Click here to load reader

Overview [Compatibility Mode]

  • View

  • Download

Embed Size (px)



Text of Overview [Compatibility Mode]

  • Overview


  • Oil and Gas Reservoirsz Porous rock (sedimentary)z Rocks mainly carbonate or sandstonez Unconventional gas (shale, coal bed, tight gas)z Trap is neededz A source of carbon (micro-organisms in seawater)z On- or Off-shore z Economics


  • OG_OV3

    Off-Shore Rigs and Platforms

  • How to Produce HCs?

    z Drill a well (gas or liquid)z Pressure differencez Mining (oil sands)a


    a. Oil is extracted by heat and caustic, Canada

  • How to Maintain Pressure Difference?

    z Reservoir pressurez Gas injectionz Water injection z Pumps (surface or submersible)z Gas liftz Minimize damage


  • Oil Recovery Modesz Primary z Secondary z Tertiary

    z Chemical z CO2 zSteam z In-situ combustion


  • Types of Injection Water

    z Seawater (SRB, SO4 scale)z Aquifer water (fines migration, SO4)z River water (fines migration, TSS)z Produced water (TSO, SRB, H2S)z Commingled water (scale formation)


    a. There are problems with all types of waters

  • Oil Processing z Oil gas separation plant (GOSP)z Separate dissolved gasesz Separate free and emulsified waterszWater contains salts (scale, corrosion)z Gases contain hydrogen sulfide


  • Problems with Produced Waters

    z Loss of production z Lifting, separation, disposal z Scale z Corrosionz Bacteriaz Emulsionsz Sanding


  • Chemicals Neededz Corrosion inhibitorsz Scale inhibitorsz Demulsifiersz Biocidesz Drag reducing agents


  • OG_OV11

    Types of Wells - Functionz Oil producerzWater injectionzWater disposalzWater supplyz Gas producerz Gas injectionz Observation (T, P, OWC, GOC, GWC)

  • OG_OV12

    Types of Wells Geometry z Verticalz Horizontalz Short radiusz Extended reachz Multi-lateral

  • OG_OV13

    Types of Wells Completion

    z Open holez Perforatedz Screensz Gravel packedz Smart completions

  • OG_OV14

    Lithologyz Carbonates z Sandstonesz Mixedz Shales

  • OG_OV15

    Carbonate Reservoirsz Calcite (CaCO3)z Dolomite CaMg((CO)3)2z Ankerite Ca(MgFe)((CO3)2)z Small amounts of clays, pyrite z Middle East, Brazil, USA, UK

  • OG_OV16

    Carbonate Rocks (2)

    z Dissolve in HClz Density of Calcite = 2.7 g/cc z Density of Dolomite = 2.85 g/ccz Natural fracturesz Positively chargedz Never use HF, H2SO4, H3PO3

  • OG_OV17

    Sandstone Rocks z Quartz (sand)z Feldspars and claysz Carbonatesz Sulfatesz Iron oxides (hematite)z Pyrite (iron sulfide)

  • OG_OV18

    Sandstone Rocks (2) z Density = 2.65 g/ccz Negatively chargedz Cementing material z Sand production z Fines migration z HF acid for silica/silicatesz Never use HF alone

  • OG_OV19

    Drilling Fluids (Mud)

    z Water-based z All oil z Oil-based

  • OG_OV20

    Function z Well controlz Cool-down the drilling bitz Carry drilling cuttings z Form filter cake z Left drilling cuttingsz Suspend solids if bit stops

  • OG_OV21

    Formulationz Water z XC-polymer (xanthan gum)z Starch, Poly-anionic cellulosez Weighting material z KClz KOH, Ca(OH)2z Drag reducing agents

  • OG_OV22

    Weighting Materials

    z Bentoniteaz Barite, BaSO4az Calcium carbonate, CaCO3z Hematite, Fe2O3z Manganese tetraoxide, Mn3O4a. Insoluble in HCl acid

  • OG_OV23

    Casing z Mainly low-carbon steel z Joints z Examples: J-55 and C-95z Letter stands for heat treatmentz Number is the minimum yield strength of steel

  • OG_OV24

    Cementz Placed between rock and casing z Zone isolation z Water shut-off

  • OG_OV25


    z Water z Class G cementz Additivesz Light weight cementz Flexible cement

  • OG_OV26

    Sand Productionz Weak rockz High drawdownz Water productionz Chemical treatments

  • OG_OV27Unconsolidated Sandstone

    Rock Integrity

  • OG_OV28

    Problemsz Accumulation in the well borez Erosion to surface valvesz Erosion to pumpsz All kinds of problems