Device and method for simulating gas intrusion and bullheading in wellbore under different inclinations

Patent metadata

Field	Value
Publication number	US-12071849-B2
Application number	US-202418620194-A
Country	US
Kind code	B2
Filing date	Mar 28, 2024
Priority date	May 12, 2023
Publication date	Aug 27, 2024
Grant date	Aug 27, 2024

Abstract

A device for simulating gas intrusion and bullheading in a wellbore under different inclinations is provided, which includes a wellbore outer pipe with an inner pipe and an LED light source therein. An outer wall of the wellbore outer pipe is provided with one or more inlets. A bubble generator is arranged outside a lower plug, and extends through the lower plug via an air inlet needle into the inner cavity of the wellbore outer pipe. An input end of the bubble generator is connected to an air compressor. A lower outlet of the wellbore outer pipe is connected to an inlet of a formation unit through a pipeline and a back pressure valve. A simulating method using such device is also provided.

First claim

What is claimed is:

1. A device for simulating gas intrusion and bullheading in a wellbore under different inclinations, comprising:
a formation unit;
an air compressor;
a bubble generator;
an air inlet needle;
a lower plug;
a back pressure valve;
a liquid storage tank;
a screw pump;
a three-way valve;
an upper plug;
one or more inlets;
a light-emitting diode (LED) light source;
a flange;
an inner pipe;
a wellbore outer pipe;
a metal bracket; and
a first angle adjusting mechanism;
wherein the inner pipe and the LED light source are provided in an inner cavity of the wellbore outer pipe; the upper plug is provided at an upper end of the wellbore outer pipe; the lower plug is provided at a lower end of the wellbore outer pipe; the flange is provided at a middle of the wellbore outer pipe, and is connected to the metal bracket through the first angle adjusting mechanism; an outer wall of the wellbore outer pipe is provided with the one or more inlets; the bubble generator is arranged outside the lower plug; an output end of the bubble generator passes through the lower plug via the air inlet needle to extend into the inner cavity of the wellbore outer pipe; an input end of the bubble generator is connected to the air compressor; a lower outlet of the wellbore outer pipe is connected to an inlet of the formation unit through a first pipeline and the back pressure valve; an outlet of the formation unit is connected to the liquid storage tank through a second pipeline; a lower end of the liquid storage tank is connected to the upper end of the wellbore outer pipe through a third pipeline, the screw pump and the three-way valve; and a camera is arranged at an outer side of the wellbore outer pipe, and is connected to a computer through a wire;
an outside of each of the one or more inlets is connected to a simulated relief well; the simulated relief well comprises a second angle adjusting mechanism, a vertical section, a first connector and a build-up section; the vertical section is connected to a first end of the build-up section through the first connector; a second end of the build-up section is connected to a corresponding one of the one or more inlets; and an outer wall of the vertical section is connected to the second angle adjusting mechanism; and
the formation unit comprises a plurality of simulated formation fractures and two simulation sleeves; the plurality of simulated formation fractures are provided between the two simulation sleeves; an adjusting rod is provided in each of the two simulation sleeves; a lower end of the adjusting rod is provided with a piston; an upper end of the adjusting rod is provided with a knob; and the piston is configured to be moved up and down to control the number of connected simulated formation fractures among the plurality of simulated formation fractures.

2. The device of claim 1 , wherein each of the plurality of simulated formation fractures is a gap formed by two acrylic sheets; a sealing plate is provided around each of the two acrylic sheets; both ends of each of the two acrylic sheets are each provided with a second connector; the gap formed by the two acrylic sheets is connected to a liquid outlet of each of the two simulation sleeves through the second connector; and an adjusting bolt is provided around each of the two acrylic sheets, and is configured to adjust a width of the gap.

3. The device of claim 2 , wherein the first angle adjusting mechanism comprises a fixing plate, one or more fixing bolts, a connecting hole, a semicircular connecting plate and a connecting bolt; the fixing plate is connected to the metal bracket through the one or more fixing bolts and the connecting hole; the semicircular connecting plate is provided at an outer side of the fixing plate; a semicircular annular adjusting groove is provided in the semicircular connecting plate; and the connecting bolt passes through the semicircular annular adjusting groove to be connected to the flange to facilitate adjustment of an inclination of the wellbore outer pipe.

4. The device of claim 3 , wherein an output end of the air compressor is connected to the input end of the bubble generator through a fourth pipeline, a pressure relief valve, a pressure stabilizing valve, a gas flow regulator and a one-way valve.

5. The device of claim 4 , wherein an output end of the screw pump is connected to the upper end of the wellbore outer pipe through the third pipeline, a first ball valve, the three-way valve and a first liquid flow meter.

6. The device of claim 5 , wherein an upper outlet of the three-way valve is connected to an upper end of the vertical section through a fifth pipeline and a second liquid flow meter.

7. The device of claim 6 , wherein the lower outlet of the wellbore outer pipe is connected to a lower end of one of the two simulation sleeves through the first pipeline, a second ball valve and the back pressure valve.

8. A method for gas intrusion and bullheading in a wellbore under different inclinations using the device of claim 7 , comprising:
step (1) testing an air tightness of the device through steps of:
under control of the computer, adjusting the first angle adjusting mechanism such that an angle between the wellbore outer pipe and ground is 90°, opening the first ball valve and adjusting the three-way valve such that the third pipeline connected to the upper end of the wellbore outer pipe is opened, and the fifth pipeline connected to the simulated relief well is closed; closing the second ball valve and starting the screw pump to fill the wellbore outer pipe with a liquid phase with a certain density and viscosity; and stopping the screw pump after the wellbore outer pipe is filled;

step (2) starting the air compressor, and adjusting the pressure relief valve and the pressure stabilizing valve to enable continuous and stable gas output; adjusting the gas flow regulator and the bubble generator to allow bubbles to be stably generated from the air inlet needle through the one-way valve, and recording a gas phase displacement at this moment; after the bubbles rise for a period of time, turning on the LED light source, adjusting a position and a focal length of the camera to make a lens of the camera parallel to the wellbore outer pipe, so as to achieve visualization of morphological changes of the bubbles during migration; and photographing a migration process of the bubbles in a static liquid phase at this moment;
step (3) controlling the gas phase displacement, opening the second ball valve, and adjusting a back pressure of the back pressure valve to simulate a formation pressure; adjusting a position of the piston through the knob, such that one or more of the plurality of simulated formation fractures are opened; rotating the adjusting bolt to form different fracture apertures between the two acrylic sheets; adjusting a liquid phase displacement and recording processes of upward migration-turning downward-bullheading of the bubbles under different liquid phase displacements, wherein when a large number of bubbles are present in the wellbore outer pipe, the liquid phase displacement is adjusted to press all of the bubbles back ahead of an experiment to eliminate an influence of bubbles carried by the liquid phase on a migration process of newly-generated bubbles;
step (4) after experiments under all liquid phase displacements are completed, adjusting the formation pressure, fracture aperture and the number of opened simulated formation fractures, and performing experiments on bubble migration and bullheading under different formation conditions; and after the experiments under all of the formation conditions are completed, adjusting an inclination of the wellbore outer pipe, and photographing migration pro

Assignees

• Univ China Petroleum East China

Inventors

• Yin Bangtang
• Ding Tianbao
• Sun Baojiang
• Wang Zhiyuan
• Gao Yonghai
• Li Hao
• Sun Xiaohui
• Wang Xuerui

Classifications

• G01V2210/64

  Geostructures, e.g. in 3D data cubes · CPC title

• E21B41/00

  Equipment or details not covered by groups E21B15/00 - E21B40/00 · CPC title

• E21B2200/20

  Computer models or simulations, e.g. for reservoirs under production, drill bits · CPC title

• G06F30/20

  Design optimisation, verification or simulation (optimisation, verification or simulation of circuit designs G06F30/30) · CPC title

• E21B49/00

  Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells · CPC title