渤中BZ油田沙二段注水时机研究及应用

Study and application of water injection timing in the second member of Sha Formation in BZ Oilfield of Bozhong

渤中BZ油田沙二段属于异常高压低渗透油藏,压力系数1.42,合理注水时机的确定对低渗透油藏注水开发至关重要。在充分调研陆地异常高压低渗透油田注水时机的基础上综合考虑低渗储层应力敏感、注采压差以及数值模拟结果,提出了渤中BZ油田沙二段最佳注水时机为压力系数降至1.0开始注水。通过实际注水试验生产效果表明:在压力系数降至1.0开始注水,既能充分利用天然能量,又能防止油层脱气、保证水驱开发效果,为油田后续全面水驱开发提供技术支撑。

The second member of Sha Formation in the BZ Oilfield of Bozhong is an abnormally high-pressure and low-permeability reservoir with a pressure coefficient of 1.42.It is very important to determine the reasonable timing of water injection for the water injection development in low-permeability reservoirs.Based on fully investigating the timing of water injection in abnormally highpressure and low-permeability onshore oilfield and considering the stress sensitivity of low-permeability reservoir,the pressure difference between injection and production wells as well as numerical simulation results,the optimal timing of water injection in the Second member of Sha Formation in BZ Oilfield of Bozhong is proposed to be the injection of water at the time when the pressure coefficient is lowered to 1.0.The results of the actual water injection test show that when the pressure coefficient drops to 1.0,starting water injection can not only make full use of natural energy,but also prevent oil reservoir degassing,ensure the effect of water drive development,and provide technical support for the subsequent comprehensive water-driven development of oil fields.