Method and arrangement for operating an extraction in a borehole
AssigneeRAG Rohol-Aufsuchungs AG
InventorChristian Burgstaller
Life of this patent
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Abstract
A method and an arrangement for operating a process for extracting a fluid in a borehole are optimized. In the case of deep wells, the location of an interface depth in the borehole is detected. A pressure measurement of the pressure at the head of the borehole is made. The pressure in the liquid in the borehole below the interface depth is determined from the measured pressure at the head of the borehole and the detected location of the interface depth. The determination of this pressure is used for regulating the performance of an extracting device for the liquid that is to be extracted.
Claims26
A method for the extraction of a fluid in a borehole in which a location of an interface depth in the borehole is detected in the case of deep wells,
- characterized
- in that a pressure measurement of the pressure at a head of the borehole is made,
- in that a location of an interface depth is detected,
- in that an acoustic event which produces acoustic pressure waves is deliberately effected for the purposes of detecting the location of the interface depth,
- in that a pressure in the liquid below the interface depth in the borehole is determined from the measured pressure at the head of the borehole and the detected location of the interface depth, the pressure in the liquid below the interface depth determined using a productivity index (PI), a supply rate (q), and a zero-bottom hole pressure supply rate (qMAX) of the borehole;
- in that an extraction device that comprises a electrically driven pump is provided in communication with the borehole, and
- in that the determination of the pressure in the liquid below the interface depth is utilised for regulating the performance of the electrically driven pump for the liquid that is to be extracted from the borehole.
A method for the extraction of a fluid in a borehole in which a location of an interface depth in the borehole is detected in the case of deep wells,
- characterized
- in that a pressure measurement of the pressure at a head of the borehole is made,
- in that a location of an interface depth is detected,
- in that an acoustic event which produces acoustic pressure waves is deliberately effected for the purposes of detecting the location of the interface depth,
- in that a pressure in the liquid below the interface depth in the borehole is determined from the measured pressure at the head of the borehole and the detected location of the interface depth,
- in that an extraction device that comprises a electrically driven pump is provided in communication with the borehole,
- in that the determination of the pressure in the fluid below the interface depth is utilised for regulating the performance of the electrically driven pump for the liquid that is to be extracted from the borehole and
- in that for the purposes of determining the pressure in the liquid in the borehole, this is determined using the following equations:
- PI
- =
- q
- P
- r
- -
- P
- wf
- (
- 1
- )
- q
- MAX
- =
- PI
- *
- P
- r
- (
- 2
- )
- q
- =
- q
- MAX
- *
- [
- 1
- -
- (
- P
- wf
- P
- r
- )
- 2
- ]
- (
- 3
- )
- v
- sg
- =
- q
- MAX
- *
- [
- 1
- -
- (
- P
- wf
- P
- r
- )
- 2
- ]
- *
- GOR
- *
- B
- g
- A
- F
- (
- 4
- )
- f
- g
- =
- v
- sg
- (
- C
- +
- D
- *
- TU
- OD
- CA
- ID
- )
- *
- v
- sg
- +
- E
- *
- [
- g
- *
- σ
- *
- (
- ρ
- o
- -
- ρ
- g
- )
- ρ
- o
- 2
- ]
- 0.25
- (
- 5
- )
- wherein PI is the productivity index;
- q is the supply rate;
- Pr is the pressure of the reservoir;
- Pwf is the flow pressure at the bottom of the borehole;
- qMAX is the supply rate in the case of “Zero Bottom Hole Pressure”;
- vsg is the empty tube gas speed;
- GOR is the ratio of gas to oil;
- Bg is the volume factor of the gas formation;
- AF is a designated surface;
- wherein the terms C, D and E are constants;
- TU is the inner pipe size;
- CA is the outer pipe size;
- ρo is the oil density;
- and
- ρg is the gas density.
A system for the extraction of a fluid in a borehole in which the location of an interface depth in the borehole is detected in the case of deep wells, and comprising:
- a pressure measuring device that is above the earth's surface for the purposes of measuring the pressure at the head of the borehole,
- a device for detecting the location of the interface depth,
- an evaluating device to which the values of the pressure measuring device and the device for detecting the location of the interface depth are supplied, wherein an empty tube gas speed and a gas bubble fraction are computed by the evaluation device using a new supply rate for each measurement of the interface depth and the pressure at the head of the borehole, and
- an extracting device for extracting the fluid,
- wherein the extracting device comprises an electrically driven pump,
- wherein the evaluating device supplies values determined from input data to a control system of the electrically driven pump.
Dependencies are inferred from the claim text.