Performance Evaluation Method Of Foaming Agentand Its Application In Sulige Gas Field

The reservoir in the Sulige gas field belongs to low-pressure,low-yield,low-abundance gas reservoirs.With the development of the gas field,the gas wells in each block have different levels of water production,and the steady production demand has led to continuous increase in the amount of drainage and gas recovery.The gas field has carried out various research methods for drainage and gas recovery,especially the promotion of foam drainage and gas recovery technologies.The application has achieved better drainage effect.However,as the number of low-pressure low-yield effusion wells increases year by year,how to adopt reasonable and effective foam drainage and gas recovery measures to effectively discharge effusion in the wellbore is a serious problem in the middle and late stages of the development of the Sulige Gas Field,and it is also the key to the long-term stability of the gas field.Based on the investigation and analysis of the current status of the Sulige gas field,the cause of water production,and the distribution of production wells,the chemical capacity method and instrumental analysis were combined to analyze the composition of the produced water from different gas wells.The advantages and disadvantages of various foam performance evaluation methods,and the scope of their application were analyzed.At the same time,the evaluation method of atmospheric pressure foam discharge agents was improved,and pressure evaluation foam was used.The new method of the agent studied in detail the influence of the pressure change and the degree of salinity,methanol,condensate and other conditions on the performance of the foam discharge agent in the foam drainage gas recovery process,and determined the type of foam discharge agent suitable for different production water gas wells.Addition and foam drainage gas production process.The results of the study show that:?1?The gas-water relationship in the gas field is complex,and the produced water is dominated by condensate water,and some areas are formation water.The produced water belongs to CaCl₂ water type;the pH average value is 6.32,basically belongs to the slightly acid water;the water salinity is high,and the highest salinity is 113305.46 mg/L.The average value is 52998.48 mg/L.?2?A comparative evaluation of commonly used bubble evacuation agent evaluation methods,air flow measurement results of reproducibility and operability is good,but can not simulate wellbore high pressure environment.?3?A wellbore pressure drop model was established.The foam moisture content and the liquid carrying capacity are important parameters reflecting the performance of the foaming agent.Based on the air flow method,a pressure evaluation device for foam discharge agent was developed,which can evaluate the performance of foam discharge agent for foaming performance,liquid carrying capacity and foam moisture content under pressurized conditions.?4?Through orthogonal experiments to determine the effect of wellbore pressure,produced water salinity,methanol content and condensate content on the foaming agent foam water content,foam water content,liquid carrying capacity performance significantly Degree of sexuality.?5?As the pressure increases,the foam volume becomes smaller and the volume per unit volume of foam increases,resulting in poor foaming at the same height of the wellbore.When the foam is exposed to external influences,it creates a perturbation effect on the liquid film that causes the foam liquid film to expand or compress.This effect is more pronounced at high salinity,and the defoaming action of methanol makes the foaming agent work at low pressure.The foam performance deteriorates,and the bubbling time increases more slowly with increasing pressure.Foam moisture content is a combination of pressure and methanol.Condensate and pressure have a certain inhibitory effect on the foaming performance of foam discharge agents.?6?By comparing the foam moisture content and the foam liquid carrying capacity of the foaming solution under different pressures,it is found that there is no positive correlation between the two.Good foaming agents for foams do not necessarily exhibit good foam carrying properties.?7?According to the gas well condition,according to the pressure evaluation results,the type,concentration,mode and cycle of the foam discharge agent were selected to optimize the foam drainage and gas recovery technology in different gas wells in Sulige and effectively reduce the fluid accumulation in the well bottom,To achieve different gas wells can carry liquid continuous production.