Subsurface Stress Pressure And Stress

2y ago
34 Views
2 Downloads
784.74 KB
6 Pages
Last View : 11d ago
Last Download : 5m ago
Upload by : Noelle Grant
Transcription

SubsurfacePressureand StressStressStress force / areaUnits Pascals, psi N/m2 kg/(m . s2)Force 50 kg * 9.8 m/s2Area 1 cm2 0.0001 m2Stress 4,900,000 Pascals686 psiGeol493KHow much is 1 Pascal? 1 Pa 0.00014 psiStress/pressure What is the difference? Car tire 230,000 Pa 1 Megapascal (1 MPa) 1 million Pa 1 x 106 Pa 145 psiOn-in convention: xyON the x-planeIN the y-direction Pressure - Scalar quantity Stress - Tensor quantity Pressure – in fluids Stress – in solid bodies2D Stress TensorStress Tensor zzNormal andShearcomponentsz zx xz xz xx xx zx zzx

Lithostatic stress/ hydrostatic stress Lithostatic stress Tectonic stress Fluid Pressure-Hydrostatic-HydrodynamicLithostatic Stress Due to load of overburden Magnitude of stress components is the same in alldirectionsgravity Lith ρ.g.zdepthdensityPressure/stress gradientsLithostatic Stress Gradient Lith ρ.g.zRock density 2000 to 3000 kg/ m3 Lith 22 to 26 Mpa/km1 psi/ft2500 kg/ m3 x 9.8 m/ s2 x 1000 m 25 MPa/km 1 psi/ft10 Mpa/km0.43 psi/ftWhat about horizontal stress?Horizontal Stress Rocks are elastic solidsHorizontal stress depends on rock compressibilityPoisson’s Ratio eyy/exx incompressible material (no volume loss) Rocks 0.1 to 0.3Hor [ ρ.g.zIf Hor ρ.g.zIf Hor ρ.g.zHorizontal stress is about 1/3 of vertical ifrocks are lithified

Comparison of vertical andhorizontal stressesWorld Stress Map – Hor directionρgzρgzSuppe, 1985VerticalMin horizontalBorehole Wall Breakouts and StressPressure/stress gradientsHorizontal Stresses Min Max22 to 26 Mpa/km1 psi/ft Max10 Mpa/km0.43 psi/ft MinCaliper log measures the shape of the boreholeOverpressure more than hydrostaticWhat about these?Why morethan 0.43?Spindletop, 1901Deepwater Horizon, 2010

Shale CompactionShale Porosityvs. Depth CurveShale compacts aswater is expelledSchmoker and Halley, 1982Over Pressure ZoneWell 1Well 2Well 3Pressure barrierSand ASand BSand CPressure sealinferred to exist inregion of highfluid pressuregradientReservoirCompartmentsFluid pressure as a function of depth, Cook Inlet Alaska - Hunt, 1990Characteristics of OverpressureZones Under-compacted shaleLow density, low sonic velocityRapid Drilling RateLow Thermal Conductivy, high TLow SalinityControlling Reservoir Pressure Drilling Mud Casing Blow-out preventers

Blow Out PreventersHow to measureformation pressureFormation TesterSchlumbergerHow to measure reservoir pressure?Drill Stem TestDrill Stem Test (DST)2. Initial Flow Period (IFP)removes effect ofmud filtrate“supercharge”3. Initial Shut-in is usedto determine a reservoirPressure (ISP)Structural Dip 1o NortheastFinal Flow Period (FFP)is used to collect a fluidsample and create apressure disturbancebeyond any damagedzone.Final Shut-in is usedto test permeability,production rate andwell damageDrill Stem Test Pressure ResultsReservoir PressureReturn to MudPres.Initial ReservoirPressureLeduc Fields,Alberta (Canada)Open ValveInitial Shut InPre-Flow ( 1 hour)FlowLeduc #1 Gas flare

Hydrodynamic SystemPhase Behavior for a singlehydrocarbonPhase Behavior of Gas-Oil MixSupercriticalfluidReservoirLiquidCritical PointBubble Point100%LiquidPressurePressureCritical pointGas75%50%25%Stock TankSupercriticalfluidSeparatorLiquid Gas5%GasTemperatureTemperatureSupercritical: density like a fluid, viscosity like a gasPhase Behavior of Wet Gas 5%25%50%GasSummary SeparatorTemperature ρ.g.zHydrostatic gradient 0.43 psi/ft or 1 Mpa/kmLithostatic gradient 1 psi/ft or 25 MPa/kmOvepressure forms when water cannot escapePressure gradient defines reservoir compartmentsArtesian aquifers can produce anomalous PMethods to control P during drillingHydrodynamic reservoirs lead to tilted oil-watercontactsPhysical state of hydrocarbons depends on P-T regimeBringing oil to the surface cools and depressurizes it

2D Stress Tensor x z xx xx zz zz xz xz zx zx. Lithostatic stress/ hydrostatic stress Lithostatic stress Tectonic stress Fluid Pressure-Hydrostatic-Hydrodynamic Lithostatic Stress Due to load of overburden Magnitude of stress components is the same in all

Related Documents:

These valves, called Subsurface Controlled Subsurface Safety Valves (SSCSVs), or velocity valves, are sized or configured to close when the loss of tubing backpressure from a disaster causes the well to flow in excess of its normal production rates. Velocity valves are sized using programs, developed by the valve manufacturers, that

Subsurface Flow Control Systems 11 11-1 Subsurface Flow Control Systems Introduction Halliburton subsurface flow control systems are designed to

1.4 importance of human resource management 1.5 stress management 1.6 what is stress? 1.7 history of stress 1.8 stressors 1.9 causes of stress 1.10 four major types of stress 1.11 symptoms of stress 1.12 coping with stress at work place 1.13 role of human resource manager with regard to stress management 1.14 stress in the garment sector

Table 4.1: Analytical results for stresses on pressure vessel SR. NO. Type of stress Magnitude (MPa) 1 Table 6.2. Stress Analysis of Pressure Vessel with Two 10 Hoop Stress 50.52 2 Longitudinal stress 25.26 V. MODELING AND ANALYSIS OF PRESSURE VESSEL The 3D model of pressure vessel is created using a CAD software Creo Parametric.

1. Stress-Strain Data 10 2. Mohr Coulomb Strength Criteria and 11 Stress Paths 3. Effect of Different Stress Paths 13 4. Stress-Strain Data for Different Stress 1, Paths and the Hyperbolic Stress-Strain Relationship 5. Water Content versus Log Stress 16 6. Review 17 B. CIU Tests 18 1. Stress-Strain Data 18 2.

(ETo) which has been correlated to the ET (evapotranspiration) of 12 cm tall cool season grass . ETo is estimated using the Penman Monteith equation also shown in Figure 3. and is strictly . crop environment such as water stress, salinity stress, oxygen stress, pollution stress, fertility stress, or stress from disease. .

Evaluation of Subsurface Exploration, Sampling, and Water-Quality-Analysis Methods at an Abandoned Wood-Preserving Plant Site at Jackson, Tennessee By William S. Parks, John K. Carmichael, and June E. Mirecki Abstract Subsurface sampling using both Direct Push Technology (DPT) and a modified-auger drilling method were evaluated in 1991 by the

REST API Security REST Authentication Overview ESC REST API uses http basic access authentication where the ESC client will have to provide a username and password when making ESC REST requests. The user name and password will be encoded with Base64 in transit, but not encrypted or hashed. HTTPS will be used in