Injection well operation optimization method

FIELD: enhanced recovery methods for obtaining hydrocarbons.

SUBSTANCE: method involves flooding production bed through injection wells with the use of pump units. In the case of terrigenous porous productive bed flooding acoustical sound resonators with resonance frequency setting are installed in injection line. This eliminates amplitude of alternating low-frequency liquid pulsation sound generated by pump units. Method also involves providing constant compression mode in productive beds and frontal oil drive from productive bed.

EFFECT: increased operational reliability.

1 ex, 3 dwg

The invention relates to the oil industry, in particular to the development of the fields.

There is a method of injection wells [1]. The essence of this method development and increasing the productivity of wells is that in the well with a large flow rate and high pressure pumped fluid does not reduce the permeability of the formation. Due to this critical zone of open cracks, enlarged pores and bridging material liquid is entrained into the formation.

In addition, when implementing produce under high pressure due to permanent deformation of the reservoir and a fracture surface cracks after removal of the pressure cracks in some cases not fully disclosed. Due to this, the permeability of the zone increases against that which was before processing.

The disadvantage of this method is that when the pressure exceeds the discharge at the mouth over the reservoir is hydraulic fracturing, and the further process of water injection becomes unmanageable.

There is a method of injection wells [2] the creation of high alternating oscillations on the bottom of a well.

The essence of the method lies in the fact that in the bottomhole formation zone through the tubing with the use of cementing units within Korotkov the time periodically pumped liquid to achieve a valid discharge pressures, which then quickly discharged through the annulus (produce "discharge").

When pumping fluid at the bottomhole formation zone reveal existing or formation of new cracks and dropping the pressure, there is a flow of fluid to the bottom with great speed.

Method of variable pressure gives a good effect in conditions of high strength rocks and relatively high formation pressures. When creating alternating pressures occur fatigue phenomena in the formation rock and the possibility of the formation and development of cracks, which increases the permeability of the zone.

The disadvantage of this method is the risk of damage to the casing when creating a pressure in excess of the allowable. For this reason, were frequently out of the wells of the system.

In addition, when creating high values of the alternating pressure in the well bore area of the reservoir is formed by a network of cracks, which reduces the efficiency of waterflooding process.

The objective of the invention is to increase the efficiency of injection wells, which are:

- no measures were taken to align the profiles of the injectivity of the reservoir;

- took measures to align profiles pickup beds.

This object is achieved by a decrease in the amplitude policycurrent fluid flow, the generated centrifugal pump, and smooth its injection into the reservoir through the discharge line acoustic resonator.

Comparative analysis of the prototype shows that the proposed method is realized a decrease in the amplitude of pulsation turbulent flow in the fluid, thereby align the profiles pickup beds.

Thus, the invention conforms to the criterion "novelty".

Comparison of the proposed solution with other technical solutions shows that the creation of a high alternating oscillations on the bottom of a well known [2]. However, it is unknown what with resonator can reduce the sound level, changing the mode of injection of fluid into the reservoir and to align the injectivity profile of a layer.

Thus, the invention meets the criterion of "inventive step".

The proposed solution can be repeatedly used on any injection wells.

Thus, the invention meets the criterion of "industrial applicability".

Physical processes in solving the problem

Following the suppression of the amplitude of the sound low frequencies (low-frequency pulsations in a liquid)generated pump units, turbulent fluid flow passes in a mode close to laminar. Increases the efficiency of the pump is in by reducing vibration of the tubes and accordingly pressure equalization pumping water into reservoirs.

In the first case, the near-well zone of the reservoir in the injection wells by reducing the values of the pulsations generated by the pump, and reducing the pressure of the injection retain a homogeneous structure.

In the second case, after carrying out work on the alignment of the profiles pickup in the injection of various compositions of the near-well zone of reservoirs of injection wells are re-emerging uniform structure. But with the resumption of flooding uploaded working solutions are washed away from colmatational cracks and the PPP once again become inhomogeneous structure. And the rhythmic pulsation of the pump units to a large extent contributes to the process of leaching of downloaded songs and the reconstruction of the two-layer model of the PPP. Re-return to a previous state is not only qualitatively, but also quantitatively. The fact that the cracks begin to "breathe" and to increase in size. In addition, in the process of water injection at the expense of the generated alternating low-frequency fluctuations of the reservoir is in a state of stress. All of this dramatically reduces the efficiency of geological and technical measures. The latter, in turn, leads to a reduction in the ultimate oil recovery.

The technology works completely eliminates these drawbacks. Cracks remain sacol is frosted, which leads to a more complete (porshneva) the displacement of oil from the first collector and increase the ultimate oil recovery.

In the proposed technology layer will be in constant compression mode that will undoubtedly contribute to increased pumping at the same discharge parameters.

Technology work

Initial conditions - injection facilities represented by terrigenous, Provimi collectors.

For injection wells:

- no measures were taken to align the profiles of the injectivity of the reservoir;

- took measures to align profiles pickup beds.

In the first case the well bore and remote areas of the layers in injection wells represent a single homogeneous geological body. Figure 1 presents the results of the interpretation of studies of injection wells. On figa homogeneous layer, and figb inhomogeneous layer.

In the second case, the near-well zone of the reservoir (PPP) in the injection wells are a heterogeneous geological environment with dual permeability - low noraway matrix and the highly conductive fractures (figb where line 1 characterizes the state of wellbore zone, and direct 2 - remote area of the reservoir).

To implement the method in the first and second cases (injection the line) pump units system of reservoir pressure maintenance using resonators.

System for the implementation of the proposed method are presented in figure 2, where 1 is the production column; 2 - tubing; 3 - resonator, for example a quarter-wave.

A quarter-wave resonator

In practice noise control in industry apply a quarter-wave resonators. In a structural sense, is a tube, closed at one end acoustically hard, and the other end is acoustically soft.

If the pipe from one end (x=l) is open, and the other end (x=l) is closed acoustically hard, then [3]

and the condition for the other end (x=l) gives

The natural frequencies are determined by the expression

where f is frequency

These resonators have several resonant frequencies

Example of calculation

It is known that the operation of centrifugal pumps is accompanied by oscillations in the audio frequency range 16 Hz to 20 kHz.

Choose standard pump tubing (tubing) six-meter. Divide it by 2 m and 4 m, i.e. get two resonator.

Then for four-meter pipe (first cavity) at the speed of sound in liquid medium With≈1500 m/s receive (according to the formula (4)), the frequencies that are absorbed from the spectrum of turbulent noise fundamental frequency f=100 Hz and its harmonics: f≈ 300 Hz, f≈500 Hz and so on

For a two-meter pipe (second cavity) at the speed of sound in liquid medium With≈1500 m/s receive (according to the formula (4)), the frequencies that are absorbed from the spectrum of turbulent noise: fundamental frequency f˜200 Hz and its harmonics: f≈600 Hz, f≈1000 Hz and so on

To extend the range of the absorbed frequencies in turbulent noise, you can add a set of resonators with the corresponding frequencies.

SOURCES of INFORMATION

1. Vaaranen, ATV and other Operation system flooding. - M.: Nedra", 1967. - S.

2. Fusariosis. Improving the performance of the wells. - M.: Nedra, 1975. S. [PROTOTYPE].

3. Skocik E. Fundamentals of acoustics (translated from German). - M.: Publishing house of foreign literature, 1958.

A method of optimizing operation of injection wells, including flooding through these wells productive layers using a pump units, characterized in that during flooding terrigenous pore productive layers in the discharge line of the set of acoustic resonators sound with a set of resonant frequencies, providing suppression of the amplitude of sound alternating low-frequency pulsations of the fluid generated by the pump units being productive layers in constant compression mode and creating conditions mode piston displacement of oil from cont the active layer.