TABLE OF CONTENTS. Chapter Heading Page

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2 TABLE OF CONTENTS Chapter Heading Page 1 Introduction 1-1 Purpose 1-2 ARC Vision and Mission 1-3 Company Profile 1-4 Surface Equipment Capabilities 1-5 Safety, Training, and Insurance Assessing Your Diagnostic Needs 2-1 Production Logging Overview 2-2 Identifying the Cause of Poor Well Performance 2-2 Measuring the Effectiveness of a Workover 2-5 Recording Profiles to Support Reservoir Management 2-5 Well Diagnosis 2-7 Multiphase (Production) Wells 2-7 Single-Phase Injection Wells 2-9 Drilling / Well Completions Memory Logging 3-1 What Is Memory Production Logging? 3-2 How Does It Work? Tool Specifications 4-1 Battery Section 4-2 Memory Section 4-3 Gamma Ray & Casing Collar Locator Section 4-4 Dielectric Section 4-5 Temperature Section 4-6 Pressure Section 4-7 Continuous Flow Meter Section 4-8 Fullbore Flow Meter Section Setting Up an MPL Project With ARC 5-1 Filling in the Job Order Form 5-2 Generic Production Log Procedure 5-5 Points to Remember 5-6 Job Sheets / Analysis Input Parameter Sheets 6 Log Presentation & Interpretation 6-1 Log Data Reporting 6-2 Log Data Analysis 6-3 Appendix Example Layout of MPL Analysis Report

3 INTRODUCTION COMPANY PROFILE ORIGIN ARC Pressure Data, Inc. had its beginnings with the Tom Hansen Company, Inc. which started its operations in 1959 as a bottomhole pressure data company. In 1965, tubing testing was added to the product line, followed ten years later with production logging and perforating. In 1981, the slickline division was spun off to create what is today ARC Pressure Data, Inc. For over a decade, ARC has been the slickline data acquisition service company leader in the Permian Basin area. TECHNOLOGY LEADER ARC made a commitment to fund the development of an electronic memory gauge with a quartz transducer in ARC Pressure Data was one of the first service companies to introduce a quartz memory pressure gauge in the Permian Basin. As the slickline company continued to grow, an emerging technology, memory production logging, was added to its pressure transient testing, general wireline, and engineering services. In 1994, an aggressive research and development effort was spearheaded by ARC, which has resulted in a reliable suite of memory-based production logging tools. The tools are designed, built, and serviced by ARC Pressure Data, Inc. Development continues with ongoing proprietary projects and a slate of additional tools to bring to market. SERVICE BY DESIGN ARC Pressure Data, Inc. offers service by design. We design the tests, service, tools, training, and manpower to meet the needs of our clients. Through flexible testing and logging procedure design, as well as multiple data acquisition methods, ARC can lower data acquisition costs, while offering customers a full array of wireline services. 1-4

4 INTRODUCTION COMPANY PROFILE ORIGIN ARC Pressure Data, Inc. had its beginnings with the Tom Hansen Company, Inc. which started its operations in 1959 as a bottomhole pressure data company. In 1965, tubing testing was added to the product line, followed ten years later with production logging and perforating. In 1981, the slickline division was spun off to create what is today ARC Pressure Data, Inc. For over a decade, ARC has been the slickline data acquisition service company leader in the Permian Basin area. TECHNOLOGY LEADER ARC made a commitment to fund the development of an electronic memory gauge with a quartz transducer in ARC Pressure Data was one of the first service companies to introduce a quartz memory pressure gauge in the Permian Basin. As the slickline company continued to grow, an emerging technology, memory production logging, was added to its pressure transient testing, general wireline, and engineering services. In 1994, an aggressive research and development effort was spearheaded by ARC, which has resulted in a reliable suite of memory-based production logging tools. The tools are designed, built, and serviced by ARC Pressure Data, Inc. Development continues with ongoing proprietary projects and a slate of additional tools to bring to market. SERVICE BY DESIGN ARC Pressure Data, Inc. offers service by design. We design the tests, service, tools, training, and manpower to meet the needs of our clients. Through flexible testing and logging procedure design, as well as multiple data acquisition methods, ARC can lower data acquisition costs, while offering customers a full array of wireline services. 1-4

5 PRESSURE CONTROL INTRODUCTION SURFACE EQUIPMENT CAPABILITIES 5000# working pressure lubricator and blowout preventer # working pressure lubricator and blowout preventer # working pressure lubricator and blowout preventer. 5000# H 2 S rated lubricator and blowout preventer. WIRELINE UNITS Single drum units mounted on: Trailers 1-ton boom trucks 2-ton boom trucks Large capsule trucks All units except trailer units capable of handling wire spools. MAST UNITS 45 mast units WIRELINE Carbon Steel Wire MP35N Wire available, rated best by NACE for H 2 S and CO 2 environments 1-5

6 SAFETY AND TRAINING In addition to company policy concerning safety and the use of drugs and alcohol, ARC actively provides the following training. This list is not all-inclusive and will be revised as needed. H2S PETROLEUM EDUCATION COUNCIL (PEC) BASIC ORIENTATION PLUS (BOP) CPR FIRST AID INSURANCE ARC provides at least the minimum required amount of insurance required for Liability, Auto Liability, and Workers Compensation. For more information, please feel free to contact ARC. 1-6

7 CHAPTER 2 ASSESSING YOUR DIAGNOSTIC NEEDS

8 ASSESSING YOUR DIAGNOSTIC NEEDS PRODUCTION LOGGING OVERVIEW PRODUCTION LOGGING OVERVIEW Introduction ARC Logging Services provides a cased-hole service to quantify fluid movement during production or injection. This service, known as Production Logging serves as a well diagnosis tool to aid in uncovering the cause of poor well performance, measure the effectiveness of various workover operations, and provide a time-lapse surveillance of injection and production profiles to support reservoir management. In many cases, production logs can indicate remedial action to be taken to improve well productivity. Identifying the Cause of Poor Well Performance Production logging is typically used as a supplement to pressure transient testing in diagnosing poor well performance. The first question to answer is whether the cause is related to the reservoir or completion. In many cases a combination of the two data analyses is needed, such as identifying which interval has a low Productivity Index (skin damage). SHALE CASING DAMAGE SHALE HIGH PRESSURE GAS ZONE CHANNEL OIL ZONE SHALE 2-2

9 ASSESSING YOUR DIAGNOSTIC NEEDS PRODUCTION LOGGING OVERVIEW Some of the more typical production problems are outlined and illustrated by Smolen 1, Hill 2, and Economides et. al. 3 within the following points of interests: 1) Poor Initial Performance Damaged zone causing significant skin effect around wellbore Plugged or ineffective perforations Poor depth control during completion (perforated out of zone) Improperly sized tubing Drawing down below bubble-point Thief zones created by commingling high and low pressured zones 2) Excessive Gas or Water Production Encroachment of water-oil contact (WOC) or gas-oil contact (GOC) Water or gas coning Fingering through high permeability zones Channeling from a nearby zone Casing damage Leaking bridge plug (short term isolation of zones) SHALE LOW K OIL ZONE HIGH K INTERMEDIATE K WATER HIGH K LOW K ORIGINAL OWC SHALE 2-3

10 ASSESSING YOUR DIAGNOSTIC NEEDS PRODUCTION LOGGING OVERVIEW 3) Abnormally Low Productivity Reservoir pressure decreases Near wellbore permeability loss due to particulate movement Relative permeability effects Fracture closure Restriction due to sand fill Increase in hydrostatic head due to increased production of a heavy phase Plugged perforations or gravel pack 4) Miscellaneous Problems Sand production Tubing, casing, or packer leaks SHALE OIL ZONE WOC CONE WATER 2-4

11 ASSESSING YOUR DIAGNOSTIC NEEDS PRODUCTION LOGGING OVERVIEW PRE-TREATMENT EVALUATION 1) Mini-frac (pump-in) falloff with estimated fracture height Temperature log for mini-frac height along with stationary pressure measurement for closure stress inflection during falloff POST-TREATMENT EVALUATION 1) Remedial cementing Top of cement after squeeze job 2) Re-perforating Compare new profile against pre-treatment profile 3) Acidizing Cooling or heating based pumped fluid or acid reaction 4) Fracturing Temperature Log Interpretation for Fracture Height 5) Water shutoff (profile modification treatments) Before and after comparison of injection profiles Measuring the Effectiveness of a Work-over As in the diagnosis of situations relating to poor or unanticipated performance, production logging can also aid in evaluating the success or failure of the work-over operations performed to remedy these problems. A before- and after-treatment measurement of the flow profile can aid in the planning and evaluation of the work-over operation. Recording Profiles to Support Reservoir Management In many ways, all of the above practical applications play a role in reservoir management. However, those issues play a role at a specific time in a reservoir s life. Monitoring a crosssection of wells making up a reservoir unit over time can provide additional information to an asset team that can aid in reservoir characterization. An injection profile is the first thing that comes to mind when one thinks of reservoir management as it pertains to waterflood surveillance. A number of surveys over time can provide an overall picture of the allocation of water for each zone. They also provide indication of formation plugging, injection out of the target zone, thief zones, and underinjected zones

12 ASSESSING YOUR DIAGNOSTIC NEEDS PRODUCTION LOGGING OVERVIEW Production profiles provide a means of monitoring the Productivity Indexes of each interval or zone with time. A procedure to run production profiles during at least four different stabilized rates can provide a way of determining pressure differences within each zone or interval early in the life of the well. In effect production logs can aid in the determination of the producing mechanism for different layers of a commingled completion. 1 James J. Smolen, Ph.D., Cased Hole and Production Log Evaluation, 1996, PenWell Publishing Company 2 A. Daniel Hill, Production Logging Theoretical and Interpretive Elements, 1990, SPE Monograph Vol. 14., Society of Petroleum Engineers Inc. 3 Michael J. Economides, A. Daniel Hill, & Christine Ehlig-Economides, Petroleum Production Systems, 1994, Prentice Hall. 4 Abdus Satter and Ganesh Thakur, Integrated Petroleum Reservoir Management A Team Approach, 1994, PennWell Publishing Company 2-6

13 ASSESSING YOUR DIAGNOSTIC NEEDS WELL DIAGNOSIS MULTIPHASE (PRODUCTION) WELLS Surface Indication of Poor Behavior / Recommended ARC Logging Objective Possible Causes Logging Service Comments Low productivity 1.Low formation 1.Flow Profile Production profile measured with permeability GR-CCL-PRES-TEMP- spinner (usually qualitative) will indicate 2.Plugged SPIN low-productivity intervals. Comparison with perforations 2.Pressure Buildup core data or openhole logs may 3.Near-wellbore Test distinguish between low permeability formation and plugged perforations or formation damage damage. Pressure transient tests will 4.Wellbore also distinguish between low permeability restrictions and near-wellbore or perforation damage. 5.Channeling or Channeling or crossflow may be indicated crossflow by temperature or flowmeter logs. 6.Lift mechanism The main lift mechanism that can problem diagnosed for problems would be to determine the operating valve on a continuous gas lift installation. Excessive water 1.High-permeability 1.Temperature, A combination of a spinner and density production zone spinner, & density or capacitance log can be used to locate 2.Channeling or capacitance water entries. Information will often be 3.Coning GR-CCL-PRES-TEMP- only qualitative. Density (pressure gradient SPIN-DIEL or gradio) or capacitance (dielectric) alone is sometimes sufficient to locate water entries. Water channeling may be located with the temperature log. Coning is difficult to distinguish from a bottom high-permeability zone; some special tests or sequence of logs run at different well rates may confirm coning. Excessive gas 1.High-permeability Temperature, spinner, Temperature log may indicate gas production zones density, and dielectric production by cool anomalies. 2.Production from GR-CCL-PRES-TEMP- Combination of spinner and density gas cap SPIN-DIEL (gradient or gradio) logs may locate gas 3.Channeling entries, though information is often 4.Coning only qualitative unless temerature directional modeling is applied in the right cases. permeability, Channeling can be identified by barriers, poor temperature. Distinguishing between pattern high-permeability zones, gas-cap placement, etc. production, and coning is difficult. Other information that may help includes well rate history, reservoir pressure history, core data, or openhole logs. 2-7

14 ASSESSING YOUR DIAGNOSTIC NEEDS WELL DIAGNOSIS MULTIPHASE (PRODUCTION) WELLS Routine reservoir 1.Single-phase Particular tool combination depends on surveillance Pressure, temperature, well conditions. Temperature should be and spinner part of all logging suites. GR-CCL-PRES-TEMP- SPIN 2.Two-phase Pressure, temperature, spinner, & density GR-CCL-PRES-TEMP- SPIN 3.Three-phase Pressure, temperature, spinner, density, and dielectric GR-CCL-PRES-TEMP- SPIN-DIEL 2-8

15 ASSESSING YOUR DIAGNOSTIC NEEDS WELL DIAGNOSIS SINGLE-PHASE INJECTION WELLS Surface Indication of Poor Behavior / Recommended ARC Logging Objective Possible Causes Logging Service Comments Low injectivity 1.Low formation 1.Flow Profile Injection profile measured with spinner permeability GR-CCL-PRES-TEMP- will indicate low-injectivity intervals. 2.Plugged SPIN Comparison with core data or openhole perforations 2.Pressure Falloff logs may distinguish between low 3.Near-wellbore Test permeability and plugged perforations or formation formation damage. damage 4.Wellbore restrictions Abnormally high 1.Channeling 1.Temperature and Temperature log can indicate channels injectivity 2.Tubing leak spinner log or leaks. Sufficient cooling from injected 3.Casing leak GR-CCL-PRES-TEMP- fluids can lead to leak detection with 4.Packer leak SPIN temperature. Spinner can suggest 5.Fractured 2.Step-rate test channeling or leaks by shape of profile or reservoir 3.Falloff test measured fluid velocity. A fractured reservoir is suggested by absence of channels or leaks as determined by logs. This can be confirmed with a Step-rate or falloff test. Low productivity in 1.Channeling or 1.Temperature and If no problems are found in injection well, offset producers leaks spinner log production well should be tested with 2.Problems in GR-CCL-PRES-TEMP- production logs and/or pressure transient producers SPIN tests. 3.Reservoir 2.Falloff test problems - directional permeability, barriers, poor pattern placement, etc. High water 1.High 1.Temperature and Injection profile measured with spinner production in permeability spinner log should locate high-permeability zones. offset producers zone(s) GR-CCL-PRES-TEMP- Temperature log may indicate a high- SPIN permeability zone in a young well. Routine reservoir 1.Temperature and Injection profile should be measured. surveillance spinner log Further tests for leaks or channels should be made if problems indicated. 2-9

16 ASSESSING YOUR DIAGNOSTIC NEEDS WELL DIAGNOSIS DRILLING / WELL COMPLETIONS Surface Indication of Poor Behavior / Recommended ARC Logging Objective Possible Causes Logging Service Comments Well treatment Required workover Flow Profile Logs Many well treatments require flow profile design and GR-CCL-PRES- before and after treatment for design evaluation TEMP-SPIN and analysis. GRADIO-and/or-DIEL Fracture-height Shut-in temperature Temperature log measures fracture height measurement GR-CCL-TEMP based on cooling by the fracture fluid. Mud kick or lost Underground Temperature Log Temperature log responds to flow into circulation blowout GR-TEMP the formation similar to an injection well. Evaluation of Flow Profile Logs Performance of perforations is inferred perforation GR-CCL-PRES- from the productivity or injectivity of performance TEMP-SPIN- zones perforated and comparison with GRADIO-and/or-DIEL core or openhole log data on reservoir permeability. Locating top of Temperature Log Temperature log run shortly after cement TEMP-Encoded Depth cementing shows warm region opposite cement resulting from heat of hydration 2-10

17 CHAPTER 3 MEMORY LOGGING

18 MEMORY LOGGING WHAT IS MEMORY PRODUCTION LOGGING? The System The ARC MPL system was designed with the ability to produce a production log equivalent to one recorded with standard conductor wireline using proven sensors and memory technology with the tools conveyed on slickline. Time & Depth File in Computer Memory Time & Data File in Tool Memory 3-2

19 MEMORY LOGGING How Does It Work? This is accomplished through the capability of recording high sample rates of data from each sensor with time and storing that into a large memory section within the MPL tool downhole. The depths of the MPL tool are recorded into a surface computer via a microprocessor-controlled encoder at the same pre-programmed sampling rate as the MPL tool sensors. The depth file, recorded in the surface computer, is merged with the sensor file, uploaded from the MPL tool upon retrieval at the surface. The merger of the files is accomplished by matching the synchronized times to give an endresult digital log that replicates a conductor wireline log in data frequency, accuracy, and resolution. TIME & DEPTH API LOG TIME & DATA 3-3

20 CHAPTER 4 TOOL SPECIFICATIONS

21 TOOL SPECIFICATIONS BATTERY SECTION ELECTRICAL SPECIFICATIONS Input Power: 4 C 3.6V Lithium Thionyl Chloride Cells 1 AA 3.6V Lithium Thionyl Chloride Cell Data Sampling: Maximum Sampling Rate 50 Samples/Sec Minimum Sampling Rate 1/Year Analog Sensor Interface: Converter Type Delta-Sigma Modulation Dynamic Range 96 db max. Digital Output 16 bits max. 4-2

22 TOOL SPECIFICATIONS MEMORY SECTION DIGITAL SENSOR INTERFACE Programmable Between: Autoscaling Frequency Measurements Totalizing Counters, 16 bits MEMORY CAPACITY Maximum Available Memory 2 Mbytes Maximum Number of Stored Points With All Sensors 130,000 With Limited Sensors 1,000,000 MECHANICAL SPECIFICATIONS Outside Diameter 1-3/8 Maximum H2S - Sour Metal K-Monel Length ENVIRONMENTAL SPECIFICATIONS Maximum Operating Temperature 300 F (150 C)** Maximum Operating Pressure 10,000 psi ** **Higher operating temperature and pressure available with advanced notice. 4-3

23 TOOL SPECIFICATIONS GAMMA RAY & CASING COLLAR LOCATOR SECTION GAMMA RAY MEASUREMENT RANGE: API Units LENGTH: (Approximately) SENSOR TYPE: Scintillation Detector CASING COLLAR LOCATOR LENGTH: (Approximately) 4-4

24 TOOL SPECIFICATIONS DIELECTRIC SECTION MEASUREMENT RANGE: Dielectric Constant 1 to 100 LENGTH: (Approximately) MEASUREMENT ACCURACY: Dielectric Constant 2% MEASUREMENT RESOLUTION: 0.10% of Full Scale Reading MAXIMUM DYNAMIC TOOL RESPONSE FOR WATER HOLDUP UP TO: 40% 4-5

25 TOOL SPECIFICATIONS TEMPERATURE SECTION MEASUREMENT RANGE: 32 F to 300 F 0 F to 150 F LENGTH: (Approximately) MEASUREMENT ACCURACY: F C MEASUREMENT RESOLUTION: F C MEASUREMENT TIME CONSTANT: 0.3 SEC Achieves 60% of full scale temperature change in 0.25 seconds 4-6

26 TOOL SPECIFICATIONS PRESSURE SECTION MEASUREMENT RANGE: 0 psi to 10,000 psi LENGTH: (Approximately) STRAIN GAUGE MEASUREMENT ACCURACY: 0.10% of Full Scale STRAIN GAUGE MEASUREMENT RESOLUTION: 0.20 psi REPEATABILITY: 0.10% of Full Scale 4-7

27 TOOL SPECIFICATIONS CONTINUOUS FLOWMETER SECTION MEASUREMENT RANGE: -200 TO +200 Rev/Sec (RPS) LENGTH: (Approximately) MEASUREMENT ACCURACY: Rev/Sec (RPS) MEASUREMENT RESOLUTION: Rev/Sec (RPS) MINIMUM DETECTABLE FLOW RATE STATIONARY READING: 200 BPD (5 Casing) Multi-pass technique of downhole calibration of the flowmeter yields very small increments of bulk velocity changes, and subsequently flow Rates 4-8

28 TOOL SPECIFICATIONS FULLBORE FLOWMETER SECTION MEASUREMENT RANGE: -200 TO +200 Rev/Sec (RPS) LENGTH: (Approximately) MEASUREMENT ACCURACY: Rev/Sec (RPS) MEASUREMENT RESOLUTION: Rev/Sec (RPS) MINIMUM DETECTABLE FLOW RATE STATIONARY READING: 100 BPD (5 Casing) Multi-pass technique of downhole calibration of the flowmeter yields very small increments of bulk velocity changes, and subsequently flow Rates 4-9

29 CHAPTER 5 SETTING UP AN MPL PROJECT WITH ARC

30 SETTING UP AN MPL PROJECT WITH ARC FILLING IN THE JOB ORDER FORM FILLING IN THE JOB ORDER FORM Pertinent Well Description, Contact Person(s), Delivery and Billing Information Wellbore & Completion Detail typically on schematic Corrosive Fluids and/or Temperature and Pressure Environment for specifying proper lubricator, wire, mast unit, instrumentation, and batteries Directions to Well Lease Job Order Form ARC has a job order form that we feel is a very important link in the communication of data acquisition objectives while providing all the necessary wellbore, fluid, and completion data to execute the project with the utmost safety and to complete a thorough interpretation of the data. The Job Order Form consists of a Well Data Sheet and two Service Data Sheets specific to Memory Production Logging. Well Data Sheet The well data sheet provides all the information necessary to run slickline in and out of your wellbore safely. This sheet is standard for all of the slickline services ARC provides. We realize that the information requested can sometimes appear like a lot more than would seem necessary, but when running any wireline in the hole, the more information the better. The safest and least cumbersome well intervention is our goal for your project. 5-2

31 SETTING UP AN MPL PROJECT WITH ARC FILLING IN THE JOB ORDER FORM MPL Data Sheet 1 The first data sheet for MPL information provides some space to discuss your objectives or goals for the production log procedure and anything you or your team think may be happening with the completion. ARC engineers study your response to these insights carefully to insure that your expectations can be met with the current instrument technology and operational capabilities. The individual intervals or perforation sets are outlined in the next section. This provides the necessary input to begin building the physical basis for the profile model. Net intervals through overall open-hole sections should also be delineated if possible. Surface fluid properties are a minimum requirement for proper production log (flow profile) interpretation. Additional, in-depth laboratory analysis is definitely a plus. And by all means, the current surface production rates of each phase as close to the time of the log are pre-requisites to valid profile interpretation. What do you expect to determine from the log and what do you think is happening? Individual perforated intervals, slotted liner windows, or open-hole intervals Current fluid properties; Preferably for the particular well being logged Current, accurate surface flow rates for each phase. A production test the day of the log would be great! 5-3

32 SETTING UP AN MPL PROJECT WITH ARC FILLING IN THE JOB ORDER FORM MPL Data Sheet 2 The final sheet wraps up with a section of information on any other factors that could affect the understanding and interpretation of the proposed production log. Recent stimulation treatments where radioactive tracers were used can change the natural gamma ray response. Cool fluids that have been pumped can alter the geothermal gradient in the static rat hole or the overall temperature response across productive intervals. Unstable flow regimes can continue for days after recent rate changes in some wells. In essence, anything that could influence the measurements to be taken during this log warrants mentioning. A list is provided detailing potential attachments to this Job Order Form as they may apply. The most important of these is an open-hole or cased-hole log from the well or wells to be logged, providing a reference (collars or gamma ray signature) to adjust each pass of the new log to the proper depth. A recent wellbore sketch or schematic can provide a great deal of the information for several sections of this form. All of those little things that could affect the log, but tend to be overlooked A checklist of preferred attachments These final sections are things that an ARC representative will fill out. However, you may wish to provide a step-by-step procedure. An ARC representative is available to work with you in the most convenient way possible to complete this Job Order Form and discuss the best procedure to achieve your objectives. The greatest chance of completing a successful data acquisition intervention is to have this Plan in place before the work is done! 5-4

33 ARC PRESSURE DATA, INC. - WELL DATA SHEET Page of TICKET/JOB NUMBER COMPANY LEASE WELL # FIELD FORMATION COUNTY STATE SCHEDULED DATE/TIME BILLING ADDRESS JOB TYPE CONTACT PHONE FAX DATA TO PHONE FAX DATA TO PHONE FAX WELLBORE INFORMATION TBG1 SIZE WT DEPTH DEPTHS FROM... KB / GL TBG2 SIZE WT DEPTH ELEV. KB GL CSG1 SIZE WT DEPTH WELLHEAD INFORMATION CSG2 SIZE WT DEPTH CONNECTION LINER SIZE WT DEPTH HEIGHT NIPPLE 1 ID DEPTH CROWN/SWAB VALVE?... Y / N NIPPLE 2 ID DEPTH FULL OPENING?... Y / N NIPPLE 3 ID DEPTH OTHER PKR ID DEPTH EXPECTED PRESSURE/TEMP. TBG ANCHOR ID DEPTH FLOWING WHP MUD ANCHOR ID DEPTH SHUT-IN WHP MISC ID DEPTH FLOWING BHP MIN ID ID DEPTH SHUT-IN BHP TD COMPLETION DETAILS PERFS GRAVEL PACK SLOTTED LINER OPEN HOLE WELL ORIENTATION (Please include deviation schedule if yes to either) WELLBORE FLUID PRECAUTIONS H2S CO2 OTHER ADDITIONAL PRECAUTIONS (Paraffin, Comp. Packer, Slugging,...) PPM / % PPM / % DEVIATED?... Y / N HORIZONTAL?... Y / N WELL DIRECTIONS / OTHER COMMENTS:

34 ARC PRESSURE DATA, INC. MPL DATA SHEET Page of JOB NUMBER LOGGING OBJECTIVE: SUSPECTED PROBLEM CONDITION OR PRODUCING SCENARIO: PERFORATIONS (Please include attachment if more than 10 intervals) INTERVAL 1 TO SPF # HOLES SIZE INTERVAL 2 TO SPF # HOLES SIZE INTERVAL 3 TO SPF # HOLES SIZE INTERVAL 4 TO SPF # HOLES SIZE INTERVAL 5 TO SPF # HOLES SIZE INTERVAL 6 TO SPF # HOLES SIZE INTERVAL 7 TO SPF # HOLES SIZE INTERVAL 8 TO SPF # HOLES SIZE INTERVAL 9 TO SPF # HOLES SIZE INTERVAL 10 TO SPF # HOLES SIZE FLUID PROPERTIES Oil Gravity Gas Gravity H2S CO2 N2 Water Gravity or PPM Chlorides Initial Gas-Oil Ratio Current Gas-Oil Ratio Bubble-Point / Dew-Point Pressure ( If known from downhole sample or recombination analysis ) ** Condensate Yield Stabilized Oil Rate Stabilized Gas Rate Stabilized Water Rate Producing / Injection time prior to log Average or Initial Reservoir Pressure from PTA Deg API * % / ppm % / ppm % / ppm ppm SCF/STB SCF/STB psia STB/MMCF STB/day MCF/day STB/day days psia * If full composition analysis of gas is known, please include copy of gas analysis ** If downhole sample or recombination analysis conducted for this well, please include copy showing representative formation volume factors, viscosities, heat capacities, etc... versus various pressures

35 ARC PRESSURE DATA, INC. MPL DATA SHEET - continued Page of JOB NUMBER OTHER FACTORS AFFECTING FLOW / INJECTION PROFILE PREVIOUS INJECTION OR PRODUCTION HISTORY / WORKOVERS: HAVE ANY RADIOACTIVE MATERIALS BEEN INTRODUCED INTO THE WELLBORE IN RECENT WELL OPERATIONS? ANY SIGNIFICANT RATE CHANGES IN PREVIOUS YEAR? PREFERRED ATTACHMENTS: OPEN HOLE LOG FOR GR-CCL DEPTH TIE-IN DEVIATION SCHEDULE WELL SKETCH PRIOR PRODUCTION LOGS (requirement) REQUIRED TOOLSTRING CONFIGURATION: LOGGING PROCEDURE:

36 SETTING UP AN MPL PROJECT WITH ARC GENERIC PRODUCTION LOG PROCEDURE General Multi-pass Spinner Survey Production Well Make sure well has a stabilized flow and monitor rates the day before or day of the log RIH with gauge ring and/or dummy string of weight bar resembling dimensions of logging tools and tag TD RIH with logging tools to approximately 50 foot above end of tubing; Begin logging down at 30 FPM over the intervals of interest and log to the deepest point of static rat hole as possible without plugging spinner. Make logging pass up at 30 FPM to at least 50 to 70 feet above uppermost interval of interest. Repeat down and up passes at 60 FPM and 90 FPM respectively. Beginning below the lowest suspected point of production entry, make stationary stops at appropriate points below and above each perforated interval or points of entry into the wellbore. Depending on available tool memory, make a 200-FPM pass all the way out of the hole if possible. This pass is optional and can be performed on a separate run to conserve memory. POH and download data; merge downhole memory data with depth data and play back raw log data to confirm useful data based on log objectives. Optional procedure for checking for potential channeling or cross-flow... Shut well in and make passes at 1 hour, 2 hours, and possibly 3 hours after shut-in for qualitative inspection of the temperature and spinner. 5-5

37 SETTING UP AN MPL PROJECT WITH ARC POINTS TO REMEMBER When it comes to all of the needs and objectives that create the need for production logging data, it would be difficult to plan for all the possible scenarios that could exist. However, there are some good things to know or be aware of when planning your next production logging intervention. If your well does not have a crown valve or swab valve, a wireline crew will have to shut the well in briefly to rig up with their lubricator. This can disrupt the well s flow if not allowed to re-stabilize. It is preferable to install a crown valve several days in advance of the logging job. Recent pumping, treatment, or other workover operations may have an impact on one or more of the measurements being recorded on a production log, especially temperature and gamma-ray measurements. Oil, gas, and water sample analysis for the well being logged provides the greatest accuracy for discerning multi-phase flow profiles. A multi-rate logging technique where the well is logged at four or five separate stabilized rates can provide estimates of each layer pressure and individual zone PI. Tail pipe below a packer that hides one or more sets of perforations creates problems with trying to determine fluid entry profiles. One or more sets of perforations covered by fill or even a T.D. just below the lowest open perforation can make it impossible to evaluate for volumetric flow or fluid ID from that set of perforations. Spinner surveys require being able to log by the zone of entry. Proper downhole calibration of the spinner depends on a no-flow zone. 5-6

38 CHAPTER 6 LOG PRESENTATION & INTERPRETATION

39 LOG PRESENTATION AND INTERPRETATION LOG DATA REPORTING LOG DATA REPORTING Field Print For a typical production log, a field print (standard API formatted log) is provided on location to confirm that reasonable data has been acquired. This initial presentation may or may not be depth corrected to a tie-in log, depending on whether such a comparison log is available at this point. API Log(s) Two formal, black and white logs and one color log are provided for raw data presentation. Interpretation is provided in bound report form. Situations may vary, but typical turn-around for the raw log presentations is from 24 to 48 hours and the interpretation is from 48 to 72 hours. As always, ARC is always prepared to provide expedited help for those scenarios where data and interpretation are needed for immediate decisions for well completions and workover. Typical Log Content Once each pass is corrected to the proper depth using either the gammaray or collar locator, usually the slowest line-speed pass of those two sensors are presented against the other curve sets. Additional log sections would include a compilation of each sensor on one presentation followed by overlays for each of Temperature, Pressure, and Spinner. A separate log section may include differential calculated curves for Temperature and Pressure. In each case, the depth track is annotated with symbols depicting perforations and other wellbore completion devices. A comment section may include a brief field interpretation and tool schematic or description. Digital Data The digital log data is available upon request in LAS (ASCII) format. This data can encompass a significant amount of memory, so there is a need to determine a storage media or transfer process. Reasonably sized data has been spanned across 1.44 MB floppy diskettes or has been compressed (*.Zip) and ed via the Internet. Larger data sets can be provided on (Iomega 100 MB) Zip disks. 6-2

40 LOG PRESENTATION AND INTERPRETATION LOG DATA REPORTING AND ANALYSIS Data/Log/Report Type Typical Turn-around I Field Print API log (Thermal paper print) On location may be depth-corrected or not II API Log 2 black & white permanent copies and 24 to 48 hours 1 color permanent copy may have a brief field interpretation III Digital Data LAS (ASCII) data on storage media 24 to 48 hours (1.44 MB floppies, 100 MB Zip disks, or ed via Internet) IV Analysis Report Qualitative and/or quantitative interpretation and 48 to 72 hours Global Statistical Analysis of Profile in bound report form with discussion and summary. LOG DATA ANALYSIS Proven Statistical Technique Applied to Production Logging For many years interpretation of production logs for the determination of how much of each phase is entering or leaving the wellbore has been somewhat of an art. Much of the art was very dependent on experience with different zones and completions in a particular area. As with any interpretive work, it was difficult for an operator to get consistent answers and there certainly was no way of verifying the results except by experimentation. With the introduction of greater resolution tools and the power of the computer, some of the theoretical physics of pipe flow, heat transfer, and material balance can now be applied to the multi-dimensional, multi-variable problem of production logging. ARC Pressure Data utilizes a software product that embodies one of the most rigorous analytical approaches to production log interpretation available. PLATO, or Production Log Analysis Tool is written and supported by Interpretive Software, Inc. New global optimization techniques are discussed in the next section, which provide a Monte-Carlo type of simulation where the results are modeled and matched against the actual tool response for verification. 6-3

41 PLATO Production Logging Analysis TOol A Global Weighted-least-squares error Optimization Technique provides a radically new approach to Production Logging Analysis

42 ARC Pressure Data, Inc. PLATO THE GLOBAL APPROACH TO PRODUCTION LOGGING ANALYSIS Traditional production logging analysis focused on data from one central tool, the flowmeter, and used a very small fraction of the log data. This produced very inaccurate results and often reduced the range of applicability to simple vertical Wells and two phase analysis. A NEW ERA IN PRODUCTION LOGGING ANALYSIS A dramatic improvement of the analysis is obtained in PLATO by using a Global Statistical Analysis Technique. An enthalpy balance model allows to use the temperature log, replacing or compensating for the often undependable data from the flowmeter. Inclusion of modern tools such as RST and WFL further enhance the predictive power of PLATO in difficult wells. In unsolvable cases PLATO will allow the analyst to determine which essential data is missing or too inaccurate. It allows the analyst to redirect efforts and obtain better results. Highly deviated and horizontal Wells can finally be addressed. FULLY INTERACTIVE GRAPHICAL INTERFACE The analyst has instantaneous information on the analysis through graphical displays of data and results, as well as numerical results readily available, from the editors. Powerful control parameters enable the analyst to quickly modify the model and evaluate improvements made by his changes. Constraints can be disabled or gradually modified. This makes it particularly easy to judge the benefits of a modification to the model. Any log data or modeling parameter can be accessed from PLATO. PLATO A UNIVERSAL TOOL FOR PRODUCTION LOGGING ANALYSIS. Exploitation conditions change from Well to Well and tools and models evolve. Traditional analysis techniques are deterministic and force the analyst to use a fixed number of known tools. Introducing a new tool or equation is difficult because an analytic solution must be found. Moreover, information from some tools must be discarded to satisfy the premises of the deterministic technique. PLATO avoids all this by simultaneously using all available data in a statistical model. In fact the more tools used, the more accurate the results. The modular and flexible construction of PLATO puts an end to the "one model fits all cases" paradigm. Mission specific applications are the key to a successful analysis of a Well. The ease, to add constraints and variables, allows to build an accurate model of the Well. Any part of the model can easily be modified: the phase conversion correlations, flow regimes, unknowns as well as any tool response equation. FAST TURN OVER AND UNINTERRUPTED ANALYSIS SESSIONS Once PLATO is started, the graphics engine and editors allow the analyst to visualize both graphically and numerically all data and parameters. The analyst can execute any installed analysis-, pre-processing- and emulation tasks as well as his own tasks; all during the same session. This greatly reduces the analysis time and risks of mistakes in manipulating data. Moreover, the "multiprogram with inconsistent user interfaces" approach is replaced by one system with multiple services. In this way PLATO guaranties a homogeneous graphics user interface for all its applications. When building his own models a user always has all the facilities such as editors, graphics engines etc.. directly as a part of his application.

43 ARC Pressure Data, Inc. PLATO A SYSTEM FOR PLA ANALYSTS, TOOL DEVELOPERS AND ENGINEERS Besides the analysis task, PLATO has a powerful emulation task allowing tool engineers and researchers to study the effect of well conditions on tools. PLATO emulates Wells through an iterative process, which determines holdups, temperature and pressure. This is impossible through direct computation. It enables researchers to realistically verify their models. By analyzing emulated data, a PLA analyst can study the causes of difficulties in evaluating existing wells and inexperienced analyst can be trained and their performances evaluated. PLATO HOW DOES IT WORK? To go from the raw data to the final result - the production profile - PLATO goes through a series of tasks, which can be performed automatically or under the user control. At each step the results can be saved away and the session interrupted. The results can be visualized at any moment. Early in the analysis, the analyst must supply global information from the field or laboratory. This information describes characteristics of the oil, gas and brine at reference conditions and the geometry of the Well. Any information can be modified easily at any time during the analysis. The information can be zoned to reflect depth dependent changes. All phase properties at Well conditions are calculated by PLATO (no charts or tables are required). In order to improve the accuracy and access all the available information in the data, the first task performed by PLATO is a preprocessing. All the available data is filtered and regression algorithms are used to remove the effects of the tool movement. This step can use all the available up- and down passes and results in consolidated pressure, pressure drop, density, hydro and temperature measurement. The second task handles flowmeter data. An optimization algorithm is used on all (or subsets of) spinner data, to determine calibration information. Thereupon, the apparent velocity is calculated for each depth. The advantage of this method, in addition to its speed and ease, is the ability to compute the velocity in zones where all spinner passes have the same polarity (e.g. in zones with fast moving phases). The third task requires some input from the analyst. By comparing the apparent velocity, temperature and pressure logs, the analyst determines the producing (injection) zones. The results are then entered into PLATO through a single zoned parameter. From this parameter PLATO builds the entire production model. The model includes many control parameters, which will enable the analyst to adjust the model. At any time the user can repeat this task and completely rework the model. The last task consists of the actual analysis. Here the complex model generated by PLATO is compared to the data. The main purpose of the task is to determine the production rates for the three phases, in each production zone. The task is performed in two modes: evaluation and global optimization. During evaluation the stored estimates of the production rates are used to calculate the phase holdups at each depth. Therefore, PLATO uses an optimization algorithm, which finds the best possible agreement with density (gradio and/or gamma ray), apparent velocity, hydro, pressure drop and temperature. The figure below is an example of the temperature tool. 3

44 ARC Pressure Data, Inc. deviate other constraints are added to account for the remaining data and physical constraints: Surface flow rates Material balance Solution gas boundaries The analyst can add constraints on the flow profile by limiting the range (min. & max.) of production rates and flow rates. At termination of the global optimization an evaluation is performed to show the results. The figures below show the reconstruction before and after global optimization. Any available tool (such as RST and WFL) can be added to this set. Other constraints pertaining to the holdups come in the equation, however. These constraints are related to the physics of the fluid, gas and well system. The most relevant constraints are: The flow regime, which is based on the Dukler analytical model. The slip velocities associated with the above regimes Any number of tools sensitive to the holdups can be added as constraints. PLATO will modify the holdups through successive iterations until it finds the best statistical agreement with all constraints. The resulting reconstruction and the holdups are progressively displayed. In evaluation mode the analyst can modify any aspect of the model and reevaluate the Well. Typically the analyst would modify production rates to study the changes to his results. The computations go very quickly, so many trials can be made. The global optimization mode goes one step further. In this mode the production rates are modified through successive iterations until the best agreement with all available data and constraints is found. Therefore, the statistical deviates (χ 2 ) calculated at each depth are added together to form a global statistical deviate. To this In a final task the flow and production rates are calculated at well conditions and a complete and comprehensive report is generated. 4

45 ARC Pressure Data, Inc. SUMMARY OF THE PRODUCT PLATO is an INTERACTIVE GRAPHICS ANALYSIS TOOL, providing fast validation of models selected by the analyst. The key features are: Global Statistical Analysis Technique allowing: Genuine 3-phase PLE analysis Accurate results in three phase and deviated Wells Simultaneous use of any number of tools and constraints Allows very complex models Extendibility to new tools and user models Powerful quality control to validate results or identify problems Emulation of production logging data Powerful controls for flexible modification of model and data Automatically determines the flow regime using the Dukler Analytical Model. Open System giving complete access to all data and model parameters. Interactive graphic visualization of all data and results Simultaneous use of depth traverses and stationary Data. Fast turnover Multi-windowed environment Architecture designed for easy integration of new tools and models Modular construction allowing integration into client software environment Cross Plots analysis Customizable smart icons Customizable & comprehensive report generated automatically Customizable Wizard system to guide the user through the analysis Customizable parameter templates for faster job preparation Operating system: Windows Windows 95 Windows NT. Additional tasks for post-processing, new tools or proprietary PVT correlation and new flow regimes and slip velocities equations can be added on request.