摘要
页岩油藏基质渗透率极低,注气吞吐是一种有效的页岩油提高采收率技术。由于人工裂缝与天然裂缝的存在,矿场试验表明注气吞吐过程中邻井气体窜流严重。注入泡沫可有效降低气体流度,增大吞吐波及体积,抑制气体在裂缝中的窜流。通过室内实验,筛选4种起泡剂,对其起泡能力和稳泡能力进行评价,优选泡沫综合性能最好的起泡剂,继而探究页岩裂缝岩心注气吞吐过程中的气窜规律,明确裂缝岩心注入泡沫后的封堵性能,以探究泡沫防窜对页岩岩心注气吞吐提高采收率的应用潜力。结果表明:质量分数为0.4%的AOS起泡剂稳定性最好;气液同注后产生的泡沫气体封堵压差增至6.67 MPa,气体突破时间增加了13.72倍;在泡沫封堵的基础上,进行5个轮次的吞吐可使总采收率提高6.58%。
The matrix permeability of shale oil reservoirs is extremely low,and gas huff-n-puff is an effective technology for enhanced oil recovery(EOR)of shale oil.Due to artificial and natural fractures,field tests showed that gas channeling from adjacent wells was serious during huff-n-puff gas injection.Injecting foam can reduce gas fluidity,increase the swept volume of huff-n-puff,and inhibit the gas channeling between fractures.Four foaming agents were screened through laboratory experiments.The foaming ability and foam stabilization were evaluated to select the foaming agent with the best comprehensive performance,and then the gas channeling law during huff-n-puff gas injection in the fractured shale core was explored.In addition,the plugging performance in the fractured core after foam injection was studied,and the potential of foam channeling control for EOR by huff-n-puff gas injection in shale cores was explored.The results demonstrate the AOS foaming agent with a mass fraction of 0.4%shows the optimal stability;the pressure difference of foamed gas plugging generated after the simultaneous injection of gas and liquid grows to 6.67 MPa,and the gas breakthrough time increases by 13.72 times;based on foam plugging,five cycles of huff-n-puff can enhance the total recovery factor by 6.58%.
作者
吴晓峰
盛家平
熊晓菲
WU Xiaofeng;SHENG Jiaping;XIONG Xiaofei(Unconventional Petroleum Research Institute,China University of Petroleum(Beijing),Beijing City,102249,China)
出处
《油气地质与采收率》
CAS
CSCD
北大核心
2022年第4期109-115,共7页
Petroleum Geology and Recovery Efficiency
基金
国家自然科学基金项目“页岩油藏空气氧化热破裂机制研究”(51974334)
中国石油战略合作科技专项“页岩油储层改造与提采一体化机理与技术研究”(ZLZX2020)
中国石油大学(北京)科研基金(2462018YJRC001)。
