利用测井资料精细评价特低渗透储层的方法

A METHOD FOR FINE EVALUATION IN EXTRA-LOW PERMEABILITY RESERVOIRS USING LOGGING DATA

宋子齐 程国建 杨立雷 于小龙 赵宏宇

Song Ziqi Cheng Guojian Yang Lilei Yu Xiaolong Zhao Hongyu

西安石油大学, 西安, 710065

Xi'an Shiyou University, Xi'an, Shaanxi 710065, China

鄂尔多斯盆地BB油田长3、长4+5特低渗透储层测井中泥浆滤液对地层侵入作用弱,直观指示油气层和水层的微电极及深、中、浅电阻率的有序排列基本消失,储层中发育的微裂缝还造成井眼的不规则扩径等,导致测井响应中来自油气的成分少,有生产能力的低孔隙度储层与无效层段之间差异很小。通过确定特低渗透储层有效厚度下限,将地层电阻率作为地质背景条件,分析岩性和电性特征及其相应的统计标准,充分利用测井资料分析、识别影响特低渗透储层参数变化特征及有效油气成分。并采用测井与地质及试油等资料综合对比研究,分析储层中不同岩性的钙质、泥质夹层的定量统计、扣除方法及其对测井曲线造成的背景值影响,特别是利用微电极电阻率测井曲线的幅度、差异及其性质,精细评价和划分了特低渗透储层,有效提高了该区目的层段特低渗透储层测井解释和有利区预测精度,为该区特低渗透油田增储上产提供了可靠依据。

Mud filtrate intrusion is weak in the extra-low permeability reservoirs Chang3 and Chang 4+5 in the BB Oil Filed,the Ordos Basin.The ordered arrangements of ML and DIL-MSFL which intuitively indicate hydrocarbon reservoir and water zone disappear.Micro-fractures in reservoir lead to the irregular enlargement of holes;hence the oil/gas composition has a smaller part in logging response.The difference is small between the productive low permeability reservoirs and the inefficient ones.Establishing the lowest limit of effective thickness,taking the formation resistivity as the geologic background,analyzing the core electrical characteristics and the relevant statistic criterion,the figure and effective oil/gas composition which affect the parameter variation in extra-low permeability reservoirs are identified by taking full advantage of logging data.Synthetically comparing the logging,geologic and oil-testing data,studying the ration statistics,deduction method and figure affection to log curves of calcic,argillan interbeds in reservoirs with different lithologic characteristics,with the latitude,difference and characteristics of ML log curves,the extra-low permeability reservoirs are finely evaluated and classified.The log interpretation and potential range prediction accuracy have been improved,providing dependable criteria for reservoir enlargement and outcome improvement in extra-low permeability oil fields.

国家自然科学基金项目(40572082)

https://doi.org/10.11781/sysydz200606595