The Chang 6

1

reservoir was the main oil-bearing beds in the study area of Ganguyi Oilfield in Ordos Basin. The exploration and development practice showed that the reservoir characteristics had strong heterogeneity in three-dimensional space

and the vertical and horizontal distribution of the reservoirs were complex

which directly restrictsed the subsequent rolling exploration and development. In the study

based on the core observations and logging data

and combined with analytical testing

the controlling effect of the reservoir macroscopic heterogeneity on the oil layer distribution was systematically and visually analyzed. The complexity of the Chang 6

1

reservoir in

the study area was caused by a variety of factors. Among them

the distribution of the sedimentary microfacies and diagenetic facies directly controlled that of the high quality reservoirs. And the interlayer heterogeneity

especially the interlayer permeability

was easy to cause the selective filling of oil

while the interlayer heterogeneity directly caused the heterogeneous distribution of oil in composite sand body. Through this study

the distribution law of ultra-low permeability and ultra-low permeability reservoirs in Ordos Basin could be better understood intuitively

which provides guidance for finding favorable zones in the future.