US3684872A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Means and method for automatically determining the interface positions of an injection fluid in a petroleum or gas reservoir using an electrolytic model of the reservoir
Assignee: Texaco Inc
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Filing: 1970-10-30
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Granted: 1972-08-15
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Expires: 1990-10-30
Abstract
Abstract WHERE Vrx and Vry are the X and Y components, respectively, of the velocity of flow in the reservoir at a point r, Q is the rate of a forcing fluid entering the reservoir, i is the total current in the electrolytic solution, Phi is the effective porosity of the medium containing the reservoirs, Sv and Sh are the vertical and horizontal scale factors, respectively, of the reservoir to the model and ARE VOLTAGE GRADIENTS IN THE X and Y directions, respectively, at a point in the model corresponding to the point r in the reservoir. the velocities are used to compute the interface positions of the petroleum or gas and the fluid in the reservoir by determining each incremental change in distance Delta s for a point, commonly referred to as a trace point of the interface between the fluid and the petroleum or gas, in accordance with the following equation: An insulated grid, having four electrode probes at each intersection, overlays an analog model, using an electrolytic solution, of a petroleum or gas reservoir so that some or all of the probes are immersed in the electrolytic solution. Electrodes representing an injection well and a withdrawal well in the reservoir introduce an alternating current in the electrolytic solution corresponding to the injection rate of a fluid in the injection well. Alternating current voltages present at the probes, resulting from the alternating current in the electrolytic solution, are processed to provide digital signals. The digital signals are applied to a digital computer which determines the fluid velocity at a point r of the reservoir in accordance with the following vector equations:
Inventors
- 👤 Alvin O Clauset Jr
- 👤 Donald L Hoyt
- 👤 Russell W Hall Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:55
CPC Classifications
G; G06; G06G; G06G7/00; G06G7/48; G06G7/57; G06G7/12; G06G7/32; G06G7/38; G06G7/40; G06G7/42
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
86 words
A system for determining a condition of a reservoir using an electrolytic model of the reservoir, comprising means for introducing an electrical current in the electrolytic model to simulate the movement of a fluid into the reservoir, a plurality of electrode probes arranged in a predetermined stationary pattern in the electrolytic model, switching means connected to the probes for passing voltages from the electrode probes, and means connected to the switching means for determining the condition in accordance with the passed voltages from the switching means.
Claim 2
Independent Claim
86 words
A system for determining a condition of a reservoir using an electrolytic model of the reservoir, comprising means for introducing an electrical current in the electrolytic model to simulate the movement of a fluid into the reservoir, a plurality of electrode probes arranged in a predetermined stationary pattern in the electrolytic model, switching means connected to the probes for passing voltages from the electrode probes, and means connected to the switching means for determining the condition in accordance with the passed voltages from the switching means.
Claim 3
Dependent Claim
116 words
A system as described in claim 1, in which the electrode probes are mounted on an insulated grid in such a manner so that voltage gradients can be determined for each point in the electrolytic model corresponding to a different intersection of the grid; the determining means includes means connected to the electrode probes for determining the voltage gradients at each point; and means connected to the voltage gradient determining means for determining the condition in accordance with the voltage gradients; and the electrical current means includes at least two electrodes, one electrode corresponding to an injection well in the reservoir, the other electrode corresponding to a withdrawal well, and means for providing the electrical current.
Claim 4
Dependent Claim
178 words
A system as described in claim 2, in which the condition to be determined is the position of the interface of the fluid with the content of the reservoir, as defined by trace points, and is computed in accordance with the following equations: Delta S Delta T(Vel) , where Delta T is an increment of time, Delta S is an incremental distance corresponding to the movement of a trace point from a previous position during the time Delta T, Vrx,Vry are the x, y velocity components, respectively, at a point r in the reservoir, Vel is the resultant velocity of the trace point, Q is the movement rate of the fluid into the reservoir in barrels per day, i is the total current in the electrolytic model in amps, Phi is the effective porosity of the medium containing the content of the reservoir, Sv and Sh are the vertical and horizontal scale factors, respectively, of the reservoir to the model, are voltage gradients at an intersection m of the grid corresponding to the point v in the reservoir.
Claim 5
Dependent Claim
152 words
A system as described in claim 3, in which the switching means include a plurality of groups of relays connected to the determining means, each relay being also connected to a different probe for passing the voltage present at the probe to the determining means when energized and for blocking the voltage when deenergized, means for providing timing pulses, means connected to the timing pulse means for counting the timing pulses, means connected to the counting means and to the relays for providing a voltage to corresponding relays in each group of relays in accordance with the count in the counting means, and means connected to the counting means and to the relays for grounding a group of relays in accordance with the count in the counting means so that only a relay that simultaneously receives a voltage from the voltage means and is grounded by the last mentioned means is energized.
Claim 6
Dependent Claim
128 words
A system as described in claim 3, in which the electrical current introduced in the electrolytic model is an alternating current, and the determining means connected to the voltage gradient determining means include amplifying means connected to the switching means and to the fixed electrical reference and amplifying the passed voltages, a phase sensitive demodulator connected to the amplifying means and to the electrical reference and controlled by a reference voltage for converting the passed voltages to direct current voltages having amplitudes and polarities corresponding to the amplitudes and phases, respectively, of the passed alternating current voltages, and an analog-to-digital converter connected to the phase sensitive demodulator and to the fixed electrical reference and providing digital signals corresponding to the direct current voltages from the phase sensitive demodulator.
Claim 7
Dependent Claim
55 words
A system as described in claim 5, in which the determining means includ a tape recorder connected to the analog-to-digital converter and to the fixed electrical reference and providing a taped record of the digital signals from the analog-to-digital converter, and a digital computer which computes the condition using the signals stored on the tape.
Claim 8
Independent Claim
69 words
A method for determining a condition of a reservoir using an electrolytic model, which comprises introducing an electrical current in the electrolytic model to simulate the injection of a fluid into the reservoir, arranging a plurality of electrode probes in a predetermined stationary pattern in the electrolytic model, controlling switching means to pass voltages present at the electrode probes and determining the condition in accordance with the passed voltages.
Claim 9
Independent Claim
69 words
A method for determining a condition of a reservoir using an electrolytic model, which comprises introducing an electrical current in the electrolytic model to simulate the injection of a fluid into the reservoir, arranging a plurality of electrode probes in a predetermined stationary pattern in the electrolytic model, controlling switching means to pass voltages present at the electrode probes and determining the condition in accordance with the passed voltages.
Claim 10
Dependent Claim
73 words
A method as described in claim 7, in which the arranging step includes mounting the electrode probes on an insulated grid in such a manner so that voltage gradients can be determined for each point in the electrolytic model corresponding to a different intersection of the grid and the determining step includes determining the voltage gradients at the points in the electrolytic model, and determining the condition in accordance with the voltage gradients.
Claim 11
Dependent Claim
94 words
A method as described in claim 8 in which the electrical current is an alternating current, the passed voltages are alternating current voltages, and which further comprises controlling the switching means to pass one voltage at a time from the electrode probes in a predetermined sequence, and the determining step includes amplifying the passed alternating current voltages, demodulating the amplified current voltages to provide direct current voltages having amplitudes and polarities corresponding to the amplitudes and the phases, respectively, of the amplified alternating current voltages, aNd converting the direct current voltages to digital signals.
Claim 12
Dependent Claim
76 words
A method as described in claim 9 in which the determining step includes subtracting a voltage from an electrode of a pair of electrode probes, from a voltage from the other electrode probe of the pair of electrode probes, and dividing the voltage different by the predetermined distance between the electrode probes of the pair of electrode probes to determine a voltage gradient at the intersection of the grid associated with the pair of electrode probes.
Claim 13
Dependent Claim
184 words
A method as described in claim 10 in which the condition to be determined is the interface position of the fluid with the content of the reservoir, as defined by trace points, and the determining step includes computing the interface position in accordance with the following equations: Delta S ( Delta T) (Vel) where Delta T is an incremental change in time, Delta S is an incremental distance corresponding to the movement of a trace point from a previous position during the time Delta T, Vrx, Vry are the x and y velocity components, respectively, at point r in the reservoir, Vel is the resultant velocity of the trace point, Q is the movement rate of the fluid into the reservoir in barrels per day, i is the total current in the electrolytic solution in amps, Phi is the effective porosity of the medium containing the petroleum or gas, Sv and Sh are the vertical and horizontal scale factors, respectively, of the reservoir to the model, are voltage gradients at an intersection m of the grid corresponding to the point r in the reservoir.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-15 | 1976-02-14 | 1976-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-15 | 1980-02-14 | 1980-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-15 | 1984-02-14 | 1984-08-15 | $7700.00 | Window Closed / Lapsed |