鄂尔多斯盆地铝土岩储层岩相成像测井特征及分布规律  

Lithofacies log identification and favorable lithofacies distribution of new types of bauxite reservoirs in Ordos Basin

作　　者：刘蝶 周金昱[1,2] 张小刚 吴越 赵太平[1,2] 田立立 杨鸣一[2,3] LIU Die;ZHOU Jinyu;ZHANG Xiaogang;WU Yue;ZHAO Taiping;TIAN Lili;YANG Mingyi(Research Institute of Exploration and Development,PetroChina Changqing Oilfield Company,Xi'an 710018,China;China National Engineering Laboratory for Exploration and Development of Low Permeability Oil and Gas Fields,Xi'an 710018,China;Exploration Division of PetroChina Changqing Oilfield Company,Xi'an 710018,China)

机构地区：[1]中国石油长庆油田分公司勘探开发研究院,陕西西安710018 [2]低渗透油气田勘探开发国家工程实验室,陕西西安710018 [3]中国石油长庆油田分公司勘探事业部,陕西西安710018

出　　处：《天然气地球科学》2024年第8期1441-1453,共13页Natural Gas Geoscience

基　　金：中国石油长庆油田分公司重大科技专项“鄂尔多斯盆地深层煤岩气赋存机理、富集规律及有效提产关键技术攻关”(编号:2023DZZ01)资助.

摘　　要：鄂尔多斯盆地陇东地区近期在太原组铝土岩层段试气获得工业气流,打破了太原组铝土岩作为下古生界奥陶系风化壳盖层的传统认识,表明铝土岩气是一种未被发现的非常规天然气气藏。为寻找有利相带、扩大气藏发现,对比岩心、测录井分析资料明确鄂尔多斯盆地太原组自上而下发育煤层、炭质泥岩、常规泥岩和含铝岩层,其中典型含铝岩具有高自然伽马、高中子、高铀、低声波时差及低钾的“三高两低”特征,基于此特征建立了声波时差与自然伽马交会图版实现了含铝岩系的快速识别;依据含铝岩主要组成矿物一水硬铝石含量差异将含铝岩细分为铝土岩、泥质铝土岩和铝土质泥岩3类岩石;结合岩心、岩石薄片、扫描电镜及成像测井资料将含铝岩划分为6种岩相:层/纹层状泥质铝土岩相,块状、层状、豆鲕状铝土岩相及弱层状、碎屑状铝土质泥岩相,并建立一套适用于太原组含铝岩的成像测井岩相识别模式库,实现了单井纵向上岩相的连续识别与划分;对比核磁共振及生产测试资料明确层状铝土岩相、豆鲕状铝土岩相发育大量粒内溶蚀孔隙,是油气聚集的有利岩相。通过研究深化了对鄂尔多斯盆地二叠系太原组含铝岩岩相成像特征及有利储层的认识,对盆地西南部太原组、东部本溪组铝土岩新类型天然气藏的勘探开发具有指导意义。In the Longdong area of the Ordos Basin,the bauxite section of the Taiyuan Formation has recently been tested to obtain industrial gas flow,which breaks the traditional understanding that the bauxite of the Taiyuan Formation is the caprock of the Lower Palaeozoic Ordovician weathered crust,indicating that bauxite gas is an undiscovered unconventional natural gas reservoir.In order to find favorable facies and expand the discovery of gas reservoirs,this paper compares the core and logging analysis data to clarify that coal seams,carbonaceous mudstones,conventional mudstones and aluminum-bearing rock formations are developed from top to bottom in the Taiyuan Formation of Ordos Basin,among which the typical aluminum-bearing rocks have the characteristics of“three highs and two lows”of high gamma,high neutron,high uranium,low sonic wave and low potassium.According to the difference in the content of the main constituent mineral diasporite monohydrate of aluminite,the aluminite was subdivided into three types of rocks:bauxite,argillaceous bauxite and bauxite mudstone.Combined with core,rock thin section,scanning electron microscope and imaging logging data,the aluminites were divided into six lithofacies:layered/striated argillaceous bauxite facies,massive,layered,soybean oolitic bauxite facies and weakly layered and clastic bauxite mudstone facies.Comparing the nuclear magnetic resonance and production test data,it is clear that the layered bauxite lithofacies and soybean oolitic bauxite facies have a large number of intragranular dissolution pores,which are favorable lithofacies for oil and gas accumulation.This paper deepens the understanding of the lithofacies imaging characteristics and favorable reservoirs of the Permian Taiyuan Formation in the Ordos Basin,which is of guiding significance for the exploration and development of new bauxite natural gas reservoirs in the Taiyuan Formation in the southwest of the basin and the Benxi Formation in the eastern part of the basin.

关 键 词：铝土岩储层 成像测井 有利岩相 太原组 陇东地区 鄂尔多斯盆地 

分 类 号：TE234.9[石油与天然气工程—油气井工程]