降压增注剂固液界面修饰实验

Experiment of Solid-liquid Interface Modification of Antihypertensive Injection

为解决文33块沙三上油藏开发中存在的高压欠注问题,室内优选出低浓度(有效浓度0.05%)降压增注剂XH207B,进行岩心薄片微观形貌修饰实验,反转近井地带亲水岩石的润湿性,在岩心中注入降压增注剂XH207B溶液,观察润湿反转前后岩心微观形貌的变化特征,揭示降压增注剂的工作原理,并通过油水两相的岩心驱替实验观察亲水储层油水两相相对渗透率变化的渗流规律,为现场施工提供指导意义,达到降压增注目的。室内实验结果表明:在较低浓度0.05%时,XH207B溶液可使亲水岩石达到中间润湿状态(接触角接近90°),并且在岩石孔喉中主要以水膜形式附着在孔喉壁面,防止亲水岩石中黏土矿物膨胀运移,改变近井地带油水界面特征,同时,降压增注剂溶液以微小水珠形式包裹在油相中促进了油水乳化作用,提高了亲水储层油水两相相对渗透率,最终使注入压差发生了一定幅度的下降,下降幅度为1.22%~6.18%,达到了降压增注的效果。

In order to solve the high pressure problem of underpressurre injection in the development of the top oil reservoir in Wen Block 33,low concentration(0.05%effective concentration)agent XH207B of decompression and augmented injection was an optimized choice in indoors experiment for the core-morphology modification experiment of core slice and alterating the rock wettability in near wellbore area.The XH207B was injected into the core to observe the characteristics of micro-morphology cores before and after wettability reversal mechanism,andthus revealed the operation principle of decompression and augmented injection agents.The seepage law of oil-water relative permeability in water-wet reservoir was observed by oil-water two-phase coreflooding experiment,which provided guiding significance for site construction and for the purpose of decompression and augmented injection.The result of laboratory experiments shows that the XH207B solution can make the water wet cores reach the intermediate wetting regime(contact angle closed to 90°)at lower concentration of 0.05%,and it is mainly attached to the wall of pore throat in form of water film,preventing the expansion and migration of clay minerals in the water wet cores and changing the oil-water interface characteristics in the near-well zones.Simultaneously,the agent solution of decompression and augmented injection is wrapped in the oil phase in form of“micro-spheres”to promote the oil-water emulsification and improve the oil-water relative permeability in water-wet reservoir.Finally,the injection pressure difference shows a certain degree of decline,the decrease range is 1.22%~6.18%,which achieved the effect of decompression and augmented injection.