Methods of swabbing liquid loaded wells, and killing wells, with the use of compression pumps, regulators and filtration techniques
A method to unload a fluid mixture from an underground production tubing, in order to reduce the hydrostatic pressure within the fluid mixture. A method to kill an oil or gas well by equalizing pressure between the production tubing, the casing annulus, and a surface tank battery, by de-pressurizing the fluid within the production tubing and the casing annulus, and by pumping a kill fluid. One goal of the methods may be to avoid discharging unwanted liquid phase or gas phase to the atmosphere, therefore reducing unnecessary emissions, and valuing the recovered products.
1 . A method of unloading a fluid mixture from underground production tubing comprising:
pulling, via a compression pump provided downstream of a well head, the fluid mixture from a vertical section of the underground tubing such that a hydrostatic pressure of the fluid mixture within the underground production tubing is reduced, wherein
the fluid mixture comprises a gas phase, a liquid phase, and a solid phase;
flowing the fluid mixture into a separation vessel to separate the gas phase, the liquid phase, and the solid phase;
flowing, via the compression pump, the gas phase and the liquid phase into a tank battery to be stored for future use, such that no portion of the gas phase or the liquid phase is vented to the atmosphere; and
continuing to pull the fluid mixture from the vertical section of the underground tubing until the reduction in hydrostatic pressure of the fluid mixture inside the underground production tubing is sufficient to re-establish a production flow out of the underground production tubing, wherein the production flow had previously been limited.
2 . The method of claim 1 ,
wherein the underground production tubing is surrounded by an underground casing, such that
a casing annulus is defined between the underground production tubing and the underground casing, the method further comprising:
injecting, via a secondary compression pump provided downstream of the well head, a surface gas phase towards the casing annulus, wherein the surface gas phase is stored inside a gas source.
3 . The method of claim 2 ,
wherein the underground production tubing includes a plunger lift and gas lift valves, and
wherein the plunger lift or the gas lift valves are used to unload the fluid mixture present within the underground production tubing.
4 . A method of killing an oil or gas well that includes a fluid mixture present within an underground production tubing and present within an underground casing annulus, the method comprising:
coupling the underground production tubing and the underground casing annulus with a surface tank battery via a well head of the oil or gas well, wherein the well head includes fluid valve connections linking the underground production tubing, the underground casing annulus and the surface tank battery;
equalizing a fluid pressure of the fluid mixture present within the underground production tubing and present within the underground casing annulus, with a fluid pressure of the fluid mixture present within the surface tank battery by adjusting positions of the fluid valve connections;
pumping, via a cross-compression pump provided downstream of the well head, the fluid mixture present within the underground production tubing and the fluid mixture present within the underground casing annulus
towards the surface tank battery; and
pumping, via the cross-compression pump, a kill fluid towards the underground casing annulus, and towards the underground production tubing,
wherein pressure gauges or sensors are provided to monitor the fluid pressure in the underground production tubing, the underground casing annulus, and the surface tank battery.
5 . The method of claim 4 , wherein during a fluid mixture drawdown,
the cross-compression pump is first configured to increase the fluid pressure of the fluid mixture present within the underground production tubing by a range of 5 psi to 20 psi [0.02 MPa to 0.14 MPa] before pumping the fluid mixture towards the surface tank battery; and
the cross-compression pump is second configured to increase the fluid pressure of the fluid mixture present within the underground casing annulus by a range of 5 psi to 20 psi [0.02 MPa to 0.14 MPa] before pumping the fluid mixture towards the surface tank battery.
6 . The method of claim 5 , wherein
the kill fluid contains mainly water, stored within a surface water reservoir.
7 . The method of claim 6 , wherein
the kill fluid is first pumped into the underground casing annulus until the fluid pressure of the fluid mixture present within the underground casing annulus reaches 0 psi [0 MPa], and
the kill fluid is second pumped into the underground production tubing until the fluid pressure of the fluid mixture present within the underground production tubing reaches 0 psi [0 MPa].
8 . A system comprising:
a compression pump configured to pull a fluid mixture from a vertical section of underground tubing, via a well head, such that a hydrostatic pressure of the fluid mixture within the underground production tubing is reduced, wherein the fluid mixture comprises a gas phase, a liquid phase, and a solid phase;
a separation vessel configured to receive the fluid mixture from the vertical section of underground tubing and separate the gas phase, the liquid phase, and the solid phase; and
a tank battery configured to receive and store the gas phase and the liquid phase of the fluid mixture for future use, wherein the gas phase and the liquid phase of the fluid mixture are conveyed from the separator to the tank battery by the compression pump such that no portion of the gas phase or the liquid phase is vented to the atmosphere.
9 . The system of claim 8 , wherein the reduction in hydrostatic pressure of the fluid mixture inside the underground production tubing is sufficient to re-establish a production flow out of the underground production tubing.
10 . The system of claim 8 , wherein the underground production tubing is surrounded by an underground casing, such that a casing annulus is defined between the underground production tubing and the underground casing, the system further comprising:
a gas source containing a surface gas phase; and
a secondary compression pump configured to inject the surface gas phase towards the casing annulus, via the well head.
11 . The system of claim 10 , wherein the casing annulus includes a packer configured to isolate the underground production tubing and the casing.
12 . The system of claim 10 , further comprising gas lift valves, wherein the surface gas phase is configured to be injected into the gas lift valves to aid in pulling the fluid mixture from the vertical section of underground tubing.
13 . The system of claim 8 , further comprising a plunger lift configured to aid in pulling the fluid mixture from the vertical section of underground tubing.