考虑启动压力梯度的堵塞器嘴后压力确定方法及其现场应用

Determination method of pressure behind blanking plug considering starting pressure gradient and its field application

为实现多层系注水开发油藏配注参数的精细设计,基于预置电缆智能测调结果,提出了一种考虑吸水启动压力梯度的堵塞器嘴后压力确定方法。首先根据井组内储层物性参数和注水井及采油井生产动态数据,确定注水井各注采层段的配注压差;其次由预置电缆智能测调系统测定的注水井各小层压力和流量数据计算各小层对应的吸水启动压力梯度;最后基于计算的配注压差和吸水启动压力梯度,确定注采井组内各小层堵塞器合理嘴后压力。基于这种方法,以大庆油田某试验区典型注采井组为例设计了分层定压注水堵塞器嘴后压力并进行了现场应用跟踪评价。结果表明:采油井平均产油量稳步提升(由1.56 t/d上升至1.93 t/d),含水率逐渐降低(由95.9%下降至93.2%),起到了良好的开发效果。研究成果为进一步开展多层系定压注水配注参数优化设计提供了技术支撑。

In order to realize fine design of water injection parameters for oil reservoirs with multiple layers,the de‑termination method of pressure behind blanking plug considering starting pressure gradient is presented based on test results of pre-installed-cable intelligent injection-measurement and adjustment system.Firstly,according to reservoir physical parameters and producer performance data in researched well pattern,the injection pressure difference of each injection-production interval of water injector is determined.Secondly,the corresponding starting pressure of each sub-layer of water injector is calculated by system-determined sub-layer pressure and flow rate da‑ta.Finally,based on calculated injection pressure difference and starting pressure gradient,the rational pressure behind blanking plug of each sub-layer of the pattern is determined.Based on the proposed method,taking typical injection-production well pattern in a test area of Daqing Oilfield as an example,pressure behind blanking plug is designed for separated sub-layer and constant-pressure water injection,and follow-up evaluation of field applica‑tion is carried out.The results show that average oil output of producers steadily increases(from 1.56 t/d to 1.93 t/d),and water cut is gradually reduced(from 95.9%to 93.2%),achieving much better developed effects.This research provides technical support for further optimization design of multiple-layer constant-pressure water-in‑jection distributing parameters.