Major technological achievements help promote high-quality development of gas fields

On July 5th, two natural gas purification units with an annual processing capacity of 4 billion cubic meters were in full production at PetroChina Anyue Natural Gas Purification Co., Ltd., located less than 200 kilometers away from the bustling Chunxi Road in Chengdu. About 11 million cubic meters of commercial natural gas depart from here every day and are transported to thousands of households through pipelines, meeting the gas needs of 69 towns and villages in Anyue County and the people in the Sichuan Chongqing region.

This is one of the production bases of the Anyue gas field in the Sichuan Basin. The Anyue gas field produces about 40 million cubic meters of natural gas per day, equivalent to 40% of the daily gas consumption in the Sichuan Chongqing region. The annual production capacity reaches 15 billion cubic meters, and in 2020, it produced 13.1 billion cubic meters of natural gas, accounting for about 7% of the total natural gas production in the country. Since its development, the Anyue gas field has driven a GDP of 640 billion yuan in the Sichuan Chongqing region. The accumulated production of natural gas is equivalent to saving 87 million tons of standard coal, reducing carbon dioxide emissions by 35 million tons, and reducing sulfur dioxide emissions by 1.7 million tons. It has played an important role in China's continuous adjustment of energy structure, the construction of an important ecological barrier in the upper reaches of the Yangtze River, and the development of the Chengdu Chongqing economic circle.

Core technology leads the establishment of an international model for efficient development of super large low porosity gas reservoirs

The Anyue gas field is located in Suining and Ziyang cities in Sichuan and Tongnan District in Chongqing. The main development layers are the Cambrian Longwangmiao Formation and the Sinian Dengying Formation, which belong to a super large ancient carbonate gas reservoir.

The formation process of carbonate gas reservoirs is unique, with complex geological conditions, deep burial, and complex gas water relationships. The development faces great uncertainty, and the development effects of different gas fields vary greatly. Efficient development faces enormous challenges.

In order to scientifically develop carbonate gas reservoirs, PetroChina Southwest Oil and Gas Field Company has carried out large-scale basic research, field experiments, and application promotion technology breakthroughs, forming a major scientific and technological innovation achievement of "efficient development technology for large-scale carbonate gas reservoirs" and establishing an international model for efficient development of super large low porosity gas reservoirs.

At the achievement appraisal and evaluation meeting organized by the Sichuan Technology Market Association, the major scientific and technological innovation achievements of "efficient development technology for large-scale carbonate gas reservoirs" were evaluated by the academician expert group as having reached the international advanced level as a whole.

This project has achieved 6 theoretical and technological innovations, established an overall efficient development model for super large overpressure carbonate water gas reservoirs, and realized the efficient development of the Moxi Longwangmiao Formation gas reservoir.

The project innovates three core technologies, forming a fine description and optimized development technology for fracture pore type carbonate gas reservoirs, establishing a high-yield well model for low porosity and strong heterogeneity carbonate gas reservoirs, solving technical problems such as efficient well location selection for deep low porosity carbonate gas reservoirs, and supporting the precise locking of favorable development zones, effectively improving the success rate of development wells.

We have established a progressive integrated water control and optimization development model, breaking through the technical bottleneck of controlling water and achieving high and stable production in low porosity and strong water invasion gas reservoirs, and enriching the theoretical system of complex carbonate gas reservoir development. Breaking through the limitations of traditional technology that cannot balance high yield and stable water control, guiding the realization of a large-scale overpressure water gas reservoir in the Moxi Longwangmiao Formation