Abstract
Abundant tight sands rich in natural gas, as a kind of unconventional energy source, have been discovered in the Ordos Basin, Central-North China, which can contribute greatly to the sustainable supply of natural gas in China. In this paper, the geological and petrophysical characteristics of a typical tight sand gas reservoir in the Upper Paleozoic of the Ordos Basin were investigated and correlated to the productivity of gas wells. Several important petrophysical relationships were revealed based on data from drill cuttings, core, and well logging, including porosity versus permeability, stress sensitivity to permeability, and rock density versus porosity. Their effects on well's productivity were discussed. The productivity of the targeted reservoir was analyzed and classified using a formation capacity method (K·H factor), and was compared with the production data of similar tight sand and low permeability blocks in the region, which can provide good reference for the field development.
•Petrology characteristics of tight sandstone gas reservoir was analyzed.•Petro-physical properties including porosity, permeability and stress sensitivity to permeability was studied.•The rock density and porosity have a good linear relationship, while the modulus has close correlation with porosity.•Productivity of Linxing block was analyzed using formation capacity method.