特低渗透油藏CO2驱流度控制技术

摘要

The injected CO2,will flow in the advantage ehannel of reservoir firstly,so the ethylene diamine is chosen as a profile control agent for controlling fluid mobility and preventing CO2 breakthrugh from advantage channel.Considering the characteristics of resevoir physical properties of CO2,pilot,static performauce,plugging strength,injectivity and mobility control of the profile control system were experimentally evaluated.The experiment results show that the viscosity of profile control system is stable at 14 000.0 mPa.s with good strength.CO2 breakthrough is restrained and the breakthrough pressure is 9.1 MPa after plugging with the profile control system.The injectivity of compound slug with pre-injection slug,profile control agent and protection plug is better than profile control agent only in extra-low permeability reservoir.Since the injecting profile control system blocks the dominant channel effectively,the swept volume of CO2 flooding is expanded and oil recovery is improved ultimately.%为控制CO2驱优势通道流体流度,选用乙二胺作为调剖剂,并结合延长油田CO2驱试验区储层物性特征,对调剖剂体系静态、封堵强度、注入性及流度控制性进行了实验评价 结果表明:地层条件下,调剖剂体系黏度稳定于14 000.0mPa·s,体系强度较高;在一定压力范围内能够抑制气体的窜逸,调剖剂封堵后,CO2气体突破压力为9.1 MPa;特低渗透储层注入前置段塞+调剖剂体系+保护段塞,体系注入性较好;注入调剖剂体系后可有效封堵优势通道,扩大CO2驱波及体积,提高原油采收率.