摘要
岩石类型识别是中东碳酸盐岩储层品质及储量预估极为关键的一步。为了更好地识别Mishrif组碳酸盐岩储层岩石类型,进行精确储层分类,准确建立符合研究区的渗透率模型,有必要研究符合研究区实际情况的识别方法。实践表明,目前基于毛管压力曲线、流动单元、核磁共振测井资料的识别方法能够有效的判别岩石类型,但必须有大量且准确的实验资料,而少数取芯井段可以运用该方法,无法在全油田范围内推广使用。本文根据岩芯、薄片、测井资料,综合研究西古尔纳油田Mishrif组碳酸盐岩储层沉积、四种岩石类型测井响应以及孔渗特征,提出基于常规测井资料的重构参数识别法。通过选择与岩石类型、孔隙变化相关性强的中子、密度测井曲线,以及与岩石的粒度大小、沉积速率有关的自然伽马、电阻率为两组敏感测井参数,重构能够表征岩石类型的新参数RN与RG。研究表明,当RN≤0,RG≥10.6为颗粒灰岩;当0<RN<0.2,1.1<RG<9.4为泥粒灰岩;当RN>0.2,0.11<RG<1.3为粒泥灰岩。利用重构的两个新参数与岩石类型的关系联合预测岩石类型,与录井、取芯描述相对比,符合度达90%,未取芯井中识别的岩石类型分布与整个区域的沉积环境能够匹配上,证实重构参数法能够识别与预测岩石类型的有效性与可推广性,可应用于整个中东地区,解决国家一带一路石油战略过程中因岩芯资料少而无法精确评价非取芯井储层品质以及准确预估产量的难题,满足中东地区实际储层评价及生产开发的需要。
Rock type identification is a key step in the estimation of carbonate reservoir quality and reserves in the Middle East.In order to recognize the rock types of carbonate reservoirs in the Mishrif Formation better,carry out reservoir classification accurately,and establish a permeability model in line with the study area accurately,based on the core,thin section,and logging data,this paper comprehensively studies carbonate reservoir deposition of Mishrif Formation in the West Qurna Oilfield,logging response of four rock types,porosity and permeability characteristics,analyzes advantages and disadvantages of foreign identification methods of carbonate rock type,proposes a reconstruction parameter identification method based on conventional logging data.Studies have shown that identification methods based on capillary pressure curves,flow units,and nuclear magnetic resonance logging data can effectively distinguish rock types,but there must be a large amount of accurate experimental data,furthermore this method can only be used in a small number of core sections,unable to be popularized and used throughout the oilfield;neutron and density curves have a strong correlation with the changes of rock types,that is,distance between the neutron and density curves of different rock types is different.Based on this distance relationship this paper reconstructs parameter RN,then establishing a quantitative relationship between RN and rock type;in the same way,natural gamma and resistivity related to rock grain size and sedimentation rate are selected as another set of sensitivity curves,then reconstructing new parameter RG,establishing the quantitative connection between RG and rock types.The relationship between the two new reconstructed parameters and the rock type is used to predict the rock type.Compared with the description of logging and coring,the conformity reaches 90%,which can meet the needs of actual reservoir evaluation,and exploration&development in the Middle East.
作者
方鑫鑫
冯宏
吴海
王云宏
Fang Xinxin;Feng Hong;Wu Hai;Wang Yunhong
出处
《国外测井技术》
2021年第3期24-31,2,共9页
World Well Logging Technology
基金
中国天然气股份有限公司重大专项2020E-2566。
