DEPOSITIONAL ENVIRONMENT AND PETROLEUM GEOLOGY OF THE PERMIAN IN GAIZE AREA, TIBET

Many buried hill reserviors in the paleozoic and Archaean were discovered in the Shengli Oilfield in recent years. It showed quite difficult for prediction of distribution of storage space and assessment of this kinds of reserviors. A fruitful progress was made during the reservior study on the buried hill namely Chengbei-30. The forming and evolution of the hill was illuminated firstly, then the detail description and distribution prediction of the secondary disoluted vugs, porosity and fractures of carbonates and metamorphite within the buried hill were made by using "integrated evaluation methoa for buried hill reserviors". Furthermore, the reservior features of dual-porosity media were summarized, which may provide some useful guidances for the study of the same reserviors.