WO1999047939A1 - Systeme et methode d'identification d'hydrocarbures par renforcement de la diffusion - Google Patents

Systeme et methode d'identification d'hydrocarbures par renforcement de la diffusion Download PDF

Info

Publication number
WO1999047939A1
WO1999047939A1 PCT/US1999/006027 US9906027W WO9947939A1 WO 1999047939 A1 WO1999047939 A1 WO 1999047939A1 US 9906027 W US9906027 W US 9906027W WO 9947939 A1 WO9947939 A1 WO 9947939A1
Authority
WO
WIPO (PCT)
Prior art keywords
brine
nmr
formation
upper limit
relaxation
Prior art date
Application number
PCT/US1999/006027
Other languages
English (en)
Inventor
Ridvan Akkurt
Original Assignee
Numar Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Numar Corporation filed Critical Numar Corporation
Priority to CA002324015A priority Critical patent/CA2324015C/fr
Priority to BR9908942-4A priority patent/BR9908942A/pt
Publication of WO1999047939A1 publication Critical patent/WO1999047939A1/fr

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N24/00—Investigating or analyzing materials by the use of nuclear magnetic resonance, electron paramagnetic resonance or other spin effects
    • G01N24/08—Investigating or analyzing materials by the use of nuclear magnetic resonance, electron paramagnetic resonance or other spin effects by using nuclear magnetic resonance
    • G01N24/081—Making measurements of geologic samples, e.g. measurements of moisture, pH, porosity, permeability, tortuosity or viscosity

Definitions

  • the present invention relates to nuclear magnetic resonance (NMR) borehole measurements and more particularly to separation of signals from different fluids using user- adjusted measurement parameters.
  • NMR nuclear magnetic resonance
  • NMR nuclear magnetic resonance
  • Various methods exist for performing measurements of petrophysical parameters in a geologic formation Nuclear magnetic resonance (NMR) logging, which is the focus of this invention, is among the best methods that have been developed for a rapid determination of such parameters, which include formation porosity, composition of the formation fluid, the quantity of movable fluid, permeability among others. At least in part this is due to the fact that NMR measurements are environmentally safe and are unaffected by variations in the matrix mineralogy.
  • NMR logging is based on the observation that when an assembly of magnetic moments, such as those of hydrogen nuclei, are exposed to a static magnetic field they tend to align along the direction of the magnetic field, resulting in bulk magnetization.
  • the rate at which equilibrium is established in such bulk magnetization upon provision of a static magnetic field is characterized by the parameter T lf known as the spin-lattice relaxation time.
  • T 2 spin-spin relaxation time
  • T 2 also known as transverse relaxation time
  • Both relaxation times provide information about the formation porosity, the composition and quantity of the formation fluid, and others.
  • diffusion refers to the motion of atoms in a gaseous or liquid state due to their thermal energy. Self-diffusion is inversely related to the viscosity of the fluid, which is a parameter of considerable importance in borehole surveys. In a uniform magnetic field, diffusion has little effect on the decay rate of the measured NMR echoes. In a gradient magnetic field, however, diffusion causes atoms to move from their original positions to new ones, which moves also cause these atoms to acquire different phase shifts compared to atoms that did not move. This contributes to a faster rate of relaxation.
  • NMR measurements of these and other parameters of the geologic formation can be done using, for example, the centralized MRIL ® tool made by NUMAR, a Halliburton company, and the sidewall CMR tool made by Schlumberger .
  • the MRIL ® tool is described, for example, in U.S. Pat. 4,710,713 to Taicher et al . and in various other publications including:
  • T 1 contrast 5 is due to the fact that light hydrocarbons have long T x times, roughly 1 to 3 seconds , whereas T x values longer than 1 second are unusual for water-wet rocks.
  • typical T x ' s are much shorter 0 than 1 sec, due to the typical pore sizes encountered in sedimentary rocks, providing an even better contrast.
  • the short wait time T ws is chosen large enough to allow full recovery of the brine signal, i.e., T HS > 3 max (T 1/Water )
  • T WL is selected such that T WL > T- L of the light hydrocarbon, usually assumed to be gas.
  • the differential spectrum is formed by 0 subtracting the T 2 distribution measured at T ws from the one measured at T WL . Because T x recovery of the water signal is essentially complete at both wait times, this signal is eliminated following the substraction, and the differential spectrum is therefore due only to a hydrocarbon signal. 5 While the DSM method has been applied successfully for the detection of gas and the separation of light hydrocarbons, there are several problems associated with it that have not been addressed adequately in the past .
  • DSM requires a logging pass associated with 0 relatively long wait times (T H approximately 10 sec) .
  • DSM-based logging is by necessity relatively slow.
  • the required T ⁇ contrast may disappear in wells drilled with water-based mud, even if the reservoir contains 5 light hydrocarbons. This can happen because water from the mud invades the big pores first, pushing out the oil and thus adding longer T 2 ' s to the measurement spectrum.
  • DSM or standard NMR time domain analysis (TDA) methods have limited use either because there is no separation in the 0 ⁇ 2 domain, or because the two phases are too close and can not be picked robustly.
  • the present invention is based on forcing diffusion as 0 the dominant relaxation mechanism for the brine phase in NMR measurements of a geologic formation.
  • certain measurement parameters are changed as to enhance the role of diffusion relaxation in the brine phase.
  • the enhanced diffusion relaxation in turn establishes an upper limit for the T, 5 distribution of the brine phase, which limit can be calculated. Once this upper limit is found, any phase having a longer T 2 can be identified unambiguously as not being brine, i . e . , as a hydrocarbon.
  • the measurement parameters which are varied in ° accordance with the present invention to establish an upper limit in the T 2 distribution of the brine phase are the interecho time T E and the magnetic field gradient G of the tool.
  • the brine phase can be separated from hydrocarbons using time domain analysis techniques based on performing enhanced diffusion measurements.
  • a method for nuclear magnetic resonance measurements of the petrophysical properties of a geologic formation comprising the steps of: providing a set of NMR measurement parameters that establish an upper limit in the apparent transverse relaxation T 2A of a brine phase of the formation; obtaining a pulsed NMR log using the provided set of measurement parameters; determining from the NMR log a distribution of transverse relaxation times; and estimating from the distribution of transverse relaxation times the contribution of the hydrocarbon phase as distinct from brine .
  • FIG. 1 is a partially pictorial, partially block diagram illustration of an apparatus for obtaining nuclear magnetic resonance (NMR) measurements in accordance with a preferred embodiment of the present invention
  • FIG. 2 is a block diagram of the system in accordance with a preferred embodiment which shows individual block components for controlling data collection, processing the collected data and displaying the measurement results;
  • FIG. 3 illustrates the use of diffusion-dominated relaxation in accordance with the present invention to establish an upper limit in the apparent relaxation time T 2A in a NMR measurement ;
  • FIGs . 4 (a-c) are T 2 plots that illustrate the separation of the brine phase using enhanced diffusion.
  • FIG. 5 is laboratory data from a Berea sandstone at 100% water saturation, illustrating the shift in the T 2 spectra as the interecho time T E increases.
  • FIGs. 6 and 7 provide examples of using the enhanced diffusion method in accordance with the present invention to separate different fluid phases.
  • Fig. 1 illustrates an apparatus constructed and operative in accordance with a 5 preferred embodiment of the present invention for obtaining nuclear magnetic resonance (NMR) measurements.
  • the apparatus includes a first portion 106, which is arranged to be lowered into a borehole 107 in order to examine the nature of materials in the vicinity of the borehole.
  • the first portion 106 comprises a magnet or a plurality of magnets 108, which preferably generate a substantially uniform static magnetic field in a volume of investigation
  • the first portion 106 also comprises an RF antenna coil 116 which produces an RF magnetic field at the volume of investigation 5 109.
  • a magnetic field gradient coil or plurality of coils,
  • the 20 method of the present invention has a field direction preferably collinear with the substantially uniform field and has a substantially uniform magnetic field gradient.
  • the magnetic field gradient may or may not be pulsed, i.e., switched on and off by switching the dc current flowing through the coil or coils 110.
  • the magnet or magnets 108, antenna 116 and the gradient coil 110 constituting portion 106 are also referred to as a probe.
  • the antenna together with a transmitter/receiver (T/R) matching circuit 120, which typically includes a resonance capacitor, a T/R switch and both to-transmitter and 30 to-receiver matching circuitry, are coupled to an RF power amplifier 124 and a receiver preamplifier 126.
  • a power supply 129 provides the dc current required for the magnetic field gradient generating coils 110. All the elements described above are normally contained in a housing 128 which is passed through the borehole. Alternatively, some of the above elements may be located above ground.
  • control circuitry for the logging apparatus including a computer 50, which is connected to a pulse programmer 60 that controls the operation of a variable frequency RF source 36 as well as an RF driver 38.
  • RF driver 38 also receives input from the variable frequency source 36 through a phase shifter 44, and outputs to RF power amplifier 124.
  • RF receiver amplifier 126 The output of RF receiver amplifier 126 is supplied to an RF receiver 40 which receives an input from a phase shifter 44.
  • Phase shifter 44 receives an input from variable frequency RF source 36.
  • Receiver 40 outputs via an A/D converter with a buffer 46 to computer 50 for providing desired well logging output data for further use and analysis.
  • Pulse programmer 146 controls the gradient coil power supply 129 enabling and disabling the flow of current, and hence the generation of static or pulsed field gradients, according to the commands of the computer 50.
  • Fig. 1 depicts a preferred embodiment of the system used in accordance with the present invention. Other systems may also be used in alternative embodiments.
  • Fig. 2 is a block diagram of a generic system used in accordance with the present invention, and shows individual block components for controlling data collection, processing the collected data and displaying the measurement results.
  • the tool's electronic section 30 comprises a probe controller and pulse echo detection electronics. The output signal from the detection electronics is processed by data processor 52 to analyze the relaxation characteristics of the material being
  • the output of the data processor 52 is provided to the parameter estimator 54.
  • Measurement cycle controller 55 provides an appropriate control signal to the probe.
  • the processed data from the log measurement is stored c in data storage 56.
  • Data processor 52 is connected to display 58, which is capable of providing a graphical display of one or more measurement parameters, possibly superimposed on display data from data storage 56.
  • Fig. 2 The components of the system of the present invention shown in Fig. 2 can be implemented in hardware or software, 0 or any combination thereof suitable for practical purposes.
  • Figs. 1 and 2 Details of the structure, the operation and the use of logging tools, as illustrated in Figs. 1 and 2 are also discussed, for example, in the description of the MRIL ® tool to Numar Corporation, and in U.S. patents 4,717,876; 5 4,717,877; 4,717,878; 5,212,447; 5,280,243; 5,309,098;
  • the present invention is based on forcing diffusion as the dominant relaxation mechanism for the brine phase in NMR measurements of a geologic formation.
  • the main relaxation mechanisms that affect the T 2 relaxation 5 times in rocks are molecular motion in fluids, surface relaxivity at the pore walls, and molecular diffusion in magnetic field gradients.
  • the first relaxation mechanism is due to local motions, such as molecular 0 tumbling and typically is observed in relatively large pores.
  • the second relaxation mechanism is surface relaxation at the pore walls. This relaxation mechanism is very
  • the third relaxation mechanism is the diffusion of molecules in magnetic field gradients, such as those generated by Numar Corporation's MRIL ® tool. Ordinarily, diffusion is a predominant relaxation mechanism only for gas.
  • T 2D reflects
  • T 2D is a function of the interecho time T E used in the measurement, of the diffusion coefficient for water D, and the magnetic field gradient G generated by the measurement device. This function is given by the well known Carr-Purcell equation for the diffusion- induced relaxation l/T 2D ⁇
  • the present invention is more specifically based on the observation that the interecho spacing T E and the magnetic field gradient G are user-controlled parameters, so that by changing them the user can affect the dominant relaxation mode, forcing it to be of diffusion type. For this reason, the approach is referred to in this application as enhanced diffusion (ED) .
  • the T E parameter can be modified by the pulse programmer 60.
  • the gradient G is a function of the operating frequency, which is also user-adjustable. Therefore, by adjusting operator-controlled parameters of the NMR
  • this upper limit can be computed using Eqn. (2) above .
  • an upper limit for the longest T 2 for the brine phase can be determined as a function of T E , G, D w , such that any phase with T 2 ' s longer than this upper limit is unambiguously identified as not being brine, i.e., as hydrocarbon.
  • the interecho spacing T E must be large, and the magnetic field gradient G must also be large.
  • Fig. 4 illustrates the separation of the brine and oil spectra in T 2 space in accordance with the present invention.
  • Fig. 4a shows a typical brine and oil T 2 spectral distribution.
  • Fig. 4b shows the T 2 spectrum when surface relaxation is dominant for brine.
  • the T 2 spectrum is bi-modal, indicating the presence of two fluid phases, there is a clear area of overlap, so that the two fluid phases cannot be fully separated.
  • Fig. 4c shows a typical brine and oil T 2 spectral distribution.
  • Fig. 4b shows the T 2 spectrum when surface relaxation is dominant for brine.
  • the T 2 spectrum is bi-modal, indicating the presence of two fluid phases, there is a clear area of overlap, so that the two fluid phases cannot be fully separated.
  • the T 2 limit is determined by the lowest G value for the gradient, because this value determines the longest T 2 due to diffusion.
  • Eqn. (3) which value is selected from practical considerations including an understanding of the distribution 0 of the magnetic field gradient of the tool.
  • the present invention need not be a fixed number. Instead, this upper limit may take a range of values, and in a specific application can be determined from actual measurements parameters and various practical considerations. c For example, in a specific embodiment of the method of the present invention, probabilities associated with a range of transverse relaxation values are assigned, and the selection of an actual upper limit value is refined on the basis of prior measurements and hypothesis testing.
  • a dual wait -time pulse sequence is run to collect the required NMR measurement data.
  • Dual wait -time sequencing capability not requiring separate logging passes is provided 5 by the MRIL ® tool as described, for example, in co-pending application Ser. No. 08/822,567 assigned to the assignee of the present application, which is incorporated for all purposes.
  • a single wait-time pulse sequence can also be 0 used, since there will be T 2 separation between the two phases regardless of any T ⁇ contrast .
  • the interecho times T E used in the enhanced-diffusion measurements of the present invention are longer compared with those used in standard DSM measurements (which typically are less than about 1.2 msec) .
  • the T E parameter c of the sequence is selected dependent on the temperature of the formation, the magnetic field gradient G generated by the tool (which is a function of the tool diameter, the temperature and the operating frequency for the tool) , as well as the expected viscosity of the oil. Generally, the higher the expected oil viscosity, the longer the T E . 0
  • the wait times T w used in accordance with the present invention are typically chosen between about 300 and 3000 milliseconds, but can be made substantially shorter because T- L separation is not used, and therefore is not an issue in ED measurements. It should be noted that because the wait 5 times T w for enhanced diffusion (ED) measurements in accordance with the present invention are much shorter compared to conventional DSM or time-domain analysis (TDA) applications (roughly about 3.5 seconds for ED compared to 11 seconds for DSM) , logging speeds are much faster. This 0 presents a significant advantage of the system and method of the present invention. It can be appreciated that because of the shorter wait times used by ED measurements, the method of the present invention can also result in increased vertical resolution at a given logging speed, because more data can be collected per unit length. 5
  • the number of echoes acquired in ED measurements in accordance with the present invention is significantly smaller compared with that for conventional applications. In a specific embodiment, approximately about
  • the ED system and method of the present invention can be used instead of or in addition to standard NMR measurements in a number of practical situations.
  • the method of the present invention is particularly well suited for applications where the T x contrast disappears or is reduced for some reason, and the standard DSM approach would fail.
  • ROS residual oil saturation
  • Another application of the ED measurements in accordance with the present invention is dealing with vugs in carbonates. Because of their large pore sizes, water filled vugs have long T 2 ' s and can easily be misinterpreted as oil . Given that T 2 separation is achieved, an oil-filled vug will not be misinterpreted in ED, since it will have T 2 ' s longer than the upper limit. On the other hand, the T 2 value from a water- filled vug will be less than the determined upperbound value using the present invention, regardless of whether a vug is connected or disconnected. The present invention eliminates the possibility of including any water-filled VU 99Y porosity in the hydrocarbon volume estimation. Further, ED measurements in accordance with the present invention are applicable in cases where the oil is more viscous.
  • T 2 ' s for oil decrease as the viscosity of the oil increases.
  • the separation between brine and water using, for example, DSM techniques would become more difficult for more viscous oils.
  • up to a limit separation can still be maintained for high-viscosity oils by adjusting the user-controlled parameters so that Eqn. (1) holds.
  • FIG. 5 is laboratory data from a Berea sandstone at 100% water saturation, illustrating the shift in the T 2 spectra as the interecho time T E increases.
  • the magnetic field gradient is about 17 G/cm and temperature is about 60 degrees Celsius.
  • the longest T 2 is shorter than the theoretically predicted T 2D for water.
  • This data set illustrates the concept that max(T 2A ) is predictable for water.
  • FIGs . 6 and 7 provide examples of the use of the enhanced diffusion method used in accordance with the present invention to separate different fluid phases. For the logs in both figures, the following apply
  • Track 2 shading indicates oil production from the test
  • Track 1 indicates water with oil
  • the line in the ED track 5 is the predicted T 2D for the T E , temperature and tool conditions. Any signal to the right
  • the zone of interest is the sand whose top was perforated.
  • Data from ED difference spectrum has considerable energy to the right of the depth marked A in the depth track, indicating light oil.
  • the well should have been perforated well above the oil/water contact, which is obvious from the ED data.

Landscapes

  • Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Health & Medical Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Geology (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Geophysics And Detection Of Objects (AREA)

Abstract

L'invention porte sur une méthode et le système associé de séparation de phases liquides lors de mesures par RMN dans des puits (107). L'invention s'applique particulièrement à la séparation de la saumure d'avec les hydrocarbures en recourant à une diffusion renforcée pour fixer une limite supérieure à la distribution spectrale T2 de la saumure. Les paramètres modifiables en vue du renforcement de la relaxation par diffusion lors de la mesure comprennent l'espacement entre échos TE, et le gradient de champ magnétique G (110) de l'outil de mesure.
PCT/US1999/006027 1998-03-20 1999-03-19 Systeme et methode d'identification d'hydrocarbures par renforcement de la diffusion WO1999047939A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CA002324015A CA2324015C (fr) 1998-03-20 1999-03-19 Systeme et methode d'identification d'hydrocarbures par renforcement de la diffusion
BR9908942-4A BR9908942A (pt) 1998-03-20 1999-03-19 Processos para medições por ressonância magnética nuclear de propriedades petrofìsicas de uma formação geológica e para separação de hidrocarbonetos de salmoura em medições por ressonância magnética nuclear de uma formação geológica, e, aparelho para medir propriedades petrofìsicas de uma formação geológica

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US7882198P 1998-03-20 1998-03-20
US60/078,821 1998-03-20

Publications (1)

Publication Number Publication Date
WO1999047939A1 true WO1999047939A1 (fr) 1999-09-23

Family

ID=22146424

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1999/006027 WO1999047939A1 (fr) 1998-03-20 1999-03-19 Systeme et methode d'identification d'hydrocarbures par renforcement de la diffusion

Country Status (4)

Country Link
AR (1) AR014755A1 (fr)
BR (1) BR9908942A (fr)
CA (1) CA2324015C (fr)
WO (1) WO1999047939A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6316940B1 (en) * 1999-03-17 2001-11-13 Numar Corporation System and method for identification of hydrocarbons using enhanced diffusion
CN100349013C (zh) * 2005-05-27 2007-11-14 中国石油天然气股份有限公司 核磁共振测井t2谱t2截止值的确定方法
CN103675722A (zh) * 2013-11-27 2014-03-26 中国石油大学(华东) 岩石t2-g实验采集参数自动匹配方法
CN108062565A (zh) * 2017-12-12 2018-05-22 重庆科技学院 基于化工te过程的双主元-动态核主元分析故障诊断方法

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4408161A (en) * 1981-04-15 1983-10-04 Chevron Research Company Computer-controlled, portable spin echo NMR instrument and method of use
US5498960A (en) * 1994-10-20 1996-03-12 Shell Oil Company NMR logging of natural gas in reservoirs

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4408161A (en) * 1981-04-15 1983-10-04 Chevron Research Company Computer-controlled, portable spin echo NMR instrument and method of use
US5498960A (en) * 1994-10-20 1996-03-12 Shell Oil Company NMR logging of natural gas in reservoirs

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6316940B1 (en) * 1999-03-17 2001-11-13 Numar Corporation System and method for identification of hydrocarbons using enhanced diffusion
CN100349013C (zh) * 2005-05-27 2007-11-14 中国石油天然气股份有限公司 核磁共振测井t2谱t2截止值的确定方法
CN103675722A (zh) * 2013-11-27 2014-03-26 中国石油大学(华东) 岩石t2-g实验采集参数自动匹配方法
CN108062565A (zh) * 2017-12-12 2018-05-22 重庆科技学院 基于化工te过程的双主元-动态核主元分析故障诊断方法
CN108062565B (zh) * 2017-12-12 2021-12-10 重庆科技学院 基于化工te过程的双主元-动态核主元分析故障诊断方法

Also Published As

Publication number Publication date
AR014755A1 (es) 2001-03-28
BR9908942A (pt) 2000-11-28
CA2324015A1 (fr) 1999-09-23
CA2324015C (fr) 2004-04-06

Similar Documents

Publication Publication Date Title
US6366087B1 (en) NMR logging apparatus and methods for fluid typing
US7176682B2 (en) Method and apparatus for detecting hydrocarbons with NMR logs in wells drilled with oil-based muds
US7501818B2 (en) System and methods for T1-based logging
EP0835463B1 (fr) Systeme et procede de rmn permettant l'evaluation d'une formation geologique sur la base de mesures de diffusion et de relaxation
CA2449789C (fr) Systeme et procede pour determiner des saturations en huile, eau et gaz, destines a des instruments de diagraphie a faible gradient de champ
US5936405A (en) System and method for lithology-independent gas detection using multifrequency gradient NMR logging
US5680043A (en) Nuclear magnetic resonance technique for determining gas effect with borehole logging tools
US6703832B2 (en) Method for detecting hydrocarbons by comparing NMR response at different depths of investigation
WO2001013142A9 (fr) Appareil et procedes d'irm permettant de mesurer des volumes de gaz d'hydrocarbures et d'huiles d'hydrocarbures
EP0852737B1 (fr) Detection de gaz independante de la lithologie par resonance magnetique nucleaire a base de gradient
Hürlimann et al. NMR well logging
US6316940B1 (en) System and method for identification of hydrocarbons using enhanced diffusion
CA2324015C (fr) Systeme et methode d'identification d'hydrocarbures par renforcement de la diffusion
GB2434875A (en) T1 based logging

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): BR CA CN NO

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
ENP Entry into the national phase

Ref document number: 2324015

Country of ref document: CA

Ref country code: CA

Ref document number: 2324015

Kind code of ref document: A

Format of ref document f/p: F

122 Ep: pct application non-entry in european phase