CA2397916C - Resistivity and dielectric constant well core measurement system for measurement while drilling and laboratory - Google Patents
Resistivity and dielectric constant well core measurement system for measurement while drilling and laboratory Download PDFInfo
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- CA2397916C CA2397916C CA002397916A CA2397916A CA2397916C CA 2397916 C CA2397916 C CA 2397916C CA 002397916 A CA002397916 A CA 002397916A CA 2397916 A CA2397916 A CA 2397916A CA 2397916 C CA2397916 C CA 2397916C
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- 238000005553 drilling Methods 0.000 title claims description 31
- 238000005259 measurement Methods 0.000 title claims description 28
- 238000000034 method Methods 0.000 claims abstract description 25
- 239000007787 solid Substances 0.000 claims abstract description 7
- 230000000644 propagated effect Effects 0.000 claims abstract description 6
- 238000012544 monitoring process Methods 0.000 claims abstract 2
- 239000000463 material Substances 0.000 claims description 37
- 230000015572 biosynthetic process Effects 0.000 claims description 32
- 230000005670 electromagnetic radiation Effects 0.000 claims description 11
- 238000012545 processing Methods 0.000 claims description 6
- 239000007788 liquid Substances 0.000 claims description 5
- 238000004382 potting Methods 0.000 claims description 5
- 230000001902 propagating effect Effects 0.000 claims description 5
- 230000008878 coupling Effects 0.000 claims description 2
- 238000010168 coupling process Methods 0.000 claims description 2
- 238000005859 coupling reaction Methods 0.000 claims description 2
- 239000004593 Epoxy Substances 0.000 claims 3
- 229910000859 α-Fe Inorganic materials 0.000 claims 3
- 239000012530 fluid Substances 0.000 abstract description 6
- 238000011065 in-situ storage Methods 0.000 abstract description 3
- 238000005755 formation reaction Methods 0.000 description 27
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- 229930195733 hydrocarbon Natural products 0.000 description 3
- 150000002430 hydrocarbons Chemical class 0.000 description 3
- 101100194816 Caenorhabditis elegans rig-3 gene Proteins 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 239000003129 oil well Substances 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 1
- 229910001035 Soft ferrite Inorganic materials 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 230000000875 corresponding effect Effects 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000005672 electromagnetic field Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 230000000153 supplemental effect Effects 0.000 description 1
- 230000009897 systematic effect Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000013022 venting Methods 0.000 description 1
- 230000035899 viability Effects 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
- E21B47/01—Devices for supporting measuring instruments on drill bits, pipes, rods or wirelines; Protecting measuring instruments in boreholes against heat, shock, pressure or the like
- E21B47/017—Protecting measuring instruments
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
- G01V3/00—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation
- G01V3/18—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation specially adapted for well-logging
- G01V3/30—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation specially adapted for well-logging operating with electromagnetic waves
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B25/00—Apparatus for obtaining or removing undisturbed cores, e.g. core barrels or core extractors
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- 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
- E21B49/02—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 by mechanically taking samples of the soil
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- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Fluid Mechanics (AREA)
- Geochemistry & Mineralogy (AREA)
- Geophysics (AREA)
- Remote Sensing (AREA)
- General Physics & Mathematics (AREA)
- Soil Sciences (AREA)
- Electromagnetism (AREA)
- Geophysics And Detection Of Objects (AREA)
- Measurement Of Resistance Or Impedance (AREA)
Abstract
A highly accurate, fully compensated, high spatial resolution, wave propagation system for measuring dielectric constant and resistivity of fluids or solids in a cylindrical enclosure and method for measuring well core characteristics in-situ or in a laboratory. One embodiment of the invention relies on waves propagated from transmitters (43, 49) above and below two spaced receivers (45, 47) which transmit and receive electromagnetic waves via slots on the inner periphery of a cylinder structure. The data is then processed with a CPU either down hole for later retrieval or on the surface for real-time monitoring.
Description
RESISTIVITY AND DIELECTRIC CONSTANT WELL CORE
MEASUREMENT SYSTEM FOR MEASUREMENT WHILE DRILLING AND
LABORATORY
BACKGROUND OF THE INVENTION
Field of the Invention The present invention relates generally to measurement-while-drilling tools and specifically to resistivity and dielectric constant measuring tools.
Background and Description of the Prior Art Drilling oil wells is an extremely expensive undertaking. The more confidence that a particular formation will be productive the easier it is for a drilling company to take the financial risks associated with the drilling operation.
Technology has progressed to allow acquisition of informative data to determine the viability of a well. Two current methods of formation evaluation are the down hole measurement while drilling (MWD) method and core sample method. In the MV~ID
method, down hole instrumentation measures specified parameters of the formation surrounding the drill stem. In the core sample method, a special drill bit is used that allows the retrieval of a section of formation for evaluation by surface measuring devices. In some cases the instrumentation for MWD is used down hole while also drilling a core sample to measure the properties of the surrounding formation for later comparison to core sample data recorded on the surface.
A technique used for evaluating formations surrounding an earth borehole is to measure the resistivity and dielectric constant of the formation. Porous formations with high resistivity and dielectric constant generally indicate the presence of hydrocarbons while porous formations with low resistivity and dielectric constant are normally water saturated and contain no hydrocarbons.
Typically, tools used to measure these formation characteristics during drilling use a wave propagation tool to measure phase delay and attenuation of electromagnetic waves propagating in the formation over a predefined interval.
Such devices are described in detail in U.S. Pat. No. 3,551,797 and U.S. Pat. No.
4,968,940. All conventional devices for use during drilling use antennas on the outside of a drill collar to transmit or receive the signal. The general direction of advancement is always toward higher data accuracy with higher reliability.
The methods for evaluation of core samples for geophysical parameters which are of interest to the person skilled in the art in the study of oil wells being drilled utilize, for example, the natural radioactivity of the core sample, the absorption of a known radiation emitted by a known source arranged in proximity to the core sample, and the value of the liquid saturation of the core sample (which value is measured by induction).
To date, this type of parameter has been measured and/or detected by first retrieving a core sample and then arranging the core sample which has been withdrawn from the well substantially horizontally on the ground and by moving a carriage equipped with the measuring instrument or instruments manually along the core sample.
Parameters of the abovementioned type can be influenced by the environment of the core sample at the time of measurement, or else similar parameters originating from the environment may be added to the corresponding parameters of the core sample during the measurement taken therefrom. Thus, when the core sample is arranged horizontally, since one of its sides is closer to the ground than the other, this difference in distance may affect the result of the measurement, or else the ground may influence the instruments because of its proximity, this being increasingly so since this proximity is asymmetrical relative to the mass of the core sample as a whole. Overall, lack of accessibility to the core sample makes it difficult to optimize the measurement.
The present invention combines the advantages of core sampling with the advantages of MWD to provide an apparatus and method to determine the characteristics of a core sample while the sample is in its original environment and while in its original orientation relative to the surrounding formation.
SUMMARY OF THE INVENTION
It is a general objective of the present invention to provide an improved measurement-while-drilling (MWD) tool and method for obtaining highly accurate data regarding resistivity and dielectric constant parameters of solids, liquids or a combination thereof, whether flowing or stationary, while core drilling a well or in a laboratory.
This objective can be met with an in-situ core sample measuring embodiment wherein a core sample is measured within the core sample cavity of a drill stem by situating a receiving antenna, a plurality of transmitters and a plurality of receivers in a core drill stem such that the electromagnetic waves propagate through the core sample within the core sample cavity rather than the formation surrounding the drill stem.
This objective may also be met in a laboratory environment with a cylindrical cavity containing the sample to be measured. The cylindrical cavity being equipped with electromagnet wave propagation instrumentation as mentioned in the above drilling system. Other features and advantages will become clear in the following detailed description.
Accordingly, in one aspect of the present invention there is provided an apparatus for measuring a parameter of interest of a material in a subterranean formation, the apparatus comprising:
(a) a cylindrical enclosure for enclosing the material;
(b) at least one transmitter having an antenna on the inside of the cylindrical enclosure for propagating electromagnetic radiation in the material at at least two frequencies;
(c) at least one receiver having an antenna on the inside of the cylindrical enclosure axially displaced from the at least one transmitter for measuring electromagnetic radiation in the material at each of the at least two frequencies, the measurements being indicative of the parameter of interest;
(d) a core bit operatively coupled to the cylindrical enclosure for separating the material from the subterranean formation; and (e) a drilling tubular for conveying the cylindrical enclosure into a borehole in the subterranean formation wherein the drilling tubular is selected from the group consisting of (A) a drill string and (B) a coiled tubing.
According to another aspect of the present invention there is provided a method for determining a parameter of interest of a material comprising:
(a) operatively coupling a core bit to a cylindrical enclosure;
(b) conveying the cylindrical enclosure into a borehole in a subterranean formation on a drilling tubular selected from the group consisting of (A) a drill string and (B) a coiled tubing;
(c) operating the core bit for separating the material from the subterranean formation;
(d) enclosing the material in the cylindrical enclosure;
(e) propagating electromagnetic radiation in the material using at least one transmitter antenna on the inside of the cylindrical enclosure transmitting at least two frequencies; and (f) measuring with at least one receiver antenna on the inside of the cylindrical enclosure axially disposed from the at least one transmitter the propagated electromagnetic radiation in the material at each of the frequencies, the measurements indicative of the parameter of interest.
3a BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will now be described more fully with reference to the accompanying drawings in which:
Figure 1 depicts a drilling system.
Figure 2A prior art shows a conventional measurement system simplified diagram.
Figure 2B is a simplified diagram of the present invention.
Figure 3A is a detailed view of the data acquisition portion of the present invention with a cutaway showing a sample contained therein.
3b Figure 3B is an enlarged cross sectional view of an aperture in the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is a highly accurate; fully compensated, high spatial resolution, wave propagation system for measuring dielectric constant and resistivity of fluids or solids in a cylindrical enclosure. The system can be used for measuring well core characteristics in-situ or in a laboratory, and can also be used for measuring fluids, solids or combination thereof either during flow or stationary inside the cylindrical cavity. Systematic unknown variables which affect measurement have led to inaccuracies in other resistivity and dielectric constant measurement systems.
~ne embodiment of the present invention relies on waves propagated from transmitters spaced symmetrically above and below two spaced receivers which conununicate electromagnetically via slots on the inner periphery of a cylindrical structure.
Referencing Fig. 1, an overall simultaneous drilling and logging system that incorporates an electromagnetic wave propagation resistivity and dielectric constant measurement system according to this invention will now be described in greater detail.
A well 1 is being drilled into the earth under control of surface equipment including a rotary drilling rig 3. In accordance with a conventional arrangement, rig 3 includes a derrick 5, derrick floor 7, draw works 9, hook 11, kelly joint I5, rotary table 17, and drill string 19 that includes drill pipe 21 secured to the lower end of kelly joint 15 and to the upper end of a section of drill collars including an upper drill collar 23, an intermediate drill collar (not separately shown), and a lower drill collar measurement tubular 25 immediately below the intermediate sub. A drill bit 26 is carried by the lower end of measurement tubular 25. During well drilling operations the drill bit will be a conventional bit when the main purpose is to reach a desired depth. The conventional drill bit will be replaced by a coring bit when core samples are desired. The purpose of the core bit is to retain within the drill string a sample of the borehole called a core sample. The core sample is typically brought to the surface for testing and analysis to determine the characteristics of the formation at the depth from which the core sample was taken. It will be explained later in this description the relationship to current drilling measurements systems, core measurement systems and the present invention.
Drilling fluid, or mud as it is commonly called, is circulated from a mud pit through a mud pump 29, past a desurger 31, through a mud supply line 33, and into swivel 13. The drilling mud flows down through the kelly joint 15 and an axial central bore in the drill string, and through jets (not shown) in the lower face of the drill bit. The drilling mud flows back up through the annular space between the outer surface of the drill string and the inner surface of the borehole to be circulated to the surface where it is returned to the mud pit through a mud return line 35. A
shaker screen (not shown) separates formation cuttings from the drilling mud before the mud is returned to the mud pit.
The overall system in Fig. 1 uses mud pulse telemetry techniques to communicate data from down hole to the surface while drilling operations take place.
To receive data at the surface, there is a transducer 37 in mud supply line 33. This transducer generates electrical signals in response to drilling mud pressure variations, and the electrical signals are transmitted by a surface conductor 39 to a surface electronic data processing system 41.
Mud pulse telemetry techniques provide for communicating data to the surface about numerous down hole conditions sensed by well logging transducers or measurement systems that ordinarily are located on and within the drill collar nearest the drill bit. The mud pulses that define the data are produced by equipment within the intermediate sub. Such equipment typically comprises a pressure pulse generator operating under control of electronics contained within an instrument housing to allow drilling mud to vent through an orifice extending through the logging collar wall. Each time the pressure pulse generator causes such venting, a negative pressure pulse is transmitted to be received by surface transducer 37. An alternative conventional arrangement generates and transmits positive pressure pulses.
The circulating drilling mud provides a source of energy for a turbine-driven generator sub-assembly located in the intermediate sub, and the turbine-driven generator sub-assembly generates electrical power for the pressure pulse generator and for various circuits including forming part of the preferred embodiment of this invention. As an alternative or supplemental source of electrical power, batteries may be provided, particularly as a backup for the turbine-powered generator.
In general, previous MWD systems measure the formation surrounding the drill stem as shown in Fig. 2A. The measurement of surrounding formation parameters is accomplished by having electromagnetic waves transmitted alternately from transmitters 43 and 49. The waves pass through the surrounding formation and are received by receivers 45 and 47. Contrast this conventional measurement with the simplified diagram of the measuring system of the present invention shown in Fig.
2~. For an MWD embodiment, the present invention can be utilized down hole conveyed on a tool such as a drill string or a coiled tubing. Transmitters 51 and 57 pass electromagnetic fields through a core sample 50 and the fields are picked up by receivers 53 and 55. Such a symmetric arrangement of transmitters about the receivers makes it possible to fully compensate for any linear changes to the measurement system. U.S. Patent 5,811,973 issued to Meyer, Jr. and having the same assignee as the present invention discloses a propagation resistivity measurement-while-drilling system used to determine the resistivity (or conductivity) of the connate formation fluid, the dielectric constant of the dry rock matrix, and the water filled porosity of the formation. One or more transmitter- receiver pairs are utilized with the transmitter component of the transmitter- receiver pairs operating at a plurality of frequencies. Water filled porosity measurements can be combined with an independent measurement which responds to the total fluid porosity of the formation to obtain a measure of formation hydrocarbon saturation in fresh or saline connate water environments. The contents of U.S. Patent 5,811,973 are fully incorporated here by reference.
Refer now to Fig. 3A which shows the data acquisition portion of the preferred embodiment of the present invention in detail. A cylindrical enclosure 59, which may be a modified core barrel, contains a liquid, solid, gas or combination sample 61, either flowing or stationary. The sample in the case of the MWD
embodiment is a core sample. Transmitter T1 63 generates an electromagnetic wave to be passed through sample 61 and received by receivers R1 65 and R2 68, The wave is propagated and received via antennas 64 and 66 respectively. In an alternating fashion, transmitter T2 69 generates an electromagnetic wave to be passed through sample 61 and received by receivers Rl 65 and R2 68. The waves from T1 and T2 are propagated and received via antennas 70 and 68 respectively. The transmitters are fixed within the cylindrical enclosure 59 about the inner surface. A
plurality of apertures 60 (shown for T1 only) are provided for each transmitting antenna.
In Fig. 3B, an enlarged aperture cross section is shown which is substantially similar to all other apertures in the preferred embodiment. An electromagnetic shielding material 73 such as a soft ferrite is positioned within each aperture for protecting the cylindrical enclosure from the electromagnetic radiation.
Toward the inner surface, antenna wire 64 is fixed in said apertures with and a potting material 71 which also provides protection for said antenna wire. In a preferred embodiment, the potting material is an epoxy resin.
In an alternate embodiment of the invention (not shown) the transmitter antenna is set in a circumferential recess on the inside of the cylinder. This embodiment is structurally weaker than the slotted design of Fig. 3A-3B.
Data recorded by the receivers can be either transmitted in real time to the surface or alternately can be recorded with recording instrumentation down hole (not shown) for later retrieval. For the real time data transmission embodiment, signals from the receivers are transmitted to the surface by a transmission path, transferred to a central processing unit (CPU) for processing. The processed data comprising measures of the parameters of interest, such as an amplitude resistivity or a phase resistivity, are correlated with depths from a drill collar depth indicator (not shown), and an output to a recorder which displays the computed parameters of interest as a function of depth at which the input measurements were made. An alternate embodiment comprises a processor unit (not shown) mounted within the drill collar 23 to perform data processing down hole. In order to most effectively utilize memory capacity, it is often desirable to process measured'data down hole and store processed results rather than the more voluminous measured data.
It should be understood that the invention is in no way limited to the described embodiments, and that many changes may be made to these embodiments without departing from the scope of the present invention. Other embodiments would be obvious to those versed in the arts to which the invention pertains.
MEASUREMENT SYSTEM FOR MEASUREMENT WHILE DRILLING AND
LABORATORY
BACKGROUND OF THE INVENTION
Field of the Invention The present invention relates generally to measurement-while-drilling tools and specifically to resistivity and dielectric constant measuring tools.
Background and Description of the Prior Art Drilling oil wells is an extremely expensive undertaking. The more confidence that a particular formation will be productive the easier it is for a drilling company to take the financial risks associated with the drilling operation.
Technology has progressed to allow acquisition of informative data to determine the viability of a well. Two current methods of formation evaluation are the down hole measurement while drilling (MWD) method and core sample method. In the MV~ID
method, down hole instrumentation measures specified parameters of the formation surrounding the drill stem. In the core sample method, a special drill bit is used that allows the retrieval of a section of formation for evaluation by surface measuring devices. In some cases the instrumentation for MWD is used down hole while also drilling a core sample to measure the properties of the surrounding formation for later comparison to core sample data recorded on the surface.
A technique used for evaluating formations surrounding an earth borehole is to measure the resistivity and dielectric constant of the formation. Porous formations with high resistivity and dielectric constant generally indicate the presence of hydrocarbons while porous formations with low resistivity and dielectric constant are normally water saturated and contain no hydrocarbons.
Typically, tools used to measure these formation characteristics during drilling use a wave propagation tool to measure phase delay and attenuation of electromagnetic waves propagating in the formation over a predefined interval.
Such devices are described in detail in U.S. Pat. No. 3,551,797 and U.S. Pat. No.
4,968,940. All conventional devices for use during drilling use antennas on the outside of a drill collar to transmit or receive the signal. The general direction of advancement is always toward higher data accuracy with higher reliability.
The methods for evaluation of core samples for geophysical parameters which are of interest to the person skilled in the art in the study of oil wells being drilled utilize, for example, the natural radioactivity of the core sample, the absorption of a known radiation emitted by a known source arranged in proximity to the core sample, and the value of the liquid saturation of the core sample (which value is measured by induction).
To date, this type of parameter has been measured and/or detected by first retrieving a core sample and then arranging the core sample which has been withdrawn from the well substantially horizontally on the ground and by moving a carriage equipped with the measuring instrument or instruments manually along the core sample.
Parameters of the abovementioned type can be influenced by the environment of the core sample at the time of measurement, or else similar parameters originating from the environment may be added to the corresponding parameters of the core sample during the measurement taken therefrom. Thus, when the core sample is arranged horizontally, since one of its sides is closer to the ground than the other, this difference in distance may affect the result of the measurement, or else the ground may influence the instruments because of its proximity, this being increasingly so since this proximity is asymmetrical relative to the mass of the core sample as a whole. Overall, lack of accessibility to the core sample makes it difficult to optimize the measurement.
The present invention combines the advantages of core sampling with the advantages of MWD to provide an apparatus and method to determine the characteristics of a core sample while the sample is in its original environment and while in its original orientation relative to the surrounding formation.
SUMMARY OF THE INVENTION
It is a general objective of the present invention to provide an improved measurement-while-drilling (MWD) tool and method for obtaining highly accurate data regarding resistivity and dielectric constant parameters of solids, liquids or a combination thereof, whether flowing or stationary, while core drilling a well or in a laboratory.
This objective can be met with an in-situ core sample measuring embodiment wherein a core sample is measured within the core sample cavity of a drill stem by situating a receiving antenna, a plurality of transmitters and a plurality of receivers in a core drill stem such that the electromagnetic waves propagate through the core sample within the core sample cavity rather than the formation surrounding the drill stem.
This objective may also be met in a laboratory environment with a cylindrical cavity containing the sample to be measured. The cylindrical cavity being equipped with electromagnet wave propagation instrumentation as mentioned in the above drilling system. Other features and advantages will become clear in the following detailed description.
Accordingly, in one aspect of the present invention there is provided an apparatus for measuring a parameter of interest of a material in a subterranean formation, the apparatus comprising:
(a) a cylindrical enclosure for enclosing the material;
(b) at least one transmitter having an antenna on the inside of the cylindrical enclosure for propagating electromagnetic radiation in the material at at least two frequencies;
(c) at least one receiver having an antenna on the inside of the cylindrical enclosure axially displaced from the at least one transmitter for measuring electromagnetic radiation in the material at each of the at least two frequencies, the measurements being indicative of the parameter of interest;
(d) a core bit operatively coupled to the cylindrical enclosure for separating the material from the subterranean formation; and (e) a drilling tubular for conveying the cylindrical enclosure into a borehole in the subterranean formation wherein the drilling tubular is selected from the group consisting of (A) a drill string and (B) a coiled tubing.
According to another aspect of the present invention there is provided a method for determining a parameter of interest of a material comprising:
(a) operatively coupling a core bit to a cylindrical enclosure;
(b) conveying the cylindrical enclosure into a borehole in a subterranean formation on a drilling tubular selected from the group consisting of (A) a drill string and (B) a coiled tubing;
(c) operating the core bit for separating the material from the subterranean formation;
(d) enclosing the material in the cylindrical enclosure;
(e) propagating electromagnetic radiation in the material using at least one transmitter antenna on the inside of the cylindrical enclosure transmitting at least two frequencies; and (f) measuring with at least one receiver antenna on the inside of the cylindrical enclosure axially disposed from the at least one transmitter the propagated electromagnetic radiation in the material at each of the frequencies, the measurements indicative of the parameter of interest.
3a BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will now be described more fully with reference to the accompanying drawings in which:
Figure 1 depicts a drilling system.
Figure 2A prior art shows a conventional measurement system simplified diagram.
Figure 2B is a simplified diagram of the present invention.
Figure 3A is a detailed view of the data acquisition portion of the present invention with a cutaway showing a sample contained therein.
3b Figure 3B is an enlarged cross sectional view of an aperture in the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is a highly accurate; fully compensated, high spatial resolution, wave propagation system for measuring dielectric constant and resistivity of fluids or solids in a cylindrical enclosure. The system can be used for measuring well core characteristics in-situ or in a laboratory, and can also be used for measuring fluids, solids or combination thereof either during flow or stationary inside the cylindrical cavity. Systematic unknown variables which affect measurement have led to inaccuracies in other resistivity and dielectric constant measurement systems.
~ne embodiment of the present invention relies on waves propagated from transmitters spaced symmetrically above and below two spaced receivers which conununicate electromagnetically via slots on the inner periphery of a cylindrical structure.
Referencing Fig. 1, an overall simultaneous drilling and logging system that incorporates an electromagnetic wave propagation resistivity and dielectric constant measurement system according to this invention will now be described in greater detail.
A well 1 is being drilled into the earth under control of surface equipment including a rotary drilling rig 3. In accordance with a conventional arrangement, rig 3 includes a derrick 5, derrick floor 7, draw works 9, hook 11, kelly joint I5, rotary table 17, and drill string 19 that includes drill pipe 21 secured to the lower end of kelly joint 15 and to the upper end of a section of drill collars including an upper drill collar 23, an intermediate drill collar (not separately shown), and a lower drill collar measurement tubular 25 immediately below the intermediate sub. A drill bit 26 is carried by the lower end of measurement tubular 25. During well drilling operations the drill bit will be a conventional bit when the main purpose is to reach a desired depth. The conventional drill bit will be replaced by a coring bit when core samples are desired. The purpose of the core bit is to retain within the drill string a sample of the borehole called a core sample. The core sample is typically brought to the surface for testing and analysis to determine the characteristics of the formation at the depth from which the core sample was taken. It will be explained later in this description the relationship to current drilling measurements systems, core measurement systems and the present invention.
Drilling fluid, or mud as it is commonly called, is circulated from a mud pit through a mud pump 29, past a desurger 31, through a mud supply line 33, and into swivel 13. The drilling mud flows down through the kelly joint 15 and an axial central bore in the drill string, and through jets (not shown) in the lower face of the drill bit. The drilling mud flows back up through the annular space between the outer surface of the drill string and the inner surface of the borehole to be circulated to the surface where it is returned to the mud pit through a mud return line 35. A
shaker screen (not shown) separates formation cuttings from the drilling mud before the mud is returned to the mud pit.
The overall system in Fig. 1 uses mud pulse telemetry techniques to communicate data from down hole to the surface while drilling operations take place.
To receive data at the surface, there is a transducer 37 in mud supply line 33. This transducer generates electrical signals in response to drilling mud pressure variations, and the electrical signals are transmitted by a surface conductor 39 to a surface electronic data processing system 41.
Mud pulse telemetry techniques provide for communicating data to the surface about numerous down hole conditions sensed by well logging transducers or measurement systems that ordinarily are located on and within the drill collar nearest the drill bit. The mud pulses that define the data are produced by equipment within the intermediate sub. Such equipment typically comprises a pressure pulse generator operating under control of electronics contained within an instrument housing to allow drilling mud to vent through an orifice extending through the logging collar wall. Each time the pressure pulse generator causes such venting, a negative pressure pulse is transmitted to be received by surface transducer 37. An alternative conventional arrangement generates and transmits positive pressure pulses.
The circulating drilling mud provides a source of energy for a turbine-driven generator sub-assembly located in the intermediate sub, and the turbine-driven generator sub-assembly generates electrical power for the pressure pulse generator and for various circuits including forming part of the preferred embodiment of this invention. As an alternative or supplemental source of electrical power, batteries may be provided, particularly as a backup for the turbine-powered generator.
In general, previous MWD systems measure the formation surrounding the drill stem as shown in Fig. 2A. The measurement of surrounding formation parameters is accomplished by having electromagnetic waves transmitted alternately from transmitters 43 and 49. The waves pass through the surrounding formation and are received by receivers 45 and 47. Contrast this conventional measurement with the simplified diagram of the measuring system of the present invention shown in Fig.
2~. For an MWD embodiment, the present invention can be utilized down hole conveyed on a tool such as a drill string or a coiled tubing. Transmitters 51 and 57 pass electromagnetic fields through a core sample 50 and the fields are picked up by receivers 53 and 55. Such a symmetric arrangement of transmitters about the receivers makes it possible to fully compensate for any linear changes to the measurement system. U.S. Patent 5,811,973 issued to Meyer, Jr. and having the same assignee as the present invention discloses a propagation resistivity measurement-while-drilling system used to determine the resistivity (or conductivity) of the connate formation fluid, the dielectric constant of the dry rock matrix, and the water filled porosity of the formation. One or more transmitter- receiver pairs are utilized with the transmitter component of the transmitter- receiver pairs operating at a plurality of frequencies. Water filled porosity measurements can be combined with an independent measurement which responds to the total fluid porosity of the formation to obtain a measure of formation hydrocarbon saturation in fresh or saline connate water environments. The contents of U.S. Patent 5,811,973 are fully incorporated here by reference.
Refer now to Fig. 3A which shows the data acquisition portion of the preferred embodiment of the present invention in detail. A cylindrical enclosure 59, which may be a modified core barrel, contains a liquid, solid, gas or combination sample 61, either flowing or stationary. The sample in the case of the MWD
embodiment is a core sample. Transmitter T1 63 generates an electromagnetic wave to be passed through sample 61 and received by receivers R1 65 and R2 68, The wave is propagated and received via antennas 64 and 66 respectively. In an alternating fashion, transmitter T2 69 generates an electromagnetic wave to be passed through sample 61 and received by receivers Rl 65 and R2 68. The waves from T1 and T2 are propagated and received via antennas 70 and 68 respectively. The transmitters are fixed within the cylindrical enclosure 59 about the inner surface. A
plurality of apertures 60 (shown for T1 only) are provided for each transmitting antenna.
In Fig. 3B, an enlarged aperture cross section is shown which is substantially similar to all other apertures in the preferred embodiment. An electromagnetic shielding material 73 such as a soft ferrite is positioned within each aperture for protecting the cylindrical enclosure from the electromagnetic radiation.
Toward the inner surface, antenna wire 64 is fixed in said apertures with and a potting material 71 which also provides protection for said antenna wire. In a preferred embodiment, the potting material is an epoxy resin.
In an alternate embodiment of the invention (not shown) the transmitter antenna is set in a circumferential recess on the inside of the cylinder. This embodiment is structurally weaker than the slotted design of Fig. 3A-3B.
Data recorded by the receivers can be either transmitted in real time to the surface or alternately can be recorded with recording instrumentation down hole (not shown) for later retrieval. For the real time data transmission embodiment, signals from the receivers are transmitted to the surface by a transmission path, transferred to a central processing unit (CPU) for processing. The processed data comprising measures of the parameters of interest, such as an amplitude resistivity or a phase resistivity, are correlated with depths from a drill collar depth indicator (not shown), and an output to a recorder which displays the computed parameters of interest as a function of depth at which the input measurements were made. An alternate embodiment comprises a processor unit (not shown) mounted within the drill collar 23 to perform data processing down hole. In order to most effectively utilize memory capacity, it is often desirable to process measured'data down hole and store processed results rather than the more voluminous measured data.
It should be understood that the invention is in no way limited to the described embodiments, and that many changes may be made to these embodiments without departing from the scope of the present invention. Other embodiments would be obvious to those versed in the arts to which the invention pertains.
Claims (24)
1. An apparatus for measuring a parameter of interest of a material in a subterranean formation, the apparatus comprising:
(a) a cylindrical enclosure for enclosing the material;
(b) at least one transmitter having an antenna on the inside of the cylindrical enclosure for propagating electromagnetic radiation in the material at at least two frequencies;
(c) at least one receiver having an antenna on the inside of the cylindrical enclosure axially displaced from the at least one transmitter for measuring electromagnetic radiation in the material at each of the at least two frequencies, the measurements being indicative of the parameter of interest;
(d) a core bit operatively coupled to the cylindrical enclosure for separating the material from the subterranean formation; and (e) a drilling tubular for conveying the cylindrical enclosure into a borehole in the subterranean formation wherein the drilling tubular is selected from the group consisting of (A) a drill string and (B) a coiled tubing.
(a) a cylindrical enclosure for enclosing the material;
(b) at least one transmitter having an antenna on the inside of the cylindrical enclosure for propagating electromagnetic radiation in the material at at least two frequencies;
(c) at least one receiver having an antenna on the inside of the cylindrical enclosure axially displaced from the at least one transmitter for measuring electromagnetic radiation in the material at each of the at least two frequencies, the measurements being indicative of the parameter of interest;
(d) a core bit operatively coupled to the cylindrical enclosure for separating the material from the subterranean formation; and (e) a drilling tubular for conveying the cylindrical enclosure into a borehole in the subterranean formation wherein the drilling tubular is selected from the group consisting of (A) a drill string and (B) a coiled tubing.
2. The apparatus of claim 1 further comprising a processor for processing data measured by the at least one receiver, wherein the processed data comprises measures of the parameters of interest.
3. The apparatus of claim 1 or 2, wherein the parameter of interest is selected from the group consisting of (i) resistivity and (ii) dielectric constant of the material.
4. The apparatus of any one of claims 1 to 3, wherein the material is at least one of a (i) liquid, (ii) solid, and (iii) a gas.
5. The apparatus of claim 4, wherein the material is flowing.
6. The apparatus of claim 4, wherein the material is stationary.
7. The apparatus of claim 1, wherein the at least one transmitter comprises at least two transmitters, the at least one receiver comprises at least two receivers, and wherein the at least two transmitters are symmetrically arranged about the at least two receivers.
8. The apparatus of any one of claims 1 to 6, wherein the at least one transmitter antenna is set in a circumferential recess on the inside of the cylindrical enclosure.
9. The apparatus of claim 8 further comprising a ferrite material positioned in the recess for shielding the cylindrical enclosure from electromagnetic radiation.
10. The apparatus of claim 8 further comprising an epoxy potting material for fixing the at least one transmitter antenna in the recess and protecting the antenna from damage.
11. The apparatus of any one of claims 1 to 6, wherein each said antenna is set in a plurality of apertures on the inside of the cylindrical enclosure.
12. The apparatus of claim 11 further comprising a ferrite material positioned in the apertures for electromagnetic shielding of the cylindrical enclosure.
13. The apparatus of claim 11 further comprising an epoxy potting material for fixing the antenna in the apertures and protecting the antenna from damage.
14. A method for determining a parameter of interest of a material comprising:
(a) operatively coupling a core bit to a cylindrical enclosure;
(b) conveying the cylindrical enclosure into a borehole in a subterranean formation on a drilling tubular selected from the group consisting of (A) a drill string and (B) a coiled tubing;
(c) operating the core bit for separating the material from the subterranean formation;
(d) enclosing the material in the cylindrical enclosure;
(e) propagating electromagnetic radiation in the material using at least one transmitter antenna on the inside of the cylindrical enclosure transmitting at least two frequencies; and (f) measuring with at least one receiver antenna on the inside of the cylindrical enclosure axially disposed from the at least one transmitter the propagated electromagnetic radiation in the material at each of the frequencies, the measurements indicative of the parameter of interest.
(a) operatively coupling a core bit to a cylindrical enclosure;
(b) conveying the cylindrical enclosure into a borehole in a subterranean formation on a drilling tubular selected from the group consisting of (A) a drill string and (B) a coiled tubing;
(c) operating the core bit for separating the material from the subterranean formation;
(d) enclosing the material in the cylindrical enclosure;
(e) propagating electromagnetic radiation in the material using at least one transmitter antenna on the inside of the cylindrical enclosure transmitting at least two frequencies; and (f) measuring with at least one receiver antenna on the inside of the cylindrical enclosure axially disposed from the at least one transmitter the propagated electromagnetic radiation in the material at each of the frequencies, the measurements indicative of the parameter of interest.
15. The method of claim 14 further comprising using a processor for processing the data to determine measures of the parameters of interest.
16. The method of claim 15, wherein the processor is at a location selected from the group consisting of (i) down hole on a drill string and (ii) on the surface for real time monitoring.
17. The method of any one of claims 14 to 16, wherein the parameter of interest is selected from the group consisting of (i) resistivity and (ii) dielectric constant of the material.
18. The method of any one of claims 14 to 17, wherein the material is selected from the group consisting of (i) a liquid, (ii) a solid, and (iii) a gas.
19. The method of claim 18, wherein the material is flowing.
20. The method of claim 18, wherein the material is stationary.
21. The method of any one of claims 14 to 20, wherein the at least one transmitter comprises at least two transmitters, the at least one receiver comprises at least two receivers, and wherein the at least two transmitters are symmetrically arranged about the at least two receivers.
22. The method of any one of claims 14 to 20, wherein the location of the at least one transmitter antenna and the at least one receiver antenna is selected from the group consisting of (i) a recess in the enclosure and (ii) a plurality of apertures in the enclosure.
23. The method of claim 22 further comprising shielding the cylindrical enclosure from electromagnetic radiation with a ferrite material.
24. The method of claim 22 further comprising fixing the at least one transmitter antenna and the at least one receiver antenna in place with an epoxy potting material.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US17702700P | 2000-01-19 | 2000-01-19 | |
| US60/177,027 | 2000-01-19 | ||
| PCT/US2001/001729 WO2001053855A1 (en) | 2000-01-19 | 2001-01-19 | Resistivity and dielectric constant well core measurement system for measurement while drilling and laboratory |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2397916A1 CA2397916A1 (en) | 2001-07-26 |
| CA2397916C true CA2397916C (en) | 2007-04-24 |
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ID=22646882
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002397916A Expired - Lifetime CA2397916C (en) | 2000-01-19 | 2001-01-19 | Resistivity and dielectric constant well core measurement system for measurement while drilling and laboratory |
Country Status (4)
| Country | Link |
|---|---|
| CA (1) | CA2397916C (en) |
| GB (1) | GB2377761B (en) |
| NO (1) | NO335416B1 (en) |
| WO (1) | WO2001053855A1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7168508B2 (en) | 2003-08-29 | 2007-01-30 | The Trustees Of Columbia University In The City Of New York | Logging-while-coring method and apparatus |
| CN103675924B (en) * | 2013-12-16 | 2017-01-18 | 淮南矿业(集团)有限责任公司 | Tunnel radio-wave penetration collection system |
| CN105715255B (en) * | 2016-01-26 | 2019-06-25 | 中国石油集团长城钻探工程有限公司 | The device of stratigraphic boundary detection and formation resistivity measurement |
| CA3148239A1 (en) | 2019-07-23 | 2021-01-28 | Schlumberger Canada Limited | Downhole communication devices and systems |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4873488A (en) * | 1985-04-03 | 1989-10-10 | Schlumberger Technology Corporation | Induction logging sonde with metallic support having a coaxial insulating sleeve member |
| US4996489A (en) * | 1989-03-31 | 1991-02-26 | Halliburton Logging Services, Inc. | Laboratory technique for measuring complex dielectric constant of rock core samples |
| FR2700851B1 (en) * | 1993-01-26 | 1995-04-14 | Sgn Soc Gen Tech Nouvelle | Device and method for taking samples of a material. |
| US5453693A (en) * | 1993-10-01 | 1995-09-26 | Halliburton Company | Logging system for measuring dielectric properties of fluids in a cased well using multiple mini-wave guides |
| US5811973A (en) * | 1994-03-14 | 1998-09-22 | Baker Hughes Incorporated | Determination of dielectric properties with propagation resistivity tools using both real and imaginary components of measurements |
| US6003620A (en) * | 1996-07-26 | 1999-12-21 | Advanced Coring Technology, Inc. | Downhole in-situ measurement of physical and or chemical properties including fluid saturations of cores while coring |
-
2001
- 2001-01-19 CA CA002397916A patent/CA2397916C/en not_active Expired - Lifetime
- 2001-01-19 WO PCT/US2001/001729 patent/WO2001053855A1/en active Application Filing
- 2001-01-19 GB GB0216744A patent/GB2377761B/en not_active Expired - Lifetime
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2002
- 2002-07-18 NO NO20023450A patent/NO335416B1/en not_active IP Right Cessation
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| Publication number | Publication date |
|---|---|
| NO20023450L (en) | 2002-09-13 |
| GB0216744D0 (en) | 2002-08-28 |
| NO335416B1 (en) | 2014-12-08 |
| NO20023450D0 (en) | 2002-07-18 |
| GB2377761A (en) | 2003-01-22 |
| CA2397916A1 (en) | 2001-07-26 |
| GB2377761B (en) | 2004-06-23 |
| WO2001053855A1 (en) | 2001-07-26 |
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