Reviews of the exploration history of stratigraphic wells in the Sichuan Basin and analysis of the obtained geological effects

The project of exploratory drilling of stratigraphic wells in the Sichuan Basin in the 1950s made great success, through which the following five great discoveries and one first record were prized by the State Council in China: the first brine spring, the first giant gas field, the first ancient gas pay zone, the first large paleo-uplift of Leshan - Longnushi within the basin were found and proved, the first deepest well was drilled, and it was the first time to obtain the information of the basin basement. In addition, the geological effects achieved through this successful project are presented herein. (1) It provided the basis for the choice of battle sites in the "great battle" for finding more oil and gas resources in the 1960s. (2) A complete strata profile of the whole basin was got and four Paleozoic pay zones were discovered including the Tertiary, Ordovician, Cambrian, and Sinian formations, which directed the further discoveries of other giant gas fields. (3) The obtained basin basement data provided important reference for the researchers to study the basic geological sciences in China. In conclusion, (1) at the early period of gas exploration in a basin, the integrated geological interpretation through data from some stratigraphic wells combined with the seismic profiles was effective for overall and systematic regional oil and gas explorations (2) this project was a successful example for the strategic shift of oil and gas exploration in the Sichuan Basin and had a good start for the oil and gas exploration and development in this basin in the following next 6 decades.