XX盆地古中央隆起带基岩岩性测井识别方法

Recognition Method of Bedrock Lithology Based on Logs in Paleo-Central Uplift Zone of XX Basin

XX盆地古中央隆起带基岩储层岩性复杂,综合考虑成因、矿物成分结构及构造等因素,确定基岩岩性定名原则。对研究区167块基岩响应特性进行分析,以基岩地质分类和命名为基础,应用地层元素测井技术或者自然伽马和密度孔隙度与中子孔隙度差值交会图,在二维平面上确定基岩成分类别,即中基性火成岩/中基性火成岩成分变质岩、酸性火成岩/酸性火成岩成分变质岩、砂岩变质岩和泥岩变质岩,再根据成像测井从三维立体层面刻度基岩岩石结构,进而对基岩准确命名。利用测井资料独立识别全井段岩性是一种高效的基岩储层岩性识别方法,为储层参数的求取和流体性质的识别奠定基础。该方法在XX盆地古中央隆起带进行推广应用,基岩储层岩性识别符合率达92.7%,取得较好的应用效果。

This article mainly aims at the complex lithology of the bedrock reservoir in the paleo-central uplift zone of XX basin.In this study,based on the comprehensive consideration of the genesis,mineral composition,structure and construction of bedrock,the principle of bedrock lithology naming is determined.This study analyzes the response characteristics of 167 bedrock blocks in the study area.The naming principle is based on bedrock geological classification and naming,applying advanced element capture energy spectrum log,natural gamma and density porosity and neutron porosity difference,and determining the bedrock composition category(plan basic igneous rock/medium basic igneous rock metamorphic rock,acid igneous rock/acidic igneous rock metamorphic rock,sandstone metamorphic rock and mudstone metamorphic rock),and calibrate the bedrock rock structure from the third three-dimensional level according to the imaging log,and give the bedrock rock accurate naming.Using logging data to identify the lithology of the entire well section become an efficient and good method for bedrock reservoir lithology identification,for the acquisition of reservoir parameters and lay the foundation for the identification of fluid properties.This method has been popularized and applied in the paleo-central uplift zone of XX Basin,and the coincidence rate of lithology identification of bedrock reservoirs has reached 92.7%,and achieves good application results.