According to PetroChina News report on 22 August 2018, PetroChina â Jilin achieved gas flow from a tight gas appraisal well, Deshen 80, in the Southeast Uplift of Songliao Basin. The well tested 3.85 MMcf/d possibly from the Lower Cretaceous following fracking work in July 2018. The well was drilled in the Baojia sub-sag of the Dehui Sag in Songliao Basin.  The Dehui Sag covers an area about 4,000 sq km in the southern part of the Songliao Basin. Exploration in the Dehui Sag began in the 1970s. Several conventional fields have been discovered, such as the Nongâan, Xiaohelong, Wanjinta and Buhai fields. The sag was estimated to hold about 1.5 Bbbl of oil and 6 Tcf of gas resource potential.   Background information  In 2014, Deshen 17 tight gas block was discovered with reservoir of volcanic rocks in the Yingcheng Formation. The reservoir has average porosity less than 8% and average permeability less than 0.05 mD. The discovery was put on development in 2015, a development well, Deshen 17-1, was reported to test gas in 2016.  In 2012, PetroChina - Jilin tested gas in Deshen 11 and Deshen 12 in the Dehui sag. Deshen 11 was drilled in the Huajia Structure Belt of the Dehui Sag. The well tested 1.87 MMcf/d (53 MMcm/d) of gas from sandstone reservoirs in the Huoshiling Formation. As of 2018, a total of 12 appraisal wells have been completed in the Deshen 11 tight gas block.  In 1999, CNPC - Jilin drilled Deshen 4 in the Dehui Sag with gas shows encountered. Deshen 2 and Deshen 5 were drilled at the same year without results reported.
PetroChina â Jilin achieved gas flow from a tight gas appraisal well, Deshen 80, in the Southeast Uplift of Songliao Basin. The well tested 3.85 MMcf/d possibly from the Lower Cretaceous following fracking work in July 2018. The well was drilled in the Baojia sub-sag of the Dehui Sag in Songliao Basin.