WO2004076814A1 - Prevision du debit de donnees par telemesure au cable - Google Patents

Prevision du debit de donnees par telemesure au cable Download PDF

Info

Publication number
WO2004076814A1
WO2004076814A1 PCT/IB2004/000506 IB2004000506W WO2004076814A1 WO 2004076814 A1 WO2004076814 A1 WO 2004076814A1 IB 2004000506 W IB2004000506 W IB 2004000506W WO 2004076814 A1 WO2004076814 A1 WO 2004076814A1
Authority
WO
WIPO (PCT)
Prior art keywords
wireline
operating characteristic
data rate
down hole
modeling
Prior art date
Application number
PCT/IB2004/000506
Other languages
English (en)
Inventor
Jr. Joseph M. Steiner
Jr. Llyod D. Clark
Ramon Hernandez-Marti
Soetjipno Chip Soetandio
Suzanne D. Richardson
Original Assignee
Schlumberger Canada Limited
Services Petroliers Schlumberger
Schlumberger Holdings Limited
Schlumberger Technology B.V.
Sofitech, N.V.
Schlumberger Technology 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
Priority claimed from US10/780,013 external-priority patent/US20050182870A1/en
Application filed by Schlumberger Canada Limited, Services Petroliers Schlumberger, Schlumberger Holdings Limited, Schlumberger Technology B.V., Sofitech, N.V., Schlumberger Technology Corporation filed Critical Schlumberger Canada Limited
Publication of WO2004076814A1 publication Critical patent/WO2004076814A1/fr

Links

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
    • E21B47/12—Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling

Definitions

  • the present invention generally relates to the field of data acquisition systems and more particularly to a wireline logging systems employing modular tool strings to acquire data where each module or tool in the tool string has its own data rate requirements.
  • Wireline logging refers generally to the surveying of oil or gas wells to determine their geological, petrophysical, or geophysical properties using electronic measuring instruments.
  • the electronic instruments are conveyed into a wellbore with a cable, referred to as a wireline cable. Measurements made by downhole instruments secured to the wireline cable are transmitted back to a data processing system located at the surface through electrical conductors in the wireline cable. Electrical, acoustical, nuclear and imaging tools are used to stimulate and measure the formations and fluids within the well bore. Telemetry instruments then transmit the digital data to the surface.
  • the wireline cable also provides the electrical power needed to operate the logging tools.
  • a fixed data rate is specified for the telemetry system at the start of a logging job based on the requirements for the tools and the engineer's judgement.
  • the specified data rate represents the maximum sustainable data rate at the existing environmental conditions.
  • the existing environmental conditions typically means the conditions encountered at the surface of some existing or proposed well site whether on land or offshore. Then, once a cable is inserted in the well bore, the customer wants to begin taking meaningful data immediately because of the rig time expense associated with wireline logging.
  • Well bores may extend deep into the earth's surface where the environmental conditions existing at the end of a wireline cable will frequently differ dramatically from the surface conditions.
  • the temperature at the end of a well bore of any appreciable depth is almost certainly greater than the surface temperature.
  • the data capacity of the cable diminishes. In some cases, the capacity may decrease to a maximum sustainable data rate that is insufficient to support the equipment in the tool string. It would be desirable to implement a system and method for anticipating the down hole data rate prior to inserting the cable into the ground and for modifying the tool string to ensure that the tool string data rate requirements do not exceed the attainable data rate.
  • a wireline logging method including estimating a data rate requirement associated with a tool string to be connected to a wireline cable and determining an operating characteristic of a wireline cable at the surface.
  • the operating characteristic is indicative of the wireline cable's data rate capacity.
  • a down hole value of the operating characteristic is modeled and a down hole data rate capacity is derived based thereon.
  • the tool string is modified to remove or add tools to the tools string to match the tool string's data rate requirements with the estimated data rate capacity of the tool string and cable.
  • determining the operating characteristic is achieved measuring the operating characteristic of the wireline cable as a function of frequency, determining the attenuation of the wireline cable, or determining the signal-to- noise ratio (SNR) of the wireline cable.
  • Modeling the down hole value of the operating characteristic may be performed based on a linear temperature gradient assumption or based on a two-part temperature gradient assumption in which the temperature is constant or decreasing for a first part of the wireline and the temperature gradient is linear for a second part of the wireline.
  • FIG 1 illustrates selected components of a wireline logging system suitable for use with the present invention
  • FIG 2 is a conceptual illustration of a borehole having at least one section that departs substantially from vertical;
  • FIG 3 is a conceptual illustration of an offshore borehole
  • FIG 4 illustrates selected components of a wireline logging tool string suitable for use in connection with the present invention
  • FIG 5 is a graphical illustration of the change in characteristics of a wireline logging cable at two different temperatures
  • FIG 6 is a flow diagram of a method of anticipating the down hole data rate characteristics of a wireline logging system according to an embodiment of the present invention.
  • FIG 7 is a block diagram of selected elements of a system for determining the suitability of inserting a tool string into a well bore according to an embodiment of the invention.
  • the present invention contemplates a wireline logging system and method in which the data rate characteristics of a wireline measurement tool are modeled to predict the characteristics of the tool at an anticipated temperature and depth.
  • the anticipated temperature represents the temperature likely to be encountered down hole.
  • action can be taken to reduce the data rate requirements of the tool string if the predicted characteristics suggest that the wireline will not be able to support the required data rate when the tool string is down hole.
  • the invention eliminates the need for a potentially time consuming and costly trial-and-error procedure to determine if a given tool string will function properly down hole.
  • Wireline logging system 100 includes a tool string 101 connected to a distal end 103 of a wireline cable 110 that is inserted into a well bore 112. Casing 114 line may line some or all of the well bore 112. A proximal end 105 of wireline cable 110 is connected to a winch 111 positioned on a truck 113 at the surface of the well bore.
  • the temperature at proximal end 105 of wireline cable 110 is indicated as T sur fac e and the temperature at distal end 103 of cable 110 (the down hole temperature) is indicated as T .
  • Depths of well bore 112 may exceed 30,000 feet (9144 m). At such depths, the temperature T at distal end 103 of cable 110 is typically substantially higher than the temperature (T SU rf ace ) at proximal end 105.
  • well bore 112 may be characterized as a substantially straight or linear well bore that is substantially vertical in orientation. This is a suitable accurate characterization for many actual well bores.
  • FIG 2 and FIG 3 at least two other well bore orientations are likely to be encountered. These two particular orientations are explicitly illustrated because the assumptions regarding temperature gradient along wireline cable 110 that apply to the orientation of wireline cable in FIG 1 are not accurately applicable to the orientations depicted in FIG 2 and FIG 3.
  • the wireline cable 110 includes a portion that is substantially horizontal or non-vertical with respect to the surface. This orientation is not uncommon because a horizontal well typically penetrates a greater length of the reservoir and can offer significant production improvement over a vertical well.
  • a linear temperature gradient is assumed for the substantially vertical wireline orientation of FIG 1.
  • the temperature T d at the distal end 103 of cable 110 is measured or estimated when the well bore is first drilled or logged.
  • the temperature profile is then assumed to be linear from T d to T surface .
  • the wireline orientation of FIG 2 requires a different profile assumption because a substantial portion of the wireline is at temperature T d .
  • a linear temperature profile assumption would be unacceptably optimistic as applied to a wireline oriented as in FIG 2.
  • the wireline orientation of FIG 3 represents an offshore implementation where a significant portion of the cable 110 extends through a body of water before entering the earth at the seabed.
  • a linear temperature profile would likely result in excessive constraints because the actual temperature profile would be less harsh than a linear profile. More than likely, the temperature would actually decrease from T surface at the surface to a minimum temperature at the bottom of the sea. From there, the temperature profile would likely assume the linear increase model of the vertically oriented FIG 1.
  • one embodiment of the invention incorporates algorithms enabled to perform wireline characteristic modeling based on one of these three basic orientations.
  • tool string 101 includes a telemetry cartridge 102 and a series of tools 104-109.
  • the various tools 104-109 of tool string 101 may enable the measurement of formation properties such as electrical resistivity, density, porosity, permeability, sonic velocities, gamma ray absorption, formation strength and various other characteristic properties.
  • Other tools may provide means for determining the flow characteristics in the well bore while still other tools include electrical and hydraulic power supplies and motors to control and actuate the sensors and probe assemblies.
  • control signals, measurement data, and electrical power are transferred to and from the logging tool via the wireline.
  • Telemetry cartridge 102 includes gathering and transmitting the well data generated by the various tools 104-109 to the surface via wireline cable 110. For at least two reasons, the data rate capacity of wireline cable 110 is subject to important minimum requirements. First, telemetry cartridge 102 is typically engaged in real-time data collection. In many instances, for example, data is being acquired as wireline cable 110 and tool string 101 move through a formation. If the data rate cannot support the real time acquisition of data, important data is lost. Moreover, higher data rates are required to reduce the amount of time that must be spent measuring or characterizing the formation. Wireline customers typically continue to incur rig time costs during the logging process, and these rig time costs may equal or exceed the cost of the wireline services.
  • tool string 101 includes a first tool 104 requiring a 200 kbps data rate, a second tool 106 requiring 300 kbps, a third tool 108 requiring 400 kbps, and so forth.
  • tool string 101 has a composite data rate requirement of 1000 kbps.
  • the wireline cable system cannot support its required data rate down hole, one (or more) of the modules will be unable to transmit all of its data to the surface.
  • the wireline cable would then have to be withdrawn from the well bore, the tool string would have to be modified such as by removing one or more modules to reduce the composite data rate requirement of the tool string, and the modified tool string would then be re-inserted into the well bore all at great cost and time to the customer.
  • the present invention addresses this problem by identifying tool strings likely to encounter data rate problems down hole before those tool strings are put down hole. Conversely, an overly pessimistic projection of the down hole data rate may result in additional cost when unnecessary additional runs are required. In either case, the invention optimizes the tool string and wireline cable that are actually placed into the ground to the maximum sustainable down hole data rate.
  • the most significant variable affecting a wire line system's data rate capacity is temperature.
  • temperature typically varies dramatically from the surface to the tool string.
  • temperature differential between the surface and the terminus of a well bore is the primary reason that a wireline system that has a particular data rate capacity at the surface has a lower data rate capacity when down hole.
  • SNR signal- to-noise ratio
  • AWGN additive white Gaussian noise
  • FIG 5 also indicates that SNR delta, (the difference between lower temperature trace 122 and the higher temperature trace 124) is also a function of frequency. Whereas the SNR delta is relative stable or constant at lower frequencies, the delta is strongly frequency dependent at higher frequencies. The non-linearity of the relationship between SNR and temperature adds to the complexity of predicting the down hole data rate capacity of a given wireline system.
  • Portions of the present invention may be implemented as a set or sequence of computer executable instructions (i.e., software) that, when executed, enable a user to estimate the data rate capacity of a wireline logging system such as system 100.
  • the software may be stored in a volatile, computer-readable storage element such as computer's main memory (typically DRAM) storage or in an external or internal cache memory (typically SRAM) of a microprocessor or set of microprocessors.
  • portions of the software may be stored in a non- volatile, storage element such as a hard disk, floppy diskette, CD ROM, DVD, magnetic tape, flash memory device, and the like.
  • FIG 6 a flow diagram illustrates an embodiment of a method 130 for determining the suitability of a tool string for use in a well bore. Portions of method 130 may be implemented as or executed by computer software.
  • a tool string is defined or specified (block 132) by an engineer.
  • Specifying the tool- string includes specifying not only the modules that are needed based on the measurements or data in which the customer is interested, but also the acquisition modes of those modules.
  • a required data rate is computed (block 134).
  • the tool string is specified as a computer model in some form of hardware description language.
  • a computer program may determine the required data rate using archived empirical data, some form of heuristic determination method, or a combination of the two.
  • One or more characteristics of the actual wireline system are then measured (block 136) to enable the determination of the wireline's data rate capacity.
  • the measured characteristic(s) include the cables' SNR.
  • the wireline measurement and characterization are typically performed at the well bore site before inserting the cable into the well bore.
  • a portable computer system (described in greater detail with respect to FIG 7) which may be mounted on or otherwise attached to truck 113 (FIG 1) facilitates the wireline characterization.
  • the computer system is attached to or connected to an offshore logging cab or a portable system.
  • the computer system includes software to calculate the data rate capacity based on the measured value of SNR.
  • the data rate capacity determined in block 136 is then compared (block 138) to the data rate requirement determined in block 134. If the required data rate exceeds the wireline system's data rate capacity, corrective action is taken by modifying (block 152) the tool string in a manner that reduces the system's data rate requirements. The required data rate and wireline data rate capacity could then be re-computed in block 134 and 136 until the system's data rate exceeds its required data rate.
  • the present temperature also referred to herein as the surface temperature
  • An expected down hole temperature is then provided (block 142).
  • the expected down hole temperature may represent an engineer's estimate of the maximum temperature likely to be encountered within a well bore or empirical data acquired when the well bore was drilled, or it may be the result from previous logging of the well or another well in the vicinity.
  • a modeled value of SNR represents the system's estimate of the wireline system's SNR when located within the well bore.
  • the software or system responsible for modeling the SNR based on the two temperature values assumes a substantially linear temperature gradient from surface to well bore end. Under this assumption, the down hole expected temperature represents the temperature at the true vertical depth of the tool string 101. In this case, the linear temperature gradient that is assumed is generally acceptable for determining a modeled value of SNR.
  • the SNR of a wireline exhibiting the orientation of FIG 2 may be modeled using a two-part temperature profile assumption in which the second part 115 of wireline 110 is subjected to a constant temperature T d while a linear temperature gradient is applied to the first part 113 of the wireline.
  • the linear temperature gradient assumption is generally overly pessimistic because the portion of the wireline within the sea will generally experience an inverted temperature gradient. In other words, the temperature will decrease from the surface until it reaches a minimum at the sea bed. As the wireline penetrates the earth below the sea bed, the temperature begins to rise again.
  • This type of orientation may be modeled using a theoretical temperature profile in which the surface temperate decreases linearly until a minimum is achieved at the sea bed at which point the temperature increases linearly until the down hole temperature is reached at the end of the wireline.
  • Other embodiments of the invention may incorporate additional and/or more sophisticated temperature profile models, including combinations of these models. These three basic temperature profiles are explicitly illustrated because they represents three of the most common wireline orientations likely to be encountered in the field.
  • the down hole wireline system is modeled to obtain an estimate of the wireline's operational characteristics based on factors including the system's characteristics as measured at the surface and the temperature profile assumed for the wireline.
  • the modeling of the wireline system may include the use of tables of empirical data representing measured wireline characteristic data for various temperatures and wireline configurations. Such tables, for example, may include measurements of wireline cable characteristics that are normalized with respect to length at temperatures of 80, 85, and 90° C and so forth. This information might represent historical data acquired within a field or lab site of a data logging services company such as Schlumberger.
  • Modeling the down hole SNR would then include a process in which the wireline is modeled as a series of discrete sections, where each section is assumed to experience a single temperature. The historical data could then be applied to each of the theoretically discrete section to arrive at a composite model of the wireline. Other embodiments may employ algorithmic methods, including interpolation or extrapolation, to derive a theoretical value of the characteristic or characteristics of interest.
  • a maximum sustainable down hole data rate is calculated (block 146) based on the modeled values of the wireline characteristics. If the characteristics include SNR, for example; the modeled SNR is used to determine a maximum down hole data rate. [0037] The down hole data rate is then compared (block 148) to the data rate required for the defined tool string. If the tool string requires a higher data rate than the wireline can achieve down hole as determined by the wireline modeling, the engineer is informed and requested to modify the tool string in some way to reduce the required data rate. The required data rate could be reduced by, for example, removing one or more modules from the tool string, by altering their acquisition modes, or a combination of both.
  • the process of modeling the SNR or other characteristic(s) and determining a maximum, projected down-hole data rate is repeated until the achievable data rate exceeds the data rate required by the tool string. It is also possible that the available data rate exceeds the tool string's requirements, allowing faster logging or the addition of one or more tools to the tool string.
  • the wireline system Upon successfully determining that the achievable down hole data rate exceeds the data rate requirements of the defined tool string, the wireline system is inserted into the well bore (block 150).
  • the achievable data rate can be fully exploited and costly trial and error procedures, in which a determination that a tool string's data rate requirements cannot be supported is not made until the tool is in the well, can be minimized or avoided entirely.
  • FIG 7 depicts selected elements of a system 160 for determining the suitability of placing a particular tool string down hole in a wireline logging operation.
  • system 160 includes an SNR analyzer 162, a modeling algorithm 164, empirical data 168, and a temperature sensor 166.
  • System 160 receives inputs in the form of a tool string definition 163 and an expected down hole temperature.
  • tool string definition 163 may include the data rate requirements of the tool string.
  • SNR analyzer 162 may calculate the data rate requirements of the defined tool string.
  • the wireline orientation is assumed to be substantially vertical and the temperature profile may be assumed to be linear as discussed previously. In some embodiments, alternative temperature profile and wireline orientation may replace the default assumptions.
  • the elements of system 160 operate on the inputs to produce information indicating whether the wireline system has sufficient down hole bandwidth to support the defined tool string.
  • the SNR analyzer 162 is configured to determine the SNR characteristics of the wireline cable, typically under relatively benign environmental conditions such as might be encountered at the surface of an offshore platform or a wellbore. SNR analyzer 162 determines the SNR characteristics for the wireline cable at various frequencies usually including all of the carrier frequencies employed by the telemetry cartridge.
  • the temperature sensor 166 provides the surface temperature to the system. Based on the delta between the sensed temperature and the expected down hole temperature provided by the engineer, the SNR characteristics of the wireline are determine projected based using, in appropriate cases, modeling algorithm 164, empirical SNR data 168, or a combination thereof.
  • the information generated by system 160 may be as simple as a GO / NO GO indicator to a field engineer indicating that the currently defined tool string is likely to encounter data transmission problems unless modified.
  • the information output from system 160 may include more detailed information about the tool string such as, for example, how much data rate is required for each individual tool string module, how much the required data rate exceeds the theoretical maximum data rate, and so forth.
  • the analyzer may include facilities to modify itself by deleting or otherwise altering one or more modules that are contributing to the problem and re-running the modeling to determine if the wireline has sufficient bandwidth for the re-defined toolstring.
  • the goal is to incorporate a relatively light weight or mobile computer system that is suitable for performing the system characterization processes described herein.
  • the present invention contemplates a wireline system in which the system's characteristics are modeled prior to going down hole in an effort to fully utilize the achievable data rate, allow faster logging and/or fewer runs, and reduce the amount of time spent reworking a tool string that cannot be supported. It is understood that the form of the invention shown and described in the detailed description and the drawings are to be taken merely as presently preferred examples. It is intended that the invention is limited only by the claim language.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Mining & Mineral Resources (AREA)
  • Remote Sensing (AREA)
  • Geophysics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Testing Or Calibration Of Command Recording Devices (AREA)

Abstract

L'invention porte sur un procédé de diagraphie au câble qui consiste à évaluer un besoin de débit de données associé à une colonne d'outil de diagraphie destinée à être reliée au câble et à déterminer une caractéristique de fonctionnement d'un câble métallique à la surface. La caractéristique de fonctionnement donne une indication de la capacité de débit de données du câble métallique. Avant d'introduire le câble métallique dans un trou de forage, on modélise une valeur de fond de trou de la caractéristique de fonctionnement à partir de laquelle on calcule la capacité de débit de données du fond de trou. Dès que l'on a établi que le besoin de débit de données estimé ne correspond pas à la capacité de débit de données du fond de trou, on modifie la colonne pour lui enlever ou lui ajouter des outils afin que les besoins en débit de données de la colonne concordent avec la capacité de débit de données de la colonne et du câble.
PCT/IB2004/000506 2003-02-28 2004-02-27 Prevision du debit de donnees par telemesure au cable WO2004076814A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US45083003P 2003-02-28 2003-02-28
US60/450,830 2003-02-28
US10/780,013 2004-02-17
US10/780,013 US20050182870A1 (en) 2004-02-17 2004-02-17 Wireline telemetry data rate prediction

Publications (1)

Publication Number Publication Date
WO2004076814A1 true WO2004076814A1 (fr) 2004-09-10

Family

ID=32930578

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2004/000506 WO2004076814A1 (fr) 2003-02-28 2004-02-27 Prevision du debit de donnees par telemesure au cable

Country Status (1)

Country Link
WO (1) WO2004076814A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010057437A1 (fr) * 2008-11-22 2010-05-27 西部钻探克拉玛依钻井工艺研究院 Procédé et système de transmission de données dans un puits
CN101737034A (zh) * 2008-11-22 2010-06-16 西部钻探克拉玛依钻井工艺研究院 一种井筒数据传输方法及系统
US9464325B2 (en) 2004-05-07 2016-10-11 The Henry M. Jackson Foundation For The Advancement Of Military Medicine, Inc. Methods of diagnosing or treating prostate cancer using the erg gene, alone or in combination with other over or under expressed genes in prostate cancer

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5365229A (en) * 1992-11-16 1994-11-15 Halliburton Logging Services, Inc. Adaptive telemetry system for hostile environment well logging
WO2001049001A1 (fr) * 1999-12-24 2001-07-05 Schlumberger Limited Procede et appareil destines a la transmission de donnees concernant un puits de forage sur des frequences porteuses multiples
WO2001093441A1 (fr) * 2000-05-26 2001-12-06 Xtremespectrum, Inc. Procede et systeme de communication a spectre etale a bande ultra large

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5365229A (en) * 1992-11-16 1994-11-15 Halliburton Logging Services, Inc. Adaptive telemetry system for hostile environment well logging
WO2001049001A1 (fr) * 1999-12-24 2001-07-05 Schlumberger Limited Procede et appareil destines a la transmission de donnees concernant un puits de forage sur des frequences porteuses multiples
WO2001093441A1 (fr) * 2000-05-26 2001-12-06 Xtremespectrum, Inc. Procede et systeme de communication a spectre etale a bande ultra large

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9464325B2 (en) 2004-05-07 2016-10-11 The Henry M. Jackson Foundation For The Advancement Of Military Medicine, Inc. Methods of diagnosing or treating prostate cancer using the erg gene, alone or in combination with other over or under expressed genes in prostate cancer
WO2010057437A1 (fr) * 2008-11-22 2010-05-27 西部钻探克拉玛依钻井工艺研究院 Procédé et système de transmission de données dans un puits
CN101737034A (zh) * 2008-11-22 2010-06-16 西部钻探克拉玛依钻井工艺研究院 一种井筒数据传输方法及系统
CN101737034B (zh) * 2008-11-22 2013-07-10 西部钻探克拉玛依钻井工艺研究院 一种井筒数据传输方法及系统

Similar Documents

Publication Publication Date Title
US9422803B2 (en) Passive magnetic ranging for SAGD and relief wells via a linearized trailing window kalman filter
AU2014396852B2 (en) Employing a target risk attribute predictor while drilling
US10145985B2 (en) Static earth model calibration methods and systems using permeability testing
MX2009001262A (es) Metodo y sistema para produccion de presion de poro.
AU2008364323A1 (en) Data transmission systems and methods for azimuthally sensitive tools with multiple depths of investigation
CA2833719A1 (fr) Procedes et systemes pour estimer une resistivite et une porosite de formation
US9341739B2 (en) Apparatus and method for estimating geologic boundaries
WO2006120366A1 (fr) Methode d'analyse de l'efficacite en pression dans des formations souterraines
US8902701B2 (en) Methods, apparatus and articles of manufacture to determine anisotropy indicators for subterranean formations
US20170321545A1 (en) Functional earth model parameterization for resistivity inversion
US6708781B2 (en) System and method for quantitatively determining variations of a formation characteristic after an event
WO2018027089A1 (fr) Contrôle automatique de la qualité d'une diagraphie pétrophysique
US20050182870A1 (en) Wireline telemetry data rate prediction
US20170335664A1 (en) Fluid Loss Determination Apparatus, Methods, and Systems
US11248463B2 (en) Evaluation of sensors based on contextual information
RU2312375C2 (ru) Способ коррелирования каротажных диаграмм
US10370955B2 (en) Method of calculating pore pressure while drilling
WO2004076814A1 (fr) Prevision du debit de donnees par telemesure au cable
CA2913163C (fr) Estimation de calendriers de forage optimaux
US20200003675A1 (en) Incremental time lapse detection of corrosion in well casings
US20130075158A1 (en) Methods and Apparatus to Determine Slowness of Drilling Fluid in an Annulus
US11892586B2 (en) Interpretation of dielectric tool measurements using general mixing laws
US20210238997A1 (en) Determination Of Representative Elemental Length Based On SubSurface Formation Data
AU2015200156B2 (en) Methods and systems for estimating formation resistivity and porosity
WO2023250080A1 (fr) Détermination de distance annulaires et de densité de boue par densité gamma et réponses d'outil acoustique

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): BW GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
DPEN Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed from 20040101)
122 Ep: pct application non-entry in european phase
DPE2 Request for preliminary examination filed before expiration of 19th month from priority date (pct application filed from 20040101)