Application And Foaming Process Development Of Pressure-activated Sealant

The well leaking stoppage is a hot research topic in the oil and gas industry all the time,traditional repair method is gradually cannot meet the needs of the I eak because of long repair time,high management cost and low success rate.In re cent years,new stoppage methods are increasing,successful application cases began to emerge.Pressure-activated sealant is beginning to be a new research direction in the field of oil leakage,it's a potential anti-leakage technique.The technology mode led on the blood vessels in the human body automatically repair mechanism,repair the holes and cracks from inside the pipelines.It is a kind of economic,environme ntal protection,secure repair proposal for its high repair efficiency and short repair time.The pressure-activated sealant has good application prospect in underpressure leaking stoppage.This paper expounds the mechanism and method in sealant's working process,makes further research in evaluation method of the demulsification particle size,and also makes related evaluation to its temperature tolerance,viscoelasticity and mechan ical property.We selected the ratio of laboratory reagents that can be used in differ ent leakage rate,optimized the laboratory formula and enhanced the applicability of the formula.The reaction time can change the size of demulsification particles,the pH of system can change sealant's viscoelastic,additives and different ratio of syste m can change the high-temperature stability of the plugging agent.A foaming pressure-activated sealant that simulate biological trauma repair was developed to overcome the leakage of low-pressure gas well in the process of produ ction operation.The process that affect foam performance was optimized,including f oaming agent,stabilizing agent,stabilizer and environmental impurities.Laboratory st udy showed that the process is excellent with adding amount of-1%foaming agent,0.6%stabilizing agent,0.5%stabilizer;pH=7.0,the sealant has fine foaming and st abilizing ability,the half-life maintains 72h;It has good foaming ability when enviro nmental impurity contents lower than 8%.The mechanism of foam drainage was stu died by observing the bubbles' form in the process of foam drainage.Simulation result shows that the foaming pressure-activated sealant can effectively suppressed the leakage,which pressure at 10MPa and water leakage rate is 500mL/min.And the pipeline sealed by pressure-activated sealant can withstand pressure up to 8.5MPa;the liquid pressure-activated sealant can effectively suppressed the leakage,which pressure at 10MPa and water leakage rate is 1000mL/min.And the pipeline sealed by pressure-activated sealant can withstand pressure up to 35MPa.Through the well site engineering practical application,it verified the effect of sealant plugging,also accumulated valuable experiences for practical engineering application.