CN-121991671-A - Low-foam water content foam drainage agent for drainage gas production

Abstract

The invention discloses a low-foam water content foam drainage agent for drainage and gas production, which comprises the following components by volume percent, 95% of compound betaine, 3% of nano foam stabilizer and 2% of fluorocarbon surfactant, wherein the compound betaine is formed by compounding alpha-sodium alkenyl sulfonate and cocamidopropyl betaine, the compound proportion of the alpha-sodium alkenyl sulfonate and the cocamidopropyl betaine is 1:2, the nano foam stabilizer is a fumed silica aqueous solution, wherein the mass fraction of silica is 2%, the fluorocarbon surfactant is a nonionic fluorocarbon surfactant, and the low-foam water content foam drainage agent provided by the invention can solve the problems of large pressure drop and difficult liquid carrying of a shaft in a low-pressure low-yield gas well of the conventional foam drainage agent, has good foaming height and foam stability under the condition of greatly reducing foam water content, is low in the variety and dosage of the low-foam water content foam drainage agent, is simple to prepare, and does not cause damage to a reservoir after injection.

Inventors

• WANG JINCHANG
• WANG PING
• YANG YIJUN
• LIU YUXIANG
• ZHOU RUILI
• XUE CHAOYANG

Assignees

• 中国石油化工股份有限公司
• 中国石油化工股份有限公司华北油气分公司

Dates

Publication Date

20260508

Application Date

20241108

Claims (5)

1. 1. A foam discharging agent with low foam water content for discharging and gas production is characterized by comprising the following components by volume percent, 95% of compound betaine, 3% of nano foam stabilizer and 2% of fluorocarbon surfactant.
2. 2. The foam drainage agent with low foam water content for drainage and gas production according to claim 1, wherein the compound betaine is formed by compounding alpha-sodium alkenyl sulfonate and cocamidopropyl betaine, and the compound ratio of the alpha-sodium alkenyl sulfonate to the cocamidopropyl betaine is 1:2.
3. 3. The low-foam water content foam drainage agent for drainage and gas production according to claim 1, wherein the nano foam stabilizer is a fumed silica aqueous solution, and the mass fraction of silica is 2%.
4. 4. A low foam moisture content foam blowing agent for drainage and gas production according to claim 3, wherein the silica is a fumed silica powder having a specific surface area of 200m2/g.
5. 5. The low foam water content foam drainage agent for drainage and gas production according to claim 1, wherein the fluorocarbon surfactant is a nonionic fluorocarbon surfactant.

Description

Low-foam water content foam drainage agent for drainage gas production Technical Field The invention relates to the technical field of oil and gas field chemical agents, in particular to a low-foam water content foam drainage agent for drainage and gas production. Background The foam drainage gas production process technology plays an important role in exploitation and development of a water-gas well, not only greatly improves the liquid carrying capacity of the gas and reduces the accumulated liquid of a shaft, but also prolongs the later production time of the gas well, thereby improving the final recovery ratio. The gas well yield gradually approaches to or is lower than the conventional foam drainage liquid carrying critical flow rate along with the reduction of the pressure and the yield of the gas well, the drainage effect and the benefit are poorer and worse, the well closing, the pressure re-injection and the liquid discharge are needed after the foam drainage, the workload is large, and the normal production of the gas well is influenced. The conventional foam discharging agent has the thought that the foam formed after the foaming agent is added reduces the gas-liquid surface tension and the liquid density on the one hand, and on the other hand, the water content in the formed foam is required to be high, namely, the water quantity discharged by one-time foam discharging is as high as possible. The more the water content in the foam, the higher the foam density, and the higher the mixed gas-liquid density, the more the gas well flow rate is reduced to a certain degree, and the conventional foam discharging is failed. Aiming at the problem that the conventional foaming agent is low in efficiency or ineffectiveness in a low-pressure low-yield well, based on the critical foam carrying flow calculation theory, a novel foaming agent with lower foam surface tension and lower foam water content than the conventional foaming agent needs to be developed. At present, related patent documents related to a low-foam water content foam discharging agent are fewer, for example, patent publication No. CN111218267A discloses a low-foam water content foam discharging agent and a preparation method thereof, and the foam discharging agent consists of 35% -40% of dioctyl methyl hydroxysulfopropyl betaine, 0.1% -1% of sodium perfluor octyl sulfonate, 60001% -4% of polyethylene glycol and 55% -60% of water, so that the problem of poor foam discharging operation effect under the ultra-low pressure low-yield condition that the well bottom pressure is lower than 10MPa and the gas well flow is lower than 5000m < 3 >/d can be obviously and effectively solved. However, the foam height of the foam discharging agent is general, and the liquid carrying rate of the foam discharging agent is not tested. Disclosure of Invention The invention aims to provide a low-foam water content foam drainage agent for drainage and gas production, which is used for solving the problems of large pressure drop of a shaft and difficult liquid carrying of the conventional foam drainage agent in a low-pressure low-yield gas well. The invention discloses a foam drainage agent with low foam water content for drainage and gas production, which comprises the following components in percentage by volume, 95% of compound betaine, 3% of nano foam stabilizer and 2% of fluorocarbon surfactant. Further, the compound betaine is formed by compounding alpha-sodium alkenyl sulfonate and cocamidopropyl betaine, and the compounding ratio of the alpha-sodium alkenyl sulfonate to the cocamidopropyl betaine is 1:2. Further, the nano foam stabilizer is a fumed silica aqueous solution, wherein the mass fraction of the silica is 2%. Further, the silica is a fumed silica powder having a specific surface area of 200m2/g. Further, the fluorocarbon surfactant is a nonionic fluorocarbon surfactant. Compared with the prior art, the low-foam water content foam drainage agent for drainage and gas production has the advantages that the problems of large well bore pressure drop and difficult liquid carrying of the existing foam drainage agent in a low-pressure low-yield gas well can be solved, the foam drainage agent has good foaming height and foam stabilizing performance under the condition of greatly reducing foam water content, the types and the dosage of the used medicine agent are small, the preparation steps are simple, and reservoir damage cannot be caused after injection. The nanometer foam stabilizer can effectively reduce liquid film liquid discharge rate and greatly improve foam stabilizing capacity, the nonionic fluorocarbon surfactant can reduce the surface tension of a foam discharging agent system by utilizing the characteristic of high surface activity of the nonionic fluorocarbon surfactant and is beneficial to foam formation, so that the produced foam is finer and more stable and the foam water content is lower through the synergistic effect of various surfactant