Susceptivity evaluation and protection countermeasures for the reservoir rocks in the first member of the Dongying Formation in the Nanpu region, Hebei

The oil reservoirs on the braided delta front slope in the first member of the Dongying Formation in the Nanpu region have the features of moderate porosity and low permeability with strong heterogeneity. In the light of experimental procedures for susceptivity evaluation, a variety of tests are conducted in the laboratory in which the experimental conditions are similar to those in the stages of well drilling and water injection recovery in the oil fields. The results of research indicate that the studied reservoir rocks have both the water and salinity susceptivity.In these cases, the protection countermeasures for the reservoir rocks should be suggested, including the calculation of the depths for the infiltration of the drilling mud so as to arrange suitable progress of drilling construction, and the decrease of soakage periods of mud and adoption of highly effective hole-shooting bullets in order to wipe off mud contamination to the reservoir rocks.