Micro-geological causes and macro-geological controlling factors of low-resistivity oil layers in the Puao Oilfield  

作　　者：Tan Fengqi Li Hongqi Liu Hongtao Jiang Fucong Yu Hongyan 

机构地区：[1]School of Resource and Information Technology, China University of Petroleum, Beijing 102249, China [2]State Key Laboratory of Petroleum Resource and Prospecting, China University of Petroleum, Beijing 102249, China [3]The No.7 Oil Production Factory, Daqing Oilfield Company, PetroChina, Heilongjiang 163515, China

出　　处：《Petroleum Science》2009年第3期246-253,共8页石油科学（英文版）

基　　金：supported by the National Natural ScienceFoundation Project(No.40173023)

摘　　要：Low-resistivity oil layers are often missed in logging interpretation because of their resistivity close to or below the resistivity of nearby water layers. Typical low-resistivity oil layers have been found in the past few years in the Putaohua reservoir of the Puao Oilfield in the south of the Daqing placanticline by detailed exploration. Based on a study of micro-geological causes of low-resistivity oil layers, the macro-geological controlling factors were analyzed through comprehensive research of regional depositional background, geological structure, and oil-water relations combined with core, water testing, well logging, and scanning electron microscopy data. The results showed that the formation and distribution of Putaohua low-resistivity oil layers in the Puao Oilfield were controlled by depositional environment, sedimentary facies, diagenesis, motive power of hydrocarbon accumulation, and acidity and alkalinity of reservoir liquid. The low-resistivity oil layers caused by high bound-water saturation were controlled by deposition and diagenesis, those caused by high free-water saturation were controlled by structural amplitude and motive power of hydrocarbon accumulation. Those caused by formation water with high salinity were controlled by the ancient saline water depositional environment and faulted structure and those caused by additional conductivity of shale were controlled by paleoclimate and acidity and alkalinity of reservoir liquid. Consideration of both micro-geological causes and macro-geological controlling factors is important in identifying low-resistivity oil layers.Low-resistivity oil layers are often missed in logging interpretation because of their resistivity close to or below the resistivity of nearby water layers. Typical low-resistivity oil layers have been found in the past few years in the Putaohua reservoir of the Puao Oilfield in the south of the Daqing placanticline by detailed exploration. Based on a study of micro-geological causes of low-resistivity oil layers, the macro-geological controlling factors were analyzed through comprehensive research of regional depositional background, geological structure, and oil-water relations combined with core, water testing, well logging, and scanning electron microscopy data. The results showed that the formation and distribution of Putaohua low-resistivity oil layers in the Puao Oilfield were controlled by depositional environment, sedimentary facies, diagenesis, motive power of hydrocarbon accumulation, and acidity and alkalinity of reservoir liquid. The low-resistivity oil layers caused by high bound-water saturation were controlled by deposition and diagenesis, those caused by high free-water saturation were controlled by structural amplitude and motive power of hydrocarbon accumulation. Those caused by formation water with high salinity were controlled by the ancient saline water depositional environment and faulted structure and those caused by additional conductivity of shale were controlled by paleoclimate and acidity and alkalinity of reservoir liquid. Consideration of both micro-geological causes and macro-geological controlling factors is important in identifying low-resistivity oil layers.

关 键 词：Daqing placanticline Puao Oilfield Putaohua oil layer low-resistivity oil layers microgeological causes macro-geological controlling factors 

分 类 号：P618.13[天文地球—矿床学] X928.03[天文地球—地质学]