斯伦贝谢LWDintroductio.ppt

Presented by:Wang Ruo,Aug 2003,LWD Introduction,MWD/LWD techniques,Why do we use LWD?MWD/LWD basicsLWD MeasurementsResistivity:Propagation and Laterolog Density/Neutron&Sonic toolsLWD measurements for horizontal well-boresApplication of Image and Azimuthal measurementsWell Placement(GeoSteering)Methods,Well Planning,Directional Drilling&New Drilling Technologies,Well Planning in a geological environmentSurvey Uncertainty DD New Technologies,What is MWD/LWD?,Real-time Surveys for Directional ControlInclination,azimuth,toolfaceReal-time Drilling Mechanics data for Drilling Optimisation and Safety including:Weight-on-Bit,Downhole Torque-at-BitReal-time Formation Measurement including:Resistivity,Density,Porosity,A system which provides real-time data from measurements made near the drill bit during the drilling process,1927:First Wireline log run in France by Schlumberger brothers1929:Jokosky files a patent on the concept of mud pulse telemetry1950:Arp invents positive mud pulse system1960s:Teledrift tool developed-mechanical inclinometer with positive mud pulse,still used todayGodbey of Mobil develops the mud siren system1971:First successful test of mud siren by Mobil R&D1978:Teleco commercial with Directional MWD1980:Schlumberger/Anadrill introduces multi-sensor MWD,A Brief History of MWD-the early days,A Brief History of MWD-the birth of LWD,1981:Gentrix(Eastman)introduces PPT directional MWDExlog introduces NPT multi-sensor MWD1983:Teleco introduces RGD1984:NL Baroid introduces Recorded Lithology Log(RLL)Electromagnetic resistivity and Gamma Ray logTeeco,Anadrill,Exlog,and Gearhart offer Resistivity and GR services1986:NL Baroid introduces Triple Combo LWD1989:Sperry introduces Triple Combo LWDSchlumberger/Anadrill introduces Triple Combo LWD,A Brief History of MWD-imaging at the bit,1990:Teleco commercial with Triple Combo1992:Schlumberger/Anadrill introduces the IDEAL(Integrated Drilling Evaluation and Logging)system including:RAB(Resistivity at Bit),GeoSteering ToolBorehole Imaging,Acoustic Caliper1993:Baroid(NL Sperry)introduces Near Bit Inclinometer1995:Commercial slim-hole resistivity tools developed1996:Schlumberger/Anadrill introduces Triple Combo for slim holes1999:Schlumberger introduces Real-Time formation imaging2001:Schlumberger introduces Seismic Measurement While Drilling,VISION LWD Services,Alphabet soup,ARCx-Array Resistivity Compensated,2 MHz and 400 KHz resistivityARC4=4”OD(=Impulse)ARC6=6”ODARC8=8”ODARC9=9”ODRABx-Resistivity At the BitUpgraded to GeoVision Resistivity(GVR)GST Geosteering tool(6”OD)ADNx Azimuthal Density NeutronADN4=4”ODADN6=6”ODADN8=8”OD.ISONIConly called ISONIC,More Alphabet soup,MWDImpulse 4”ODPowerPulsePP6 6”ODPP8 8”ODPP9 9”ODTool Combinations:Visionxxx Triple combo string,ARC-MWD-ADNVision475=4”OD(Impulse-ADN)Vision675=6”OD(ARC6-PP6-ADN6Vision825=8 1/4”OD(ARC8-PP8-ADN8),Formation Evaluation Optimization,Well Deviation,Seismic or Formation Evaluation Complexity,low,low,high,high,Why use LWD?,Scenario AHigh rig cost High drilling risk High well placement risk LWD preferred,Scenario BLow rig costLow drilling riskLow well placement riskWL preferred,or,or,and,and,Whats Special About LWD?,Measurements are made soon after drillingBefore formation alterationBefore hole washes outBefore fluid invasionTime becomes a factor in interpretation,LWD sensors are usually rotatingResistivity&Density Images Azimuthal formation evaluation,Whats Special About LWD?,LWD tools are often run in high angle boreholesHorizontal evaluation-special interpretation issuesMay require 3D interpretationMeasurements often crossing bedsAnisotropy issues,*,LWD Operating Modes,Telemetry:clean signals through dirty mud,MWD Data Transmission,Design considerations:Reliability Maximized data update rate Minimal impact on drilling operations,All MWD tools use mud-pulse telemetry to transmit data to surface:Analog to Digital signals(1 and 0)Digital signals to pressure pulsesPressure pulses transmitted through the mud column,MWD Telemetry Systems,A hydraulic poppet valve momentarily restricts the flow of mud to generate an increase in pressure,Controlled valve vents mud briefly to the annulus,decreasing the pressure,Rotary valve(siren)restricts the mud flow to create a modulating positive pressure wave,MWD Continuous Wave Telemetry,Mud Pulser and Turbine Assembly,As Mud flows through the MWD tool the pressure required to force the mud to flow changes as the Modulator opens and closes,Test Bench,Combined environmentVertical shocksHigh temperature life testingMultiple tools qualifiedLCM tests at 50 lb/bbl medium nut plugSeveral thousand pumping hours in flow loops,Engineering Qualification,Example Telemetry Data Frame,The Old Way,LWD Real Time,In Time,The highest data rates in the industry mean you get the data you need,when you need it.,Why put up with a minimal suite of poor quality logs in real time?,Why control the drilling to get good log data?,LWD Real Time,In Time,LWD isnt just giving you wiggly lines its your eyes to monitor the drilling process.,Why wait 2 minutes and 10 feet for your next update of pressure,surveys or toolface?,Why risk not having the data you need,at the moment you need it?,When you can have it every 20 seconds?,Two-way communication can avoid a trip and save$Robust telemetry copes with harsh conditionsHigh LCM capacity modulator,MWD Systems,PowerPulse,Impulse,SlimPulse,ROP vs Measurements,At 12 bps Schlumberger provides a 8 sec RT update rate,*2 data points per foot for Real Time Triple Combo(D&I,GR,2 Resistivities,Density,Neutron),At 6 bps Schlumberger provides a 16 sec RT update rate,At 3 bps Schlumberger provides a 32 sec RT update rate,Max ROP to have 2 data per foot versus sampling rate,Fundamentals of LWD Depth,Which Depth is That?,What is the depth of this formation top?,MWD Depth Measurement,Time-Depth Data,Time-Depth File Example,Data vs Time-Data vs Depth,+Data vs Time,=Data vs Depth,Depth vs Time,Time Based Data,Time to Depth Conversion,0.00 Gamma Ray 150.00,Depth Based Data,0.00 Gamma Ray 150.00,Depth Corrections,MWD/LWD Depth is tied to Drillers Depth at the end of each stand.Depth corrections are manually entered and stored in the time-depth file future use.Data is stretched or compressed across an interval,Where is the well?,Downhole Surveys,What is a downhole survey?A point along the path of a well is defined by a directional survey.The survey defines the three dimensional position of that point in space.The survey consists of:A Measured Depth along the well pathAn Inclination at that measured depthAn Azimuth at that measured depth.,Why are wellbore surveys necessary?,Indicate the actual shape of the wellbore.Allow us to monitor that actual wellbore shape Vs.our desired wellbore shape.Why do we want to monitor this.To reach our target.Stay within lease boundaries.Satisfy local regulatory agencies.Construct accurate subsurface maps.,Inclination and Azimuth,Relative Survey Tool Accuracy,Toolface Display,Data can be displayed on multiple locations simultaneouslyPresentation can be edited to suit the particular application,Remote monitoring is also possible-this is particularly useful for real-time well control by shore-based teams.,Geosteering Surveying,Traditional surveying may give a systematic error,Continuous D&I in Geosteering,Has the potential to provide higher vertical resolutionCould be combined with AIM for further improvement,Cont D&I would provide surveys at any desired interval,Logging While Drilling tools,SLB Formation Evaluation tools,Resistivity Tools,Fundamentals of Resistivity measurement,Pulse fires,Wave travelsthrough formation,Signal changesPhase and Strengthas it passes through formation,2 MHz Propagation Tools,Signal change is proportional to the formation Resistivity,ARC Tool Family,Basic 2 MHz/400 Khz Measurement,2 MHz resistivity volume of investigation,Borehole Compensation,Accuracy needs BHC,Invasion Profiling(answer product),Multiple Depths of Investigation allow software inversionto evaluate True Resistivity and invasion diameter,ARC inversion software,Answer productRt,RxoDi(diameter of invasion),Laterolog Resistivity Tools,Electrodes force Direct Current into the Formation,Current leaving the tool is inversely proportional to the Formation Resistivity,GeoVISION Resistivity Tool,Wireline Dual Laterolog Response,High Resistivity Carbonate Formation,GeoVision Response,High Resistivity Carbonate Formation,GeoSteering Tool,-Resistivity and Gamma Ray sensors at the bit leads to identification of geological boundaries while drilling-Inclination at the bit gives accurate placement of the wellbore-Trajectory corrections based on geological results,Propagation-the Good and the Bad,Relatively deep depth of investigationWill work in non-conductive bore holesAnisotropy processing(using multiple Phase and Attenuation measurements)Relatively poor vertical resolutionNon-directional measurementStrongly affected by high-angle effects,Laterolog-the Good and the Bad,Excellent vertical resolutionCan produce images for structure analysisAzimuthal measurementMeasure point can be very close to(at)the bitVery little high-angle effectsWill not work in non-conductive bore holesRelatively shallow depth of investigation,Neutron Tools,LWD Nuclear measurements,LWD Neutron-Density,Wireline Neutron-Density,Azimuthal Density Neutron,-Azimuthally focused density neutron measurements-Provides density,neutron porosity,photoelectric effect and ultrasonic caliper-Sector density measurements minimize borehole effects-Neutron porosity measurement corrected for environmental effects-All azimuthal data can be imaged for geological interpretation and geosteering applications-Can be run in all mud types,Neutron DetectorsLINC CoilsNeutron SourceElectronic CarrierDensity SourceDensity DetectorsUltrasonic SensorBatteriesTool Bus,Nuclear Safety,Retrievable sources for:-Safe fishing operations-Ease of abandonment-No loss of dataSafety of personnel-Radiation exposure minimized-Rig crew can operate on rig floor without exposure to radiation,LWD Repeat,WL Main Log,TAB=27 hrs,TAB=75 hrs,VISION Density,Azimuthal Density Neutron,Azimuthal Density measurements are used to steer the well to productive zones.In Zone“A”all density quadrants indicate gas.In Zone“B”,the upper quadrant indicates the wellbore is exiting the top of the reservoir.In Zone“C”,only the bottom quadrant identifies the gas zone below.A“best”density measurement could not differentiate between the layers.,Dips from density images,VISION825 Density Neutron Tool moving in borehole ROBB is improved by IDD,Image Derived Density,Sonic While Drilling,SONIC While Drilling-Features,Real-Time compressional delta-t(40-180 us/ft)Sonic Porosity as alternative to Nuclear PorosityCombine to give Real-Time Quad combo,SONIC While Drilling-Benefits,Better quality data before borehole alterationEnhance safety by use of real-time Pore Pressure predictionReduced geophysical risk by placing the bit on the seismic map,Real-time LWD sonic data is combined with density measurements.From this combination,synthetic seismograms are computed to accurately place the drill bit on the seismic map while drilling to identify casing and coring points.,ISONIC-Correlating with the seismic,Real-Time Overpressure Detection,Geosteering Technologies,Geometrically or Geologically?,Measurements to aid GeoSteering,At-Bit measurements:AIM,GSTReduce reaction timeAzimuthal Measurements(Images)GVR,ADNReal time formation dipResolve directional uncertainty,At bit measurements shorten reaction time,Shortened reaction time,Benefits of At Bit Measurements,Straighter,smoother wellboreFewer inclination corrections mean less sliding-greater overall ROPTight TVD targets(0.5 TVD)Improved accuracy in landing and drilling horizontal wellsSidetrack confirmation within 2 MD,AIM Inclination at the Bit,-Resistivity and Gamma Ray sensors at the bit leads to identification of geological boundaries while drilling-Inclination at the bit gives accurate placement of the wellbore-Trajectory corrections based on geological results,GeoSteering Tool,The Distance-to-Contact Question,Problem 1:Faults,Problem 2:Dips,Azimuthal Readings,Scenario A,Scenario B,Limitations of conventional measurements,Azimuthal test,Result,Azimuthal Measurements,A single detector takes a series of measurements around the borehole as the drill string is rotatingADN:16 Density readings around the borehole wallGVR:56 Resistivity readings around the borehole wall,New Generation tools utilize Azimuthal measurements,Quadrants,Sectors,and Bins.,Orientation component-Azimuthal LWD,Real Time Images from GVR Tool,Japex RT GVR Image Example,Real-time Dips From GeoVISION,Azimuthal Density GeoSteering,Azimuthal Density measurements are used to steer the well to productive zones.In Zone“A”all density quadrants indicate gas.In Zone“B”,the upper quadrant indicates the wellbore is exiting the top of the reservoir.In Zone“C”,only the bottom quadrant identifies the gas zone below.A“best”density measurement could not differentiate between the layers.,RM,RT,RM,RT,ADN Real-time vs Memory Image,RTI,RMI,Good agreement with RM imageBandwidth:8 scans of data compressedrequires.8 bps high resolution option recently added(1.5 bps),Geometric Vs.Geologic,Information prior to drilling,Usually,the only guide to formation dip is a structure map,Geometric Drilling,An initial formation model,but is the structure what we think it is?,However,the formation actually is,GeoSteering keeps the wellbore in the reservoir,If the wellbore is GeoSteered,Structure maps only give a vague guide,The real structure is often different,Malaysia example,Pre-Job model Post-Job Interpretation,If the well had been drilled according to plan,it would have landed below the target zone.,Geological error,A error of only 1 degree in the formation dip,will mean that the structure will drop 1m TVD in only 57m MD.Structural dip from Seismic is often only accurate to+/-2 to 3Seismic structure maps cannot resolve small featuresSmall throw faults,abandoned channels,features smaller than 20m etc.may not be seen,Well placement process road map,Phase#1Plan,Phase#2Execute,Phase#3Evaluate,Building a 1-D Formation Model,To begin,offset data must be loaded,converted to TST,then squared to produce a 1-D formation model,Merging with Geological Knowledge,A structure map and well trajectory then gives an idea of apparent formation dip,Gives a 2-D Geological Model,Once the formation dip is known,the 1-D formation model can be stretched into 2-D and the trajectory can be laid on top.,From the 2-D Geological Model,Since the formation properties are known,the software can then simulate the readings of specific tools,including geometrical effects such as anisotropy,polarization,etc.This can be done for:Resistivity(Propagation and Laterolog)Gamma RayDensityNeutronSonic,Structural Model,The Inform3D*Modelling Process,Inform3D*Model,Curtain Section is the fundamental representation of an Inform3D modelCurtain Section