Sichuan Basin newly explored over 100 billion cubic meters of shale gas field

On November 24, the Information Office of Sinopec announced that Sinopec's "Deep Land Engineering Sichuan-Chongqing Natural Gas Base" had made another major breakthrough. The first phase of proven geological reserves of Qijiang shale gas field submitted by Sinopec Exploration Branch and Southwest Petroleum Bureau 145.968 billion cubic meters was approved by the expert group of the Ministry of Natural Resources, marking the birth of another large-scale integrated shale gas field with more than 100 billion cubic meters in China.

Qijiang Shale Gas Field is located in Qijiang District of Chongqing City and Xishui County of Guizhou Province, located in the complex tectonic zone of the southeastern margin of Sichuan Basin, which is transformed by strong tectonic movement and has surface and underground characteristics."Double complex" characteristics.The gas field is the first medium and deep layer discovered in the complex structure area of the basin margin in China.-Deep shale gas large gas field. Generally speaking, shale gas with a buried depth of more than 3500 meters is defined as deep shale gas. The buried depth of shale layer in Qijiang shale gas field spans from 1900 meters to 4500 meters, and the buried depth of the main part is more than 3500 meters.

The overlying strata of deep shale gas are complex, and there are many world-class problems such as large shale burial depth and changeable in-situ stress, which have high technical requirements and great difficulty in exploration and development. Sinopec attaches great importance to deep shale gas exploration and innovation to form a new understanding of shale gas geological theory in complex structural areas.In order to solve the basin marginThe problem of unclear understanding of shale gas reservoir formation in the "double complex" area, the research team relies on the national and Sinopec scientific research projects, as well as the national key laboratory platform, through more than 10,000 laboratory analyses of more than 1320 meters underground core, reveals the pore development and maintenance mechanism of deep deep water continental shelf facies shale, and makes it clear that deep shale can develop "high pore" high-quality reservoirs, innovation to form a new understanding of deep shale gas "overpressure rich gas.

For the complex structure area of shale gas buried deep span,For the difficult problem of "dessert" prediction, the research team collected high-precision three-dimensional seismic data of deep shale gas covering an area of 3662 square kilometers in the complex area of the southeast basin edge of Sichuan, and collected drilling data of shale gas wells that have been drilled in southern Sichuan. After repeated argumentation, the deep shale gas seismic prediction technical method with pressure coefficient and gas content, fracture prediction and horizontal in-situ stress difference as the core has been innovated, it is equivalent to CT scanning of the formation, realizing the "leap" of deep shale gas "dessert" prediction technology from scratch to fine ".In view of the low and unstable output of the early exploration well test, the research team innovated to form deep shale."Dense cutting, pressurized expansion, balanced extension, filling" three-dimensional fracture network fracturing technology. This technology initially opens up the "seven meridians and eight veins" of deep shale, and shale gas flows out continuously along these three-dimensional channels, with remarkable production effect.

It is understood that in the field of deep shale gas, Sinopec has deep shale gas resources in the mineral rights area of the Sichuan Basin.6.3 trillion cubic meters is an important area for shale gas to increase storage and production in the future.

Source: People's Daily Online-Chongqing Channel