3470895
Description
Mind Map by Hoa Truong, updated more than 1 year ago
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Created by Hoa Truong
about 9 years ago
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PRIMARY RECOVERY MECHANISM
- PERFORMANCE CHARACTERISTICS
- Ultimate recovery factor
- Press decline rate
- GOR
- Water Production
- Ultimate recovery factor
- Recover oil by natural
drive mechanisms
- Production of HC
without add extra
energy to reservoir
- NATURAL DRIVES
- COMPACTION DRIVE
- rock & liquid expansion
- materials present: crude oil, connate water, rock
- as reser. press decr. -> rock& fluid expand due to
their compressibilities-> grains expand-> bulk
volume incr. -> reduce poro/pore V + fluid expand
-> oil & water force out of pore space to wellbore
- liquids & rock: slightly compressible -> can
overcome the press drop due to production->
rapid press decline during production
- constant GOR = gas solubility at bubble point press
- least effective
drive: only
recover small
% OIIP
- rock & liquid expansion
- DEPLETION DRIVE
- As production, Press decr. < bubble Press ->
gas form (GAS LIBERATION from oil)+ expand ->
push oil to wellbore -> incr. oil production->
until reach critical press-> gas get inside
wellbore instead of oil-> reduce oil production
- also called SOLUTION GAS
/DISSOLVED GAS/
INTERNAL GAS
- press decr. rapidly & continuously. little/no water
production. rapid inc. GOR . rapid incr. oil production
until reach critical press at which rapid decr.
- 5-30% recovery OIIP, best
for secondary recovery
- As production, Press decr. < bubble Press ->
gas form (GAS LIBERATION from oil)+ expand ->
push oil to wellbore -> incr. oil production->
until reach critical press-> gas get inside
wellbore instead of oil-> reduce oil production
- GAS CAP DRIVE
- As press decr. during production -> gas cap expand (gas
expand to occupied V loss by oil produced + gas liberate
from oil) to maintain press -> push the oil to well bore
- Develop wells positions: drills many wells at
different depth -> determine GOR production from
these wells -> shut down wells which produced
excessive gas or use to re-inject gas back to reservoir
- present of a gas cap
with little/no water
drive
- Press fall slow, continuously. no/little water produce. GOR rise continuously
- 20-40%,larger
recovery than
depletion drive
- incr. size of gas cap, high vertical
permeability, low oil viscosity ->
greater Gas cap drive -> inc.
recovery % OIIP
- As press decr. during production -> gas cap expand (gas
expand to occupied V loss by oil produced + gas liberate
from oil) to maintain press -> push the oil to well bore
- WATER DRIVE
- as production, Press decr. & V of oil decr. ->
water replace oil V (water move into pore
space)-> maintain press -> push oil to wellbore
- as compactivity of water < oil, water source in
reser. need to connect to a large water body
- At water invaded zone, polymers can
be inject to inc. viscosity so the water
can get through oil to wellbore
- Gradual press decline (water maintain
press drop). little change in GOR.
- much higher
recovery % OIIP
than other
drives. 35-75%
- as production, Press decr. & V of oil decr. ->
water replace oil V (water move into pore
space)-> maintain press -> push oil to wellbore
- GRAVITY-DRAINAGE DRIVE
- need a slow flowrate of production for
gas to have time to move up to the gas cap
- As production, press decr. -> gas lubricate
from oil -> go up to gas cap due to gravity
(gas density < oil density) -> opposite
force push oil down & into wellbore
- bigger gas cap -> greater gravity-drainage drive
- occur as result of difference
densities of reser. fluids
- rapid press decr. Low GOR. form
secondary gas cap in undersaturated
reser. little/no water produce.
- can excess 80% recovery OIIP
- need a slow flowrate of production for
gas to have time to move up to the gas cap
- COMBINATION DRIVE
- combination of different natural
drives in one reservoir
- combination of different natural
drives in one reservoir
- COMPACTION DRIVE
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