to research per-
formance pumping units increased to 0.16 m/kWh. To release water from the soil moisture capacity 10%, conductivity y = 4,5 - 10 - 1 1/ohm-cm and the coefficient k 2 = 0.1m/0.9 kWh required to 1m.
The effectiveness of the electric field is determined by the coefficient K has the dimension of m/a, i.e, determining how many meters of piezometric head unit corresponds to the applied voltage. In the case of complete coincidence of the boundary surfaces of the electric and hydrodynamic field configuration and the latter does not change the impact of the electric field is equivalent to the change in the value of piezometric head.
The greatest effect is to increase the intake capacity is achieved using electro-osmosis. In issue [7], the authors investigated the possibility of electroosmotic effect on the displacement of oil by water.
In all cases, the use of electroosmotic effects led to the isolation of additional quantities of oil sample, leading obviously to reduce residual oil saturation. Improved recovery are within a few percent of the original oil content. However, the authors found themselves out of work in the influence of salt water on the displacing oil recovery, which was noted in their findings.
If a solid electrolyte is to make the electrodes conductive and the voltage feed to them, the electrolyte ions are set in motion, and an electric current. Positively charged ions (cations) move towards the negative electrode (cathode), negative ions (anions) move to the positive electrode (anode). Reaching the corresponding electrode, ions give him redundant or obtain the missing electrons and become neutral atoms or molecules.
Mineralized water as the electrolyte is moved by the difference potential, moreover, under the influence of the field E. current is dehydrated clay minerals also leads to increased permeability to water and oil.
A significant role in the movement of saline water also plays a so-called double force, which is formed on the surface of minerals concentrating negative charges. In a double-layer two different interlayer: one fixed at the mineral surface and the second movable.
The interaction between these layers is expressed as in-building. If you have any e-field occurs brine electroosmotic flow in the movable sublayer.
Additional water consumption due to electroosmotic effects in the persistent form of the electric and hydro-dynamic field is proportional to the electric current, and also depends on the relative positions of sources of inflow and electrodes.
Depending on the chemical nature of the electrolyte and the electrodes, ions are neutralized or stand on the
electrodes, or react with the electrodes or diluent. The chemical reactions that take neutralize ions form a secondary reaction. Products of secondary reactions at the electrodes are allocated or go into solution.
Thus, the current flow through the electrolyte to the electrodes accompanied by the release components electrolyte electrode system - a typical electrolyte occurs acid-reduction reaction. Occurs at the cathode recovery process -Transfer electron action from the solution, and the anode oxidation process occurs - electron anions returns. Therefore, the cathode is the reducing agent, anode-oxidant.
As is well known, mineralized water oil fields are typical electrolytes - aqueous solutions of salts and composition are calcium chloride, magnesium chloride, and hydrocarbonatrium water.
Oil, consisting mainly of a mixture ofvarious hydrocarbons, is a dielectric. However, some oil formation conductivity different from the conductivity of the same oil to the surface. In situ oil is in equilibrium with the buried water, partially saturated with moisture and gas.
Oil-water-gas in the pores are in dynamic equilibrium. Because of the large oil resistance, can not be electrolyzed.
When electro processing layers converts electrical energy into heat, which is accompanied by changes in temperature, evaporation and condensation, chemical reactions (electrolysis), electro osmosis, electrophoresis and mechanical deformations of the rock matrix.
When electro processing formation around the current conductor, a magnetic field acting on the charged particles, and exerts a force on adjacent current-carrying conductors.
Liquid particles that are in the low-permeability in-terlayers will experience than the pressure forces the action of electric and magnetic forces. The electric current excites the magnetic field, ie, has a magnetizing force is numerically equal to the most current.
The magnetic field acts on the magnetic substance dissolved in a liquid and a solid dielectric; last magnetizing reinforce the magnetic field. Especially enhanced field, when the ferromagnetic material and contains cause additional mechanical strength.
Thus, arising electroprocessing seams magnetic and electric forces can effectively drain the reservoir heterogeneity and remove residual oil from non-performing layers.
References:
1. Gaiman M. A., Namikov A. G. Application of electro-osmotic exposure to oil field. Tr. Institut of oil. - Volume 3, - M. - 1955. - 955. 138-144.
2. Brodsky A. I. Physical chemistry G. P.M.-L, - 1948.
3. The electro kinetic properties of capillary systems. Proceedings of the USSR Academy of - M-L. - 1956.
4. Polivanov K. M. and others. The use of electro and hydraulic structures. Magazine ''Electricity № 8'', - 1951.
5. Endel K. Electrochemical binding clays - P. 18, 226, - 1935.
6. Titkov N. I., Korzhuev A. S., Nikitkina V. A., Smolyaninov V. About applying an electric current to the exercise of rocks on the walls of wells. Proceedings of the Institute of oil of the USSR Academy, t. H1, - 1958.
7. Devlikamov V. V. and others. Enhanced oil recovery using electro osmosis. News of Higher Schools. Series of Oil and Gas, - 1958.
DOI: http://dx.doi.org/10.20534/AJT-17-3.4-22-26
Hajan Hajiyev,
PhD in Petroleum Engineering, Associate Professor SRI of "Geotechnological problems of oil gas, and chemistry"
E-mail: hacan.hacisoy@gmail.com Nazim Nasibov,
PhD in Petroleum Engineering Khazar University
Baku, Azerbaijan E-mail: nazim-nasibov@yahoo.com
Wave device for near wellbore zone treatment
Abstract: Near wellbore zone treatment using pressure impulse creating device is considered. Proposed a new high frequency wave creating devicethat provides the possibility of strengtheningcreated pressure impulses.
