盘古梁长6油藏见效见水特征分析

Analysis on Effective and Water Breakthrough Characteristics of Chang 6 Reservoir in Pan guliang Area

盘古梁长6油藏是一个特低渗、低压、低丰度的"三低"岩性油藏,天然微裂缝和人工压裂裂缝发育,随着开发的不断深入,油藏进入中含水开发阶段,含水上升速度加快,主侧向井矛盾加剧,持续稳产难度加大。结合油藏地质特征与生产特征,该油藏见效特征规律分3种类型(上升型、稳定型、见水型),以见效稳定型为主。见水特征规律为大部分油井含水处于较低水平,产能较高,但伴随着含水率的升高,单井日产油量逐渐减小,且下降幅度较大。分析见水原因主要包括:裂缝沟通造成主向井含水快速上升;高渗带的影响;由于物性不均造成水驱不均,导致油井见水;中部高采出程度井含水上升;产液强度偏大造成含水上升。通过研究中含水开发阶段的见效见水特征并制定相应的治理对策,对油藏持续稳产具有重要意义。

Chang 6Reservoir of Panguliang Oilfield belonged to a reservoir with 3low features,that was the super-low permeability,low pressure and low abundance,where the natural and artificial fractures were developed,with the deepening of oilfield development,the reservoir entered into a middle water-cut stage,and the exploitation was faced many serious difficulties including water cut quickened up,stable yield was more difficult,and so on.Based on the characteristics of reservoir geology and production,the reservoir effective features were divided into three types,including the rising water-cut,stable water-cut and water breakthrough.The mean types were effective and stable water cut.The water breakthrough characteristics indicated that the water cut was low with high productivity,but with the increase of water cut,daily oil production of single well was reduced seriously.The main reasons tof water breakthrough included that quick increase of water cut was induced by fracture communication and influence was caused in high permeability zones.Uneven water drive was induced by non-uniformed physical property,and water breakthrough was also caused.And water content is raised in the wells with high recovery percent and large recovery intensity.Then,water breakthrough characteristics and its effect on reservoir development are also studied corresponding measures for prevention is developed.It is of great significance for sustainably stabilizing oil production in the reservoir.