Study On Dynamic And Static Experiments Of Self-Adaptive Movable Gel

As a kind of non-renewable resource,the difficulty of oil extraction becomes more and more serious with the development of mining technology.At present,most of China's oil fields have entered the high water cut stage,even the ultra-high water cut stage,and the reservoir heterogeneity is serious,which leads to the fact that many traditional exploitation technologies are not enough to further enhance oil recovery.At present,the deep profile control technology can effectively block the deep high permeability layer,use the low permeability layer,increase the swept area and the swept efficiency of water flow,and it has been adopted by oil fields one after another.Among them,movable gel profile control and flooding is an important technical means to reduce the water cut of crude oil and improve oil recovery in the background of high permeability,high water cut,poor reservoir geological uniformity and weak profile control and flooding effect of traditional profile control agents.Self-adaptive gel system is diluted and dissolved by high salinity formation water on the ground,and the system is injected into the formation at high pressure.With the gradual dilution of formation water,the salinity of the system decreases.Through practical experience and effective calculation,after the system enters the deep part of the formation,it can be gelled and plugged,and the plugging removal process can be achieved by injecting high salinity formation water into the formation.In this paper,the gel-forming rate of N1 and N2 adaptive gels is analyzed by static experiment,and the adaptive salinity range of adaptive movable gel system is defined.Through dynamic experiment,according to the injection pressure and residual resistance coefficient,the plugging and unblocking performance rules of N1 and N2 adaptive gels with different permeability are defined.At the same time,CP-M precision constant flow pump plug container and pressure sensor are used to monitor the pressure change in real time under the condition of ensuring the stable injection speed.Combined with the resistance coefficient and residual resistance coefficient,the usage and optimal usage conditions of gel are determined,which helps the oilfield to determine the optimal usage conditions of gel to a certain extent,give full play to the profile control performance of gel and reduce unnecessary losses.The results show that:(1)Under static conditions,the gel-forming rate of adaptive movable gel gradually increases with the increase of salinity,and can reach 80% when the salinity reaches20,000-65,000 mg/L,and then gradually decreases with the increase of salinity,and the range of adaptive salinity increases with the increase of temperature.(2)Under the dynamic condition,the self-adaptive movable gel system has good injectivity,and the residual resistance coefficient of the core increases with the increase of core permeability,and the plugging degree reaches 75%,but the residual resistance decreases rapidly when the system temperature rises.It can be seen that the self-adaptive movable gel has the best gel formation and the highest plugging degree when the salinity is 20,000-65,000mg/L.