A Study of Sedimentary Environment and Reservoir Quality of the Carboniferous Donghe Sandstone in the Tarim Basin

Very thick, fine–grained quartzose sandstone of the Lower Carboniferous (called the Donghe sandstone) was discovered in Donghe–1 well in the Tarim basin. Highly–productive commercial oil and gas flows were obtained when a well completion test was conducted. This important discovery proved that the quartzose sandstone is a prospecting target with good prospects. After that, other two paying oil and gas flows were found in the Lower Carboniferous in the Tazhong–4 and Tazhong–10 structures (Tazhong means central Tarim), equivalent to the Donghe sandstone. The Tazhong–4 structural oil field is the biggest oil field ever discovered. Therefore it is of guiding importance in oil and gas exploration to deepen the study of sedimentary and reservoir features and the sedimentary environment of the Donghe sandstone and to build a sedimentary model in order to understand the reservoir distribution pattern.