摘要
注水井经过长期高压注水,其周围储层物性会发生不同程度的变化。利用套前、套后的自然伽马测井曲线,评价地层泥质含量的变化情况;在套管井中进行双源距补偿中子测井和交叉偶极阵列声波测井确定地层目前的孔隙度,与裸眼井的孔隙度对比,定量评价地层孔隙度的变化情况;进行压力降落测试确定地层的有效渗透率,与以前的试井分析结果对比,评价有效渗透率的变化情况;进行脉冲中子全谱测井确定储层目前含水饱和度,分别与原始和完井时的含水饱和度对比,评价含水饱和度的变化情况。通过3口井现场试验得出:在非射孔层位以及射孔非主力生产层位,注水井长期高压注水对储层物性影响较小;在射孔的主力生产层位,注水井长期高压注水对储层物性的影响较大,当孔隙度变化量大于4%,含水饱和度高于90%,关井初期地层压力降落幅度大、速度快,有效渗透率明显变大时,主力吸水层位已形成注水优势通道,需要采取封堵措施。研究成果为油田水淹层解释、下步综合治理、实现精细注水提供了依据。
After a long period of the high-pressure water injection,the reservoir physical properties around the injection well have been changed with different degrees. With the help of the natural gamma logging curves of the open hole and case hole,the changes of the shale content have been evaluated; the current porosities are determined by the dual-spaced compensated neutron logging and cross dipole array acoustic logging in the case hole,and moreover comparing with the porosities in the open hole,the changes of the formation porosity are quantitatively calculated; the formation effective permeabilities are ensured by the pressure drop test,and furthermore comparing with the analyzed results of the previous well test,the variations of the effective permeability are evaluated; the current water saturations of the reservoirs are assessed and made sure by pulse neutron full spectrum logging,and then comparing with the original and ones at the stage of well completion,the changes of the water saturation are evaluated. The field tests of the three wells show that for the non-perforation layers and perforated less-important production layers,the influences of the long-period high-pressure water injection on the reservoir physical properties are greatly smaller; for the main perforated production layers,the influences are rather serious,when the change of theporosity is greater than 4%,the water saturation is greater than 90%,the pressure drop is serious and very quick at the beginning of the closed-in well and the effective permeabilities are increased obviously and greatly,the predominant channels are formed in the main water-intake layers,thus the plugging measures and stimulations are must be adopted. The study achievements have provided the sound bases for the interpretation of the water-flooded zones,management of the future comprehensive and realization of the fine water injection of the oilfield.
出处
《大庆石油地质与开发》
CAS
CSCD
北大核心
2016年第6期148-154,共7页
Petroleum Geology & Oilfield Development in Daqing
基金
国家科技重大专项(2011ZX05020-007)
关键词
注水井
测井
泥质含量
孔隙度
渗透率
含水饱和度
大孔道
injecting/injection well(or injector)
well logging
shale content
porosity
permeability
water saturation
big/large channel
