US3895520A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Well logging method using well logging tools run through a drill stem test string for determining in-situ change in formation water saturation values
Assignee: ConocoPhillips Co
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Filing: 1973-07-27
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Granted: 1975-07-22
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Expires: 1993-07-27
Abstract
Abstract An improved well logging method for determining formation evaluation parameters in a zone of interest wherein a drill stem test string is run in a formation borehole and a logging tool is run through an opening extending through a portion of the drill stem test string during a first and a second logging run, the logging tool having a tool response indicative of the formation water saturation value (SW). A sample portion of the formation fluid in the zone of interest is removed between the first and the second logging runs producing a change in the formation water saturation value, the logging tool response produced during the first logging run being indicative of a first formation water saturation value (SW1) and the logging tool response produced during the second logging run being indicative of the second formation water saturation value (SW2). In one form, the logging tool responses produced during the first and the second logging runs are each plotted on a comparable scale of a chart such that the separation between the plots of the logging tool responses is indicative of the formation potential productivity in the zone of interest and, in one other form, the differences between the logging tool responses produced during the first and the second logging runs are each plotted on a comparable scale of a chart producing a differential curve plot indicative of the formation potential productivity in the zone of interest.
Inventors
- 👤 Walter H Fertl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 04:48
CPC Classifications
E; E21; E21B; E21B49/00; G; G01; G01V; G01V9/00
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
197 words
A well logging method comprising: positioning s drill stem test string or the like in a borehole near the formation zone of interest; positioning a logging tool through a portion of the drill stem test string or the like generally near the formation zone of interest during a first logging run; obtaining a first log from said logging tool having a first logging run tool response responsive to the formation fluid generally within the zone of interest; removing a sample portion of the formation fluid generally from the formation zone of interest, thereby producing an in-situ change in the formation fluid in the zone of interest; retrieving the sample portion of the formation fluid obtained from the formation zone of interest; and obtaining a second log from said logging tool through a portion of the drill stem test string or the like generally near the formation zone of interest during a second logging run, the logging tool having a second logging run tool response responsive to the formation fluid generally within the zone of interest, whereby the first and the second logging run tool responses indicating the formation potential productivity generally within the formation zone of interest.
Claim 2
Dependent Claim
197 words
A well logging method comprising: positioning s drill stem test string or the like in a borehole near the formation zone of interest; positioning a logging tool through a portion of the drill stem test string or the like generally near the formation zone of interest during a first logging run; obtaining a first log from said logging tool having a first logging run tool response responsive to the formation fluid generally within the zone of interest; removing a sample portion of the formation fluid generally from the formation zone of interest, thereby producing an in-situ change in the formation fluid in the zone of interest; retrieving the sample portion of the formation fluid obtained from the formation zone of interest; and obtaining a second log from said logging tool through a portion of the drill stem test string or the like generally near the formation zone of interest during a second logging run, the logging tool having a second logging run tool response responsive to the formation fluid generally within the zone of interest, whereby the first and the second logging run tool responses indicating the formation potential productivity generally within the formation zone of interest.
Claim 3
Dependent Claim
62 words
The method of claim 1 defined further to include: receiving the first and the second logging run tool responses; and plotting the first and the second logging run tool responses on a comparable scale of a chart, the separation between the plots of the first and the second logging run tool responses indicating the formation potential productivity in the zone of interest.
Claim 4
Dependent Claim
48 words
The method of claim 1 defined further to include: receiving the first and the second logging run tool responses; and plotting the differences between the first and the second logging run tool responses, the plot of the differences indicating the Formation potential productivity in the zone of interest.
Claim 5
Dependent Claim
111 words
The method of claim 1 wherein the drill stem test string or the like includes an opening extending through a portion thereof, and wherein the step of positioning the drill stem test string or the like includes positioning the drill stem test string or the like to a location in the formation borehole disposing a portion of the opening through the drill stem test string or the like near the zone of interest; and wherein the steps of running the logging tool during the first and the second logging runs are each defined further as lowering the logging tool through the opening in the drill stem test string or the like.
Claim 6
Dependent Claim
145 words
The method of claim 4 wherein the drill stem test string or the like includes a drill stem test apparatus positionable in a sample position for receiving the sample portion of the formation fluid, and wherein the step of positioning the drill stem test string for receiving the sample portion of formation fluid is defined further to include the step of: positioning the drill stem test string or the like in the formation borehole disposing the drill stem test apparatus near the zone of interest prior to the positioning of the drill stem test string or the like in the sample position; and positioning the drill stem test string or the like in the formation borehole disposing a portion of the opening through the drill stem test string or the like near the zone of interest prior to the running of the second logging run.
Claim 7
Dependent Claim
102 words
The method of claim 1 wherein the drill stem test string or the like includes a drill stem test apparatus positionable in a sample position for receiving the sample portion of the formation fluid, and wherein the step of positioning the drill stem test string for receiving the sample portion of formation fluid is defined further to include the step of: positioning the drill stem test string or the like in the formation borehole disposing the drill stem test apparatus near the zone of interest prior to the positioning of the drill stem test string or the like in the sample position.
Claim 8
Dependent Claim
62 words
The method of claim 1 wherein the steps of running the first and the second logging runs are each defined further to include running a logging tool having a tool response indicative of the formation water saturation value providing first and second logging run tool responses (SW1) and (SW2), indicative of the formation potential productivity generally within the formation zone of interest.
Claim 9
Dependent Claim
62 words
The method of claim 1 wherein the steps of running the first and the second logging runs are each defined further to include running a logging tool having a tool response indicative of the formation porosity index ( Phi L) or the like, the first and the second logging run tool responses indicating the movable gas within the formation zone of interest.
Claim 10
Dependent Claim
59 words
The method of claim 8 defined further to include the steps of: determining the formation gas index (GI) in the zone of interest in the formation borehole via the following expression: GI Phi L1 - Phi L2 and plotting the differences between the first and the second logging run tool responses, the plot indicating the formation gas index (GI).
Claim 11
Dependent Claim
73 words
The method of claim 1 wherein the steps of running the first logging runs are each defined further to include a pulsed neutron logging tool having a tool response responsive to the thermal neutron capture cross section of the formation fluid generally within the zone of interst, the first and the second logging run responses ( Sigma R1) and ( Sigma R2) indicating the formation productivity generally within the formation zone of interest.
Claim 12
Dependent Claim
91 words
The method of claim 10 defined further to include the steps of: analyzing the retrieved formation fluid sample, including: determining the thermal neutron capture cross section of the water ( Sigma W) in the zone of interest in the formation borehole; determining the thermal neutron capture cross section of the hydrocarbons ( Sigma HC) present in the zone of interest in the formation borehole; and determining the formation porosity ( Phi ) in the zone of interest in the formation borehole; and determining the formation movable hydrocarbons (MHC) via the expression:
Claim 13
Dependent Claim
75 words
The method of claim 10 defined further to include the steps of: analyzing the retrieved formation fluid sample, including: determining the thermal neutron capture cross section of the water ( Sigma W) in the zone of interest in the formation borehole; and determining the thermal neutron capture cross section of the hydrocarbons ( Sigma HC) present in the zone of interest in the formation borehole; and determining the formation hydrocarbon index (HI) via the expression:
Claim 14
Dependent Claim
76 words
The method of claim 10 defined further to include the steps of: analyzing the retrieved formation fluid sample, including: determining the thermal neutron capture cross section of the water ( Sigma W) in the zone of interest in the formation borehole; and determining the thermal neutron capture cross section of the hydrocarbons ( Sigma HC) present in the zone of interest in the formation borehole; determining the formation hydrocarbon bulk volume (HBV) via the following expression:
References Cited (Backward Citations)
US3306102A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-21 | 1979-01-20 | 1979-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-21 | 1983-01-20 | 1983-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-21 | 1987-01-20 | 1987-07-22 | $7700.00 | Window Closed / Lapsed |