Abstract: Biyang depression is located in the south-western part of Henan province. It is one of the sub-depressions in the Nanyang basin, with a total area of 1000 sq. km. Two oilfields have been discovered so far. The depression is petroliferous in spite of its small size and has its distinct features in petroleum geology. Biyang depression is an inland fresh-water, faulted basin. The conditions for oil generation were excellent due to the deeply faulted subsidence of the basin and the high speed of sedimentation. The sediments in the basin come from many sources, with seven sandstone bodies of different types extending deep into the source rock area, forming reservoirs at favorable locations. At present, oilfields have been discovered in the front parts of two sandstone bodies. Anticlines are not developed in the basin, as the main traps for hydrocarbons are lithological, generally of the updip shale-out type, which account for 86.3% of the total proven reserves. This type of hydrocarbon traps has not been explored adequately in our country, so it gives us a useful clue for finding more non-anticlinal fields. The property of the crude oil is unique with high paraffin content(33～45%), high pour point(39～44℃), especially the high content of ozokerite (5～11%)with dropping point to 80℃, which is rarely seen in China and abroad. The reason of its occurrence is yet to be investigated.

摘要： 泌阳凹陷位于河南省南部唐河县和泌阳县之间,是南阳盆地中一个次一级的凹陷。该凹陷面积虽小,但含油丰富,有一些独特的石油地质特征。