RU2687706C1 - Method of operating watered gas wells - Google Patents

Abstract

FIELD: gas industry.

SUBSTANCE: invention relates to methods of operation of flooded gas wells and transportation of their products. In the method of liquid removal from the bottomhole of a gas well using the technology of operation along the concentric lift tubing strings the formation fluid is supplied from the formation to the well, formation fluid is divided at the bottomhole into a gas stream and a gas-liquid stream with mechanical impurities, conveying the gas stream to the wellhead at a rate which does not provide fluid lifting, transporting a gas-liquid stream with mechanical impurities at the wellhead with pressure higher than that of the gas stream and at a rate providing lifting of the liquid with mechanical impurities, introduction of hydrate- and ice-formation inhibitor into well production, well production with hydrate- and icing formation inhibitor is transported to complex gas preparation unit. Gas-liquid flow downstream of the wellhead is directed to separation for separation from gas of liquid phase, suspended particles are separated from liquid phase, removing the precipitate, directing the cleaned liquid phase to the nearby absorbing well, introducing the separated gas into the gas stream, introducing a hydrate- and ice-formation inhibitor into the mixed gas stream and then mixed gas flow is transported with hydrate- and icing agent inhibitor to complex gas treatment plant.

EFFECT: technical result consists in increasing the flow rate of the gas well and reducing the consumption of the hydrate- and icing formation inhibitor by increasing the hydraulic efficiency of the gas-collecting pipeline and reducing its effect on operating characteristics of the water-flooded gas well.

1 cl, 1 dwg, 1 tbl

Description

The invention relates to the gas industry, in particular, to methods of operating watered gas wells and transporting their products.

A known method of removing fluid from gas wells and plumes (see RF Patent 2017941) includes transporting reservoir fluid from wells to the comb of a complex gas treatment unit, separating reservoir fluid to separate moisture and mechanical impurities from gas, compressing gas, entering absorbent gas flow , removal of absorbent from the gas flow, removal of gas from the installation, supply to the ejector of a part of gas after compression, periodic transportation of low-pressure formation fluid from the well or wells through the ridge in the ejector under reduced pressure and increased speed, lowering the wellhead and bottomhole pressure of the well and increasing the speed of transportation of formation fluid in the well, removing liquid from the well and plume to the complex gas treatment unit, feeding the gas mixture from the ejector to the comb, mixing the gas mixture after ejection with gas from the gas treatment complex wells.

The disadvantage of this method is the periodic transportation from the wells of low-pressure formation fluid, which causes a variable pressure at the wellhead and the associated fluctuations of depression on the reservoir. The alternating pressure in the bottomhole formation zone contributes to the destruction of rock with the sand in the well and the formation of sand plugs at the bottom. As a result, the well flow rate decreases to a complete stop and repairs are required. In addition, when the ambient temperature is negative, gas is transported together with a liquid through a pipeline to install an integrated gas treatment unit. Hydrate or ice plugs may form in the pipeline. Due to the lack of data on the volumes of the removed liquid phase with cyclical pressure changes in the well, an excessive amount of hydrate or ice inhibitor is required to prevent hydrate and ice deposition.

The closest analogue to the proposed technical solution is a method of removing liquid from the bottom of a gas well using the technology of concentric lift columns (V.Z. Minlikayev, D.V. Dikamov, S.V. Mazanov, A.Yu. Koryakin, M.A. Donchenko / Operational experience of well 514 of the Cenomanian deposit of the Urengoi OGKM equipped with concentric lift columns // Gas industry / Monthly scientific-technical and production journal. - M .: Gazoil Press, 2015. No. 5. P. 29-33), including the flow of formation fluid from the reservoir to the well fluid separation of the reservoir fluid at the bottom of the well into the gas flow and gas-liquid flow, transporting the gas flow to the wellhead at a speed that does not lift the liquid, transporting the gas-liquid flow to the wellhead at a pressure higher than that of the gas flow , introduction of a gas-liquid stream into the gas stream, introduction of a hydrate and ice formation inhibitor to the well production, transportation of a well production with a hydrate and ice formation inhibitor to the mouth posing the comprehensive gas treatment unit.

This method ensures stable operation of the well at a constant depression on the reservoir due to the maintenance of a predetermined different pressure in the annular space and the central tubing and transportation of the gas-liquid flow through the central tubing with a speed that ensures

fluid at the wellhead. This prevents the formation of sand plugs at the bottom of the well, and the uniform removal of fluid from the well reduces the flow rate of the inhibitor of hydrate and ice formation.

The disadvantage of this method is that the transportation through the gas gathering pipeline of gas with well fluid to the installation of complex gas treatment leads to a decrease in the hydraulic efficiency of the gas gathering pipeline. Due to the additional hydraulic resistance in the gas gathering pipeline, the wellhead pressure of the gas flow and the gas-liquid flow and the bottom hole pressure of the well increase. As a result, the well rate decreases. In addition, at a certain ambient temperature, in order to prevent the formation of hydrates and ice in the gas collection pipeline, the supply of an inhibitor of hydrate and ice formation to the well production is required.

The aim of the invention is to increase the flow rate of the gas well and reduce the consumption of the inhibitor of hydrate and ice formation by increasing the hydraulic efficiency of the gas collecting pipeline and reduce its impact on the performance of the water-flooded gas well.

This goal is achieved as follows.

In the method of removing liquid from the bottom of a gas well using the technology of concentric lift columns including the flow of formation fluid from the reservoir into the well, separation of the formation fluid at the bottom of the well into the gas flow and gas-liquid flow with mechanical impurities, transporting the gas flow to the wellhead at a speed not providing lifting fluid, transporting gas-liquid flow with mechanical impurities at the wellhead with a pressure higher than that of

gas flow and at a speed that provides lifting fluid with mechanical impurities, introducing a hydrate and ice formation inhibitor into a well’s production, transporting a well’s product with a hydrate and ice formation inhibitor to a complex gas treatment unit, unlike the prototype, a gas-liquid stream after the wellhead is sent for separation to separate the liquid phase from the gas, the suspended particles are separated from the liquid phase, sediment is removed, the purified liquid phase is directed to an absorbing well located nearby, lead the separated gas into the gas stream is introduced into the mixed gas stream gidrato inhibitor and ice formation is transported a mixed gas stream with an inhibitor gidrato and ice formation on the gas processing installation.

The invention is illustrated by the flow chart of FIG. one.

The illustration shows the following elements:

1 - production well;

2 - perforations;

3 - lift column;

4 - central lift column;

5 - pipeline;

6 - reducing device;

7 - pipeline;

8 - pipeline;

9 - separator;

10 - pipeline;

11 - pipeline;

12 - gas collection pipeline;

13 - pipeline;

14 - filter;

15 - pipeline;

16 - pipeline;

17 - absorbing well.

The reservoir fluid flows through the perforations 2 to the bottom of the production well 1, and due to the different pressures in the Elevator 3 and the Central Elevator 4, as well as due to the different height of the suspension, the Elevator 3 and the Central Elevator 4 are divided into gas flow and gas-liquid flow. The gas flow is sent to the lift column 3 and rises at the wellhead, and then enters the pipeline 5 for supply to the reducing device 6, which is limited by the flow rate through the lift column and creates a pressure in it higher than in the central lift column 4. From the reducing Device 6 gas stream is directed to the pipeline 7.

The gas-liquid flow is directed to the central lift column 4 and rises to the wellhead. The pipeline 8 directs the gas-liquid stream to the separator 9 for separating the liquid phase from the gas. The separated gas through the pipeline 10 is introduced into the gas stream of the pipeline 7. The inhibitor of hydrate and ice formation is introduced into the mixed gas stream of the pipeline 7 through the pipeline 11. The mixed gas stream with the inhibitor of hydrate and ice formation from the pipeline 7 is fed into the gas collecting pipeline 12 through which the gas is transported on the installation of integrated gas treatment.

The liquid phase from the separator 9 is directed through the pipeline 13 to the filter 14 for the separation of suspended solids. The pipeline 15 is removed from the filter 14 sediment, and the purified liquid phase from the filter 14 through the pipeline 16 is sent to the adjacent absorbing well 17.

Such an invention provides gas transportation from a well without a well fluid to an integrated gas treatment unit and reduction of hydraulic losses in a gas collection pipeline during transportation of a mixed gas stream with an inhibitor of hydrate and ice formation. As a result, the throughput capacity of the gas gathering pipeline and its productivity increase, which allows reducing wellhead pressure and increasing well production. The consumption of methanol is also reduced to prevent hydrate and ice formation during the transportation of gas through the gas collection pipeline.

To assess the effectiveness of the proposed method in the Urengoy oil and gas condensate field, technological modeling of the operation of a watered gas well was carried out, the gas collecting pipeline from which has a length of 6650 m, diameter 273 mm, wall thickness 14 mm. The wellhead pressure of the production well is determined by the inlet pressure at the gas treatment unit and the hydraulic pressure loss in the gas collection pipeline. Table 1 shows the operating parameters of the production well and gas gathering pipeline 12 from the well to the integrated gas treatment unit before and after the invention.

According to the invention, the gas production rate of the production well due to a decrease in hydraulic pressure losses in the gas collection pipeline 12 (by 3.4 times) and a decrease in wellhead pressure is 18% more than in the prototype. The specific consumption of methanol, which prevents the formation of ice deposition to a temperature of minus 7 ° C, decreased by 19.8 times.

Claims (1)

The method of removal of liquid from the bottom of a gas well according to the technology of operation along concentric lift columns, including the flow of formation fluid from the formation into the well, separation of formation fluid at the bottom of the well to the gas flow and gas-liquid flow with mechanical impurities, transportation of the gas flow to the wellhead at a speed not lifting fluid, transporting a gas-liquid stream with mechanical impurities at the wellhead with a pressure higher than that of the gas stream and at a rate ensuring lifting fluid with mechanical impurities, introducing a hydrate and ice formation inhibitor into the production of a well, transporting a well production with a hydrate inhibitor and ice formation to a complex gas treatment unit, characterized in that the gas-liquid flow after the wellhead is directed to separation to separate the gas from the gas , the suspended particles are separated from the liquid phase, the sediment is removed, the purified liquid phase is sent to an absorbing well located nearby, the separated gas is introduced into the gas flow, an inhibitor of hydrate and ice formation is introduced into the mixed gas stream; a mixed gas stream with an inhibitor of hydrate and ice formation is transported to a complex gas treatment unit.

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