Research And Application On Flow Characteristics Of Low Mobility Reservoir

To further understand flow characteristics of the low mobility reservoir,taking Xiaoji oilfield and Zaoyuan oilfield in Dagang oilfield for example.Aiming at the problems of low producing rate, low recovery rate and lowreserves producing degree in the process of the low mobility reservoirdevelopment. Through studying the research results and the analysis of theliterature about non-Darcy flow, the research ideas and content isdetermined, and non-Darcy flow experiments and numerical simulationhave been done lots of work. The research of experiment and numericalsimulation is the major research tools.The flow in the low mobility reservoir is diverge from the Darcy’ lawthrough the core flow experiments. The characteristic of porous flow in lowmobility reservoir is discussed. Then the characteristic of non-Darcy flowis studied. The paper ensures the relationship and regular among thresholdpressure, reservoir permeability and fluid viscosity. The distribution map ofthreshold pressure gradient in research region is depicted,. And through themap, we can master the distribution regularity of threshold pressuregradient and be well prepared for the reservoir engineering research.The framework and detail steps of the feature model of reservoirdevelopment are described in this paper. Reservoir features model containsgeological properties, production characters and permeation fluid traits.Basing on the reservoir features model, the paper researches the reservoirstartup conditions and status in multilayer reservoir by analyzing the effect of oil viscosity, the vertical heterogeneity, the well spacing, pressuredifference between production and injection and zonal injection status,especially in low fluidity reservoir. The final research objective is toformulate the corresponding injectionervoir. Measures to optimize the lowfluidity reservoir startup conditions, which includes: reasonable well space,zonal injection, stimulation of injection, increasing liquid production, wellpattern optimizing, acidizing and hydraulic fracturing, etc. And gives theguiding technological parameters for the measures discussed above.The Well test data show that the layer interference is serious in the areaof study. Reservoir simulation method is applied to study the reservoirstartup status and conditions. In the simulation process, the pressuregradient is a key parameter for the low fluidity reservoir.The measures to improve the development effect of low mobilityreservoir are studied. Injection-production pressure system characteristicshave shown that the pressure drawdown of injection well and productionwell is near the wellbore. There is a reasonable range of producing pressuredrop because the formation pressure change affects permeability, otherwise,the productivity will be declined. The threshold pressure gradient andinterlayer interference are the main factors affecting the degree ofutilization in low mobility multilayered reservoir. In order to reflect thedevelopment characteristics of the low mobility multilayered reservoir, thethreshold pressure gradient must be considered in reservoir numericalsimulation.