1.School ofPetroleum Engineering, Xi′an University ofPetroleum, Xi′an 710061, China;
2.Gudao Production Group ofShengli Oil Field Limited Company,Dongying Shandong 257231, China)
Based on coring information, laboratory test data and dynamic logging information of the formation,the paper elaborated
on the changing feature of the lithology, physical property, oil bearing property and electrolysis property for sandstone reservoir in
Gudao oil field during low water bearing period,medium water bearing period and high water bearing period respectively. Because
of long-term injection exploitation, within the reservoir the clay volume, carbonate content, oil saturation and bound water satura-
tion was reduced, and average pore diameter and rock grain size was increased, which led to an increase of the permeability and
porosity. However, with overall growth of physical property, the discrepancy of the parameter for porosity and permeability was
raised. At the same time, the physical property became worse due to the water sensitivity and rate sensitivity.Additionally,inter-
val travel, spontaneous potential and induction resistivity changed obviously. There was a difference in change level for reservoir
parameter of different lithology. For example, the change level for reservoir parameter of silt is less than that of fine sand.