Trabajo presentado en el 24 WGC. Disponible en CD en la biblioteca. Solicite este trabajo por email a biblio@iapg.org.ar

Over the past decade, in the Upper Paleozoic of Ordos basin, PetroChina Changqing Oilfield Company has been eye-catching for a large, 100-billion-cubic- meters-level gasfield found every two years averagely. Especially in recent years, a situation of progressive incremental of 500 billion cubic meters natural gas reserves submitted annually has been formed in the Sulige exploration area. The rapid growth of proven gas reserves makes Sulige region become the first unitary large-scale natural gas district with trillion cubic meters in China [1-4]. The annual gas production from tight sandstone reservoirs reaches more than 10 billion cubic meters. For tight sandstone gas reservoirs in Ordos basin, a number of scholars have been carried out a lot of discussion in the relevant literatures [5-34]. But most of them concentrated in the discussion of common features such as low porosity, low permeability, low abundance, low-pressure, no bottom-water, no edge-water etc., and less attention to the characteristics of their personality. At present, nearly 1000 wells are drilled through the Upper Paleozoic of the basin. Yulin, Zizhou and Sulige gas fields have been put into large-scale development one after another. In-depth exploration and development of Upper Palaeozoic tight sandstone gas reservoirs provides favorable conditions for revealing the characteristics and controlling factors of accumulation. Based on natural gas exploration and development practice and comprehensive geological study results of the basin’s Upper Paleozoic in recent years, the authors mainly discuss the geological features and unique reservoir controlling factors of this type of gas reservoirs in the paper, looking forward to improve constantly the geological theory of tight sandstone gas accumulation and to promote continuous deepening of exploring for such gas reservoirs.