Overcome technical bottlenecks and eliminate stubborn diseases of gas wells——A documentary record of the comprehensive treatment of sulfur deposition in Puguang Gas Extraction Plant

In March, the spring in Bashan and Shushui is bright
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On March 14, technicians from the gas production plant of the Puguang Branch of Zhongyuan Oilfield restored 150,000 cubic meters of natural gas at the wellhead after implementing the wellbore sulfur control operation on Well D405-4H

"Since the gas production plant has promoted and applied the innovative technology of comprehensive treatment of sulfur deposits in the Puguang gas field, measures have been taken for 351 wells to block gas wells due to sulfur deposits in the gas field, and a total of 310 million cubic meters of wellhead gas has been restored to ensure that the gas field production is running smoothly at a high level
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" Puguang Branch Liang Meisheng, deputy director of the gas extraction plant, said

Focus on targeted research to find a cure for diseases

Focus on targeted research to find a cure for diseasesFocus on targeted research to find a cure for diseases

The Puguang gas field is the largest high-sulfur gas field in China.
As the main gas supply source for the "Sichuan-East Gas Transmission" project, it has maintained stable and high production for a long time since it was put into production 12 years ago
.

As the main block of the Puguang gas field, the Dawan block has achieved stable production for 8 years, and the current production accounts for half of the gas field

With the continuous and efficient development of the Puguang Gas Field, the formation pressure has gradually decreased, the precipitation of elemental sulfur dissolved in natural gas has increased, and sulfur deposition has occurred in the wellbore and surface flow of gas wells
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Liang Meisheng said: "The phenomenon of sulfur deposition in the Dawan block is particularly serious

By classifying gas wells, the technicians of the plant established a calculation model for the amount of sulfur-carrying gas in different well types, found out the law of elemental sulfur precipitation in the wellbore, and used the chart to determine the blockage status to quickly predict the wellbore blocking status
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They innovatively established a wellbore-reservoir integrated coupling model for sulfur deposition, clarified the impact of sulfur blockage on gas field production, and quantified gas well blockage for classified management and control, optimized the measure period and injection process, and innovatively formed one well, one strategy for wellbore sulfur deposition.

Implementing one well and one strategy for precise and efficient sulfur removal

　Implement one well, one strategy for precise and efficient sulfur removal　Implement one well, one strategy for precise and efficient sulfur removal

　　In order to effectively release the production capacity of gas wells, the technicians of the plant combined the production performance of gas wells blocked by sulfur to determine the stage of development of sulfur deposition in the wellbore and the degree of influence on the gas volume.
According to the three production parameters of wellbore gas volume, oil pressure and temperature, the blockage status of the gas well was accurately judged.

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They optimized and adjusted technical countermeasures in accordance with the idea of ​​"preventing disease treatment", quantified the indicators for judging the degree of blockage in each well, insisted on using total gas production and profit as optimization indicators, and optimized the sulfur control strategy for one well and one strategy in real time during the whole process, and coordinated the wellbore solution of sulfur-dissolving agents.

　　In view of the blockage of the gas well and the process flow, the technicians of the plant optimize the process parameters and indicators according to the gas well production and production reduction rate, and apply large pressure differential blowout + wellbore hot washing + dissolved sulfur cleaning + coiled tubing flushing and other wellbore sulfur deposition treatment The technical sequence ensures accurate and efficient desulfurization of gas wells and maximizes the gas production of gas wells within a certain period of time
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Since last year, the plant has carried out a total of 139 wells of sulfur deposition control with one well and one strategy, with a cumulative recovery of 210 million cubic meters of gas

　　Optimizing the Injection Process to Improve the Opening Time Rate

Optimize the injection process to increase the rate of opening wells Optimize the injection process to increase the rate of open wells

　　"Sulfur deposition treatment is to effectively release gas well productivity and maximize benefits
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" Liang Meisheng said, and saving sulfur deposition treatment costs is also our way to reduce costs and increase efficiency

　　In the process of sulfur deposition control, the technicians of the plant focused on optimizing the cost of sulfur-dissolving agent formulations
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On the premise of ensuring a good effect of blocking removal, the plant has reduced the cost of sulfur-dissolving agent from 80,000/ton to 20,000/ton by continuously optimizing the formula of sulfur-dissolving agent
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　　At the same time, the plant further optimized the injection process of sulfur-dissolving agent, and optimized the original sulfur-dissolving agent to be based on physical dispersion, and optimized it to chemically-dissolved sulfur, so that the shut-in time for gas well sulfur deposition treatment was reduced from the original 6 hours to 6 hours.
2 hours, and the validity period is increased from 15 days to 20 days, which greatly improves the efficiency of well opening
.
Since last year, the plant has applied the innovative technology of comprehensive treatment of sulfur deposition in the Puguang gas field in the Dawan block, implemented 91 wells of wellbore plug removal, reduced the shut-in time by 364 hours, reduced the impact of gas volume by 7.
52 million cubic meters, and increased profits by 7.
853 million yuan
.