Special foam drainage method for low-gas-yield water-flooded well, foam drainage agent and foam drainage device

Abstract

The invention relates to foam drainage gas production, in particular to a special foam drainage method for a low-gas-yield water-flooded well, a foam drainage agent and a foam drainage device. A chemical mode or/and a physical mode is/are adopted to stir accumulated liquid in the low-gas-yield water-flooded well and generate fluctuation, the fluctuating accumulated liquid makes the foam drainage agent put into the accumulated liquid mix with air water in the accumulated liquid to generate foam, and accordingly foam drainage gas production of the low-gas-yield water-flooded well is achieved. The foam drainage agent is prepared from, by weight percentage, 10-25% of non-ionic surfactant, 20-45% of zwitter-ion surfactant, 15-25% of anion surfactant and the balance a foaming agent. Ultrasonic equipment, a micro fan and carbon dioxide injection equipment are adopted as the foam drainage device. Due to the structure, the special foam drainage method for the low-gas-yield water-flooded well, the foam drainage agent and the foam drainage device have the advantage of breaking the technical bottleneck that the effective technology of foam drainage cannot be applied to the low-gas-yield water-flooded well.

Description

technical field [0001] The invention relates to gas extraction by foaming, in particular to a special foaming method, foaming agent and foaming device for water-flooded wells with low production gas. Background technique [0002] The Sichuan-Chongqing region is one of the important natural gas producing areas in my country. However, the proportion of gas reservoirs with water is as high as about 80%. With the development, water intrusion has had a huge impact on the effective development of gas reservoirs. It will inevitably lead to water flooding of the gas well and reduce the recovery rate of the gas reservoir. [0003] At present, the main technical means for the later development of water-gas reservoirs in the Sichuan-Chongqing area is drainage and gas recovery, and a technical system represented by foam drainage, gas lift, and electric submersible pumps has been formed. Among them, bubble row [foam row refers to foam drainage] gas extraction is a method of injecting a s...

AI Technical Summary

Problems solved by technology

[0008] However, during the use of the above-mentioned conventional foaming agent, it is necessary for the gas well to have a certain output before the foaming agent can be stirred to generate foam.

For wells with low production and wells that have been flooded [we usually call them low-production gas flooded wells], bubble drainage technology will not be used

Therefore, how to realize drainage and

Images