China's largest carbonate gas field has produced a total of 72.6 billion cubic meters of gas

According to the news of PetroChina's Southwest Oil and Gas Field on the 3rd: as of June 30, China's largest carbonate gas field, PetroChina's Anyue Gas Field, has produced a total of 7.4 billion cubic meters of natural gas this year, an increase of about 5% year-on-year, and has produced a total of 72.6 billion cubic meters of gas since it was put into operation. From major discoveries to sustained and stable production, PetroChina's major scientific and technological projects have helped the efficient development of "super gas fields".

Anyue gas field is located in Suining, Ziyang and Tongnan District, Sichuan Province and Tongnan District, Chongqing, with proven reserves of more than one trillion cubic meters. The porosity of the gas field reservoir is low, it is easy to water invasion, and the efficient development is facing great challenges.

During the "13th Five-Year Plan" period, PetroChina Southwest Oil and Gas Field organized a special project on "Efficient Development Technology for Large Carbonate Gas Reservoirs", and fully supported the efficient development of "super gas fields" through core technologies such as fine gas reservoir description, high-yield well cultivation, and overall water control.

According to reports, the Southwest Oil and Gas Field has innovated the formation of fractured-pore carbonate gas reservoir fine gas reservoir description technology, and accurately constructed a high-yield geological model with the high-yield target identification technology of "multi-component composite geological model + scattering wave numerical simulation", and the "transparent gas reservoir" has come into view. More than 1,000 square kilometers of favorable development areas have been selected in the southwest oil and gas field, and the success rate of development wells has reached 100%, and the proportion of high-yield gas wells per million cubic meters has reached 79%, rewriting the traditional perception that "low-pore gas reservoirs are difficult to produce high-yield".

For the Anyue gas field, especially the Longwangmiao Formation gas reservoir, the number one problem of "water intrusion" must be solved. In view of the problems of high requirements for the optimal development of low-porosity and strong water intrusion carbonate gas reservoirs and the difficulty of stable production of gas reservoirs, the Southwest Oil and Gas Field has established an overall water control technology for low-amplitude and high-pressure water-bearing carbonate gas reservoirs, and a full-life cycle progressive water control development model of "early prevention and control of water surge, medium-term prevention and control of flooding, and late prevention and control of water sealing".

The Southwest Oil and Gas Field has also innovated a series of key technologies for the development of real-time intelligent active water control in strong water intrusion gas reservoirs, creating a domestic record of efficient numerical calculation of 80 million grid models, which is much more detailed than the 20 million grid model that is second in China. The real form of the underground is restored as much as possible, the level of dynamic forecasting of development is greatly improved, the water erosion situation is accurately predicted 3 months in advance, the formulation time of the production optimization plan is reduced from 1 week to 20 minutes, and the accurate fitting and simulation prediction of complex water erosion characteristics are realized.

In terms of drilling technology, the Southwest Oil and Gas Field has solved the problems of low mechanical penetration rate and frequent formation overflow in complex lithologic formations through the formation of large-scale deep sulfur-bearing carbonate gas reservoirs with large inclination wells and horizontal well drilling and production technology, overcome the technical problems of differentiated transformation of low-porosity and strong heterogeneous reservoirs, and realized the effective control of well control risks in the whole drilling cycle, providing effective guarantee for the safe and efficient development of Anyue Gas Field.

It is reported that in 2020, the annual gas production of Anyue gas field accounted for about 7% of the annual gas production in China. Since the development of the gas field, it has boosted the GDP of Sichuan and Chongqing by 640 billion yuan, produced natural gas that can replace 87 million tons of standard coal, reduce carbon dioxide emissions by 35 million tons, and reduce sulfur dioxide emissions by 1.7 million tons, which has played an important role in building an important ecological barrier in the upper reaches of the Yangtze River and boosting the construction of the Chengdu-Chongqing Economic Circle.