LT5719B - Method for injecting of liquid into a bore - Google Patents

Abstract

The invention relates to methods for control of liquids which flow to and from bores and can be used for injecting of liquids into bores where static fluid level is below the mouth of the borehole. Method for injecting of liquid comprises a feeding of liquid by a tube when liquid is injected by tube which is immersed in such a depth in which by reason of pressure does not pass gas dissolved in the liquid. In mentioned tube is installed reverse valve which prevents liquid leak when a flow stopped.

Description

TECHNICAL FIELD OF INVENTION

The invention also relates to methods of controlling the flow of extracted fluids from wells and can be used to inject liquids into wells where the static fluid level is below the wellhead.

State of the art

There are various ways of separating gas from liquids (separators, venting devices). However, they are effective only when the fluid flow is continuous. When the flow of fluid stops, the drop in pressure results in the release of gas in the liquid, which, when renewed, mixes with the liquid and clogs the pores of the injection bed. Current state of the art does not provide effective solutions to this problem. The focus is on protecting the injection wells from mechanical contamination. Methods of drilling and completing injection wells are disclosed in EP 1509675 31.10.2007 and DE 60316433T2 19.06.2008, which describe how well drilling and bore column assembly are to be performed to prevent mechanical portions of the rock layer of the injection bed. The borehole column does not provide any means to prevent the injection layer from blocking gas.

The methods of injecting a fluid in the schematic diagrams of geothermal complexes involve its injection through a submerged tube. This is illustrated on 08-11-2006 in the report "Beurteilung dės Fundigkeitsrisikos and geothermischen Bohrungen" by Rudiger Schulz, GGA Institut, at the Deep Geothermal Forum in Darmstadt, Germany. This method does not involve the retention of liquid in the submerged tube.

The essence of the invention

When the flow of liquid stops, the pressure drop can lead to abundant gas release along its path and the formation of gas reservoirs in wells where the static liquid level is below ground level. After resuming the flow of traffic

-2EN 5719 B

DESCRIPTION OF THE INVENTION "Method of injecting a liquid into a well" The evolved gas mixes with the liquid, enters the injection layer and clogs the pores of the rock. Drilling injectability (ability to absorb fluid) drops.

A method for injecting a liquid into a well is described to prevent it from being blocked by the gas evolved when the flow is stopped. For this purpose, a tube (2) with a non-return valve (3) is immersed in the injection well (1). Submerged to a depth where, under pressure, the gas can no longer escape from the liquid. The other end of the pipe is connected to the switching valve (4). From the valve (4) to the borehole (1), the pipe (2) is inclined with a slope for easy gasification and filling with liquid.

Before resuming a stopped flow of liquid, the following sequence is required:

1. Close the shut-off valve (1).

2. Open the gas valve (7).

3. Gasify and fill the dip tube (2).

4. Move shift valve to position connecting fluid line (5) with buffer tank (6).

5. Run the fluid into the buffer tank (6) until the gas that has been evacuated through the track (5) and before it has been expelled.

6. Position shift valve in position connecting fluid line (5) to submerged pipe (2).

7. Increase the flow pressure to open the non-return valve (3).

8. Close the degassing tap (7) after raising the fluid level in the borehole and expelling gas from the top of the borehole.

After these operations, the fluid flows in a closed system and no longer mixes with the gas evolved during parking.

and step 3, if possible (automated or sufficient staff), can be performed in conjunction with step 5.

The degassing tap (7) can be used to connect a vacuum pump, if required.

Description of the drawing figures

One figure is given. It shows:

1. Injection well;

2. Submersible tube;

-3EN 5719 B

Description of the Invention Method for Injecting Liquid into a Well

3. Check valve;

4. Shift valve;

5. Track;

6. Buffer capacity;

7. Drain valve.

Description of Embodiment of the Invention

The invention can be implemented in all wells injected with liquids containing the evolved gas and which accumulate gas due to the level of the liquid below the surface of the earth.

In order to obtain a positive result, it is necessary to carry out the sequence and the steps described in the description of the invention.

Claims (1)

Definition of the Invention A method of injecting liquids into a borehole, comprising supplying a liquid through a pipe, wherein the liquid is injected through a pipe submerged at a depth at which no gas dissolved in the liquid is released due to pressure, and a non-return valve is provided when the flow stops.