On June 26, Sinopec News Office reported that Sinopec East China Oil and Gas Company deployed the risk exploration well Pingdi 1HF well in the Wulong area of Chongqing. It has produced more than 8 million cubic meters of gas in the past two years, and its stable daily gas production has reached 4.6. 10,000 cubic meters, and the preliminary evaluation of single well recoverable reserves is 40 million cubic meters. The breakthrough of continuous stable production and high production of this well proves that shallow normal pressure shale gas has good exploration and development potential.
Well Pingdi 1HF belongs to the Nanchuan shale gas field, the target layer is buried at a depth of about 1,000 meters, and the pressure coefficient is 0.99, which is a typical shallow normal pressure shale gas. The well was put into production in April 2021, and for the first time in April 2023, a liquid drive rodless pump was used in the well for test production, realizing spontaneous production of shallow shale. The breakthrough of this well can revitalize the shallow normal-pressure shale gas in the Laochangping anticline with a buried depth of 500-2000 meters. The favorable area covers an area of 244 square kilometers and the resource volume is 97 billion cubic meters.
Shallow atmospheric shale gas wells have the advantages of shallower well depth and lower investment costs. However, compared with high-pressure shale gas, normal-pressure shale gas formations have weaker energy, insufficient gas content, lower single-well production, and more difficult profitable exploitation.
In view of the production characteristics of shallow atmospheric shale with large gas-liquid volume and high water-gas ratio that cannot be self-sprayed, the company uses jet pumps for drainage, and achieved good results in testing a daily gas production of 11,000 cubic meters. At the same time, based on the study of shale adsorption characteristics and desorption laws, the research team innovatively proposed that the adsorbed gas can only be desorbed and recovered in large quantities after the bottomhole flow pressure has to drop below the sensitive pressure, just like the suction principle of vacuum packaging. Multiple rounds of drainage process optimization and demonstration have been carried out. For the first time, a liquid-driven rodless pump was used for test production in this well, which strengthened liquid drainage to reduce flow pressure and promoted the release of adsorbed gas.
The Nanchuan shale gas field of East China Oil and Gas Company is my country's first normal pressure shale gas field, located in the complex structural belt of the basin margin. Since it was put into production in 2017, as of the end of May 2023, a total of 5.825 billion cubic meters of shale gas has been produced, and the current daily gas production has reached 4.2 million cubic meters. clean energy. As the degree of development continues to increase, the gas field is facing problems such as low pressure and low production in old wells, and insufficient production capacity. East China Oil & Gas Branch has achieved efficient development, stable production and increased production of atmospheric shale gas through the integrated joint research model of exploration-development, geology-engineering, scientific research-production.