渤海油田化学驱注入井解堵剂构建、性能和注入工艺

Construction，Performance and Injection Technology of Plugging Remover for Chemical Flooding Injection Wells in Bohai Oilfield

孙惠茹 卢祥国 何 欣 刘进祥 高建崇 崔天宇 唐晓旭

SUN Huiru LU Xiangguo HE Xin LIU Jinxiang GAO Jianchong CUI Tianyu TANG Xiaoxu

渤海J油田经历长期化学驱，注入井储层低渗透部位堵塞严重，常规解堵措施效果较差，亟待开发新型解堵剂和解堵工艺。为此，以渤海油田目标油藏聚合物驱水井返排堵塞物为研究对象，开展了化学驱注入井解堵剂构建、性能评价和工艺研究。结果表明，目标油田化学驱水井返排堵塞物由87.77%水、3.83%原油、2.76%聚合物和 5.64%无机垢构成，其中无机垢主要包括 59.1% SiO2、25.9% CaCO3和 11.4% MgCO3，同时含有少量的 BaCO3、 SrCO3、BaSO4、SrSO4和 Fe2O3。根据堵塞物成分，构建了由有机溶剂、解聚剂和溶垢剂等组成的新型解堵剂。优选出的有机溶剂为甲苯与正戊醇的混合物（质量比9∶1～7∶3），解聚剂为0.5%～1.0%过硫酸铵，溶垢剂为5.46%溶垢剂1（α-环糊精包合体和β-环糊精包合体）+0.54%柠檬酸。3种类型解堵剂依次加药的溶垢效果好于复配加药方式，按解聚剂+有机溶剂+溶垢剂（质量比为1∶2∶3）的加药顺序，对堵塞物的溶垢率为98.1%。岩心解堵实验结果表明，新型解堵剂对无机混合垢和聚合物堵塞的解堵率超过80%。与单独解堵作业相比，无机凝胶调剖+解堵联合作业兼具“堵”和“疏”双重功效，采收率增幅提高6.9百分点。

The J oilfield in Bohai has experienced long-term chemical flooding，and the low permeability part of the injected well reservoir is seriously blocked. The effect of conventional plugging removal measures is poor. It is urgent to develop new plugging remover and plugging removal process. Therefore，taking the backflow blockage of polymer flooding wells in the target reservoir of Bohai oilfield as the research object，the construction，performance evaluation and process research of plugging remover for chemical flooding injection well were carried out. The results showed that the backflow blockage of chemical flooding wells in the target oilfield was composed of 87.77% water，3.83% crude oil，2.76% polymer and 5.64% inorganic scale. The inorganic scale mainly included 59.1% SiO2，25.9% CaCO3 and 11.4% MgCO3，meanwhile contained a small amount of BaCO3，SrCO3，BaSO4， SrSO4 and Fe2O3. According to the composition of blockage，a new type of plugging remover composed of organic solvent， depolymerization agent and scale-dissolving agent was constructed. The preferred organic solvent was a mixture of toluene and n-pentanol（mass ratio of 9∶1—7∶3），the depolymerization agent was 0.5%—1.0% ammonium persulfate，and then the scale-dissolving agent was 5.46% scale-dissolving agent 1（α-cyclodextrin inclusion and β-cyclodextrin inclusion）and 0.54% citric acid. The scale-dissolving effect of three types of plugging remover in turn was better than that of compound dosing method. According to the dosing sequence of depolymerization agent，organic solvent and scale-dissolving agent （mass ratio of 1∶2∶3），the scale-dissolving rate of the blockage was 98.1%. The results of core plugging removal experiments showed that the new plugging remover had a plugging removal rate of more than 80% for inorganic mixed scale and polymer plugging. Compared with single plugging removal operation，the combined operation of inorganic gel profile control and plugging removal had dual effects of “plugging”and“dredging”. The recovery rate was increased by 6.9 percentage points.

10.19346/j.cnki.1000-4092.2024.03.018