Hubbert Analysis (1940)

1. Hubbert Analysis (1940) • Gw flow porous media is a mechanic process that overcomes frictional forces along a flow path • Hydraulic potential is defined as the mechanic energy per unit mass or per unit volume of fluid • Gw moves from areas with high potential energy to areas with low potential energy

2. Physical Quantities define hydraulic potential • Elevation • Fluid pressure p g Real flow direction Gravity (elevation effect)

3. Hubbert analysis (How much work required to lift fluid from a standard state to a new elevation z) • work to lift fluid w1 = mgz • work to compress fluid w2 = • Work to accelerate fluid W3 = P, v z Z = 0, P = P0

4. Hydraulic potential () ~0 (hyd. potential per unit mass) (hyd. potential per unit volume) Elevation Pressure

5. Heads at point A Piezometer • Hydraulic head h • Water table surface to sea level • Elevation head z • Bottom of piezometer (point A) to sea level • Pressure head  • Water table surface to point A  h A z Sea level

6. Relationship between  and h

7. Hydrodynamics of oil migration (Hubbert, 1954) Slope (dip) of tilted oil-water interface If no hydraulic gradient (no water movement) Horizontal interface

10. Hydrodynamics of oil migration • Oil-water interface dips in the same direction as hydraulic gradient • Faster gw flow (dh/dl increases), steeper oil-water interface • Required conditions to trap oil • Geologic structure dip in the same direction as the hydraulic gradient (or oil-water interface) • dip of geologic structure > dip of oil-water interface

12. Multiphase Flow Gas (floater) Water DNAPL (sinker) g

13. Mechanisms of basin-scale fluid migration • Gravity (topographically-driven) • Compaction • Density-driven • Tectonic-driven

14. Topographic-driven flow

15. Compaction-driven flow (Gulf of Mexico)

16. Groundwater flow and overpressure in the Gulf of Mexico Basin

17. (a) Volumetric Strain -2e-6 +2e-6 -4e-6 +4e-6 Dsitance along dip (km) Distance along strike (km)

18. (b) Induced heads -10 +10 -20 +20 Distance along dip (km) Distance along strike (km)

19. Density-driven flow (hydrothermal convection)

22. Louann Salt

23. carbonate groundwater Groundwater associated with evaporites Meteoric water affected by mixing N S Louann Salt

24. Organic maturation • Time temperature index (TTI) • n= 0, T = 100-110C • n = 1, T= 110-120C • n = 2, T= 120-130C • TTI = 15-160, oil generation window • TTI = 500-1000, deadline for preserving oil • TTI =1,500, deadline for preserving wet gas

25. Organic maturation • Arrhenius model – track the fraction Xo (or %) of oil generated by a source rock • A0 is the pre-exponential factor (hr-1) • EA is the activation energy (kJ/mol) • R is the gas constant (8.31432 J K-1 mol-1)

26. Organic maturation • Ao and Ea differ among various source rocks • Obtained by hydrous pyrolysis experiments • Woodford Shale (EA = 218, A0 = 6.511016) • The timing of oil generation is not the same for all source rocks • kerogen with low EA and high A0 tend to reach peak generation earlier • Higher EA and lower A0 allow Slow thermal cracking

27. Organic maturation • Vitrinite reflectance (VR) • Vitrinite is not strongly prone to oil and gas formation, is common as a residue in source rocks • the vitrinite becomes increasingly reflective as thermal rank increases. Therefore, the % reflection of a beam of white light from the surface of polished vitrinite is a function of the rank (maturity) • The VR is expressed as Ro%, the percentage of light reflected from the sample, calibrated against a material with ~100% reflectance (i.e. a mirror) • Oil window: Ro = 0.65-1.3%

30. Organic maturation of Niger basin TTI = 15-160

31. Ro = 0.65-1.3%

32. Hydrodynamics and Fluids-Sediments-Bacteria Interaction in the Permian Basin, West Texas: Mechanisms for Sulfur Ore Genesis

33. Permian Basin Why oil and mineral reservoirs are located along basin’s margins far away from their deep sources? How overpressures are maintained in this tectonically stable basin?

34. Bioepigenetic sulfur (Culberson mine)

35. MVT mineralization, Bird mine (Glass Mt.) Calcite Galena/Sphalerite 2.5 cm (from Hill, 1996)

36. Shale Evaporite Salt Limestone Sandstone Red shale Dolomite 10 1 2 3 4 5 6 7 8 9 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 A Delaware Basin Central Basin Platform A' r s i c Permian P e r m i a n Permian P r i a n Penn. Devon. Miss. A' A Silurian 1 km Ord. 20 km West Platform Fault (after Matchus & Jones, 1984)

37. Guadalupe Mountains National Park, Capitan Reef Complex

38. Hydrogeological evidence of fluid migration • Petroleum reservoirs found far from source rocks (Hill, 1990) • Biogenetic sulfur, calcite, and metal sulfates (barite, celestite) deposits (Crawford and Wallace, 1993) • Karst features (Carlsbad caverns) carved by sulfuric acid (Hill, 1990) • MVT mineralization (sphalerite, pyrite, galena) by migrating brines along basin margins(Hill, 1996) • Regional dissolution of halite by eastward recharge of meteoric water (Chaturvedi, 1993)

39. Hypothesis: groundwater migration over long distance (tens to hundreds of kilometers) driven by overpressure system and gravity, provides a framework for understanding a number of geologic phenomena

40. Objectives: • Investigate long-distance hydrocarbon migration on the basis of basin hydrodynamics (overpressure and gravity flow) and geochemical and isotopic correlations of crude oils • Characterize groundwater geochemistry and the microbiology of Culberson sulfur ore district • Assess the distribution of overpressure zone using geophysical anomalies • Create a model of bacterial sulfate reduction and oxidation reactions for the formation of bioepigenetic calcite, native sulfur, barite, and celestite

41. Geophysical data Pore pressure Seismic sonic, resistivity, conductivity and gamma logs Geochemistry data Geochemistry of crude oils Groundwater geochemistry and microbiology Isotope geochemistry of bioepigenetic minerals Fluid inclusions of biogenetic calcite Field data

42. Geochemical and Isotopic Correlation of Crude Oils (provide by TNOR)

43. 13C composition of bulk oil samples -26 -28 13C(PDB) -30 -32 Source Beds Reservoirs Carrier Beds

44. 100 % 15.54 18.75 0 10.00 30.00 40.00 20.00 Gas Chromatogram Analysis computer % detector response Time Increasing temperature (30 to 280°C)

45. 24.30 100 Ward 100 15.28 28.61 % 35.43 18.63 % 35.44 17.37 45.41 12.67 0 10.00 20.00 30.00 40.00 1.89 10.10 4.76 9.81 0 10.00 20.00 30.00 40.00 8.57 3.94 2.02 100 % 15.54 18.75 0 10.00 30.00 40.00 20.00 100 % 43.76 0 10.00 20.00 30.00 40.00 24.30 28.61 18.82 8.10 12.13 4.56 1.68 Source bed oil from DB Culberson reservoir oil • Complete spectrum gas chromatograms • Show variations in biodegradation • Not very helpful in identifying links between reservoir, carrier bed and source-rock oils • Mass fragmentograms • Used to compare heavy fractions (biological markers) • tri- and pentacyclic terpanes (m/z 191) • steranes (m/z 217)

46. 24.30 28.61 18.63 35.44 1.89 10.10 4.76 100 % 43.76 0 10.00 20.00 30.00 40.00 24.30 28.61 18.82 8.10 12.13 4.56 1.68 Mass Fragmentograms Culberson oil (66121), Castile Formation m/z 191 Time (min) Ward county oil (67150), Pennsylvanian source bed 100 % 35.43 45.41 0 10.00 20.00 30.00 40.00 tri- and pentacyclic terpanes

47. Culberson (66121) 100 32.04 % 39.33 0 10.00 20.00 30.00 40.00 Ward (67150) 33.51 100 27.72 21.32 % 23.67 6.25 38.07 3.09 11.46 16.86 43.88 0 10.00 20.00 30.00 40.00 Time (min) 33.52 28.60 21.28 5.79 2.52 14.88 10.81 m/z 217 steranes

48. W E Delaware basin Central Basin Platform 66121 Castile Overpressure zone 67150 Pennsylvanian

49. W E Delaware basin Central Basin Platform 68171 Yates Overpressure zone 67015 Strawn

50. 100 100 % % 0 0 10.00 10.00 30.00 30.00 40.00 40.00 20.00 20.00 Time (min) Time (min) 24.30 28.61 18.26 34.33 39.60 43.32 13.13 8.91 1.87 24.29 28.61 35.45 20.25 40.02 2.99 9.90 Winkler source bed oil (67015), Penn. Strawn M/Z 191 Ward reservoir oil (68171), Perm.Yates Formation tri- and pentacyclic terpanes