well logging tools and exercise_dileep p allavarapu

  • 1,663 views
Uploaded on

hints to students for simple understandings_dileep p allavarapu

hints to students for simple understandings_dileep p allavarapu

More in: Education , Technology
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
No Downloads

Views

Total Views
1,663
On Slideshare
0
From Embeds
0
Number of Embeds
1

Actions

Shares
Downloads
49
Comments
0
Likes
5

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide

Transcript

  • 1. Science Behind Logging Dileep.P.Allavarapu dpa.taeching@gmail.com /or motherindia.energy@gmail.com 9703070878
  • 2. Role of Different Disciplines Logging play any important role in exploration and production industry? Can be comparable with other techniques ? Really logging is a replacement of core recovery and analysis? Cost effective ?
  • 3. EACH DISCIPLINE HAS ITS OWN IMPORTANCE & ROLE in E&P RESERVOIR MODELING OPEN HOLE LOGGING (RES, POR, LITH LOGS) -LWD/WL MUD LOGGING CORE ANALYSIS DRILLING & LOGGING STATIC MODEL INTERPRETATION MODEL & UNCERTAINITY CERTAINITY CORE ANALYSIS 3D & VSP GEOLOGY & SEISMIC CASED HOLE /PL LOGGING (cement eval,flow rate ,fluid Tests) -WL INJUCTION DATA FLUID STUDIES DYNAMIC MODEL FLUID STUDIES 4D
  • 4. observations OPEN HOLE LOGGING (RES, POR, LITH LOGS) -LWD/WL MUD LOGGING CORE ANALYSIS CASED HOLE /PL LOGGING (cement evaluation , flow rate ,fluid Tests) -WL INJUCTION DATA FLUID STUDIES DRILLING &LOGGING operations Interrelated operations completions DRECTIONAL DRILLING CORE RECOVERY PIPING & CASING OIL TUBING (packers arrangement) PERFORATING WELL CLEANING (gravel packing , acid injunctions, compressions) INJUCTIONS
  • 5. Few things about Logging Well ,log ,logging,………? Log interpretation.
  • 6. Logging : the process of continuous recording of parameters w.r.to depth that is to obtain comprehensive information about formations in the bore hole by lowering the tool Log: the record that contains obtained and required basic information about the parameters in the bole
  • 7. Don’t miss understand…….. logs (product) logging (process) open hole cased hole LWD , WL ,….. Production well logging….. open hole cased hole Production well Lithology ,Porosity ,Resistivity, …. Other miscellaneous Sonde: Combination of lowering tool, Bore Hole/Well :Source of parameters/formation, Bore Hole Environment:Distrubed –Undisturbed condition of Bore Hole, Before production (Stage of Reservoir /Field/Basin) In production (Stage of Production) Well: Discovery(Wild cat),Exploratory ,Development Well: Production(Recovery),Injection
  • 8. Log Presentation Lithology logs SP,GR along with CALIPER, BIT SIZE Lithology: (shale ,sand ,…) Porous –permeable beds (no of ,thickness) Shale volume Resistivity logs Porosity logs Focused(latro) , Non focused types of NormalInduction Sonic ,Neutron, Density Resistivity : Formation water & True resistivity Saturation MHI Permeability indication Porosity : Effective porosity Type of fluid Contacts (GSC,GOC,OWC,GWC) Uncompacted
  • 9. Stages of Interpretation UNDERSTANDING LOG STUDY THE LOG RECORD (to take proper action in any stage of interpretation ) HEADer- MAINfo- TAILer,…. DISPLAY INFORMATION . TOOL SKETCH , CALIBRATION , PERFORMANCE & REMARKS ……… MARK THE INTERESTED ZONES QUICK LOOK INTERPRETATION (to take the readings ) POROUS –PERMEABLE ZONES : WATER /HC BEARING ,OTHER RESERVOIR ROCK UNITS TAKE READINGS & LIST OUT THE INERPRETATION FORMULA (to calculate the interpretation parameters) GR , SP , CALIPER, RESTIVITY ,MICRO RESISTIVITY, NEUTRON ,BULK DENSITY ,SONIC TRANSIT TIME DETAILED INTERPRETATION
  • 10. GR FOR IGR SP/RESISTIVITY &NEUTRON RESISTIVITY FOR Rt FOR Rw NEUTRON , BULK DENSITY ,SONIC TRANSIT TIME FOR CALIPER, MICRO RESISTIVITY FOR FOR φe k indication S w, S hc, S movable , PAY= S movable * φe Aim of logging: Calculation of S Hc * φ Preparation of a PARA LOG Why a log analyst limited his aim to e in each reservoir rock unit & S hc × φ e ? Log analyst can do but accuracy …..because cant estimate exact S hc = (1-S hr) need help of core analyst of viscosity ,permeability ….
  • 11. Interpretation parameters Rt Φ N, Φ D R w ,Ro, Rsh V sh Φ eff Sw S hc Archie’s 2nd equation Indonesian ’s equation (Archie's 1st equation about formation factor) DEPTH Rw Rt Φ eff SW S Hc S Hc × Φ eff
  • 12. Sand Stones: Log Analyst: Composition (Sand Stone) Framework of Quartz and Feldspar Grains(Majority)/ Other Fragments (Non Majority)/ Cement (Quit Limited)) Processing Engineer: Matrix (Sand Stone) K-Na, Ca Al Si3 O8 Si O2
  • 13. Shales: Frame work ,Matrix, Cement are Clay Minerals ( Kaolinite,Montmorilllonite,Illite) Minute percentage of Non Clay Minerals. 90% Clay Minerals K Feldspar derived Radio Active K rich clays Rain water derived U,Th Br salts K (12%),U Th (<500ppm) Laminar (separate layers of fine grains) Dispersed (spreaded clusters of fine grains in coarse grains) Structural (distribution mixture of fine grains in coarse grains) Which shale effects the formation more? Why? Dispersed(assumptions become wrong;cant locate cluster and estimate its distribution beyond well surroundings) >Structural>Laminar Salt : 100% NaCl (general) or 0-10% KCl +90-100%NaCl (rare) Brazile wells shows high gama in salt formations because of KCl presence ,in past north brazilen sea having more KCl salt
  • 14. Why anhydrate or gypsum are tops of salt(local gravity high)? During evaporation of sea water more saturate solution of NaCl formed and precipitated, still some minerals remain finally precipitated at top of the salt , at the end of the evaporation react with H2O form anhydrate or gypsum.
  • 15. Chemical Sources: NEUTRON SOURCE Neutron sources Gamma sourceso Cesium(Cs137) produce a steady flux of gamma rays at 662 KeV ENERGY LEAVING SOURCE 106 NEUTRON ENERGY (e V) o Am241-Be9 : emits neutrons with mean energy of 4.2 MeV. oz Californium(Cf252) : emits neutrons with mean energy of 2.35 MeV. 104 102 10 eV Electrical Generators: This device produces 14 MeV neutrons by accelerating deuterium ions into a tritium target (up to 125,000 V DC). APPROX. EPITHERMAL ENERGY REGION 1 .4 eV AVERAGE THERMAL ENERGY . 025 EV CAPTURE 01 1 10 TIM E ( µ s ) 100
  • 16. Energy state Range Interaction high >0.5Mev Inelastic scattering medium 0.5ev-0.5Mev Elastic scattering low <0.5ev Thermal capture Energy state Range Interaction high >2Mev Pair production medium 0.5Mev-0.5Mev Compton scattering low <0.5Mev PEE Remark Remark
  • 17. Why R proportional to l /A ? RMS velocity of free(week bonded )electron Collision of energized surface electron with unenergized electron Week bonded Strong bonded v v vvv v me If Area increased, no: electrons come to contact with electrode is increased Energy transmission as velocity exchange
  • 18. ELECTRICAL LOGGING TOOLS Conventional Electrical survey Tools Non-Conventional Electrical survey Tools natural artificial artificial artificial SP Normal Resistivity & Micro Resistivity (focused, non focused) Induction (short, long) Lateral RADIO ACTIVE LOGGING TOOLS Conventional Radio Active Tools Non-Conventional Radio Active Tools natural artificial artificial GR Neutron Density (Compensation) Dual energy, Litho , GR-Spectroscopy SONIC LOGGING TOOLS Conventional Sonic Tools Non-Conventional Sonic Tools artificial artificial Sonic (Compensation) Long spread , Depth derived ,Array, Wave sonic, Dipole MISCELLANEOUS LOGGING TOOLS (BH Conditions) Temperature ,Pressure…… Formation testers (BH Geometry ) Caliper,Dipmeter,…
  • 19. M M SP tool A A M N Normal Device Lateral Device
  • 20. Archie's Both Equations : Archie's experiment concludes an empirical relationship between resistivity of the water bearing formation and water, pore volume it contain and also water saturation. If Sw = 1 , means water-bearing formation Resistivity of water Resistivity of waterbearing formation Formation factor Water saturation
  • 21. Volume of Shale: The percentage of shale present in the rock unit Response in the zone of interest Shale Clean formation Indonesian Equation
  • 22. GR: The record of count rate of Natural GAMMA as a result of emission from RADIO ACTIVE MINERALS present in the ROCK UNITS RADIO ACTIVE MINERALS are more in the CLAYS & SHALES GR infer the LITHOLOGY whether rock unit is having CLAYS & SHALES or not In the first /each run (lowering tool), first track (left side of log paper) 0-100 API (10intervels) along with CALIPER,BIT SIZE , SP. GR around 30 -SAND up to 50 -SAND SHALE up to 80 -SHALE SAND up to 100- SHALE more than 100-CLAY Volume of Shale DEPTH GR Vsh END
  • 23. SP: The record of voltage variation as a result of electrolytic conduction due to salinity variation between fluids present in the ROCK UNITS electrolytic conduction is more across porous –permeable rock unit SP infer the LITHOLOGY whether rock unit is having porous& permeable SAND or not In the first /each run (lowering tool), first track (left side of log paper) 0-100 units (10intervels) along with CALIPER,BIT SIZE ,GR. SP +Ve : R mf <R w : Shale Base Line is in left side of Sand Deflection Line SP in the same well either +Ve or –Ve : crossover indicates the presence of HYDROCARBON END
  • 24. OR K=61+0.133T°F R we to R w conversion chart DEPTH SSP K 10 ˆ(SSP/K) Rwe R w END
  • 25. BIT SIZE : size of the drill-bit used CALIPER: size of the drilled hole Grater than BIT SIZE : absence of permeable rock units / factures Less than BIT SIZE : presence of permeable rock units /MUD CAKE RESISTIVITY : Apparent resistivity of the formation (can calculate true resistivity by using at least three apparent resistivity values ) Using Resistivity Tool: in saline muds , good contact between annulus electrode and BH wall. Using Induction Tool : in non saline muds In the first run (lowering tool), first track (middle of log paper) 0.2-2000 units (log scale) Configuration : App resistivity = (Geometrical factor × Observed voltage difference)/ Sending current Characteristic charts used to calculate true resistivity from apparent resistivity END
  • 26. DLL MSFL Invasion Correction charts DLL MSFL LOG RECORD (R t / R LLD )× R LLD = R t DEPTH LLD LLS MSFL LLD/LLS LLD/MSFL Rt/LLD Rsh = Rt in shale RO = Rt in WBZ Rt END
  • 27. NEUTRON: The count rate of back scattered neutron/gamma as a result of energizing rock units with neutrons (source: Am Be -16 curie) Sending neutron lose total energy and collapse into the nuclei of HYDROGEN and release a Gamma Response α Hydrogen Index In the first run (lowering tool), third track (right side of log paper) 0.54 - -0.06 (10intervels) along with SONIC ,DENSITY. NEUTRON : Gas < Oil <Water in sand Sand < Shale (bounded water) Correction for shale: Φ Nc = ΦN-(Vsh× ΦN in shale) Neutron Porosity Φ N = ΦN calibration corrected END
  • 28. DENSITY : The count rate of back scattered gamma as a result of energizing rock units with gammas (source : Cs 137) Sending gamma undergone Compton Scattering no of collisions α no of electrons in rock unit ρe ρb = 1.0704 ρe + 0.1883 In the first run (lowering tool), third track (right side of log paper) 2.8 -1.8 (10intervels) along with SONIC ,NEUTRON. DENSITY: Gas < <Oil <Water in sand Correction for shale: Φ Dc = ΦD-(Vsh× ΦD in shale) END
  • 29. Effective Porosity: Volume of interconnected pores Neutron Correction for shale: Φ Nc = ΦN-(Vsh× ΦN in shale) Density Correction for shale: Φ Dc = ΦD-(Vsh× ΦD in shale) DEPTH Φ N cal Φ NC ρb φD φDC Φeff END
  • 30. Φ N RT GR 20 97 24 24 78 23 22 69 25 28 72 26 30 52 23 Will get Rt =100 Sand Stone Matrix Point ∆t = 48, φN =0 , ρb =2.65 ΦN = 0 10 20 30 40 50 Choose Φ=20 END
  • 31. now mark the point φ=20,Rt=156.25 & draw the 80% saturation line Rw=4.878 now replace the 0.64 by 0.36,0.16,0.04 …..to get the 60%,40%,20%,…… saturation lines Sw =80% =0.8 Rt = 100/0.64 = 156.25 END
  • 32. SW =1=100% Red Points GR=23-30 Blue Points GR=30-40 Yellow Points GR=40-50 END
  • 33. Sw=0.8=80% END
  • 34. Ro =F Rw Rt= F Rwa Different Trend HC indication Main Trend Rwa line WBZ
  • 35. 50 = φ DC -10 0 10 20 30 40 GAS -10 0 10 20 30 40 50= φ NC
  • 36. Indonesian Equation S HC = (1-SW) DEPTH Rw Rt Φ eff S W S Hc S Hc × Φ eff END
  • 37. Here our goal need more data from ROCK PHYSICS LABORATORY, so it limited to S hc × φ e
  • 38. GSC GOC WOC
  • 39. Lithology GR Rt φN Sand Stone ( more compacted & dry ) Less=25 Less clay minerals More=1000 SiO2 insulator / no electrolytic conduction Less<10 More=2.6 No fluid / no H2 Closed grain packing Sand Stone ( less compacted & wet) Less=25 Less clay minerals Less<100 Saltwater conductor / electrolytic conduction More=10-30 Having H2 Moderate=2.1 (30% H2O=1 /70% SiO2 =2.6) Having oil Less=25 Less clay minerals Moderate >100-700 Oil insulator (at least 5times of R0 ) More=10-30 Having H2 (less than water zone) Moderate=1.9 (less than water zone) Having gas Less=25 Less clay minerals More >700 Gas insulator (at least 5times of More=10-30 Having H2 (less than oil Less =1.8 Having water ρb
  • 40. Lithology GR Rt φN ρb Sand-Shale ( more compacted & dry ) Less=30-50 More or less clay minerals More<100 Dry clay insulator ,bounded water in composition / not much electrolytic conduction Less=20 No fluid / bounded water H2 More=2.5 Closed grain packing (30%shale =2.3,70%sio2=2 .6) Sand-Shale ( less compacted & wet) Less=30-50 More or less clay minerals Less<50 Wet clay conductor / more electrolytic conduction More=20-40 Having H2 Moderate=2.2 (20% H2O=1 ,50% SiO2 =2.6 30%Shale 1.82.6) Having oil Less=30-50 More or less clay minerals Moderate >100-700 Oil insulator (at least 5times of R0 ) More=20-40 Having H2 (less than water zone) Moderate=1.8 (less than water zone) Having gas Less=30-50 More or less clay minerals More >700 Gas insulator (at least 5times of oil zone ) More=20-40 Having H2 (less than oil zone) Less =1.7 Having water
  • 41. Lithology GR Rt φN ρb Shale ( more compacted & dry ) More =80-100 More clay minerals (80%) More<50 Dry clay insulator / not much electrolytic conduction Less=30-40 No fluid / bounded water H2 More=2.3 Closed grain packing Shale ( less compacted & wet) More =80-100 More clay minerals Less<10 Wet clay conductor / more electrolytic conduction More=40-50 Having H2 Moderate=1.9 (30% H2O=1,70% shale=2.3) , More >100(120) More clay minerals More<50 Dry clay insulator /Less<10 Wet clay conductor Less=30-40 More 2.4 Having water Clay
  • 42. Dileep.P.Allavarapu dpa.taeching@gmail.com /or motherindia.energy@gmail.com 9703070878 Contact any Institution Dept. of Mathematics, MGR Junior College Dept. of Chemistry, LAMP Degree College Dept. of Geophysics , Andhra University Logging Base ,ONGC –Rajahmundry Asset Oil and Gas Deliveries, Infotech Enterprises Limited Gravity Observatory , Gravity Group-NGRI Seismological Observatory, Warna Canal Division-MERI UV Physics Academy Analog IAS Academy