摘要
针对高21沙二段油藏注水开发中的窜流问题,结合其突出的低渗、高盐特点,探索将具有“半透性增能和沉淀封堵水窜”双重作用的沉淀型半透膜材料应用于改善水驱,以期为类似油藏开发提供借鉴。研究结果表明,地层水中钙离子浓度高(2.1 g/L),地下原位形成CaCO_(3)沉淀,能够对水流通道形成一定的封堵(渗透率封堵率为18.9%~40.7%);更高浓度CaCl_(2)和Na2CO_(3)交替注入可以进一步增强封堵(渗透率封堵率为69.2%)。对于Cu_(2)Fe(CN)_(6)沉淀体系,其具有较强的封堵能力(渗透率封堵率为84.7%),能够形成半透膜,具备调剖渗透压增能驱油效果。沉淀类材料应用中,为了保证其封堵能力,同时防止近井堵塞(以增大调剖深度),沉淀剂应采用交替注入的方式,且交替段塞尺寸适中(0.25PV)。水段塞分隔也是防止堵塞,增大调剖深度的较好方法。
Aiming at the problem of channeling flow in water flooding development of the sha2 member in Gao21 block based on the characteristics of low permeability and high salt,the semi-permeable membrane material with the dual function of“semi-permeable pressurization and precipitation plugging water channeling”is applied to improve water flooding,which can provide reference for similar reservoir development.The results show that,the concentration of calcium ion in formation water is high(2.1 g/L),and CaCO_(3) precipitation is formed in situ,which can block the flow channel(permeability plugging rate 18.9%~40.7%);Higher concentration CaCl_(2) and Na_(2)CO_(3) alternate injection can further enhance plugging(permeability plugging rate 69.2%).For Cu_(2)[Fe(CN)_(6)]precipitation system,it has strong plugging ability(permeability plugging rate 84.7%),can form semi-permeable membrane,and has the effect of profile control-permeability pressure booster oil flooding effect.For the application of sedimentation plugging agent,in order to ensure its plugging ability,prevent near well blockage and increase profile control depth,the precipitator should adopt alternating injection mode and adopt moderate alternate plug size(0.25 PV).Water slug separation is also a good way to prevent blockage and increase profile control depth.
作者
王伟琳
WANG Weilin(Dongsheng Jinggong Petroleum Development Group Co.,Ltd.,Shengli Oil Field,Shandong Dongying 257000, China)
出处
《非常规油气》
2021年第4期84-92,共9页
Unconventional Oil & Gas
基金
山东省自然科学基金面上项目“基于可控释放型自生泡沫的低渗油藏增能-调驱一体化提高采收率方法”(ZR2020ME089)。
关键词
低渗油藏
改善水驱
沉淀型堵剂
半透膜
高矿化度
low-permeability reservoir
improving water injection
precipitation plugging agent
semi-permeable membrane
high salinity
