Reservoir Characteristics of Tight Sandstone and Sweet Spot Prediction of Dibei Gas Field in Eastern Kuqa Depression, Northwest China

Great progress has been made in the exploration of tight sandstone gas resources Kuqa depression. Dibei structural belt, which proves previously unproven favorable area for gas. The physical properties, controlling factors, and characteristics from Ahe (J1a) Formation reservoir are analyzed. results show that J1a is mainly feldspar lithic sandstone, with low porosity (average 9.1%) permeability 0.09 mD). Compaction compaction rate 61.9%) reduces more than cementation 14.3%). Secondary dissolution pores thin section 3.4%) dominate. homogenization temperature two peaks; first peak 85–110 °C, other 115–140 indicating oil experienced filling stages at 12 Ma 4.5 Ma, respectively. Eodiagenesis, A substage mesogenetic diagenesis, B diagenesis happened area. Tight developed diagenesis. main factors are: strong pore increase; charging overpressure. forming mode is: crude Late Neogene (12 Ma); densification late deposition Kangcun (7 Ma), mature natural early (4.5 formed after transformation adjustment period Quaternary (2 Ma). According to this model, it predicted southeast Yinan 2 well. This study provides guidance areas Depression.