Salt‐Lake Basin Bedrock Weathered Crust Gas Reservoir in the Altun Mountains Front of the Qaidam Basin, Western China

Abstract

The bedrock weathered crust in front of the Altun Mountains in the Qaidam Basin is different from other bedrock weathered crust, because the Qaidam Basin is a salt lake basin, the saline water fluid is infiltrated and deposited in the overlying strata, and a large amount of gypsum is filled in bedrock weathered crust, the pore structure is changed. Use core observation, polarized light microscopy, Electron probe, physical property analysis and field emission scanning electron microscopy experiments. Cracks and a small number of dissolved pores in the interior of the weathered crust, the matrix micropores are widely developed. The characteristics of matrix micropores and cracks have been studied, especially the various matrix cracks formed by tectonic and weathered, as well as the stress characteristics of small dissolved pores, physical properties such as porosity and permeability, This “dual structure” developed in the bedrock is important for guiding the exploration of the lake basin bedrock natural gas.

Detailed Study on the Sedimentary Environment of the Jialingjiang Formation in the Puguang Area, Northeast Sichuan

“…By combining the above sedimentary facies indicators and tectonic sedimentary background, the period of T1j [4][5] in the Puguang area is in a restricted-evaporative platform facies sedimentary environment as a whole. Two facies zones of the restricted platform and evaporative platform are divided, and four subfacies of the restricted lagoon, restricted tidal flat, evaporative lagoon and evaporative tidal flat, as well as several microfacies such as dolomitic lagoon, dolomitic flat, gypsum lake and salt lake can be further identified [5,6]. At the same time, the general sedimentary model of the fourth to fifth members of the Lower Triassic Jialingjiang Formation in the Puguang area has been established (Figure 3).…”