海上油田水平井网驱油规律研究

Research and Practice on Oil Displacement Law of Different Well Pattern in Offshore Oilfield

BZ油田是渤海海域以水平井井网开发的油田.结合海上油田井距大、井数少、井网复杂等开发特点,以等性相似理论为依托,依据油田实际地质情况设计试验模型,模拟不同的驱替速度下平行水平井网和直井水平井井网水驱油规律,研究不同储层非均性驱替速度和井网对水驱效果的影响.研究发现,在相对均值的储层中,采用平行水平井网低速开发,见水较慢,采出程度大,开发效果最好;在非均质(J_(k)=4,平均K为3200mD较高)高渗储层中,采用交错水平井网低速开发,见水较慢,采出程度大,开发效果最好;在非均质(J_(k)=6,平均K为1000mD较低)的高渗储层中,采用直井水平井联合井网低速开发,见水较慢,采出程度大,开发效果最好.该项研究加深对水平井井网开发规律以及剩余油分布规律认识,为油田后续的布井及开发调整提供依据.

BZ oilfield is the first oilfield successfully developed with large-scale horizontal well pattern in Bohai fluvial facies oilfield.Under the guidance of similarity theory,Combined with the characteristics of offshore oilfield,such as large well spacing,few wells and complex well pattern,the author designs a heterogeneous reservoir model according to the reservoir conditions in the study area.The water displacement of horizontal well pattern and combined well pattern under different displacement speeds is simulated.The effects of heterogeneity,displacement speed and well pattern on water displacement effect are studied by measuring the electrical characteristics,injection volume,oil production and water production of the model.It is found that in the average reservoir,the horizontal well pattern is used for lowspeed development,the water breakthrough of oil wells is slow,the EOR is large;In the heterogeneous(J,=4)high permeability reservoir,the oilfield adopts staggered well pattern low-speed development,the water breakthrough of the oil well is slow,and the EOR is large;In the heterogeneous(J_(k)=6)high permeability reservoir,the oilfield adopts the combined well pattern for low-speed development,the water breakthrough of the oil well is slow,and the EOR is large.This study deepens the understanding of the development law of horizontal well pattern and the distribution law of remaining oil,and provides a basis for oilfield development and adjustment.