低渗油藏扩容压驱工艺技术在渤南油田的应用

Application of dilatant pressure flooding technology in low permeabilityreservoir in Bonan Oilfield

为了对低渗油藏压驱注入后储层渗透率的动态响应机制以及压驱参数对增注效果的影响规律进行进一步研究,以渤南油田义7-6区块为研究对象,根据其地质特征建立了有限元数值模型,明确压驱后孔隙压力和渗透率的动态演化过程,借助油藏数值模拟软件将压驱后储层孔渗变化进行表征并进行压驱注入参数模拟和优化,对优化结果进行矿场验证。研究结果表明:1)实施压驱工艺后,储层构造和裂缝等因素造成的能量补充不均衡是导致油井增产差异明显的主要原因;2)压驱流体的携能作用会率先引起孔隙压力的显著提升,孔隙压力的改变使得地应力场的分布随之改变,进而导致储层岩心发生体积形变,最终影响储层渗透率的大小及分布;3)通过开展水驱开采效果模拟并进行压驱注入参数优选,当压驱排量为1100 m^(3)/d,注入总量为4×10^(4)m^(3)时,其增渗增产效果最好,按照优选结果实施后发现该井组的平均日产油量比之前提高3.78倍。该研究为解决低渗油藏注采困难等工程问题提供理论指导。

In order to study the dynamic response mechanism of reservoir permeability and the effect of pressure flooding parameters on injection efficiency after injection in low permeability reservoir,and the influence law of parameters on the augmented injection effect of lack of understanding of the respect such as Yi 7-6 block,Bonan Oilfield righteousness as the research object,the finite element numerical model is established according to its geological characteristics and identify the displacement after the evolution process of the dynamic pore pressure and permeability,the reservoir pore permeability changes after pressure flooding are characterized by reservoir numerical simulation software,and the injection parameters of pressure flooding are simulated and optimized,the optimization results are verified in the field.The results show that:1)After the implementation of pressure flooding technology,the imbalance of energy supplement caused by reservoir structure,fractures and other factors is the main reason for the obvious difference in oil well stimulation;2)The energy carrying effect of pressure flooding fluid will lead to the significant increase of pore pressure,and the change of pore pressure will change the distribution of geostress field,which will lead to the volume deformation of reservoir core,and ultimately affect the size and distribution of reservoir permeability;3)By simulating the exploitation effect of water flooding and optimizing the injection parameters of pressure flooding,when the displacement of pressure flooding is 1100 m^(3)/d and the total injection is 4×10^(4)m^(3),the effect of increasing permeability and increasing production is the best.According to the implementation of the optimization results,it is found that the average daily oil production of the well group is 3.78 times higher than before.This study provides theoretical guidance for solving engineering problems such as the difficulty of injection and production in low permeability reservoir.