RU2376462C2 - Method of oil well development with impulse water withdrawal regime - Google Patents

Abstract

FIELD: oil-and-gas production.

SUBSTANCE: invention related to oil-and-gas production can be used for oil reservoir production with impulse water withdrawal through production wells. Method includes allocation locally lifted areas of production reservoir and execution impulse water withdrawal through production wells on this areas. According to the invention, impulse water withdrawal executed on the initial and at later production stages. For impulse water withdrawal regime used production wells with product water content greater than 60%, with reservoir high production rate and with high static and dynamic levels of hole clearance fluid. Production of production wells executed in impulse regime on the initial and at later production stages, for impulse regime used production wells with product water content greater than 60%, with reservoir high production rate and with high static and dynamic levels of hole clearance fluid. For each well determine maximal possible hole clearance level decrease up to technically possible. After that withdraw liquid with simultaneous dynamic level recovery from maximum decreased till steady-state level. At every well execute impulse water withdrawal till complete flooding or profitable production rate.

EFFECT: oil production rate increase.

2 dwg

Description

The invention relates to the oil industry and may find application in the development of an oil reservoir using a pulsed mode of fluid withdrawal through production wells.

A known method for the development of oil deposits (RF patent No. 2096593, EV 43/20, bull. No. 32 of 11/20/1997), including the cyclic injection of the working agent through injection wells and the selection of oil through production wells. A development area with a low oil saturation of the formation and with an excess of the degree of water cut of the extracted product over the degree of development of the initial recoverable reserves is allocated to the deposits. At the development site, the cyclic mode of operation of injection wells is carried out with the restriction of injection volumes below the volume of fluid withdrawal in the area. Up to 30% of production extraction is redistributed from production wells with water cut of less than 60% with intensification of production from low-water wells. Production wells with a water cut of more than 96%, located near the injection wells, start at the moment of stopping the injection wells and stop when starting the injection wells. Production wells with a water cut of more than 96%, placed on deposits, start and stop in accordance with the start and stop of injection wells to reduce reservoir pressure and redistribute the directions of flow of reservoir fluids. The development of the site in the established mode is continued until the reservoir pressure decreases at the development site with an oil saturation of more than 0.55 to the reservoir pressure of less than 0.55 to the reservoir pressure of 2-4 MPa less than the initial one.

The disadvantages of this method are:

firstly, the method does not allow to develop an oil reservoir with the achievement of high oil recovery;

secondly, a complex technology for implementing the method, while production wells with a water cut of more than 96% are included in the development, therefore, the implementation of this method becomes economically not feasible.

Closest to the proposed invention in technical essence is a method of developing an oil reservoir (RF patent No. 2282025, IPC 7 EV 43/20, bull. No. 23 dated 08/20/2006), including the allocation of locally elevated sections of the reservoir with production wells and conducting in selected areas of forced fluid withdrawal through production wells, characterized in that the forced selection is carried out at the initial stage of development, for forced selection, production wells are used with flooding of produced products more 60%, for each well, as a forced selection, selection is established with its increase from 1.5 to tens of times, for which a forced forced selection is carried out on each well until complete watering or before watering of the produced products, 96%, the well is stopped, and technological exposure is carried out to reduction of watering of produced products, further selection of products from the well are carried out in a cyclic mode: established forced selection until full watering or to watering of 96% - well shutdown with technological Shutter speed to reduce the water cut, wherein the further operation is performed for the selective isolation or disable watery portion of the formation.

This method allows to intensify the development of the field, however, the production of the well is sharply flooded, as a result of which large volumes of produced water are produced along the way.

The objective of the invention is to provide a method that improves oil recovery of an oil field.

The problem is solved in that in the method of developing an oil reservoir, including the allocation of locally elevated sections of the reservoir with producing wells and conducting in selected areas of pulse fluid sampling through production wells, according to the invention, a pulsed fluid sampling mode is carried out both at the initial and late stages of development , for the pulse mode of fluid withdrawal, production wells are used with a water cut of produced products of more than 60%, with a reservoir productivity coefficient of at least 1.1 / Day · atm and the static levels of the annulus fluid is not less than 200 m from wellhead and dynamic levels of the annulus fluid is not less than 300 m from wellhead.

The novelty is that the development of production wells is carried out in a pulsed mode both at the initial and late stages of development, and for the pulsed mode, production wells are used with a water cut of produced products of more than 60%, with a reservoir productivity coefficient of at least 1.1 t / day · Atm and with static annular fluid levels of at least 200 m from the wellhead and dynamic annular fluid levels of at least 300 m from the wellhead, for each well, the maximum possible decrease in the annular level in pour to the bottom of the tubing string, after which fluid is sampled while the dynamic level is restored from the lowest level to the established level, a pulsed sampling mode is carried out at each well until the well production is flooded more than 98.5% or the daily oil production rate is less than 2 tons .

To implement the proposed method for the development of oil deposits using a pulse mode of fluid extraction produce:

1) the allocation of locally elevated sections of the reservoir;

2) conducting in selected areas of the pulse mode of fluid withdrawal through production wells;

3) the use of a pulse mode of fluid withdrawal in wells with the presence of undeveloped oil reserves, with a high watering rate, with a reservoir productivity coefficient of at least 1.1 t / day · atm;

4) determination of the maximum possible level of annular fluid reduction up to the bottom of the tubing string;

5) determination of the effective time of fluid flow from the rock matrix to the fracture system in a pulsed mode;

6) decrease in the level of annular fluid using inert gases or foam materials;

7) the simultaneous selection of fluid using a deep pump and the restoration of the dynamic level from the most reduced level to a constant level;

8) the process of unsteady drainage of fluid in the reservoir by a sharp increase in repression and then depression on the reservoir and the gradual restoration of downhole pressure.

Figure 1, 2 presents a diagram of various options for the operation of wells with a pulse mode of fluid withdrawal based on lowering the annular fluid level with a nitrogen compressor.

After watering well products of more than 98.5% or daily oil production of less than 2 tons, it is recommended that selective isolation or shutdown of the flooded part of the formation with compositions containing a large volume of fillers is recommended.

The proposed method for the development of oil deposits using the pulse mode of fluid extraction allows to increase oil recovery, namely:

- there is a more intensive outflow of fluid from the matrix, microcracks due to the large gradP between the cracks and the matrix;

- more efficient development of the reservoir matrix;

- involvement in the development of low drainage areas of the reservoir due to an increase in depression on the reservoir;

- an increase in the power circuit;

- an increase in the flow rate leading to the involvement of capillary-pinched oil in the development;

- an increase in fluid withdrawal in hydrophobic reservoirs leads to a more effective re-washing of film-bound oil.

Claims (1)

A method of developing an oil reservoir using a pulsed fluid sampling mode, including isolating locally elevated sections of the reservoir with producing wells and conducting on the selected fluid sampling sites both at the initial and late stages of development through producing wells with flooding of produced products more than 60%, differing the fact that the development of oil deposits is carried out through production wells in a pulsed mode both at the initial and late stages of development, and for pulsed production fluid sampling wells are used for producing wells with a water cut of produced products of more than 60%, with high formation productivity and with a high static and dynamic level of annular fluid; for each well, the maximum possible decrease in the annular level up to the technically possible is established, after which fluid sampling is performed with simultaneous recovery dynamic level from the most reduced level to a steady level, a pulse mode is taken at each well for selection to completely watered or a profitable production rate.

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