Replacing OBM with WBM? - My-Spread 2009 obm wbm rev 1.pdf Replacing OBM with WBM? Ole Iacob Prebensen,

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Text of Replacing OBM with WBM? - My-Spread 2009 obm wbm rev 1.pdf Replacing OBM with WBM? Ole Iacob...

  • Replacing OBM with WBM?

    Ole Iacob Prebensen,

    Technology Manager, European Technical Center

  • Agenda

    • Background

    • Norwegian Continental Shelf

    • Technical Challenges of Mature Fields

    • Customers challenges in the future

    • Vapour from base oils• Vapour from base oils

    • New water based drilling fluid

    • WBM versus WBM, from an environmental perspective

  • Challenges - the Norwegian Continental Shelf

    & Customer Questionnaire

    & Customer Questionnaire

  • Background

    • Technical challenges in the oil industry are becoming more complex each day:

    • Ten kilometer wells

    • Ultra high-temperature high-pressure wells

    • Wells with very limited hydraulic window

    • These scenarios are no longer the exception, rather the standard.

    • Different drilling methods to deal with such environments include managed pressure drilling and casing drilling operations.

  • Norwegian Continental Shelf

    • The NCS consists of the North Sea, the Norwegian Sea and the Barents Sea.

    • The North Sea is regarded as a matureregarded as a mature area, where most reservoirs are depleted.

  • Norwegian Continental Shelf

    • As drilling operations expands to the northern parts of Norway and into the Barents Sea and most likely beyond, the impact of drilling operations to the environment is a very sensitive topic.

    Man

    Algae

    (Skeletonema sp.)

    Sediment Reworker

    (Corophium sp.)

    Zooplankton

    (Acartia sp.)

    Fish

    (Scophthalamus sp.)

    Bioaccumulation

    Aerobic Biodegradation

    Anaerobic Biodegradation

    Water soluble?

    Water insoluble?

  • Customers Questionnaire

    “The technical challenges we face in our industry are becoming more complex and we would like your opinion in this matter,we would like your opinion in this matter,

    especially were you see tomorrow’s challenges within your own group / rig.”

  • Challenges in the industry

    TOP FIVE

    TODAY

    1 ECD Limitations

    2 Losses to the formation

    TOMORROW

    ECD Limitations

    Depleted reservoir

    3 Depleted reservoir

    4 Hole Cleaning Issue

    5 Transfer of Experience

    Losses to the formation

    Hole Cleaning Issue

    Transfer of Experience

  • ”Runners-Up”

    • Environmentally accepted chemicals

    • Wellbore strengthening

    • Zero Discharge

    • Slop / Waste handling

    • Vapour• Vapour

    __________________________________________

    Focus:

    Develop drilling fluid systems that meet these challenges......!!!

  • Solution?

    • No single solution exist that will deal with all of these topics at the same time.

    • As an example, by nature there is a conflict between using very low viscosity base oil for reduced viscosity in the drilling fluid and at the same time have low vapor from the same base oil.

    • A compromise must be met.

  • Conventional WBM

     Bit balling  Accretion  Stuck pipe Stuck pipe  Hole cleaning  Bit trips – accretion

  • Development of a new WBM system

  • Goals set for the new WBM system

    1. Develop a water based alternative with the same benefits as experienced with oil based treated micronized weight material (TMWA).

    2. Create a highly inhibitive water based drilling fluid system in order to replace existing high- performance systems.performance systems.

  • Applications

    • Intermediate sections where high-performance water based drilling fluids or conventional oil based drilling fluids are being used.

    • Narrow operating windows are experienced & ECD management is needed.

    • Long section where WBM’s have been used and• Long section where WBM’s have been used and torque is an issue.

    • Rigs where vapour is an issue.

    • Limitation to the CRI unit.

    • Logistical capacity low.

  • Drilling Fluids Comparison

    • Generally, the performance of oil based drilling fluids (OBM) is regarded as superior to their water based counterparts (WBM) due to:

     Inhibition mechanisms

    Lubricity, coefficient of friction

    Temperature stabilityTemperature stability

    Corrosion

    Wellbore stability

    • These are a few of the benefits derived from using OBM’s versus WBM’s.

  • Laboratory Testing

    The system has been tested extensively with regards to:

    • Shale Inhibition

    • Accretion Potential

    • Recovery

    • Cuttings hardness• Cuttings hardness

    • Viscosity

    • Reduce high-end viscosity w.r.t. hydraulics

    • Effect of different contaminants

    • Barite sag & Lubricity

  • Comparing WBM with WBM

  • Drilling Fluids Comparison

    • As the industry strives to achieve improved environmental solutions with regards to zero discharge and re-use of drilling fluids, the introduction of HPWBM creates the possibility of using HPWBM where OBM’s is typically used.

    • As HPWBM contains environmentally acceptable chemicals with very good inhibition characteristics,

    • As HPWBM contains environmentally acceptable chemicals with very good inhibition characteristics, the volume utilized on drilled cuttings compared to standard WBM is reduced.

  • Benefits…

    • Statement: As a result the drilling cost and impact to the environment is reduced.

    • Furthermore, a reduction in contamination of the fluid allows for HPWBM to be re-used at a higher rate than conventional WBM’s. This is due to the improved inhibition mechanisms. rate than conventional WBM’s. This is due to the improved inhibition mechanisms.

  • HPWBM v.s. Conventional WBM

    • The chemicals in the HPWBM system used for shale inhibition are classified as YELLOW chemicals according to the Norwegian Pollution Control Authority (SFT).

    • What is the environmental benefit of this system in comparison to a conventional Potassium Chloride system with glycol – used widely on the Norwegian comparison to a conventional Potassium Chloride system with glycol – used widely on the Norwegian Continental Shelf – which contains only one YELLOW chemical

    ?

  • Comparison of Dilution Rates

    • A standard KCl / Glycol system uses from 3 – 5 % by volume of yellow components, whereas the HPWBM contains 4.4 – 6 % by volume.

    • Results from 17 ½” sections drilled gave the following dilution rates of drilling fluid lost on cuttings – only:cuttings – only:

    • KCl / Glycol: 2.76 m³ drilling fluid / m³ of cuttings

    • HPWBM: 1.73 m³ drilling fluid / m³ of cuttings*

    • Conv. OBM: 1.50 m³ drilling fluid / m³ of cuttings

    * The results varied from 0.79 m³/m³ to 2.59 m³/m³

  • Environmental impact

    Yellow Products HPWBM

    Concentration %

    by volume

    Low

    Conc.

    kg / m³

    High kg

    Conc.

    kg / m³

    Shale Inhibitors 4.4 – 6 44.6 59.2

    Yellow Products KCl /

    Glycol

    Concentration %

    by volume

    Low

    Conc.

    kg / m³

    High kg

    Conc.

    kg / m³

    Glycol 3 - 5 30.3 50.5

  • Environmental impact

    Drilling Fluid

    System

    Low conc.

    kg / m³

    High conc.

    kg / m³

    Dilution factor

    m³ / m³

    Actual discharge

    Low conc.

    kg / m³

    Actual discharge

    High conc.

    kg / m³

    HPWBM 44.6 59.2 1.73 77 102

    KCl / Glycol 30.3 50.5 2.76 83 139

    Result: From 7 % - 27% reduction in discharge of yellow products when using HPWBM compared to conventional KCl / Glycol.

  • Comparison of Re-use

    TYPE % Re-use Year 1 % Re-use Year 2

    OBM 70.8 82.8

    HPWBM 57.8 66.6

    KCl / Glycol 43.3 55.5

    HPWBM Programmed Achieved

    LGS (kg/m³) < 170 < 64

    MBT (kg/m³) < 45 0 - 15

  • Summary

    New water based technology versus HPWBM:

    – Reduced viscosity without compromising sag. As a consequence; lower ECD values with the same pump output, or equal ECD with more pump output.

    – Very good shale inhibition results– Very good shale inhibition results

    Hydraulic simulations between the new WBM and conventional OBM:

    – Reduction in pump pressure

    – Lower ECD’s

  • QUESTIONS??? Thank you