Remarkable results of safe and stable production technology in high-sulfur gas fields

　　On the eve of the shutdown of Puguang gas field for technical renovation and maintenance, the daily production of natural gas from Well M504-1 remained at 900,000 cubic meters
.
"This well is a typical practice for the gas field to apply the long-term safe and stable production technology for ultra-deep and super-large high-sulfur gas fields
.
" Recently, Li Tao, manager of the development management department of Puguang Branch, said
.

　　The expert group commented that the technological achievements are leading in the world as a whole, have broad promotion value, and provide scientific and technological support for the development of high-sulfur gas fields at home and abroad
.

　　"The technology has been fully promoted and applied in the Puguang gas field, and more than 600 wells have been implemented to increase production and control decline.
The newly produced geological reserves have increased by 31.
62 billion cubic meters, and the recovery rate has increased by 6.
2 percentage points.
The stable production period of the gas field has been extended from 8 years to 11 years.
years
.
" Li Tao said
.

　　According to reports, the Puguang gas field is the first super-large high-sulfur gas field successfully put into development in China.
The long-term safe and stable production of the gas field has made positive contributions to ensuring national energy security and helping Sichuan Province build China's "big gas festival"
.
However, with the continuous and efficient development of gas fields, it faces a series of new world-class technical problems such as ultra-deep and low-grade reserves production, water control and sulfur control, safety and environmental protection, etc.
, but there is no successful experience in China that can be used for reference
.
In 2016, Puguang Branch, Sinopec Exploration and Development Research Institute, Southwest Petroleum University and other related units jointly carried out long-term safety and stable production technology research for ultra-deep and extra-large high-sulfur gas fields
.

　　The Puguang gas field is a reef-shoal facies reservoir, and the low-grade three types of reserves account for about 35%, which have not been produced in the early stage of development
.
For this reservoir, the researchers created a two-parameter petrophysical chart of phase rotation factor and a method for dividing the flow unit of reef-shoal facies reservoirs, innovatively developed a long horizontal section of horizontal wells with complex fracture acid fracturing and a small diameter through the tubing without deep penetration of the gun body.
The transmission hole process improves the reserve utilization rate
.

　　As the pressure of the gas reservoir decreases, sulfur deposits gradually precipitate out, and different degrees of "intestinal obstruction" appear in the gathering and transportation system, wellbore and reservoir, affecting the release of gas field productivity
.
Researchers have developed a high-resistance pressure-swing induced sulfur capture field experimental device.
Through the independent research and development of a numerical simulator for predicting sulfur deposition, the sulfur content can be accurately measured and the rules of sulfur deposition accumulation and migration are mastered.
The wellbore sulfur-dissolving agent with sulfur and rubber protection function and the low-cost inorganic base-catalyzed ground sulfur-dissolving agent, the effective efficiency of sulfur deposition and plugging removal is 100%
.

　　In addition, in view of the unfavorable factors of complex mountainous area, many geological disasters, strong acid corrosion, and high leakage risk in the Puguang Gas Field, researchers have successively developed high-sulfur gas well integrity evaluation and safety management and control, high-sulfur gas field collection through continuous research.
A series of supporting technologies such as safety management and control of transmission and purification systems have formed a whole-process safety and environmental protection technology for high-sulfur gas field development.
The concentration of hydrogen sulfide in tail gas has dropped by 40%
.

　　After 4 years of research, the scientific research team has innovated and formed a number of long-term safe and stable production technologies for ultra-deep and extra-large high-sulfur gas fields, and won a total of 12 invention patents and formulated 27 technical standards and specifications
.