Logging Identification Technology of Sedimentary Facies and Gas Layers within Low Pressure, Low Permeability and Low Abundance Gas Reservoirs: Example from SQW Block of the Sulige Gas Field, Ordos Basin, China

Sulige Gas Field is located in the Suligemiao area, northwest of the Ordos Basin, with a prospecting area of about 4×104km2. Owing to the strong heterogeneity in the SQW Block, one of exploration blocks in the Sulige Gas Field, remains reservoir characteristics of the gas field: lithologic gas reservoirs with characteristics of “three low” (low pressure, low permeability and low abundance). The He8 member of the Shihezi formation, the major exploration target, is deposited in braided river environment. The conventional logging data is very useful to indentify different facies and to estimate gas potential. The technology of discrimination with sedimentary facies and gas layers using logging data is established in this paper. We use the technology combining with AVO and other exploration methods to pick out 4 favorable exploration target areas with the success rate of more than 80%.