Application Of Logging In The Low Porosity And Low Permeability Reservoirs Prediction In Upper Paleozoic In The Western Of Ordos Basin

In order to predicted the relative high porosity and relative high permeability reservoirs on the background of low porosity and low permeability reservoirs of Upper Paleozoic in the western of Ordors Basin, The thesis evaluated the distribution of the relative high pore zone and the fracture zone and analyzed their genesis relationships of different region, and further selected the high-efficient reservoirs.The results in the thesis are as follows:1. The sandstone body of Yanghugou formation deposited mostly from tidal flat and lagoon. In Taiyuan formation, the southern sandstone body deposited from barrier islands, the northern sandstone body deposited from delta. In Shanxi formation, Shihezi formation and Shiqianfeng formation, the sandstone body deposited mainly from fluvial and delta deposition.2. The Helan Mountains-Hengshanbao region located at the obduction zone .The region is nearby the main formation source, earlier diagenesis phases and weak compacting action. The higher porosity reservoir belts distributed generally in Lower Shihezi formation and Shanxi formation. However, the higher porosity reservoir belts in Upper Shihezi formation only distributed in the Shenglijing tectonic zone, the Tudong fault block and the Sedong tectonic zone. The Etuokeqianqi region is within nearer distance of the main formation source, enough sediment supply. They are of great advantage to the development of secondary porosity. The higher porosity reservoir belts distributed in Lower Shihezi formation and Shanxi formation in this region. Well Lucan 1 located at the dropped side of obduction zone in the Majiatan-Huianbao region. Owing to structure uplift resulted in stratum pressure decreased, it is weak compacting action. Under the control of acidic diagenetic environment, the instability of volcanic tuff filling resulted in the development of intergranular dissolution porosity and intercrystal porosity with Kaolinite filling. The higher porosity reservoir belts developed in Shanxi formation in Well Lucan 1. The diagenesis phases of Pingliang-Shajingzi region are later. Only the higher porosity reservoir belts developed in He 6 member and Shan 1 member in Well Zhentan 1.3. The obvious fracture developed mainly in the Helan Mountains- Hengshanbao region and the Etuokeqianqi region, the northern of the western of Ordors Basin. The minor fracture developed mainly in the central and southern of the western of Ordors...