Development status and technology development trend of deep natural gas in China

Since the beginning of the 21st century, China has made a series of major breakthroughs in the field of deep-seated natural gas. Several deep-seated gas fields, such as Puguang, Keshen, Yuanba and Anyue, have been discovered and successfully developed, and two deep-seated natural gas production areas in Sichuan and Tarim have been built. However, the complex geological conditions and increasing development difficulties make the efficient development of deep natural gas face many challenges, mainly including: complex gas reservoir structure that made it difficult to describe accurately, diverse reservoir types and complex gas reservoir seepage law, high temperature, high pressure and high geostress which make it difficult to drill and complete well and increase production, complex fluid property of gas reservoir and high risk of safe and clean development. After more than ten years of research, five technical systems have been formed, including deep seismic imaging and reservoir prediction technology, deep complex gas reservoir well pattern optimization technology, deep high temperature and high pressure gas well drilling and completion technology, deep complex reservoir precise transformation technology, and deep special fluid gas production technology. With the advent of the era of low oil price, the deep-seated natural gas development technology will be further closely combined with digital and information technology to develop rapidly in the direction of low-cost, high-precision, automation and intelligence, and provide a solid guarantee for the efficient development of deep-seated natural gas resources. To sum up the development strategy of deep natural gas, we should adhere to the three-dimensional earthquake first, adhere to the scale test production and pilot test, adhere to the integration of geological engineering, adhere to technological innovation and integrated application, and determine reasonable development technology policies according to the geological characteristics of gas reservoirs.