Gravitational steam-power oil extraction method. RU patent 2245999.

FIELD: oil and gas extractive industry.

SUBSTANCE: method includes inputting working environment under pressure along thermo-isolated pipeline into oil-bearing bed and extracting oil to the surface through inputting pipeline. As working environment easily-boiling liquid is used. It is fed along force thermo-isolated pipeline with reduction assembly and sprayer at end. Easily-boiling liquid is fed under pressure, enough for dispersing easily-boiling liquid on smallest drops and forming a foam of bubbles of easily-boiling liquid and oil from bed. It is fed into inputting pipeline placed coaxially outside force pipeline. Mixture of steam of easily-boiling liquid and oil is extracted to surface. Mixture is separated, oil is gathered, and steam of liquid is condensed for repeated use in well.

EFFECT: higher efficiency.

1 dwg

The invention relates to the oil industry and is intended for transportation by pipeline gas-liquid mixture production wells oil fields.

There is a method of extracting oil from wells on the discharge and intake piping, in which oil is pumped by a pump. USSR author's certificate No. 1384871, IPC: F 17 D 1/12, 1988

The disadvantage of this method is the low performance, because the stop time of the pump the flow of production wells in the discharge line is not carried out.

There is a method of extracting oil from wells on the discharge and intake pipes, which discharge pipe with the aid of the compressor enter the working environment. Gas-liquid mixture can increase the transportation distance from the wells to the final collection point products, but only for shallow and rich deposits. The patent of Russian Federation №2029074, IPC: E 21 In 43/00,1995

The known gravitational steam method for extracting oil from wells discharge and intake piping-pressure heat-insulated pipe into the oil-bearing layer introducing the working medium under pressure and pull on the surface of the oil through the suction pipe. The patent of Russian Federation №2117756, E 21 In 43/24, 1998 (Prototype).

The disadvantage of this method is the reduction of the injection rate of steam injection during injection into the injection well. This is due to the fact that during the period of steam injection sampling fluid from the reservoir are not, thus filling the pore space of the formation of steam increases the pressure in the area of the bottom zones of the injection wells. Reduction in the rate of steam injection reduces the rate of heating of the deposits, and extended periods of its development. Another disadvantage of the known method is that the sampling period oil is the main process is the gravitational outflow of oil, the rate of which is low and hydrodynamic displacement is not used. This leads to a decrease in the rate of oil extraction.

The present invention is to increase the efficiency of field development by increasing the rate of selection of the oil due to the regulatory regimes of steam injection and oil withdrawal to reflect changes in thermodynamic state of a layer.

The technical result of the invention is the efficiency of the gravitational expiry of oil and its hydrodynamic expiration due to steam stimulation, containing high-viscosity oil.

The technical result of the invention is achieved in that in the method of extracting oil from wells on the discharge and intake piping-pressure heat-insulated pipe into the oil-bearing layer introducing the working medium under pressure and pull on the surface of the oil through the suction pipe, as the working environment using the boiling liquid, serves its pressure on insulated piping, pressure regulator node and a nozzle on the end, under pressure sufficient to disperse boiling liquid into tiny droplets and create foam arising from bubbles boiling liquid and oil from the reservoir, which serves in the intake pipe located coaxially outside pressure and extract to the surface in the form of a mixture of steam boiling liquid and oil mixture sephirot, collect the oil, and steam boiling liquid condensate for reuse in the well.

The method consists in the fact that in a well in a thermally insulated pipeline from the downstream node and a nozzle on the end is passed through the nozzle at the bottom of the wells boiling liquid, such as liquid ammonia or carbon dioxide. Boiling liquid serves under pressure sufficient to disperse filed liquid in the nozzle into tiny droplets and create a foaming mixture of oil and bubbles boiling liquid.

Thus obtained foam rises up well under the action of external compressor, and a saturated vapor pressure of the boiling liquid. A pair of liquid separated by the separator and served in a refrigeration unit in which they are transferred to a liquid state and return again to the bottom of the well. The number and the working fluid pressure regulating for process optimization in specific conditions.

Getting to the bottom of the well, boiling liquid passing through the nozzle is broken into tiny droplets (dispersed) and evaporates, forming a bubble paronetto mixture (foam). The density of this foam ρ p can be reduced to values 3-10 times lower density of pure oil. Therefore, when the formation pressure, the compressor and the vapor pressure that is equal to, for example, 10 ATM, oil foam rises to a height of 300-1000 m This provides further evacuation from the well.

The drawing is a schematic representation of the oil production from wells. Complex oil contains the intake pipe 1, the pumping of the pump 2, the compressor 3, the cooling unit 4, the pressure of the heat-insulated pipe 5, reducing the node 6, the nozzle 7, the separator 8, a connecting pipe 9 and the starting device 10.

Under the forces of gravity or force increased pressure in the oil reservoir of the oil in the well rises to a level H above the bottom of the well, covering the nozzle 7. In the nozzle 7 through the pressure reducing node 6 serves for the discharge of the heat-insulated pipe 5 of the refrigerating unit 4 boiling liquid. Getting to the nozzle 7, it is atomized, vaporized and mixes with the oil into a foam whose density ρ p is many times lower than the density of oil. The resulting foam by Archimedes ' principle and under the forces of gravity rises by collecting pipe up to a new level of H 1 , which is determined from the relation:

H 1 =H*(1+ρ oil /ρ foam ).

Oil rising from the foam is chosen by the pump 2, and the steam is separated by the separator 8 and is returned through the connecting pipe 9 in the cooling unit 4. Run the whole system in action produce the starting device 10.

When using ammonia, which T TRC =-33° (240°K) at a pressure of 1 ATM heat of vaporization r=1500 kJ/kg, during the evaporation of 1 kg is the birth of bubbles with a volume of 1.73 m 3 .

When mixing this volume of 1 m 3 of oil foam volume 2,73 m 3 weight 10 3 kg and density foam ρ p =370 kg/ m 3 .

At a gauge pressure of 10 ATM, the foam rises to the level of 300 m If excessive pressure is small, the additional pressure drop in the well due to the saturated vapor pressure becomes crucial. For ammonia vapor pressure at the temperature of +20-+30°With 10-15 ATM, respectively. Therefore, the height of rise of the foam will be determined by vapor pressure.

To calculate the specific system pumping oil from a well with a depth of 1 km we assume that in the foam volume of bubbles in 10 times more than the volume of oil. Then density foam ρ p is 10 times less than the density of oil ρ N. For definiteness, let us take ρ n =800 kg/m 3 , and ρ n =80 kg/m 3 . If you take the vapor pressure of ammonia R=8*10 5 PA (8 ATM), then the foam will completely fill the borehole with a depth of 1 km

For clarity, it is convenient to take the cross-sectional area of the hole S=0.1 m 2 , and the flow rate of the foam from the well v n =1 m/s For 1 second from the well will enter the gas volume V g =0.1 m 3 and the oil volume V h =0.01 m 3 or mass of M h =8 kg

If we assume that the density of the saturated vapor of ammonia under normal conditions ρ am =0.6 kg/m 3 , the mass of the released gas will be the value of M am =0,06 kg To create a continuous process of pumping oil performance N=8 kg/s you want to upload the same amount of liquid ammonia, with refrigerating unit, that is, 0.06 kg/s For condensation of vapor must be cooled, taking away the heat of condensation in the amount of:

Q hol =r s *M am =1,5 (MJ/kg)*0,06 (kg)=90 (kJ) per second,

r s is the specific heat of vaporization of ammonia.

It should be noted that the evaporation of ammonia in the well leads to the cooling oil. However, this cooling is relatively small. Heat oil has a value of 2 kJ/kg*K, respectively, 8 kg of oil transfer heat to the ammonia 16 kJ/K. Since the ammonia takes away from oil ~ 100 kJ/s, the cooling oil is on ΔT=6°C. If the density of the foam will be 2-3 times more, it ΔT does not exceed 3°C. Provides estimates are approximate. You should consider changing the volume and number of bubbles on the well depth due to changes in hydrostatic and hydrodynamic pressure. In particular, when a pressure change of 1 ATM on the surface layer of oil to 10 ATM at the bottom of the well (the thickness of the layer of oil), the amount of bubbles is reduced 10 times. Therefore, the average value of the volume of the bubbles throughout the entire layer thickness is 0.5-0.6 of the maximum value. As a result of this rise of the foam will be no 1000 m, and 500-600 m, when considering only static mode without taking into account the emergence of new bubbles, their movements and forces gas vapor pressure inside the bubbles when lifting.

In addition, the reservoir can produce oil in amount greater or less than 8 kg, which was adopted in the assessment. Therefore, the volume of the bubbles and the amount of the working environment must be changed due to the reduced supply of ammonia in the well.

The second example of oil production based on the use as a working fluid of carbon dioxide. It is attractive because the 2 vapour pressure at temperature 20-30°reaches 40-50 ATM. This allows you to get a particularly viscous oil with any depth. However, the comments made above about the influence of hydrostatic pressure, as well as the need for more cooling of the working fluid (T TRC =-76° (C) require calculation of the possibilities of its practical application to specific fields.

The most important point is the physical basis of the method of oil extraction. As soon as the bubble volume V 0 was born in liquid (oil), it is affected by the buoyancy force of Archimedes:

F=V 0 *(ρ oilρ pair )*g, where g is the acceleration of free fall.

The presence of this force, caused by the action of gravity, allows you to generate foam along the entire depth of the borehole. And the work of this force account work vapors of the working fluid during expansion, ultimately, aims to increase the difference between the pressure of the surrounding oil reservoir and the pressure at the bottom of the well. According to the law of communicating vessels, the oil is constantly fills the annulus pressure 5 and intake pipes 1.

The method of extracting oil from wells on the discharge and intake piping-pressure heat-insulated pipe into the oil-bearing layer introducing the working medium under pressure and pull on the surface of the oil through the suction pipe, characterized in that the quality of the working environment using the boiling liquid, serve it on the pressure insulated pipeline from the downstream node and a nozzle on the end under sufficient pressure to dispersion boiling liquid into tiny droplets and create a foam of bubbles boiling liquid and oil from the reservoir, which serves in the intake pipe located coaxially outside pressure, and extracted to the surface in the form of a mixture steam boiling liquid and oil mixture sephirot, collect the oil, and steam boiling liquid condensate for reuse in the well.