论文部分内容阅读
低渗透致密油藏的有效高效开发一直是石油工业研究的重点。低渗存量主要以水驱开发方式为主,由于储层孔喉细微、物性差、渗流阻力大等内在因素,造成低渗透油藏储层启动压差高及驱替压力梯度大,进一步导致注水困难。提高低渗透油藏开发效果的核心在于降低油水界面张力,进而降低注水启动压力梯度,提高沿程驱替压差。通过室内实验,研究了弱碱性水对低渗透、特低渗透油藏注水的影响,弱碱性水水质稳定且具有较强的润湿性,可以降低油水界面张力,适用于低渗透油藏注水。据此提出了弱碱性水加入胺类活性剂和两性表面活性剂注水的方案及建议,该复配体系具有较好的降低油水界面张力的作用,可以在较宽浓度范围内将油水界面张力降至0.001m N/m,适用于启动压力梯度很高的特低渗透油藏。在临盘油田实施4口水井,注水有效期延长6倍以上且继续有效。
The effective and efficient development of low permeability and tight reservoirs has been the focus of petroleum industry research. The low permeability reservoir is dominated by waterflood development mode. Due to the inherent pore throat fouling, poor physical properties and large seepage resistance, the low pressure reservoir reservoir start-up pressure gradient and displacing pressure gradient are large, leading to water injection difficult. The key to improve the development effect of low permeability reservoirs is to reduce the interfacial tension between oil and water, and then reduce the pressure gradient of water injection and increase the pressure drop along the displacement. Through laboratory experiments, the influence of weak alkaline water on the water injection in low permeability and ultra-low permeability reservoirs has been studied. The weak alkaline water has stable water quality and strong wettability, which can reduce the interfacial tension between oil and water and is suitable for low permeability reservoirs Water injection. Proposed a weak alkaline water to join the amine active agent and amphoteric surfactant water injection scheme and the proposal that the compound system has a better ability to reduce the oil-water interfacial tension can be a wide range of concentrations of oil-water interfacial tension Down to 0.001m N / m, suitable for start-up ultra-low permeability reservoirs with high pressure gradients. In Lingpan oilfield implementation of four wells, water flooding valid for more than 6 times and continue to be effective.