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Essentials of Geology 7th Edition (Stephen
Marshak) - chapter 12 smartwork. Exam
Questions And Answers (Guaranteed A+)
For organic material to accumulate in sediment and be preserved by burial, that organic material
must accumulate in ___ water systems. - Answer✔anoxic
Order the steps, from early- to late-stage conversion, for this sediment to become a host to
natural gas or oil. - Answer✔Earliest to Latest:
Plankton and clay floating in low-oxygen water sink and accumulate
More sediment accumulates over the plankton-rich layer and compresses it
Organic-rich sediment is transformed into organic-rich shale
Heat and pressure increase with burial depth; organics convert to kerogen
As temperature increases, kerogen turns into oil and natural gas
Reservoir rock with high ___ is the preferred reservoir rock for an oil or gas well because fluids
move through it easily. Reservoir rock that has high ___ may store much fluid. However, it's the
connection between the ___ that allow flow to occur through the rock. - Answer✔Permeability
Porosity
Pores
What physical characteristics make a rock a good source rock for hydrocarbons? In the diagram
below, indicate which is the good source rock. - Answer✔Left - poor source rock
Right - good source rock
Low ___ would cause difficulty in pumping oil directly from a source rock. -
Answer✔Permeability
A ___ is relatively impermeable; examples include shale, salt, and unfractured limestone.
Impermeable rock must overlie a ___ in order for a ___ to form. - Answer✔Seal
Reservoir rock
1|Page
Essentials of Geology 7th Edition (Stephen
Marshak) - chapter 12 smartwork. Exam
Questions And Answers (Guaranteed A+)
For organic material to accumulate in sediment and be preserved by burial, that organic material
must accumulate in ___ water systems. - Answer✔anoxic
Order the steps, from early- to late-stage conversion, for this sediment to become a host to
natural gas or oil. - Answer✔Earliest to Latest:
Plankton and clay floating in low-oxygen water sink and accumulate
More sediment accumulates over the plankton-rich layer and compresses it
Organic-rich sediment is transformed into organic-rich shale
Heat and pressure increase with burial depth; organics convert to kerogen
As temperature increases, kerogen turns into oil and natural gas
Reservoir rock with high ___ is the preferred reservoir rock for an oil or gas well because fluids
move through it easily. Reservoir rock that has high ___ may store much fluid. However, it's the
connection between the ___ that allow flow to occur through the rock. - Answer✔Permeability
Porosity
Pores
What physical characteristics make a rock a good source rock for hydrocarbons? In the diagram
below, indicate which is the good source rock. - Answer✔Left - poor source rock
Right - good source rock
Low ___ would cause difficulty in pumping oil directly from a source rock. -
Answer✔Permeability
A ___ is relatively impermeable; examples include shale, salt, and unfractured limestone.
Impermeable rock must overlie a ___ in order for a ___ to form. - Answer✔Seal
Reservoir rock
1|Page
