Resource and development prospect of widespread low-permeability sandstone gas in Ordos basin

摘要

Ordos basin is the second largest basin in China. Natural gas is rich in this basin. Total gas resource in Ordos basin is 151.6 trillion cubic meters. Of which, gas in Upper Paleozoic may be up to 100 trillion cubic meters accounting to 70% of total gas resource. Exploration of low permeability to tight sandstone gas in multi-layer series of Upper Paleozic in Ordos basin obtained great result. Several giant low permeability to tight sandstone gas fields have been found in recent years, such as Wushenqi, Zizhou, Yulin, Shenmu etc. Sulige gas field has been proved to be the largest low permeability to tight sandstone gas field in China. It shows the great exploration prospect of low permeability to tight sandstone gas in Upper Paleozoic in Ordos basin. Now, people care about low permeability to tight sandstone gas resource and its exploration potential in Upper Paleozoic in Ordos basin. In this paper, based on through analysis of present petroleum resource and exploration result, the author discussed Resources potential and development prospect of large-area low permeability sandstone gas in Ordos basin. The author proposed that low permeability to tight sandstone gas in Upper Paleozoic in Ordos basin had the following characteristics. Coal-measure source rocks are wide spread and the generation potential is great. Sand body of braided river delta in gentle slope of Craton distributes widely. Source rocks and reservoir rocks are widely overlaying. Net system of pore and fractures formed the transporting system for gas. Gas was near-source accumulated. Accumulation ratio is high. The author suggested that exploration potential of low permeability to tight sandstone gas in Upper Paleozoic in Ordos basin is great. Production of low permeability to tight sandstone gas could reach 30 billion cubic meters in 2015. Upper Paleozoic in Ordos basin will be the largest gas production province then.