海相强水驱疏松砂岩稠油薄油藏高效开发实践

Practice of Efficient Development in Marine Strong-water Flooding Loose Sandstone Heavy Oil Thin Reservoirs

南海东部海域具有一定规模的海相强水驱疏松砂岩稠油储量,该类稠油油藏开发过程中存在构造认识变化大、油井含水上升快、产量递减快、易出砂等问题。以该地区典型P油田为例,介绍海相强水驱疏松砂岩稠油薄油藏在开发实践中为应对以上问题所采取的技术对策。通过油田内部滚动开发评价,采用先“肥”后“瘦”、以大带小的方式进行开发,油田开发后通过滚动扩边逐步落实构造并实施调整;通过针对边底水油藏制定不同水平井布井策略,底水油藏采用高顶避水、寻夹避水并保持合理井距,边水油藏“批钻批投”抑制边水局部舌进的方式控制单井的含水上升速度;利用先进钻井技术实现井轨迹的精细控制,采用优质筛管防砂完井。现场实践表明,该技术对策使P油田稠油油藏高峰年产量达157×10~4m^3,大规模开发5年后采出程度达到15.5%,开辟了南海东部海域海相强水驱疏松砂岩稠油薄油藏高效开发的先例,对同类油藏的开发具有借鉴意义。

There are certain-scale of heavy oil reserves in marine strong-water flooding loose sandstone reservoirs in the eastern South China Sea.There are many issues in the development process: more understanding on structure,fast rising of water cut in oil wells,rapid decline in oil production,and being easy to sand production.Typical Oilfield P in this area was studied,and the technical countermeasure taken to deal with the above issues during the development practice was introduced.After the rolling development evaluation of the oilfield,the better and more reserves should be developed first,and then the poor reserves may be developed.The structure was gradually known well and rolling edge enlargement was implemented in the oilfield.For the edge and bottom water reservoirs,different horizontal well patterns were made.In the bottom water reservoirs,the wells should be located on the roof of the structure or above the interlayer with reasonable well spacing.In the edge water reservoirs,the wells should be drilled and put into production in a batch to restrain local edge water tongue for controlling the rising rate of water cut in the single well.Advanced drilling technology may be applied to achieving fine control of well trajectory and high-quality screen pipe may be applied to sand control and well completion.The practice shows that the peak annual oil production was up to 157 ×10^4 m^3 and the recovery degree of reserves reached 15.5% after large-scale development for 5 years after the measures were taken in the heavy oil reservoirs of Oilfield P.It is the first case of efficient development of marine strong-water flooding loose sandstone heavy oil thin reservoirs in the eastern South China Sea,and it has great significance on the development of similar reservoirs.