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Flashcards in chapter 5 vocabulary reservoir performance Deck (63)
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1
Q

Any substance that flows and yields to any force tending to change it shape is a . Both liquids and gases are fluids.

A

Fluids

2
Q

the density measure used for petroleum liquids. Expressed in degrees. The higher the______the lighter the liquid. formula for _____ = 141.5/S.G. – 131.5 (S.G. - specific gravity).

A

API gravity

3
Q

Defined as hydrocarbons that are in a gaseous state at standard conditions of one atmosphere (14.7 psi) and 60deg F. Included are methane, ethane, propane, and butane.

A

Petroleum Gases

4
Q

the minimum saturations of oil, water, or gas in the reservoir that cause the fluid to be a continuous medium, and therefore producible.

A

Critical saturations

5
Q
  • gas that is in solution in the oil under the initial reservoir pressure and temperature. Under these conditions, the gas is in the liquid state.
A

Solution gas

6
Q

the percent or fraction of the reservoirs original oil in place (OOIP) or original gas in place (OGIP) that will be recovered. Expressed in percent.

A

Recovery factor

7
Q

is from solely gas reservoirs where no “black” (non-condensate) oil is present.

A

Non-associated gas

8
Q
  • includes solution gas and gascap gas. They both occur only in association with oil.
A

Associated gas-

9
Q

is free gas trapped in the top of the structure above the oil leg.

A

Gas Cap-

10
Q

ratio of gas to oil produced or in solution in the reservoir. Units are in ft3 /bbl. or m3 /bbl.

A

Gas oil ratio (GOR)-

11
Q

Beta is the factor for the volume change undergone by the reservoir fluids when they are produced. In the case of oil, it is the ratio of the space occupied by a barrel of oil at reservoir conditions to the space occupied by a stock tank barrel (STB) of the oil. Most oils shrink when their solution gas dissipates at the surface and because of the cooler surface condition, so their Betas are greater than 1.

A

Formation volume factor (B)-

12
Q

a fluids resistance to flow. The thicker and stickier the fluid. The higher its ______.

A

Viscosity (u)-

13
Q

a light hydrocarbon liquid formed by condensation of petroleum compounds that were in the gaseous phase under initial reservoir conditions. It is highly volatile and from clear to a light yellow in color

A

Condensate

14
Q

when a reservoir is above its ___ ___ __, it has no free gas—all gas is in solution in the oil. As the reservoir is produced and pressure declines, the _____ _____ ____ is reached. Gas comes of solution, forming a free gas saturation.

A

Bubble point pressure

15
Q

is used to refer to all the artificial drive mechanisms such as waterflood, CO2 flood, steam injection, etc.

A

Enhance recovery- or improved recovery

16
Q

producing the reservoir using only the natural reservoir energy.

A

Primary recovery

17
Q

the initiation of additional recovery processes like waterflooding immediately without waiting for primary depletion.

A

Pressure maintenance

18
Q

a process that adds energy to the reservoir following primary recovery. An example is waterflooding a depleted field.

A

Secondary recovery

19
Q

follows secondary recovery. For example, CO2 flooding could follow waterflooding, which had followed primary recovery.

A

Tertiary recovery

20
Q

know whats there, no two reservoirs behave identically when produced.

A

Fluid systems

21
Q

naturally occurring near solid hydrocarbon. Must be mined.

A

Bitumen

22
Q

tar or heavy oil, low-shrinking oils (black oils), high shrinking oils (volatile oil), condensate gas, wet gas, dry gas

A

Fluids

23
Q

with more lighter ends than bitumen and small amount of gas in solution, it flows sluggishly through the reservoir

A

Tar or heavy oil

24
Q

oils viscosity is low enough for it to move through the formation readily, normally commercially producible

A

Low shrinkage oils (black oils)

25
Q

because of its low viscosity, volatile oil produces at high rates and it high Rs ( ) results in high good recovery factors

A

High shrinkage oils (volatile oils

26
Q

hydrocarbons in reservoir are gaseous at initial conditions. During initial gas production, large quantities of condensate drop out in the surface facilities

A

Condensate gas

27
Q

All hydrocarbons are in a gaseous state. When gas is produced, the associated cooling causes condensate to drop out in the surface facilities.

A

Wet gas

28
Q

gas is composed primarily of methane with small amounts of ethane, propane, and butane. These reservoirs produce no condensate

A

Dry gas

29
Q

most widespread reservoir drives. Four phases 1. Production starts, reservoir pressure declines rapidly to the bubble point. 2. The GOR (gas to oil ratio) dips below the solution GOR for a short period. 3. Gas saturation exceeded. 4. Depleted of it gas

A

Solution gas drive

30
Q

have access to aquifers that provide water to replace some or all of volume fluids produced. Provide the highest recovery rates.

A

Water drive

31
Q

free gas trapped in the top of the structure above the oil leg

A

Gas cap drive

32
Q

pressure depletion of reservoirs.

A

Gravity drainage

33
Q
  • overpressured reservoirs. North sea chalk fields example of this
A

Compaction drive

34
Q

there are no liquid hydrocarbons in the formation. Gas has lower viscosity than oil (

A

Wet and dry gas reservoirs

35
Q

initially very profitable, but it can fall off dramatically; loss of revenue from condensate sales; liquid build up in the formation restrict its permeability to gas; good candidate for recycling if found in remote area from the market.

A

Retrograde condensate gas reservoir

36
Q

dominant recovery method, used worldwide. Advantages saltwater availability, chemical compatibility, equipment availability, safe non toxic non flammable

A

Waterflooding

37
Q

saltwater and oil do not mix.

A

Fluid displacement

38
Q

water not oil adheres tightly to the surface of the sand grains.

A

Wettability

39
Q

the attraction between a surface and its wetting fluid.

A

Capillary forces

40
Q

how much the reservoir rock is actually contacted by the advancing water. It is effected by its mobility ratio.

A

Sweep efficiency

41
Q

fluids ease of movement through the reservoir.

A

Mobility ratio

42
Q
  • five spot pattern- water injected to gently encroach from the perimeters of the field
A

Injection well patterns

43
Q

used to inject heat into the formation

A

Thermal recovery

44
Q

compressed air is forced down the well providing oxygen to ignite the oil

A

Fire flooding

45
Q
  • steam injected is used in fields that are 2 ½ acres (shallow wells 200-500ft)
A

Steam flooding

46
Q

huff and puff. The most successful thermal recovery.

A

Cyclic steam flooding

47
Q

mix with

A

Miscible

48
Q

reservoir is flooded with fluid that are miscible the reservoir oil

A

Miscible flooding

49
Q

the CO2 combines with the oil, swelling and reducing its viscosity. Used the most

A

Carbon dioxide flooding

50
Q

is miscible in crude oil. But lpg is not recovered

A

Liquefied petroleum gas (LPG)

51
Q

waste gases from burning oils used.

A

Flue gas

52
Q

only at high pressures

A

Nitrogen

53
Q

cost is too great to use

A

Detergents

54
Q

unpleasant and unsafe to handle

A

Alkaline (caustic)-

55
Q

the high cost of chemicals limits commercial application

A

Mobility ratio improvement

56
Q
  • bacteria used to reduce oil viscosity ( to slow )
A

Microbial floods

57
Q

estimated volumes of crude oil, condensate, etc., anticipated to be commercially recoverable from known accumulations

A

Reserves

58
Q

can be estimated, must have operational facilities to process and transport the reserves to market.

A

Proved reserves

59
Q

can’t estimate; divided in two risk classification; probable and possible

A

Unproved reserves

60
Q

because of uncertainties in both the counting and pricing of reserves while they are still in the ground.

A

Reserves are not assets

61
Q

Both liquids and gases are

A

fluids

62
Q

When there is a gas cap, the reservoir is at

A

bubble-point pressure

63
Q

Oil viscosity is measured in

A

centipoise (cp)