基于核磁共振的CO2驱喉道动用界限——以朝阳沟油田为例
Producing limit of CO2 flooding throat based on nuclear magnetic resonance
白振强 1皮彦夫 2王清华 3宋文波 3朱琦3
作者信息
- 1. 东北石油大学石油工程学院,黑龙江大庆 163318;中国石油大庆油田勘探开发研究院,黑龙江大庆 163000
- 2. 东北石油大学石油工程学院,黑龙江大庆 163318
- 3. 中国石油大庆油田勘探开发研究院,黑龙江大庆 163000
- 折叠
摘要
依据核磁共振基本原理,通过孔隙的简化,推导出核磁共振T2驰豫时间与孔隙喉道半径关系,利用数值差值和最小二乘基本方法,结合高压压汞岩心孔喉分布,将核磁共振T2图谱转换为岩心孔喉半径分布.在此基础上,利用岩心驱替过程中含油饱和度的变化,信号幅度同步变化的基本规律,分析水驱和CO2驱不同孔喉半径的信号幅度变化曲线,判断出不同开发方式下的最小孔喉动用界限.研究表明,朝阳沟油田特低渗透区块为亲水特性,低压水驱岩样采出程度28.0％,高压水驱岩样采出程度30.0％,非混相气驱岩样的采出程度为48％,混相气驱岩样的采出程度为64％;水驱主要动用孔隙中喉半径大于1.00 μm孔的可动油,非混相驱替不可动用的最小孔喉半径为0.15 μm,混相驱没有提高喉道动用界限,但是驱替效率却大幅度提高;CO2驱替出原油中的轻质组分,残余油黏度变大,不可动流体在原有的基础上增加了 1/3～3/4,核磁共振图谱发生左移现象.研究结论为CO2驱开发方案提供重要的参考依据.
Abstract
According to the basic principle of NMR,the relation between NMR T2 relaxation time and pore throat radius was deduced through pore simplification.NMR T2 map was converted into core pore throat ra-dius distribution by using numerical difference and least square method combined with high-pressure mer-cury injection core pore throat distribution.On this basis,the change of oil saturation and the synchronous change of signal amplitude in the process of core flooding are used to analyze the change curve of signal am-plitude of different pore-throat radius of water flooding and CO2 flooding,and the minimum orifice throat production limit under different development modes is determined.The shows that the ultra-low permeabil-ity block of Chaoyanggou Oilfield is hydrophile,the recovery degree for low and high pressure water drive is 28.0％and 30.0％respectively,48％and 64％for immiscible and miscible gas drive respectively.In wa-ter flooding,movable oil is mainly used in pores with pore throat radius greater than 1 μm.In immiscible flooding,the maximum pore throat radius is 0.15 μm.Miscible flooding does not improve the throat limit,but the displacement efficiency is greatly improved.The light components in crude oil are displaced by CO2,the viscosity of residual oil increases,and the immovable fluid increases by 1/3～3/4 on the original basis,and the NMR spectrum shifts to the left.The conclusion provides a good reference for development plan of CO2 flooding.
关键词
CO2驱/核磁共振/高压压汞/喉道半径/动用界限Key words
CO2 flooding/nuclear magnetic resonance/high pressure mercury injection/throat radius/pro-ducing limit引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据