SU1512874A1 - Method of operation of underground gas storage in multilayer nonuniform collectors - Google Patents

Abstract

The invention relates to the field of underground storage of natural gas in multilayer reservoirs and can be used to create underground gas storage facilities in heterogeneous reservoirs. The purpose of the invention is to increase the active gas volume by uniformly saturating the formations (P). Heterogeneous multilayer reservoirs are opened by wells that are equipped with casing and central columns of pipes. The annular space at the level between the P overlap the packer. The permeability of each fluid is determined and gas is pumped into each fluid through the central columns and the annular space separately. At the same time, the gas is first pumped into the P with a lower permeability and it controls the injection rate. Upon reaching a production rate equal to the initial capacity of the more permeable P, the gas is pumped into both Ps. This increases the saturation of low-permeable objects, thereby increasing the volume of stored gas by 10-12%. 2 Il.

Description

The invention relates to the field of underground storage of natural gas in multilayer reservoirs and can be used to create underground gas storage facilities (UGS) in heterogeneous reservoirs.

The aim of the invention is to increase the active gas volume by uniformly saturating the formations.

The method is carried out as follows.

Non-uniform multi-layer reservoirs are opened by wells that equip casing and central columns of pipes. The inter-pipe space at the level between the layers is covered with a packer. The permeability of each reservoir is determined and gas is pumped into each reservoir through the central column and the annular space separately, with the gas being first pumped into the reservoir with a smaller volume

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With the achievement of injection capacity equal to the initial capacity of the more permeable reservoir, gas is pumped into both reservoirs

Fig, 1 shows layers with different permeability and a well, a section; Fig. 2 shows the dependence of the differential pressure on the well productivity.

Underground gas storage is created in a depleted gas condensate reservoir at a depth of 2500 m. The deposit is represented by two sandy reservoirs separated by a clay bridge G (Fig. 1). The layers differ in permeability. Upper reservoir A has average permeability

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-175 md, lower layer B -.

К, ц60 мД. Both the reservoir is opened by a single wellbore, at least one well. Between the layers in the wellbore, a packer P is installed, isolating the 25 annular space (KP) from the pump-compressor pipes (NKT). Gas can be pumped and tapped separately for each layer: A - on annular space, B - on tubing. 30 Gas injection is started to be carried out through the tubing into reservoir B with open valve B 1 and closed B2 “

. If during gas injection into reservoir B; If the initial production rate of a well with an over-35 drop in pressure of 7.0 Sha is 115 thousand m / day (Fig 2), then as the formation pressure increases, there will be a decrease in pressure drop and a decrease as a result of this with the schedule (figure 2).

At some point in time (for the case considered, this is a moment,.

when the pressure differential reaches 2.3 MPa) the well production rate for gas injection into reservoir A is equal to the initial well productivity for reservoir B. At this point, valve B2 is opened and gas injection continues to be conducted into both reservoirs simultaneously until the desired reservoir pressure is reached. Thus, without any additional capital investments and other costs, it is possible to increase the saturation of low-permeable objects, thereby increasing the volume of stored gas by 10-12%,

Invention Formula

A method of operating underground gas storage facilities in a multi-layer heterogeneous reservoir, including drilling wells, pumping and pumping stored gas into one reservoir one above the other and controlling the injection rate, and with the aim of increasing the active gas volume by uniformly saturating the formations, the wells are equipped with casing and central columns of pipes and packers located in the annular space between the formations, the permeability of each formation is determined, and the injection of gas into each formation The station is carried out through the central column and the annular space separately, with the gas being first pumped into the reservoir with a lower permeability, and once the injection rate is equal to the initial capacity of the more permeable reservoir, gas is injected into both layers.

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Claims (1)

Claim A method of operating underground gas storages in multi-layer heterogeneous reservoirs, including drilling wells, pumping and pumping stored gas into formations located one above the other and monitoring the productivity of the injection, about the number. and to the fact that, in order to increase the active volume of gas through uniform saturation of the reservoirs, the wells are equipped with casing and prices. the permeability of each formation is determined by the pipe columns and the packers located in the annulus between the layers, and gas is injected into each formation through the central column and the annulus separately, with the gas being initially pumped into the formation with 40 less permeability, and upon reaching the injection performance, equal to the initial productivity of a more permeable formation, gas is injected into both layers. /// /// /// 77 i 512874 Bl --ΊΧΓΠ --1X0 vg /// /// /77.....'777 wwwW • * * ♦ · · • · · · “· • i 9 ·. · * · 'T C · * * · · • , "·· e * · • ·%. · * < • · · ·· · + \\\\\\ W: V ** · ♦ »·: ύ ·· ♦» ··. · - ·.! ··. * · <· • · · ·, · * * *. · *.-Imax) '·' ··.: · - ···. • 1 ^: ·· s ‘·« • · ·· « " B • h ‘& $ • · · Λ · »♦ • 7 ' Ρ »·· • · · · ·· *. · I R ···» ·· and ·. ”·· * •• V fig. 1