泉28断块注天然气混相驱开发效果影响因素分析

Analysis of Factors Affecting Natural Gas Injection Miscible Flooding Development Effect in Q28 Fault Block

天然气驱作为提高采收率的主要方法已在世界范围内得到了广泛应用。为提高油藏的最终采收率,增大油田的经济效益,必须了解注天然气提高采收率的各种影响因素及其对注烃气开发效果的影响程度,从而制定出合理可行的注气方案。以泉28断块为例,针对该区地质及开发特点,建立了精细地质模型,在流体相态拟合的基础上,结合细管实验确定最小混相压力29 MPa,应用油藏数值模拟技术对注烃气混相驱开发效果影响因素进行了优化研究。结果表明,最佳注入方式为气水交替驱。最佳气水交替注入参数：在目前生产状态下继续注水开发0.5年后转注气,注气段塞尺寸为0.25-0.3 PV,注气段塞数目保持在12-16个,注气速度为0.05-0.06 PV/a,气水比为1∶1-1.5∶1。

Natural gas drive,as the main method of oil recovery increase,has been widely used in oil and gas field development all over the world.To improve ultimate recovery and economic benefit of oil and gas field development,it is necessary to understand factors possibly affecting natural gas injection miscible flooding development effect so as to identify a reasonable and feasible gas injection scheme.Taking Q28 fault block as an example,geological and development characteristics are analyzed,fine geological model is established,slim tube experiment is conducted according to liquid phase behavior fitting and the minimum misoible pressure 29 MPa is determined,and reservoir numerical simulation technique is applied to conduct optimization study on factors affecting natural gas injection miscible flooding development effect.Study results show that the best injection mode is water and gas alternate drive and the best injection parameters are given in this paper,which can provide valuable reference for subsequent natural gas injection miscible flooding development in the reservoir.