In view of the reservoir conditions in a block of Changqing Oilfield with medium temperature

high salinity and low permeability

different temperature-salt resistant associative polymers（HAWSP series） with low relative molecular weight（720.42×10

4

~ 982.55×10

4

） and different contents of dodecylallyl tetramethyl ethylene diammonium bromide（TDAD） have been designed and synthesized. Then the molecular structure of the polymer has been confirmed by infrared spectroscopy. Under the conditions of this block

the reservoir adaptability of H

AWSP series involving solution properties and application performance have been studied

and the field test has been carried out in this block. The results show that

compared with the salt-resistant partially hydrolyzed polyacrylamide（HPAM）

HAWSP series has better thickening capacity and similar aging stability（viscosity retention rate is greater than 85 % after aging for 60 days）. When the gas permeability is of 50×10

-3

μm

2

the associative polymer HAWSP-850 not only exhibits good injectability and conductivity

but also could present stronger sweeping ability in heterogeneous core with a permeability contrast of 4 times（low permeability is of 25×10

-3

μm

2

）

which can enhance the oil recovery by another 3.29 percentage points. Field tests show that the temperature-salt resistant associative polymer has better field adaptability. Compared with the conventional HPAM flooding system

it has a significant effect of reducing pressure and improving injection capacity and oil recovery. Associative polymer has important promotion significance of chemical flooding in low permeability reservoirs.