摘要
新疆克拉玛依油田QD1区克拉玛依组下亚组砾岩油藏经历长期注水开发,储集层非均质性变强,裂缝和优势通道发育,后续聚合物驱过程中出现采出井产聚浓度高等问题,影响了聚合物驱效果。为认识砾岩油藏聚合物驱产聚浓度变化规律,以该区油藏储集层特征和流体为研究对象,采用生产动态分析、理论公式计算等多种技术手段,针对聚合物驱生产阶段划分、产聚浓度上升规律、产聚浓度界限图版和聚窜井治理压力下限等开展了研究。结果表明,砾岩油藏聚合物驱生产阶段可以划分为注聚初期、见效高峰期、见效后期和后续水驱4个阶段。见效高峰期一般为2~3 a,高峰期内最大产聚浓度为737.2 mg/L,最大相对产聚浓度不超过0.550,相对产聚浓度上升率不超过2.3;140 m和120 m井距相对产聚浓度上升率合理范围为2.3~6.0,对应相对产聚浓度为0.276~0.720,产聚浓度为414.0~1080.0 mg/L;优势通道、压裂裂缝和缝道共存3种聚窜类型井治理的压力下限标准分别是8.0 MPa,10.0 MPa和9.5 MPa.此研究成果对该区及同类型油藏聚合物驱生产动态调整和聚窜井分类治理具有借鉴意义。
Over a long⁃term waterflooding development,the conglomerate reservoir of the lower Karamay formation in QD1 block of Kara⁃may oilfield in Xinjiang is featured with strong heterogeneity,developed fracture and developed preferential migration pathway.But high concentration of produced polymer in producers during subsequent polymer flooding affects the polymer flooding effect.In order to under⁃stand the variations of produced polymer concentration of polymer flooding in conglomerate reservoirs,taking the reservoir characteristics and fluids in QD1 block as research objects,the paper carries out studies related to production stage classification for the polymer flooding,rising law of the produced polymer concentration,charts of the produced polymer concentration limits and the lower injection pressure limits for polymer channeling control.The results show that the production stage of polymer flooding in conglomerate reservoirs can be classified into early stage of polymer injection,peak response stage,late response stage and subsequent water flooding stage.The peak response stage generally lasts for 2 or 3 years with the maximum produced polymer concentration of 737.2 mg/L,the maximum relative produced polymer concentration of 0.550 and the concentration rising rate of 2.3;when the well spacings are 140 m and 120 m,the reasonable rise rate of the relative concentration is 2.3~6.0,the corresponding relative concentration ranges from 0.276 to 0.720 and the produced polymer concentra⁃tion is 414.0~1080.0 mg/L.The lower limits of injection pressure for polymer channeling control in wells dominated by preferential migra⁃tion pathway,hydraulic fracture and fracture plus pathway are 8 MPa,10.0 MPa and 9.5 MPa,respectively.The research results can provide references for production performance adjustment and well treatment during polymer flooding in conglomerate reservoirs in this area.
作者
张德富
吕建荣
田秘
张菁
ZHANG Defu;LYU Jianrong;TIAN Mi;ZHANG Jing(Research Institute of Exploration and Development,Xinjiang Oilfield Company,PetroChina,Karamay,Xinjiang 834000,China)
出处
《新疆石油地质》
CAS
CSCD
北大核心
2020年第3期326-331,共6页
Xinjiang Petroleum Geology
基金
国家科技重大专项(2016ZX05010-004
2016ZX05010-005)。
关键词
克拉玛依油田
砾岩油藏
聚合物驱
产聚浓度
非均质性
界限图版
聚窜井
Karamay oilfield
conglomerate reservoir
polymer flooding
produced polymer concentration
heterogeneity
boundary chart
polymer channeling well
