巴音都兰凹陷阿尔善组碎屑岩储层特征及其主控因素

Reservoir characteristics and main controlling factors of clastic rocks in Aershan Formation of Bayindulan Sag

赵杰 李宏为 杨全凤 朱敏 吕德胜 任晓丽 赵紫印 李翔

中国石油华北油田公司地球物理勘探研究院，河北 任丘　062552

Geophysical Exploration Research Institute, Huabei Oilfield Company, PetroChina, Renqiu 062552, China

通过采用岩心观察、薄片鉴定，以及地震相、测井相、沉积相、成岩作用研究等方法，分析了二连盆地巴音都兰凹陷阿尔善组碎屑岩储层特征。结果表明：岩石类型以长石砂岩和砂砾岩为主，岩屑砂岩和长石岩屑砂岩次之，具有近物源特征；储层物性总体上属于低孔、特低渗性，但也存在相对有利的低孔、低渗储层（测井孔隙度为9.37%～11.55％，渗透率为6.14×10-3～6.27×10-3　μm2），有利于形成含油气储层。针对研究区储层特点，进一步分析认为，储层的形成和分布主要受沉积微相和成岩作用两大因素的控制。扇三角洲前缘分流河道和席状砂微相为有利储层分布相带；同时，差异压实作用、溶蚀作用和压溶作用，使得储层原生残余粒间孔、粒间溶孔、粒内溶孔及微裂缝发育并得以保存，而强烈的压实作用和胶结作用，使得储层物性整体变差。

The characteristics of clastic rocks in Aershan Formation of Bayindulan Sag, Erlian Basin are analyzed by core observation, thin section examination of rock, seismic facies, log data, sedimentary facies and diagenesis. The result shows that rock types are mainly of arkose and glutenite, while lithic sandstone and feldspar lithic sandstone are less, which are near provenances; reservoir physical property generally belongs to low porosity, extra-low permeability, but there are also relatively good low porosity low permeability reservoirs(the average log porosity is 9.37%￣11.55％, the average permeability is 6.14￣6.27 md), which is conductive to formation of oil and gas reservoir. Considering the characteristics of the reservoirs in the study area, further analysis concludes the formation and distribution of the favorable reservoirs are mainly controlled by sedimentary micro-facies and diagenesis. The distributary channel of fan delta front and sheet sand microfacies are favorable reservoir belts; differetial compaction, dissolution and pressure solution develop and preserve original residual intergranular pore,  reservoir intergranular dissolved pore, intragranular solution pores and micro cracks, but strong compaction and cementation worsen the reservoir physical property.

10.6056/dkyqt201503005